WO2016199592A1

WO2016199592A1 - Receiving device and receiving method

Info

Publication number: WO2016199592A1
Application number: PCT/JP2016/065676
Authority: WO
Inventors: 田中　勝之; 征二江坂; 高橋　英樹; 裕之鎌田; 哲宏二見
Original assignee: ソニーセミコンダクタソリューションズ株式会社
Priority date: 2015-06-10
Filing date: 2016-05-27
Publication date: 2016-12-15

Abstract

The present disclosure pertains to a receiving device and receiving method which make temperature compensation at low power consumption possible when receiving a GNSS signal. On the basis of the temperature near an oscillation unit for generating an oscillation signal having a prescribed frequency, a baseband conversion unit corrects the frequency of an IF (Intermediate Frequency) signal converted from a GNSS (Global Navigation Satellite System) signal by using the oscillation signal. For example, this disclosure is applicable to a receiving device or the like for receiving a GNSS signal from a GPS (Global Positioning System), a GLONASS (GLObal NAvigation Satellite System), a Beidou, or a Galileo.

Description

Receiving apparatus and receiving method

The present disclosure relates to a receiving apparatus and a receiving method, and more particularly, to a receiving apparatus and a receiving method that can perform temperature compensation with low power consumption when receiving a GNSS (Global Navigation Satellite System) signal.

Conventionally, GNSS receivers are mainly mounted on car navigation systems (for example, see Patent Document 1). In recent years, however, the market for GNSS receivers has expanded as the importance of location information has increased, and GNSS receivers are also used in battery-powered products such as mobile phones such as smartphones, DSCs (digital still cameras), watches, and wearable products. It has come to be installed. Therefore, it is desired to reduce the power consumption of the GNSS receiver. In particular, wristwatches and wearable products have high expectations for low power consumption because of their small batteries and small battery capacity.

GNSS means GPS (Global Positioning System) in the United States, GLONASS (GLObal NAvigation Satellite System) in Russia, Beidou in China, Galileo in EU (European Union), and Japanese quasi-zenith satellites as complementary satellites. Is a general term.

GNSS receiver analog circuits have been reduced in power consumption due to advances in circuit technology, and digital circuits have also been reduced in power consumption due to miniaturization of CMOS (Complementary Metal-Oxide Semiconductor) processes. As a result, a GNSS receiver whose power consumption is less than 10 mW has been realized.

However, in order to achieve high performance, in the GNSS receiver equipped with TCXO (temperature compensated crystal oscillator) that performs temperature compensation on the oscillation frequency, the power consumption of TCXO in the power consumption of the entire GNSS receiver is large. The power consumption cannot be reduced sufficiently.

That is, the GNSS receiver can narrow the frequency step and the frequency range when detecting the carrier frequency by using a highly accurate and highly stable TCXO. As a result, a weak GNSS signal can be captured and kept synchronized. However, since TCXO has a temperature compensation circuit that compensates for frequency fluctuations due to temperature, it consumes more power than a crystal oscillator that does not have a temperature compensation circuit. For example, the power consumption of a GNSS receiver increases from 0.3 mw to 3 mW by providing a TCXO instead of a crystal oscillator without a temperature compensation circuit.

If the power consumption of the GNSS receiver is reduced to about a few milliwatts, the power consumption of the TCXO will increase in the power consumption of the entire GNSS receiver, and the power consumption of the TCXO can be ignored in reducing the power consumption of the GNSS receiver. Disappear.

In contrast, a GNSS receiver equipped with a crystal oscillator that does not have a temperature compensation circuit instead of TCXO reduces power consumption but significantly degrades performance.

Specifically, when receiving a GPS signal, the GNSS receiver integrates the GPS signal in units of 1-bit length (20 ms). Therefore, the frequency step when detecting the carrier frequency is 50 Hz or less. On the other hand, the frequency range needs to be the sum of the frequency error due to Doppler shift (about ± 3 kHz) and the frequency error of LO (Local Oscillator) signal.

The LO signal frequency error is 48 times the crystal oscillator error (eg ± 20 ppm) when the LO signal frequency is 32.736 MHz, and the LO signal frequency error (eg ± 0.5 ppm) with the TCXO 40 times. As a result, the frequency range extends from about 5 kHz to over 30 kHz.

This means that the signal processing until the GPS signal is synchronously captured is greatly increased, and it is difficult to maintain the performance with the same power consumption. In addition, frequency fluctuation due to temperature greatly affects performance even after synchronous acquisition.

JP 2013-257255 A

Therefore, it is desired to perform temperature compensation with low power consumption in the GNSS receiver.

The present disclosure has been made in view of such a situation, and makes it possible to perform temperature compensation with low power consumption when receiving a GNSS signal.

A receiving apparatus according to an aspect of the present disclosure is based on a temperature in the vicinity of an oscillation unit that generates an oscillation signal having a predetermined frequency, and uses an IF (Intermediate) signal converted from a GNSS (Global Navigation Satellite System) signal using the oscillation signal. Frequency) is a receiving device including a signal correction unit that corrects the frequency of the signal.

The reception method according to one aspect of the present disclosure corresponds to the reception device according to one aspect of the present disclosure.

In one aspect of the present disclosure, an IF (Intermediate Frequency) converted from a GNSS (Global Navigation Satellite System) signal using the oscillation signal based on a temperature in the vicinity of an oscillation unit that generates an oscillation signal of a predetermined frequency. The frequency of the signal is corrected.

According to one aspect of the present disclosure, a GNSS signal can be received. Further, according to one aspect of the present disclosure, temperature compensation can be performed with low power consumption when a GNSS signal is received.

It should be noted that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a block diagram showing an example of composition of a 1st embodiment of a receiving device to which this indication is applied. It is a figure which shows the example of a correction table. It is a graph showing the relationship between temperature data and temperature. It is a graph showing the 1st example of the relationship between temperature data and a frequency shift. It is a graph showing the relationship between the difference of the measured value of frequency deviation of FIG. 4, the difference of a predicted value, and temperature data. It is a graph showing the 2nd example of the relationship between temperature data and a frequency shift. It is a graph showing the relationship between the difference of the measured value of frequency deviation of FIG. 6, the difference of a predicted value, and temperature data. It is a graph showing the 3rd example of the relationship between temperature data and a frequency shift. It is a block diagram which shows the structural example of the frequency conversion part of FIG. It is a block diagram which shows the structural example of the baseband conversion part of FIG. It is a figure which shows the structural example of the channel circuit which comprises the synchronous holding | maintenance part of FIG. It is a figure explaining the reset by PNG of FIG. 3 is a flowchart illustrating a reception process of the reception device in FIG. 1. It is a figure which shows the other example of a correction table. It is a block diagram which shows the structural example of the correction | amendment part of 2nd Embodiment of the receiver which applied this indication. [Fig. 20] Fig. 20 is a block diagram illustrating a configuration example of a third embodiment of a reception device to which the present disclosure is applied. It is a block diagram which shows the structural example of the frequency conversion part of FIG. [Fig. 20] Fig. 20 is a block diagram illustrating a configuration example of a fourth embodiment of a reception device to which the present disclosure is applied. It is a block diagram which shows the structural example of the frequency conversion part of FIG.

Hereinafter, modes for carrying out the present disclosure (hereinafter referred to as embodiments) will be described. The description will be given in the following order.
1. First embodiment: receiving apparatus (FIGS. 1 to 14)
2. Second Embodiment: Receiver (FIG. 15)
3. Third embodiment: receiving apparatus (FIGS. 16 and 17)
4). Fourth embodiment: receiving apparatus (FIGS. 18 and 19)

<First embodiment>
(Configuration example of first embodiment of receiving apparatus)
FIG. 1 is a block diagram illustrating a configuration example of a first embodiment of a reception device to which the present disclosure is applied.

1 includes an oscillation signal generator 11 and a receiver 12 having input terminals 12a to 12c. The receiving device 10 is a GNSS receiver that receives and demodulates an RF (Radio-Frequency) signal transmitted from GPS, GLONASS, Beidou, and Galileo, and generates position information.

Specifically, the oscillation signal generator 11 includes a crystal resonator 21,

capacitors

22 and 23, a thermistor 24, a capacitor 25, a resistor 26, and a capacitor 27.

Both ends of the crystal resonator 21 of the oscillation signal generation unit 11 are connected to the GND via the capacitor 22 and the capacitor 23, and are connected to the input terminal 12a and the input terminal 12b of the reception unit 12.

The thermistor 24 is provided in the vicinity of the crystal resonator 21. One of the thermistors 24 is connected to GND, and the other is connected to a capacitor 25, one end of a resistor 26 having a resistance value R, and an input terminal 12c of the receiving unit 12. The other end of the resistor 26 is connected to the power source of the voltage V _p and one end of the capacitor 27, and the other end of the capacitor 27 is connected to GND. As described above, the resistance value R _th of the thermistor 24 varies depending on the temperature T in the vicinity of the crystal resonator 21, and a signal of the voltage V _th corresponding to the temperature T is input to the input terminal 12c.

The reception unit 12 includes an inverter 41, a resistor 42, a buffer 43, a PLL (Phase Locked Loop) PLL unit 44, an antenna 45, a frequency conversion unit 46, a baseband conversion unit 47, a synchronization acquisition unit 48, a synchronization holding unit 49, an ADC ( An analog digital converter 50, an LPF (low pass filter) 51, a CPU (central processing unit) 52, a timer 53, and a memory 54. The receiving unit 12 is formed of, for example, an IC (Integrated Circuit) chip such as an LSI (Large Scale Integration).

Both ends of the inverter 41 and the resistor 42 of the receiving unit 12 are connected to the input terminal 12a and the input terminal 12b. The crystal resonator 21, the capacitor 22, the capacitor 23, the inverter 41, and the resistor constitute a crystal oscillation circuit 13 (oscillation unit) and generate an oscillation signal having a predetermined frequency. Here, it is assumed that the nominal oscillation frequency of the crystal oscillation circuit 13 is 32.736 MHz. The oscillation signal is supplied to the buffer 43.

The buffer 43 converts the input oscillation signal into a rectangular wave so that there is no influence on the crystal oscillation circuit 13 and supplies it to the PLL unit 44 and the frequency conversion unit 46.

The PLL unit 44 doubles the frequency of the oscillation signal input from the buffer 43 and generates the clock CLK. The PLL unit 44 supplies the clock CLK to the frequency conversion unit 46, the baseband conversion unit 47, the synchronization acquisition unit 48, and the synchronization holding unit 49. Here, the frequency of the clock CLK is assumed to be twice the frequency of the oscillation signal, but the frequency of the clock CLK is not limited to this.

The antenna 45 receives an RF signal transmitted from GPS, GLONASS, Beidou, and Galileo, and outputs it to the frequency converter 46.

The frequency converter 46 down-converts the frequency of the RF signal received by the antenna 45 to IF (Intermediate Frequency) by using the frequency of the oscillation signal supplied from the buffer 43 by 48 times, and converts the RF signal into an IF signal. Convert to Further, the frequency conversion unit 46 performs A / D (Analog / Digital) conversion (discretization) on the analog IF signal using the clock CLK as a sampling clock, and the digital IF signal obtained as a result is a baseband conversion unit. Output to 47.

Since the carrier frequency of GPS and Galileo is different from the carrier frequency of GLONASS and the carrier frequency of Beidou, the frequency converter 46 performs the above-described processing on the RF signal of GPS and Galileo, the RF signal of GLONASS, and the RF signal of Beidou. Do this separately for each.

The baseband conversion unit 47 performs frequency conversion or the like on the I-phase component and Q-phase component of the digital IF signal supplied from the frequency conversion unit 46 according to the clock CLK, and an I signal that is a signal of the I-phase component And a Q signal that is a Q phase component signal. At this time, the baseband conversion unit 47 (signal correction unit) oscillates due to the temperature T by correcting the frequency of the signal used for frequency conversion of the IF signal based on the frequency correction value a supplied from the CPU 52. A frequency shift of the IF signal due to the frequency variation of the signal is corrected.

The baseband conversion unit 47 outputs the baseband signal to the synchronization capturing unit 48 and the synchronization holding unit 49. For the same reason as the frequency conversion unit 46, the baseband conversion unit 47 also performs the above-described processing separately on the GPS and Galileo RF signals, the GLONASS RF signal, and the Beidou RF signal.

The synchronization acquisition unit 48 stores the baseband signal output from the baseband conversion unit 47 in a memory (not shown) according to the clock CLK. When the synchronization capturing unit 48 starts capturing the baseband signal into the memory, the synchronization capturing unit 48 notifies the synchronization holding unit 49 of the start.

The synchronization acquisition unit 48 reads the baseband signal held in the memory according to the clock CLK, performs synchronization acquisition of the spreading code in the baseband signal, and detects the phase h [chip] of the spreading code, the carrier frequency, etc. To do. In addition, the synchronization acquisition unit 48 detects the identification information (for example, satellite number for identifying the GPS satellite) of the source positioning satellite. The synchronization acquisition unit 48 supplies the phase h of the spread code to the synchronization holding unit 49 and supplies the carrier frequency, identification information, and the like to the CPU 52.

The synchronization acquisition unit 48 can be configured by, for example, a digital matched filter using a fast Fourier transform. Examples of the digital matched filter include using the technique disclosed in Japanese Patent Laid-Open No. 2003-232844, but are not limited thereto.

The synchronization holding unit 49 performs a demodulation process for performing spectrum despreading and demodulation on the baseband signal supplied from the baseband conversion unit 47 according to the clock CLK, and obtains a navigation message. Specifically, the synchronization holding unit 49 performs spreading code synchronization holding processing on the baseband signal supplied from the baseband conversion unit 47 in accordance with the clock CLK.

At this time, the spreading code (PN) generation in the synchronization holding process of the spreading code based on the notification of the start of capturing and the phase h supplied from the synchronization acquisition unit 48 and the frequency correction value a supplied from the CPU 52 Reset the process. Thereby, the synchronization holding unit 49 corrects the synchronization deviation of the spread code due to the frequency deviation of the clock CLK accompanying the frequency variation of the oscillation signal due to the temperature T. That is, the synchronization holding unit 49 (clock correction unit) corrects the frequency shift of the clock CLK by correcting the synchronization shift of the spreading code based on the frequency correction value a.

Also, the synchronization holding unit 49 performs carrier synchronization holding processing on the baseband signal using the generated spreading code according to the clock CLK. As a result, the baseband signal is demodulated and a navigation message is generated. At this time, the synchronization holding unit 49 corrects the frequency of the signal used for demodulation based on the correction value b of the frequency supplied from the CPU 52, so that the frequency of the clock CLK accompanying the frequency variation of the oscillation signal due to the temperature T is corrected. The carrier synchronization deviation due to the deviation is corrected. That is, the synchronization holding unit 49 (clock correction unit) corrects the frequency deviation of the clock CLK by correcting the carrier synchronization deviation based on the frequency correction value b. The synchronization holding unit 49 supplies the navigation message to the CPU 52.

Note that the synchronization acquisition unit 48 and the synchronization holding unit 49 can perform processing for each positioning satellite in parallel.

The ADC 50 is connected to the input terminal 12c, and acquires a signal having a voltage V _th corresponding to the temperature T input to the input terminal 12c. When the selection signal SEL is turned on by the CPU 52 or the like, the ADC 50 A / D converts the signal of the voltage V _th using the reference voltage RefVoltage according to the sampling clock SCLK, and generates 10-bit temperature data. The ADC 50 supplies temperature data to the LPF 51.

LPF 51 averages the temperature data supplied from ADC 50, generates 12-bit temperature data X, and supplies it to CPU 52.

Based on the temperature data X supplied from the LPF 51, the CPU 52 (reading unit) reads correction information representing the correction value a and the correction value b of the frequency corresponding to the temperature data X from the correction table stored in the memory 54. Is read.

This read frequency is lower than the conversion frequency of the ADC 50 (frequency of the sampling clock SCLK), for example. Thereby, the resolution of temperature detection can be raised. For example, when the conversion frequency of the ADC 50 is four times faster than the frequency of reading the correction value a and the correction value b, an improvement in temperature detection accuracy equivalent to 1 bit can be expected on average. The reading frequency can be set higher than 10 Hz, for example, and the conversion frequency of the ADC 50 can be set to 256 Hz or 32 Hz, for example.

In addition, when the number of bits of the ADC 50 is large and the accuracy of temperature detection is sufficient, the conversion frequency of the ADC 50 and the frequency of reading the correction value a and the correction value b may be the same. In this case, the LPF 51 may not be provided. Further, the conversion frequency of the ADC 50 is set to a frequency that is earlier than the temperature fluctuation when the receiving device 10 is used, for example.

The CPU 52 supplies the correction value a represented by the correction information to the baseband conversion unit 47 and the synchronization holding unit 49, and supplies the correction value b to the synchronization holding unit 49.

The CPU 52 acquires the delay time from when the GPS, GLONASS, Beidou, and Galileo orbit data, time information, and RF signal are transmitted to when they are received, based on the navigation message supplied from the synchronization holding unit 49. . Then, based on the orbit data, the time information, and the delay time of the RF signal, the CPU 52 obtains the three-dimensional position of the receiving device 10 by simultaneous equations (positioning calculation) and generates position information representing the three-dimensional position. . For the generation of this position information, a Doppler shift detection result is also used as necessary.

Note that the CPU 52 may obtain the speed of the receiving device 10 based on the position information and generate speed information indicating the speed. The position information and the speed information are displayed on a display device (not shown) or used for various processes, for example. Further, the CPU 52 performs control of each block of the receiving unit 12 and the like.

The timer 53 is used, for example, for generating various timing signals for controlling the operation of each block of the receiving unit 12 and for referring to time.

The memory 54 includes, for example, ROM (Read Only Memory), RAM (Random Access Memory), SDRAM (Synchronous Dynamic Random Access Memory), flash memory, and the like. The ROM that constitutes the memory 54 stores a correction table that is generated based on the temperature characteristics of the crystal oscillation circuit 13 and associates values that can be taken as temperature data X with correction information. The ROM stores control data such as programs used by the CPU 52 and calculation parameters. Further, a program executed by the CPU 52 is temporarily stored in the RAM.

The oscillation signal generation unit 11 of the reception device 10 configured as described above, and the input terminals 12a to 12c of the reception unit 12, the inverter 41, the resistor 42, the buffer 43, the PLL unit 44, the antenna 45, the frequency conversion unit 46, The ADC 50 is an analog circuit that processes an analog signal. The baseband conversion unit 47, the synchronization acquisition unit 48, the synchronization holding unit 49, the LPF 51, the CPU 52, and the memory 54 of the reception unit 12 are digital circuits that process digital signals.

Also, the reception intensity of RF signals transmitted from GPS, GLONASS, Beidou, and Galileo is less than thermal noise, and the C / N (Carrier / noise) ratio is well below 0 dB. However, since these RF signals are spread spectrum, the receiving apparatus 10 can demodulate with the processing gain of the spread spectrum. For example, the processing gain of spread spectrum with respect to the data length of 1 bit of the RF signal transmitted from the GPS is 10 Log (1.023 MHz / 50) ≈43 dB.

(Example of correction table)
FIG. 2 is a diagram illustrating an example of a correction table stored in the memory 54 of FIG.

The correction table in FIG. 2 is a table in which correction values a and b are associated as correction information with each value that can be taken as 12-bit temperature data X.

As described above, the frequency of the signal used for generating the IF signal is 48 times the frequency of the oscillation signal. Therefore, in each temperature data X, the correction value a (X) used for correcting the frequency shift of the IF signal due to the frequency variation of the oscillation signal due to the temperature T is the difference between the frequency of the oscillation signal and the nominal frequency in the temperature data X. Is set to 48 times the frequency deviation Δf (X), that is, 48Δf (X). For example, when the frequency deviation Δf (X) is 20 ppm of the frequency of the oscillation signal and the frequency of the oscillation signal is 32.736 MHz, about 31 kHz is set as the correction value a (X).

Further, in each temperature data X, the correction value b (X) used for correcting the frequency shift of the clock CLK accompanying the frequency variation of the oscillation signal due to the temperature T is, for example, the frequency shift of the clock CLK and the frequency of the clock CLK. Set to a ratio. Since the clock CLK is obtained by doubling the frequency of the oscillation signal, for example, when the frequency deviation Δf (X) is 20 ppm of the frequency of the oscillation signal, the correction value b (X) is 20 × 10 ^−6. Or it is set to 20 which is ppm value.

The frequency deviation Δf (X) is determined based on an actual measurement value of the frequency deviation Δf (X) or an average temperature characteristic of each element constituting the crystal oscillation circuit 13. Hereinafter, a method for determining the frequency shift Δf (X) based on the actually measured value of the frequency shift Δf (X) will be described.

(Relationship between temperature data and temperature)
FIG. 3 is a graph showing the relationship between the temperature data X and the temperature T.

In FIG. 3, the horizontal axis represents the temperature data X, and the vertical axis represents the temperature T [° C.]. The solid line represents the relationship between the measured value of the temperature data X and the temperature T, and the dotted line represents the relationship between the predicted value of the temperature data X and the temperature T.

The temperature data X can be predicted as follows. That is, the resistance value R _th [Ω] of the thermistor 24 at the temperature T [K] is expressed by the following equation (1).

R ₀ [Ω] is a resistance value of the thermistor 24 at a reference temperature T ₀ [K] (for example, 298.15 K), and B [K] is a B constant.

When the resistance value R of the resistor 26 is equal to the resistance value R ₀ , the voltage V _th of the signal input to the input terminal 12 c is connected to the resistance value R _th , the resistance value R ₀ , and the resistor 26 of the thermistor 24. Using the voltage V _p of the power supply, it is expressed by the following equation (2).

Therefore, the relationship between the temperature T and the voltage V _th is expressed by the following equation (3) according to the equations (1) and (2).

Therefore, the relationship between the temperature T and the temperature data X can be predicted based on the relationship between the voltage V _th and the temperature data X and the equation (3).

As shown by the dotted line in FIG. 3, the relationship between the predicted temperature data X and the temperature T becomes a curve due to the non-linearity of the temperature characteristic of the thermistor 24 and the non-linearity of the conversion characteristic of the ADC 50. The solid line representing the relationship between the actually measured value of the temperature data X and the temperature T substantially overlaps this dotted line. Therefore, it can be said that the relationship between the temperature T and the voltage V _th can be defined by the above-described equation (3).

(Relationship between temperature data and frequency deviation 48Δf)
FIG. 4 is a graph showing the relationship between the temperature data X and the frequency shift 48Δf.

In FIG. 4, the horizontal axis represents temperature data X, and the vertical axis represents frequency deviation 48Δf [Hz]. The solid line represents the relationship between the temperature data X and the measured value of the frequency shift 48Δf (X), and the dotted line represents the relationship between the temperature data X and the predicted value of the frequency shift 48Δf (X). The same applies to FIG. 6 described later.

For example, the measured value of the frequency shift 48Δf (X) is monitored by monitoring the temperature data X and the frequency of the LO signal used for frequency conversion in the frequency converter 46 while changing the temperature by placing the receiving device 10 in a thermostat. Is measured. The temperature data X is monitored by, for example, the CPU 52, and the frequency of the LO signal is monitored by a measuring instrument such as a spectrum analyzer.

Note that the actual value of the frequency deviation 48Δf (X) is subjected to frequency correction that is generated by the synchronization holding unit 49 by inputting an RF signal having a predetermined frequency generated with high accuracy by the signal generator to the receiving device 10. It may be measured by monitoring the unsynchronized IF signal carrier synchronization (frequency error of NCO (numerically controlled oscillator) incorporated in the synchronization holding unit 49) by the CPU 52.

In addition, the measured value of the frequency shift 48Δf (X) is an oscillation calculated when the receiving apparatus 10 receives the RF signal from the positioning satellite and as a result, the position information is generated using the IF signal that is not subjected to frequency correction. It may be measured by monitoring the exact frequency of the signal.

When the frequency deviation 48Δf (X) is actually measured for all the temperature data X, the actually measured values of the frequency deviation 48Δf (X) are used for calculating the correction value a and the correction value b.

On the other hand, when the frequency deviation 48Δf (X) is not actually measured for all the temperature data X, the relationship between the temperature data X and the frequency deviation 48Δf (X) is as follows using the measured values of the frequency deviation 48Δf (X). In this way, it is modeled.

That is, the temperature characteristic of the frequency shift Δf (T) of the oscillation signal at the temperature T is a cubic curve represented by the following equation (4).

C _{0 to} C ₃ are coefficients.

Therefore, a model expression representing the relationship between the temperature data X and the frequency shift Δf (X) can be generated based on the above-described equations (3) and (4) and the relationship between the voltage V _th and the temperature data X. . This model formula can be expressed by a polynomial as shown in the following formula (5), for example.

Note that the frequency deviation Δf (X) includes the nonlinearity of the temperature characteristic of the thermistor 24 and the nonlinearity of the conversion of the ADC 50 to the third-order temperature characteristic of the frequency of the oscillation signal. Is the value of X ₀ is a constant.

In equation (5), for example, by setting the coefficient C _n so that the difference between the predicted value and the actual measurement value of the frequency deviation 48Δf (X) becomes small in all temperature data X, the temperature data X and the frequency deviation 48Δf ( The relationship of X) is modeled. Based on the equation (5) in which the coefficient C _n is set, the predicted values of the frequency shifts 48Δf (X) of all the temperature data X are obtained and used for calculating the correction values a and b.

As shown in FIG. 4, the dotted line representing the relationship between the temperature data X and the predicted value of the frequency shift 48Δf (X) is the same as the solid line representing the relationship between the temperature data X and the measured value of the frequency shift 48Δf (X). The curve becomes the next or higher.

FIG. 5 is a graph showing the relationship between the temperature data X and the difference between the actually measured value and the predicted value of the frequency shift 48Δf (X) in FIG.

5, the horizontal axis represents the temperature data X, and the vertical axis represents the difference [Hz] between the actually measured value and the predicted value of the frequency shift 48Δf (X). The same applies to FIG. 7 described later.

The temperature characteristic of the frequency deviation 48Δf (T) is a cubic curve, and the temperature characteristic of the thermistor 24 and the conversion characteristic of the ADC 50 are non-linear. Therefore, when the frequency shift Δf (X) in the entire range of the temperature data X is modeled by one model formula, as shown in FIG. 5, the difference between the measured value and the predicted value of the frequency shift 48Δf (X) increases. In the example of FIG. 5, the differences at high temperature, room temperature, and low temperature are large.

This difference is reduced to some extent by increasing the order n of the model formula. However, since the change in the temperature characteristic of the measured value of the frequency shift 48Δf (X) at high and low temperatures is large, the order n can be increased. The difference cannot be reduced more than a certain amount.

Therefore, as shown in FIG. 6, the entire range of the temperature data X is, for example, a range A of 80 (85 ° C.) to 250 (50 ° C.), a range B of 250 (50 ° C.) to 780 (0 ° C.). , 780 (0 ° C.) to 940 (−25 ° C.), and the relationship between the temperature data X and the frequency shift 48Δf (X) may be modeled for each of the ranges A to C.

In this case, in each of the ranges A to C, the coefficient C _n of Equation (5) is set so that the difference between the predicted value and the actual measurement value of the frequency shift 48Δf (X) becomes small. At this time, when the temperature data X is the boundary (250) between the range A and the range B, the predicted value of the frequency shift 48Δf (X) based on the range A formula (5) and the frequency shift based on the range B formula (5). The predicted value of 48Δf (X) coincides with the condition that the differential value (slope) of the expression (5) in the range A and the expression (5) in the range B are continuous. Further, when the temperature data X is the boundary (780) between the range B and the range C, the predicted value of the frequency shift 48Δf (X) according to the range B formula (5) and the frequency shift 48Δf according to the range C formula (5). The predicted value of (X) matches, and the condition that the differential value of equation (5) in range B and equation (5) in range C continues is imposed.

When such a condition is imposed, the relationship between the temperature data X of the entire range and the predicted value of the frequency shift Δf (X) becomes a smooth curve. For example, when the order n is 3, the function representing the relationship between the temperature data X of the entire range and the predicted value of the frequency shift Δf (X) is a cubic B-spline function that is the most general spline function. Therefore, the difference between the predicted value of the frequency deviation Δf (X) and the actually measured value can be further reduced.

As described above, by modeling the relationship between the temperature data X and the predicted value of the frequency shift Δf (X) in each of the ranges A to C, the difference between the predicted value of the frequency shift 48Δf (X) and the actual measurement value is As shown in FIG. 7, it becomes smaller than the case of FIG.

The number of divisions of the temperature data X is not limited to three. For example, as shown in FIG. 8, the temperature data X can be divided into five ranges D to H. Here, the order n in the equation (5) is a value of 3 or more. However, when the number of divisions of the temperature data X is large, even if the order n is 2, the relationship between the temperature data X and the frequency shift 48Δf (X). Can be accurately modeled, so that the order n can be set to 2.

In the above description, the correction value a and the correction value b are calculated based on the actual measurement value of the frequency deviation 48Δf (X). However, the correction value a and the correction value b are calculated based on the actual measurement value of the frequency deviation Δf (X). The value a and the correction value b may be calculated. In this case, the actual measurement value of the frequency deviation Δf (X) is measured by monitoring the temperature data X and the frequency of the oscillation signal while changing the temperature by placing the receiving device 10 in a thermostat, for example.

(Configuration example of frequency converter)
FIG. 9 is a block diagram illustrating a configuration example of the frequency conversion unit 46 of FIG.

9 includes an LNA (Low Noise Amplifier) 71, processing units 72-1 to 72-3, and a local oscillation circuit (LO (Local Oscillator)) 73.

The LNA 71 amplifies the RF signal supplied from the antenna 45 and supplies it to the processing units 72-1 to 72-3.

The processing units 72-1 to 72-3 are processing units for GPS and Galileo RF signals, GLONASS RF signals, and Beidou RF signals, respectively. Since the processing units 72-1 to 72-3 have the same configuration, only the processing unit 72-1 is shown and described.

The processing unit 72-1 includes a mixer 91, an LPF (Low Pass Filter) 92, an amplifier 94, and an ADC 97.

The mixer 91 mixes the LO signal (local oscillation signal) supplied from the local oscillation circuit 73 and the RF signal supplied from the LNA 71, thereby reducing the frequency to an intermediate frequency (IF) within several MHz lower than the carrier frequency. Output the converted IF signal. Typical intermediate frequencies are, for example, 4.092 MHz, 1.023 MHz, 0 Hz, and the like, but are not limited thereto.

The LPF 92 extracts a low frequency component from the frequency components of the IF signal supplied from the mixer 91 and supplies the low frequency component to the amplifier 94.

The amplifier 94 amplifies the IF signal supplied from the LPF 92 and supplies it to the ADC 97. The ADC 97 converts the analog IF signal supplied from the amplifier 94 into a digital IF signal using the clock CLK supplied from the PLL unit 44 of FIG. 1 as a sampling clock. The ADC 97 supplies the digital IF signal to the baseband converter 47 shown in FIG.

The local oscillation circuit 73 is constituted by, for example, a PLL circuit. The local oscillation circuit 73 generates an LO signal having a frequency 48 times the frequency of the oscillation signal, using the oscillation signal supplied from the buffer 43 in FIG. The local oscillation circuit 73 supplies the LO signal to the mixer 91.

As described above, the frequency converter 46 generates the LO signal by multiplying the frequency of the oscillation signal by 48 times, so the frequency variation of the LO signal is 48 times the frequency variation of the oscillation signal. Further, since the frequency conversion unit 46 converts the RF signal into the IF signal using the LO signal, the frequency variation in the digital IF signal output from the frequency conversion unit 46 is 48 times the frequency variation in the oscillation signal. .

(Configuration example of baseband converter)
FIG. 10 is a block diagram illustrating a configuration example of the baseband conversion unit 47 of FIG.

10 includes a DC cancel unit 111 and processing units 112-1 to 112-3.

The DC cancel unit 111 cuts each DC component (DC component) of the I signal and the Q signal in the IF signal output from the ADC 97 (FIG. 9) of the frequency conversion unit 46, and cancels the DC offset. The DC cancel unit 111 supplies the resulting I signal and Q signal to the processing units 112-1 to 112-3.

The processing units 112-1 to 112-3 are processing units for GPS and Galileo IF signals, GLONASS IF signals, and Beidou IF signals, respectively. Since the processing units 112-1 to 112-3 have the same configuration, only the processing unit 112-1 is shown and described.

The processing unit 112-1 includes an LPF 131, a decimation 132, a multiplier 134, a multiplier 135, and an NCO 136.

The LPF 131 cuts the high frequency components of the I signal and the Q signal supplied from the DC cancel unit 111 and supplies them to the decimation 132. The decimation 132 reduces the sampling frequency of the I signal and Q signal supplied from the LPF 131 to, for example, 1/4 times, supplies the I signal to the multiplier 134, and supplies the Q signal to the multiplier 135. The decimation 132 may not be provided.

The multiplier 134 multiplies the I signal supplied from the decimation 132 by the intermediate frequency signal supplied from the NCO 136, thereby converting the frequency of the IF signal from the intermediate frequency to, for example, zero, and outputs the baseband signal I. Generate a signal. The multiplier 134 supplies the baseband signal I signal to the synchronization acquisition unit 48 and the synchronization holding unit 49 of FIG.

The multiplier 135 multiplies the Q signal supplied from the decimation 132 by the intermediate frequency signal supplied from the NCO 136, thereby converting the frequency of the IF signal from the intermediate frequency to, for example, zero. Generate a signal. The multiplier 135 supplies the Q signal of the baseband signal to the synchronization acquisition unit 48 and the synchronization holding unit 49 of FIG.

NCO 136 is a variable frequency NCO. The NCO 136 corrects a preset intermediate frequency (for example, 4.092 MHz) based on the correction value a supplied from the CPU 52, and generates a corrected intermediate frequency signal. The NCO 136 supplies an intermediate frequency signal to the multiplier 134 and the multiplier 135. As a result, it is possible to correct the LO signal frequency shift due to the temperature shift Δf (X) of the oscillation signal due to temperature.

As described above, in the baseband conversion unit 47, the frequency of the intermediate frequency signal to be generated is corrected based on the correction value a. Therefore, the frequency shift in the IF signal is corrected, and a baseband signal having no frequency shift is obtained. Generated. The NCO 136 corrects the frequency of the intermediate frequency signal at intervals sufficiently shorter than the temperature variation time.

(Configuration example of channel circuit)
FIG. 11 is a diagram illustrating a configuration example of a channel circuit constituting the synchronization holding unit 49 of FIG.

The synchronization holding unit 49 includes four or more channel circuits corresponding to each positioning satellite, and performs processing in parallel in each channel circuit.

In FIG. 11, the channel circuit 150 will be described.

As shown in FIG. 11, the channel circuit 150 includes a Costas loop 151, a correlation detector 152, an integrator 153, a binarization circuit 154, and a DLL (Delay Lock Loop) 155.

The Costas loop 151, the correlation detector 152, the accumulator 153, and the binarization circuit 154 of the channel circuit 150 perform carrier synchronization holding processing and extract a navigation message. The DLL 155 also performs spreading code synchronization holding processing.

Specifically, the Costas loop 151 includes multipliers 171 to 174, LPF 175 and LPF 176, a binarization circuit 177, a phase detector 178, a loop filter 179, and an NCO 180. The process of the Costas loop 151 is performed according to the clock CLK supplied from the PLL unit 44 of FIG.

The multiplier 171 of the Costas loop 151 performs a spreading code (hereinafter, spreading code P) in which the phase supplied from the DLL 155 is P (Prompt) with respect to the I signal output from the processing unit 112-1 (FIG. 10). Spectrum despreading is performed. The multiplier 171 supplies the spectrum despread I signal to the multiplier 173.

Further, the multiplier 172 of the Costas loop 151 performs spectrum despreading by multiplying the Q signal output from the processing unit 112-1 by the spreading code P supplied from the DLL 155. The multiplier 172 supplies the Q signal subjected to spectrum despreading to the multiplier 174.

The multiplier 173 multiplies the I signal supplied from the multiplier 171 by the cosine component of the signal generated by the NCO 180 and supplies the result to the LPF 175. The multiplier 174 multiplies the Q signal supplied from the multiplier 172 by the sine component of the signal generated by the NCO 180 and supplies the result to the LPF 176.

The LPF 175 is a frequency component represented by the cutoff frequency information of the I signal supplied from the multiplier 173 based on the cutoff frequency information supplied from the CPU 52 of FIG. Is supplied to the binarization circuit 177, the phase detector 178, and the correlation detector 152.

The LPF 176 cuts the frequency component represented by the cutoff frequency information in the Q signal supplied from the multiplier 174 based on the cutoff frequency information supplied from the CPU 52 based on the processing result of the synchronization acquisition unit 48. To the phase detector 178 and the correlation detector 152.

The binarization circuit 177 binarizes the I signal supplied from the LPF 175 and supplies it to the CPU 52 as a navigation message.

The phase detector 178 detects a phase error between the carrier and the signal generated by the NCO 180 based on the signals supplied from the LPF 175 and the LPF 176, and supplies the detected phase error to the NCO 180 via the loop filter 179. As a result, the phase of the signal generated by the NCO 180 is controlled to be synchronized with the phase of the carrier.

The loop filter 179 integrates the phase error supplied from the phase detector 178 based on the parameter specifying the filter characteristic supplied from the CPU 52 and generated based on the processing result of the synchronization acquisition unit 48, and sets the NCO 180. A control signal to be controlled is generated. The loop filter 179 supplies a control signal to the NCO 180.

The NCO 180 is composed of a variable frequency NCO. The NCO 180 corrects the carrier frequency based on the frequency information representing the carrier frequency determined based on the processing result of the synchronization acquisition unit 48 supplied from the CPU 52 of FIG. 1 and the correction value b. As a result, the carrier synchronization shift due to the frequency shift of the clock CLK can be corrected.

The NCO 180 generates a corrected carrier frequency signal based on the control signal supplied from the loop filter 179 so as to synchronize with the carrier phase. The NCO 180 supplies the cosine component of the generated signal to the multiplier 173 and supplies the sine component to the multiplier 174.

The correlation detector 152 calculates the square sum (I ² + Q ² ) of the I signal supplied from the LPF 175 and the Q signal supplied from the LPF 176, and supplies it to the integrator 153. The accumulator 153 accumulates the square sum (I ² + Q ² ) supplied from the correlation detector 152 by the bit length based on the bit length of the navigation message supplied from the CPU 52, thereby obtaining the base. A correlation value P between the band signal and the spreading code P is generated. The integrator 153 supplies the correlation value P to the CPU 52 and the binarization circuit 154.

The binarization circuit 154 compares the correlation value P supplied from the integrator 153 with a predetermined threshold value. When the correlation value P is larger than the threshold value, the binarization circuit 154 supplies the spread code lock information indicating that the synchronization holding is in the locked state to the CPU 52. On the other hand, when the correlation value P is equal to or smaller than the threshold value, the binarization circuit 154 supplies the spread code lock information indicating that the synchronization holding is in the unlocked state to the CPU 52.

The DLL 155 includes multipliers 191 to 194, LPF 195 and LPF 196, correlation detector 197, accumulator 198, multipliers 199 to 202,

LPF

203 and 204, correlation detector 205, accumulator 206, phase detector 207, loop filter. 208, NCO 209, and PNG 210.

The multiplier 191 of the DLL 155 includes an I signal output from the processing unit 112-1 and a spreading code (hereinafter referred to as a spreading code E) in which the phase supplied from the PNG 210 is E (Early) ahead of P. The spectrum is despread by multiplying by. The multiplier 191 supplies the spectrum despread I signal to the multiplier 193.

The multiplier 192 performs spectrum despreading by multiplying the Q signal output from the processing unit 112-1 and the spreading code E supplied from the PNG 210. The multiplier 192 supplies the Q signal subjected to spectrum despreading to the multiplier 193.

The multiplier 193 multiplies the I signal supplied from the multiplier 191 by the cosine component of the signal generated by the NCO 180 and supplies the result to the LPF 195. The multiplier 194 multiplies the Q signal supplied from the multiplier 192 by the sine component of the signal generated by the NCO 180 and supplies the result to the LPF 196.

The LPF 195 is a frequency component represented by the cutoff frequency information of the I signal supplied from the multiplier 193 based on the cutoff frequency information supplied from the CPU 52 in FIG. Is cut and supplied to the correlation detector 197.

The LPF 196 cuts the frequency component represented by the cutoff frequency information in the Q signal supplied from the multiplier 194 based on the cutoff frequency information supplied from the CPU 52 based on the processing result of the synchronization acquisition unit 48. To the correlation detector 197.

The correlation detector 197 calculates the square sum (I ² + Q ² ) of the I signal supplied from the LPF 195 and the Q signal supplied from the LPF 196, and supplies it to the accumulator 198 and the phase detector 207. The accumulator 198 accumulates the bit length of the navigation message supplied from the CPU 52 to generate a correlation value E between the baseband signal and the spread code E. The accumulator 198 supplies the correlation value E to the CPU 52.

The processing of the multipliers 199 to 202, the

LPFs

203 and 204, the correlation detector 205, and the accumulator 206 is a spreading code (hereinafter referred to as spreading code) whose phase is delayed from P instead of the spreading code E. (L) is input from the PNG 210, and is the same as the processing of the multipliers 191 to 194, the

LPFs

195 and 196, the correlation detector 197, and the accumulator 198. Therefore, detailed description is omitted. By this processing, the accumulator 206 outputs a correlation value L, which is a correlation value between the baseband signal and the spreading code L, to the CPU 52, and the square sum (I ² + Q ² ) of the I signal and the Q signal is the phase. This is supplied to the detector 207.

The phase detector 207 uses the difference of the sum of squares (I ² + Q ² ) supplied from the correlation detector 197 and the correlation detector 205 as a phase error between the spreading code P and the spreading code in the GPS baseband signal. To detect. The phase detector 207 supplies the detected phase error to the NCO 209 via the loop filter 208. Thereby, the phase of the spreading code P is controlled to be synchronized with the phase of the spreading code in the GPS baseband signal.

The loop filter 208 integrates the phase error supplied from the phase detector 207 on the basis of the parameter specifying the filter characteristic supplied from the CPU 52 and generated based on the processing result of the synchronization acquisition unit 48, and sets the NCO 209. A control signal to be controlled is generated. The loop filter 179 supplies a control signal to the NCO 209.

NCO 209 is composed of a variable frequency NCO. The NCO 290 corrects the carrier frequency represented by the frequency information based on the frequency information supplied from the CPU 52 and the correction value b. Based on the control signal supplied from the loop filter 208, the NCO 209 generates a signal having a corrected carrier frequency so that the phase of the spreading code P is synchronized with the phase of the spreading code in the GPS baseband signal. The NCO 209 supplies the generated signal to the PNG 210.

The PNG 210 generates a spreading code E, a spreading code P, and a spreading code L based on the signal supplied from the NCO 209. The generation of the spreading code E, spreading code P, and spreading code L is reset based on the correction value a supplied from the CPU 52 and the phase h supplied from the synchronization acquisition unit 48.

Thereby, the synchronization deviation of the spreading code P due to the frequency deviation of the clock CLK is corrected, and the spreading code P whose phase is synchronized with the spreading code in the GPS baseband signal is generated. Accordingly, the Costas loop 151 can accurately perform spectrum despreading on the GPS baseband signal using the spreading code P. As a result, the Costas loop 151 can demodulate the navigation message.

The correction of the carrier synchronization error by the NCO 180 and the correction of the synchronization error of the spreading code by the NCO 209 and the PNG 210 are performed at intervals sufficiently shorter than the temperature variation time.

(Description of reset by PNG)
FIG. 12 is a diagram for explaining reset by the PNG 210 of FIG.

As shown in FIG. 12, the synchronization acquisition unit 48 notifies the synchronization holding unit 49 of the start of the acquisition of a baseband signal into a built-in memory (not shown). In response to the notification, the synchronization holding unit 48 requests the CPU 52 to start the timer 53 and starts the timer 53.

The synchronization acquisition unit 48 reads the baseband signal held in the memory according to the clock CLK, acquires the synchronization of the spread code in the baseband signal, and detects the phase h. The synchronization acquisition unit 48 supplies the detected phase h to the synchronization holding unit 49. The phase of the spreading code is affected by the Doppler frequency of each positioning satellite from when the baseband signal is read until the phase h is supplied to the synchronization holding unit 49.

When the phase h is supplied from the synchronization acquisition unit 48, the PNG 210 of the synchronization holding unit 49 uses the following equation (6) based on the correction value a supplied from the CPU 52 to calculate the phase h due to the frequency deviation of the clock CLK. The shift Δh is obtained.

Note that Ti is a delay time from the start of capturing the baseband signal into the memory of the synchronization capturing unit 48 to the resetting of the PNG 210. Δfd is a carrier frequency shift including the Doppler shift amount detected by the synchronization acquisition unit 48.

Based on the phase h and the shift Δh, the PNG 210 has the spreading code E, the spreading code P, and the spreading code after the count value of the timer 53 becomes an integral multiple of 1 ms and only after the sum of the phase h and the shift Δh (h + Δh). Reset the generation of L. As a result, the synchronization shift of the spreading code P due to the frequency shift of the clock CLK can be corrected. The PNG 210 resets the generation of the spreading code E, the spreading code P, and the spreading code L not only when the phase h is supplied but also when the correction value a is updated.

The details of the process in which the synchronization holding unit 49 resets the generation of the spreading code E, the spreading code P, and the spreading code L based on the phase h detected by the synchronization capturing unit 48 are, for example, “A High Performance GPS Solution for Mobile Use ”, Katsuyuki Tanaka, Takayasu Muto, Katsuya Hori, Mikio Wakamori, Koichiro Teranishi, Hideki Takahashi, Masayuki Sawada, Matt Ronning, ION GPS 2002.

(Description of processing of receiving device)
FIG. 13 is a flowchart for explaining a reception process of the reception device 10 of FIG.

In step S11 of FIG. 13, the receiving apparatus 10 performs setting such as an intermediate frequency of the NCO 136 of FIG. 10 as an initial setting.

In step S12, the receiving device 10, generates the oscillation signal, the generation of voltage V _th of the signal, A / D conversion of the voltage V _th of the signal, generating a clock CLK, the reception of the RF signal, to the IF signal from the RF signal Starts initial operations such as conversion and A / D conversion of IF signals.

In step S13, the LPF 51 averages the 10-bit temperature data supplied from the ADC 50, generates 12-bit temperature data X, and supplies it to the CPU 52.

In step S14, the CPU 52 reads the correction value a and the correction value b corresponding to the temperature data X from the correction table stored in the memory 54 based on the temperature data X supplied from the LPF 51.

In step S15, the CPU 52 corrects the intermediate frequency of the NCO 136 set in step S11 based on the correction value a by supplying the correction value a to the baseband conversion unit 47. As a result, the baseband converter 47 generates a corrected intermediate frequency signal, and converts the digital IF signal supplied from the frequency converter 46 into a baseband signal using the signal. The baseband conversion unit 47 outputs the baseband signal to the synchronization acquisition unit 48 and the synchronization holding unit 49. Note that the processing in steps S15 to S24 is performed for each positioning satellite.

In step S16, the synchronization capturing unit 48 captures the baseband signal output from the baseband converting unit 47 into a memory (not shown). The synchronization acquisition unit 48 notifies the synchronization holding unit 49 of the start of the acquisition. With this notification, the timer 53 is started.

In step S17, the synchronization acquisition unit 48 reads the baseband signal held in the memory, performs synchronization acquisition of the spreading code in the baseband signal, and detects the phase h and carrier frequency of the spreading code. The synchronization acquisition unit 48 detects positioning satellite identification information and the like. Then, the synchronization acquisition unit 48 supplies the detected phase h of the spread code to the synchronization holding unit 49 and supplies the carrier frequency, identification information, etc. to the CPU 52.

In step S18, the CPU 52 corrects the carrier frequencies of the NCO 180 and the NCO 209 (FIG. 11) based on the correction value b by supplying the correction value b to the synchronization holding unit 49.

In step S19, the CPU 52 supplies the correction value a to the synchronization holding unit 49, thereby causing the PNG 210 (FIG. 11) to reset the generation of the spreading code based on the correction value a and the phase h, and to set the phase of the spreading code to the phase. Correct to h + Δh.

In step S20, the CPU 52 sets the threshold value of the binarization circuit 154, the cutoff frequency information, the frequency information, the bit length of the navigation message, etc. to the channel circuit 150, and starts the operation of the channel circuit 150.

In step S21, the channel circuit 150 performs demodulation processing on the baseband signal supplied from the baseband converter 47 using the corrected carrier frequency signal to obtain a navigation message.

In step S22, the CPU 52 generates position information based on the navigation message supplied from the synchronization holding unit 49.

In step S23, the receiving apparatus 10 determines whether or not to continue the receiving process. When it is determined in step S23 that the reception process is to be continued, in step S24, the receiving apparatus 10 performs the continuation process. In the continuation process, steps S13 to S15, S18, S21, and S22 are performed. However, the processing relating to the correction according to the temperature in steps S13 to S15, and S18, the demodulation processing in step S21, and the position information generation processing in step S22 are each independently performed periodically or aperiodically depending on the application. To be done. For example, the position information generation process may be periodically performed every second, the demodulation process may be performed every 1 second or more, and the process related to temperature correction may be performed periodically every 1 second or less. After the process of step S24, the process returns to step S23.

On the other hand, if it is determined in step S23 that the reception process is not continued, the process ends. Note that FIG. 13 illustrates the reception process of the reception device 10 in a simplified manner. In the actual reception process, a number of processes such as satellite replacement according to reception conditions and environmental factors, and channel channel 150 setting change are performed. Is further included.

As described above, since the receiving apparatus 10 corrects the frequency of the IF signal based on the temperature data X, the frequency shift Δf (X) of the oscillation signal due to temperature fluctuation can be achieved without controlling the frequency of the crystal oscillation circuit 13. The influence on the IF signal can be suppressed. That is, the temperature compensation of the IF signal can be performed.

Further, since the receiving device 10 corrects the frequency of the clock CLK based on the temperature, the influence of the frequency shift Δf (X) on the clock CLK can be suppressed without controlling the frequency of the crystal oscillation circuit 13. . That is, the temperature compensation of the clock CLK can be performed.

As a result, an increase in synchronization acquisition time due to frequency deviation Δf (X), loss of synchronization of carriers and spreading codes, demodulation errors, position information and speed information, detection accuracy degradation such as Doppler shift, or detection errors can be prevented and received. The performance (sensitivity, position detection speed, etc.) of the apparatus 10 can be improved.

In addition, since the receiving device 10 does not need to perform temperature compensation on the frequency of the oscillation signal, power consumption can be reduced compared to a receiving device including a TCXO that performs temperature compensation on the frequency of the oscillation signal. it can. As a result, the battery duration of the mobile terminal or wearable terminal in which the receiving device 10 is mounted can be increased.

In the above description, the correction information registered in the correction table is the correction value a and the correction value b. However, if the correction information is a value that allows the correction value a and the correction value b to be calculated, The correction value a and the correction value b may not be used. For example, as shown in FIG. 14, the correction information may be the coefficients C _{0 to} C ₃ and the constant X ₀ of the model formula represented by the above-described formula (5).

In the example of FIG. 14, the temperature data X is divided into five ranges D to H as shown in FIG. 8, and the relationship between the temperature data X and the frequency shift 48Δf (X) is modeled in each of the ranges D to H. Has been. The order n is 3 or more.

Accordingly, in the correction table of FIG. 14, the coefficients C _{0 to} C ₃ and the constant X _{0 of the} model formula represented by the above-described formula (5) in the range are registered in association with each of the ranges D to H. Yes.

When the correction table of FIG. 14 is stored in the memory 54, the CPU 52 reads the coefficients C _{0 to} C ₃ and the constant X ₀ corresponding to any of the ranges D to H including the temperature data X supplied from the LPF 51. Then, the CPU 52 calculates the frequency shift Δf (X) by the above-described equation (5) using the read coefficients C _{0 to} C ₃ and the constant X ₀ . The CPU 52 supplies a value obtained by multiplying the frequency deviation Δf (X) by 48 to the baseband conversion unit 47 and the synchronization holding unit 49 as a correction value a, and corrects the ratio between the frequency deviation Δf (X) and the frequency of the oscillation signal. b is supplied to the synchronization holding unit 49.

Note that the memory 54 may store both the correction table of FIG. 2 and the correction table of FIG.

In the first embodiment, the relationship between the temperature data X and the frequency deviation Δf (X) is modeled based on the actual measurement value of the frequency deviation Δf (X). Since the temperature characteristic of the frequency shift Δf (X) has individual variations, when modeling is performed based on the actual measurement value of the frequency shift Δf (X), it is necessary to perform modeling for each receiving device 10.

<Second Embodiment>
(Configuration Example of Correction Unit of Second Embodiment of Receiving Device)
The configuration of the second embodiment of the receiving apparatus to which the present disclosure is applied is that the correction table is not stored in the memory 54, and the accurate frequency and temperature data X of the oscillation signal obtained by the CPU 52 during the positioning calculation process. 1 is the same as the configuration of the receiving apparatus 10 in FIG. 1 except that the correction value a and the correction value b are calculated based on. Therefore, hereinafter, only the correction unit which is realized by the CPU 52 and the memory 54 and calculates the correction value a and the correction value b based on the accurate frequency of the oscillation signal obtained in the positioning calculation process and the temperature data X will be described. To do.

FIG. 15 is a block diagram illustrating a configuration example of the correction unit 230.

15 includes a calculation unit 231, multiplication units 232-0 to 232-n, subtraction units 233-0 to 233-n, holding units 234-0 to 234-n, multiplication units 235-0 to 235- n, an integration unit 236, a subtraction unit 237, a multiplication unit 238, and a correction value calculation unit 239. Calculation unit 231, multiplication units 232-0 to 232-n, subtraction units 233-0 to 233-n, multiplication units 235-0 to 235-n, integration unit 236, subtraction unit 237, multiplication unit 238, and correction value calculation The unit 239 is realized by the CPU 52. The holding units 234-0 to 234-n are realized by an SDRAM or a flash memory of the memory 54.

The correction unit 230 corrects the difference between the accurate frequency of the oscillation signal obtained in the positioning calculation process and the nominal oscillation frequency of the crystal oscillation circuit 13, and the frequency deviation Δf (modeled by the above-described equation (5)). The correction value a and the correction value b are calculated based on the model formula of Formula (5) while updating the coefficient C _n so that the square error of X) is minimized.

That is, when the frequency deviation Δf (k) at time k is calculated by the above-described model equation (5) using the temperature data X (k) at time k and the coefficient C _n (k) at time k, The frequency shift Δf (k) is expressed by the following equation (7).

Further, the sum of the square errors of the accurate frequency of the oscillation signal at time k obtained in the positioning calculation process, the deviation Δf ₀ (k) of the nominal oscillation frequency of the crystal oscillation circuit 13, and the frequency deviation Δf (k). E is represented by the following formula (8).

The minimum value of the total sum E of square errors in equation (8) is given by a coefficient C _n which is 0 as a result of partial differentiation of the sum E by a coefficient C _n as shown in the following equation (9).

Such an update recurrence formula of the coefficient C _n is expressed by the following formula (10) by the steepest descent method (LMS (Least Mean Square)).

The coefficient C _n (k + 1) is the coefficient C _n at time k + 1, and μ is a learning coefficient.

Therefore, the correction unit 230 calculates the correction value a and the correction value b based on the model expression of Expression (5) while updating the coefficient C _n according to Expression (10).

Specifically, the temperature data X (k) at time k supplied from the LPF 51 is input to the calculation unit 231 of the correction unit 230 every hour. The computing unit 231 subtracts the constant X ₀ from the temperature data X (k), and raises (X (k) −X ₀ ) obtained as a result to the 0th to nth power. The calculation unit 231 supplies (X (k) −X ₀ ) ⁰ obtained as a result to the multiplication unit 232-0 and the multiplication unit 235-0, and (X (k) −X ₀ ) ¹ is supplied to the multiplication unit 232- 1 and the multiplier 235-1. Further, the calculation unit 231 applies (X (k) −X ₀ ) ² ,..., (X (k) −X ₀ ) ⁿ to the multiplication unit 232-2, the multiplication unit 235-2,. ., To the multiplier 232-n and multiplier 235-n.

The multiplication unit 232-i (i = 0, 1, 2,..., N) is supplied from the operation unit 231 (X (k) −X ₀ ) ⁱ and μe (from the multiplication unit 238). k) and the resulting μe (k) (X (k) −X ₀ ) ⁱ is supplied to the subtracting unit 233-i.

The subtracting unit 233-i subtracts μe (k) (X (k) −X ₀ ) ⁱ supplied from the multiplying unit 232-i from the coefficient C _i (k) supplied from the holding unit 234-i. . As described above, the calculation of Expression (10) described above is performed, and the coefficient C _i (k + 1) is obtained. The multiplication unit 232-i supplies the coefficient C _i (k + 1) to the holding unit 234-i.

The holding unit 234-i reads the held coefficient C _i (k) when μe (k) (X (k) −X ₀ ) ⁱ is input to the subtraction unit 233-i, and the subtraction unit 233-i i is supplied to the multiplier 235-i. When the coefficient C _i (k + j) (j is an integer greater than 1) is supplied from the subtractor 233-i, the holding unit 234-i converts the held coefficient C _i (k) to the coefficient C _i ( k + j). Accordingly, the coefficient C _i (k) is updated every j times.

Note that the initial value of the coefficient C _i (k) is, for example, an average value of the coefficient C _i obtained by modeling based on an actual measurement value of the frequency shift Δf (X) in a plurality of receiving apparatuses. In addition, the holding unit 234-i holds the coefficient C _i even during sleep.

The multiplication unit 235-i multiplies (X (k) -X ₀ ) ⁱ supplied from the calculation unit 231 and the coefficient C _i (k) supplied from the holding unit 234-i, and obtains the result. C _i (k) (X (k) −X ₀ ) ⁱ is supplied to the integrator 236.

The accumulating unit 236 performs the calculation of the above equation (7) by adding all the C _i (k) (X (k) −X ₀ ) ⁱ supplied from the multiplying unit 235-i, and the frequency shift Δf (K) is obtained. The accumulating unit 236 supplies the frequency shift Δf (k) to the subtracting unit 237 and the correction value calculating unit 239.

The difference Δf ₀ (k) is input to the subtraction unit 237 every j times. The subtraction unit 237 subtracts the frequency shift Δf (k) supplied from the integration unit 236 from the shift Δf ₀ (k) to obtain e (k), and supplies it to the multiplication unit 238.

The multiplication unit 238 multiplies e (k) supplied from the subtraction unit 237 and the learning coefficient μ, and supplies the resulting μe (k) to the multiplication units 232-0 to 232-n.

The correction value calculation unit 239 obtains the correction value a by multiplying the frequency shift Δf (k) supplied from the integration unit 236 by 48, and the ratio between the frequency shift Δf (k) and the frequency of the oscillation signal is used as the correction value b. Ask. The correction value calculation unit 239 supplies the correction value a to the baseband conversion unit 47 and the synchronization holding unit 49, and supplies the correction value b to the synchronization holding unit 49. Thereby, based on the correction value a, the frequency of the IF signal after the IF signal at time k is corrected, and the frequency of the clock CLK after the clock CLK at time k is corrected.

As described above, in the correction unit 230, the temperature data X (k) is input every time, and the deviation Δf ₀ (k) is input every j time. Therefore, the update frequency of the coefficient C _i (k) is lower than the calculation frequency of the correction value a and the correction value b. For example, the update frequency of the coefficient C _i (k) can be made lower than 1 Hz, and the calculation frequency of the correction value a and the correction value b can be made higher than 10 Hz. Since the temperature characteristic of the crystal oscillation circuit 13 does not change in a short time, there is no problem even if the update frequency of the coefficient C _i (k) is lower than the calculation frequency of the correction value a and the correction value b.

In the correction unit 230, the calculation frequency of the correction value a and the correction value b is lower than the conversion frequency of the ADC 50. Thereby, the resolution of temperature detection can be raised similarly to 1st Embodiment.

In the correction unit 230 in FIG. 15, the deviation Δf ₀ (k) is periodically input to the subtraction unit 237 every j times, but only when the positioning calculation is stably performed. You may make it input into the subtraction part 237 periodically. Judgment of whether the positioning calculation is performed stably is performed, for example, based on whether all the C / N of the navigation message obtained from the RF signal transmitted from GPS, GLONASS, Beidou, and Galileo is good .

The correction unit 230 performs both the update of the coefficient C _i (k) and the calculation of the frequency shift Δf (k), but the update of the coefficient C _i (k) and the calculation of the frequency shift Δf (k). May be performed independently. In this case, the coefficient C _i (k) may be stored in the memory 54 as a correction table. This correction table includes not only the coefficient C _i (k) but also the exact frequency or deviation Δf _{0 of} the oscillation signal obtained in the positioning calculation process used for updating the coefficient C _i (k). (K) may be registered.

In the reception process of the receiving apparatus according to the second embodiment, instead of reading out the correction value a and the correction value b corresponding to the temperature data X in step S14, the correction value a and the correction value b are calculated based on the temperature data X. Except for this point, it is the same as the reception process of FIG.

As described above, the receiving apparatus according to the second embodiment corrects the frequency of the IF signal and the frequency of the clock CLK based on the accurate frequency of the oscillation signal and the temperature data X obtained in the positioning calculation process. Therefore, for example, the difference between the accurate frequency of the oscillation signal obtained in the positioning calculation process and the nominal oscillation frequency of the crystal oscillation circuit 13 and the frequency deviation Δf (X (X) modeled by the above-described equation (5) are used. ), The correction value a and the correction value b can be calculated by updating the coefficient C _n as needed.

Therefore, it is not necessary to previously measure the actual measurement value of the frequency deviation Δf (X) for each receiving device, and the cost of the receiving device can be reduced. Even when the temperature characteristics of the crystal oscillation circuit 13 change due to aging, the accuracy of the correction value a and the correction value b can be maintained. Furthermore, the accuracy of the correction value a and the correction value b improves as the usage time of the receiving device becomes longer.

In the second embodiment, as in the first embodiment, the entire range of the temperature data X is divided into a plurality of ranges, and the relationship between the temperature data X and the frequency deviation Δf (X) is determined for each range. It can also be modeled. In this case, the correction unit 230 is provided for each range of the temperature data X, and the coefficient C _i (k) is updated for each range of the temperature data X. However, the coefficient C _i (k) of each range is subject to a restriction that the frequency shift Δf (X) at the boundary of each range and the differential value of Equation (5) are continuous.

<Third Embodiment>
(Configuration example of third embodiment of receiver)
FIG. 16 is a block diagram illustrating a configuration example of the third embodiment of the reception device to which the present disclosure is applied.

16, the same reference numerals are given to the same components as those in FIG. 1. The overlapping description will be omitted as appropriate.

16 is different from the configuration of the receiving device 10 in FIG. 1 in that a receiving unit 251 is provided instead of the receiving unit 12. The receiving device 250 corrects the frequency of the IF signal by generating the LO signal from the oscillation signal based on the correction value a, and generates the clock CLK from the oscillation signal based on the correction value b, thereby generating the frequency of the clock CLK. Correct.

Specifically, the configuration of the receiving unit 251 includes a PLL unit 270, a frequency converting unit 271, and a baseband converting unit instead of the PLL unit 44, the frequency converting unit 46, the baseband converting unit 47, the synchronization holding unit 49, and the CPU 52. 272, a synchronization holding unit 273, and a CPU 274 are different from the configuration of the receiving unit 12.

The PLL unit 270 of the receiving unit 251 is a PLL circuit capable of digitally controlling the frequency, for example, a fractional N PLL circuit often used in wireless devices. The PLL unit 270 (clock correction unit) corrects the frequency of the clock CLK from twice the frequency of the oscillation signal based on the correction value b supplied from the CPU 274. The PLL unit 270 uses the oscillation signal supplied from the buffer 43 to generate a clock CLK having a corrected frequency. As a result, the frequency shift of the clock CLK accompanying the frequency variation of the oscillation signal due to temperature is corrected.

The PLL unit 270 supplies the clock CLK to the frequency conversion unit 271, the baseband conversion unit 272, the synchronization acquisition unit 48, and the synchronization holding unit 273. Here, it is assumed that the frequency of the clock CLK before correction is twice the frequency of the oscillation signal, but the frequency of the clock CLK before correction is not limited to this.

The frequency converter 271 corrects the frequency of the LO signal from 48 times the frequency of the oscillation signal based on the correction value a supplied from the CPU 274. The frequency converter 271 uses the oscillation signal supplied from the buffer 43 to generate an LO signal having a corrected frequency. The frequency conversion unit 271 down-converts the frequency of the RF signal received by the antenna 45 to IF using the LO signal, and converts the RF signal into an IF signal. As described above, since the frequency conversion unit 271 generates the IF signal using the LO signal having the frequency corrected based on the correction value a, the frequency shift of the IF signal due to the frequency variation of the oscillation signal due to temperature is corrected. can do.

Further, the frequency conversion unit 271 performs A / D conversion on the analog IF signal using the clock CLK as a sampling clock, and outputs the resulting digital IF signal to the baseband conversion unit 272.

The baseband conversion unit 272 performs frequency conversion or the like on the digital IF signal I signal and Q signal supplied from the frequency conversion unit 271 according to the clock CLK, and converts the signal into a baseband signal. The baseband conversion unit 272 outputs the baseband signal to the synchronization acquisition unit 48 and the synchronization holding unit 273.

The frequency conversion unit 271 and the baseband conversion unit 272 perform the above-described processing separately for each of the GPS signal and the Galileo RF signal, the GLONASS RF signal, and the Beidou RF signal.

Similarly to the synchronization holding unit 49, the synchronization holding unit 273 performs a demodulation process on the baseband signal supplied from the baseband conversion unit 272 according to the clock CLK for each positioning satellite to obtain a navigation message. However, since the frequency deviation of the clock CLK has already been corrected by the PLL unit 270, the frequency deviation of the clock CLK is not corrected. The synchronization holding unit 273 supplies the navigation message to the CPU 274.

As with the CPU 52 in FIG. 1, the CPU 274 (reading unit), based on the temperature data X supplied from the LPF 51, reads from the correction table stored in the memory 54 the frequency correction value a corresponding to the temperature data X. And the correction value b is read. The CPU 274 supplies the correction value a to the frequency conversion unit 271 and supplies the correction value b to the PLL unit 270.

In addition, the CPU 274 generates position information based on the navigation message supplied from the synchronization holding unit 273, similarly to the CPU 52. Further, the CPU 274 performs control of each block of the receiving unit 251 and the like.

(Configuration example of frequency converter)
FIG. 17 is a block diagram illustrating a configuration example of the frequency conversion unit 271 in FIG.

17, the same reference numerals are given to the same components as those in FIG. 9. The overlapping description will be omitted as appropriate.

17 differs from the configuration of the frequency conversion unit 46 of FIG. 9 in that a local oscillation circuit 291 is provided instead of the local oscillation circuit 73. The frequency conversion unit 271 of FIG.

The local oscillation circuit 291 is a local oscillation circuit capable of digitally controlling the frequency of a signal to be generated. For example, the local oscillation circuit 291 is a fractional N PLL circuit often used in wireless devices. The local oscillation circuit 291 (signal correction unit) corrects the frequency of the LO signal from 48 times the frequency of the oscillation signal based on the correction value a supplied from the CPU 274 in FIG. The local oscillation circuit 291 generates an LO signal having a corrected frequency by using the oscillation signal supplied from the buffer 43 in FIG. The local oscillation circuit 291 supplies the LO signal to the mixer 91.

<Fourth embodiment>
(Configuration example of fourth embodiment of receiver)
FIG. 18 is a block diagram illustrating a configuration example of the fourth embodiment of the reception device to which the present disclosure is applied.

18, the same reference numerals are given to the same components as those in FIGS. 1 and 16. The overlapping description will be omitted as appropriate.

18 is different from the configuration of the receiving device 250 in FIG. 16 in that a receiving unit 311 is provided instead of the receiving unit 251. The receiving device 310 in FIG. The receiving device 310 corrects the frequency of the clock CLK by generating the clock CLK using the LO signal generated from the oscillation signal based on the correction value a.

Specifically, the configuration of the receiving unit 311 is different from the configuration of the receiving unit 251 in that the PLL unit 270 is not provided and that the frequency converting unit 331 and the CPU 332 are provided instead of the frequency converting unit 271 and the CPU 52. .

Similarly to the frequency conversion unit 271 in FIG. 16, the frequency conversion unit 331 of the reception unit 311 receives an LO signal having a frequency corrected based on the correction value a supplied from the CPU 332 and an oscillation signal supplied from the buffer 43. Use to generate. The frequency conversion unit 331 down-converts the frequency of the RF signal received by the antenna 45 to IF using the LO signal, and converts the RF signal into an IF signal. As described above, the frequency shift of the IF signal accompanying the frequency variation of the oscillation signal due to temperature is corrected.

Further, the frequency conversion unit 331 divides the frequency of the LO signal by 1/24 and generates a clock CLK. Therefore, the frequency deviation of the clock CLK accompanying the frequency fluctuation of the oscillation signal due to temperature is corrected simultaneously with the frequency deviation of the IF signal. The frequency conversion unit 331 supplies the clock CLK to the baseband conversion unit 272, the synchronization acquisition unit 48, and the synchronization holding unit 273.

Further, the frequency conversion unit 331 performs A / D conversion on the analog IF signal using the clock CLK as a sampling clock, and outputs the resulting digital IF signal to the baseband conversion unit 272.

The CPU 332 (reading unit) reads the correction value a of the frequency corresponding to the temperature data X from the correction table stored in the memory 54 based on the temperature data X supplied from the LPF 51. The CPU 332 supplies the correction value a to the frequency conversion unit 331.

Further, the CPU 332 generates the position information based on the navigation message supplied from the synchronization holding unit 273, similarly to the CPU 52. In addition, the CPU 332 performs control of each block of the reception unit 311 and the like.

18, only the correction value a may be registered in the correction table in association with the temperature data X.

(Configuration example of frequency converter)
FIG. 19 is a block diagram illustrating a configuration example of the frequency conversion unit 331 in FIG.

Of the configurations shown in FIG. 19, the same reference numerals are given to the same configurations as those in FIG. 17. The overlapping description will be omitted as appropriate.

19 differs from the configuration of the frequency converter 271 in FIG. 17 in that a frequency divider 351 is newly provided.

A frequency divider 351 (clock generation unit) divides the frequency of the LO signal generated by the local oscillation circuit 291 by 1/24 to generate a clock CLK. The frequency divider 351 supplies the clock CLK to the ADC 97, the baseband conversion unit 272, the synchronization acquisition unit 48, and the synchronization holding unit 273. The clock CLK supplied to the ADC 97 is used as a sampling clock for A / D conversion of the IF signal.

In the first to fourth embodiments, the receiving device receives RF signals from four positioning satellites of GPS, GLONASS, Beidou, and Galileo, but receives RF signals from five or more positioning satellites. The position information may be generated based on the RF signal. In order to eliminate the influence of the error between the time in the receiving apparatus and the time of the positioning satellite, it is necessary to receive RF signals from four or more positioning satellites.

The thermistor 24 may be constituted by a temperature detection diode. Further, the crystal unit 21 and the thermistor 24 may be integrated as long as the thermistor 24 is provided in the vicinity of the crystal unit 21, or may be configured separately. Further, when the temperature sensor is built in a receiving unit formed of an IC chip, the thermistor 24 can be omitted by bringing the IC chip and the crystal resonator 21 close to each other. In this case, the correction value a and the correction value b are determined based on the temperature data detected by the temperature sensor.

This disclosure can also be applied to a receiving device including a TCXO instead of a crystal oscillation circuit. That is, although it is smaller than the crystal oscillation circuit, the frequency shift of the oscillation signal due to the temperature also occurs in the TCXO. Therefore, also in a receiving device including a TCXO instead of a crystal oscillation circuit, by applying the present disclosure, it is possible to correct the frequency shift of the IF signal and the clock due to the frequency shift of the oscillation signal due to temperature. As a result, the performance (sensitivity, position detection speed, etc.) of the receiving apparatus can be improved.

Further, the effects described in the present specification are merely examples and are not limited, and other effects may be obtained.

Furthermore, the embodiments of the present disclosure are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure.

For example, in the third embodiment, either the correction of the frequency shift of the IF signal or the correction of the frequency shift of the clock CLK may be performed in the same manner as in the first embodiment.

Further, in the third embodiment and the fourth embodiment, as in the second embodiment, the correction value a and the correction are performed based on the accurate frequency and temperature data X of the oscillation signal obtained in the positioning calculation process. The value b may be calculated.

In addition, this indication can also take the following structures.

(1)
A signal correction that corrects the frequency of an IF (Intermediate Frequency) signal converted from a GNSS (Global Navigation Satellite System) signal using the oscillation signal based on the temperature in the vicinity of the oscillation unit that generates an oscillation signal of a predetermined frequency A receiving device comprising a unit.
(2)
The signal correction unit is configured to correct the frequency of the IF signal by correcting the frequency of the signal used for frequency conversion of the IF signal based on the temperature. Receiver device.
(3)
The signal correction unit corrects the frequency of the IF signal by generating an LO (Local Oscillator) signal used for converting the GNSS signal into the IF signal based on the temperature from the oscillation signal. The receiving device according to (1) configured to be.
(4)
The receiving device according to (3), further including: a clock generation unit that generates a clock used for processing the IF signal using the LO signal.
(5)
A clock correction unit for correcting a frequency of a clock used for processing the IF signal based on the temperature;
The receiving device according to any one of (1) to (3), wherein the clock is generated using the oscillation signal.
(6)
The receiving device according to (5), wherein the clock correction unit is configured to correct the frequency of the clock by correcting the frequency of a signal used for demodulation of the IF signal based on the temperature. .
(7)
The receiving device according to (6), wherein the clock correction unit is configured to correct a frequency of the clock by resetting a spreading code generation process for the IF signal based on the temperature.
(8)
The receiving device according to (5), wherein the clock correction unit is configured to correct the frequency of the clock by generating the clock from the oscillation signal based on the temperature.
(9)
A reading unit that reads out correction information indicating a correction value of the frequency of the IF signal corresponding to the temperature;
The receiving device according to any one of (1) to (8), wherein the signal correction unit is configured to correct the frequency of the IF signal based on the correction information read by the reading unit. .
(10)
The correction value is determined based on a carrier synchronization shift of an IF (Intermediate Frequency) signal before frequency correction converted from a GNSS (Global Navigation Satellite System) signal having a predetermined frequency. ).
(11)
The receiving device according to (9), wherein the correction value is determined based on the predetermined frequency detected using an IF signal before frequency correction converted from a predetermined GNSS signal.
(12)
The receiving apparatus according to any one of (9) to (11), wherein an expression representing a relationship between the temperature and the correction value is set for each temperature range.
(13)
The signal correction unit corrects the frequency of the IF signal after the IF signal based on the predetermined frequency and the temperature detected using the IF signal whose frequency is corrected by the signal correction unit. The receiving device according to any one of (1) to (8), configured as described above.
(14)
The signal correction unit, based on the predetermined frequency and the temperature detected using the IF signal whose frequency is corrected by the signal correction unit, the temperature and the IF signal corresponding to the temperature The receiving device according to (13), configured to update an expression representing a relationship with a frequency correction value and to correct the frequency of the IF signal based on the expression.
(15)
The receiving device
A signal correction that corrects the frequency of an IF (Intermediate Frequency) signal converted from a GNSS (Global Navigation Satellite System) signal using the oscillation signal based on the temperature in the vicinity of the oscillation unit that generates an oscillation signal of a predetermined frequency A reception method including steps.

10 receiving device, 13 crystal oscillation circuit, 47 baseband converting unit, 49 synchronization holding unit, 52 CPU, 250 receiving device, 270 PLL unit, 271 frequency converting unit, 274 CPU, 310 receiving device, 331 frequency converting unit, 332 CPU

Claims

A signal correction that corrects the frequency of an IF (Intermediate Frequency) signal converted from a GNSS (Global Navigation Satellite System) signal using the oscillation signal based on the temperature in the vicinity of the oscillation unit that generates an oscillation signal of a predetermined frequency A receiving device comprising a unit.
The reception according to claim 1, wherein the signal correction unit is configured to correct a frequency of the IF signal by correcting a frequency of a signal used for frequency conversion of the IF signal based on the temperature. apparatus.
The signal correction unit corrects the frequency of the IF signal by generating an LO (Local Oscillator) signal used for converting the GNSS signal into the IF signal based on the temperature from the oscillation signal. The receiving device according to claim 1, wherein the receiving device is configured to be.
The receiving apparatus according to claim 3, further comprising: a clock generation unit that generates a clock used for processing the IF signal using the LO signal.
A clock correction unit for correcting a frequency of a clock used for processing the IF signal based on the temperature;
The receiving device according to claim 1, wherein the clock is generated using the oscillation signal.
The receiving device according to claim 5, wherein the clock correction unit is configured to correct the frequency of the clock by correcting the frequency of a signal used for demodulation of the IF signal based on the temperature.
The receiving device according to claim 6, wherein the clock correction unit is configured to correct the frequency of the clock by resetting a spreading code generation process for the IF signal based on the temperature.
The receiving device according to claim 5, wherein the clock correction unit is configured to correct the frequency of the clock by generating the clock from the oscillation signal based on the temperature.
A reading unit that reads out correction information indicating a correction value of the frequency of the IF signal corresponding to the temperature;
The receiving device according to claim 1, wherein the signal correction unit is configured to correct the frequency of the IF signal based on the correction information read by the reading unit.
The correction value is configured to be determined based on a carrier synchronization shift of an IF (Intermediate Frequency) signal before frequency correction converted from a GNSS (Global Navigation Satellite System) signal having a predetermined frequency. The receiving device described in 1.
The receiving device according to claim 9, wherein the correction value is determined based on the predetermined frequency detected using an IF signal before frequency correction converted from a predetermined GNSS signal.
The receiving apparatus according to claim 9, wherein an expression representing a relationship between the temperature and the correction value is set for each temperature range.
The signal correction unit corrects the frequency of the IF signal after the IF signal based on the predetermined frequency and the temperature detected using the IF signal whose frequency is corrected by the signal correction unit. The receiving device according to claim 1, configured as described above.
The signal correction unit, based on the predetermined frequency and the temperature detected using the IF signal whose frequency is corrected by the signal correction unit, the temperature and the IF signal corresponding to the temperature The receiving apparatus according to claim 13, configured to update an expression representing a relationship with a frequency correction value and correct the frequency of the IF signal based on the expression.
The receiving device
A signal correction that corrects the frequency of an IF (Intermediate Frequency) signal converted from a GNSS (Global Navigation Satellite System) signal using the oscillation signal based on the temperature in the vicinity of the oscillation unit that generates an oscillation signal of a predetermined frequency A reception method including steps.