US20080232522A1

US20080232522A1 - Method and System for Integration of Bluetooth and FM Local Oscillator Generation into a Single Unit Using a DDFS

Info

Publication number: US20080232522A1
Application number: US11/754,460
Authority: US
Inventors: Ahmadreza Rofougaran; Maryam Rofougaran
Original assignee: Broadcom Corp
Current assignee: Broadcom Corp
Priority date: 2007-03-19
Filing date: 2007-05-29
Publication date: 2008-09-25
Also published as: US7920893B2; US20080232507A1; US8509356B2; US20090251210A1; US7554404B2; US8249650B2; US8369889B2; US8238825B2; US7933568B2; US20080231537A1; US7915999B2; US20110206099A1; US7990333B2; US7925222B2; US8600315B2; US20080233889A1; US8175543B2; US20080231536A1; US20110291911A1; US20080231422A1

Abstract

Certain aspects of a method and system for integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS) may be disclosed. Aspects of the method may include generating a clock signal at a particular frequency in a chip that handles communication of Bluetooth signals and FM signals. The generated clock signal may be divided to produce a frequency divided clock signal, which may be mixed with the generated clock signal to enable transmission and/or reception of Bluetooth signals. The generated clock signal or the frequency divided clock signal may be selected for clocking one or more direct digital frequency synthesizers (DDFSs) to enable transmission and/or reception of the FM signals.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This application makes reference to, claims priority to, and claims benefit of U.S. Provisional Application Ser. No. 60/895,698 (Attorney Docket No. 18372US01) filed Mar. 19, 2007.
This application also makes reference to:
U.S. patent application Ser. No. ______ (Attorney Docket Number 18372US02) filed on even date herewith;
U.S. patent application Ser. No. ______ (Attorney Docket Number 18575US02) filed on even date herewith;
U.S. patent application Ser. No. ______ (Attorney Docket Number 18576US02) filed on even date herewith;
U.S. patent application Ser. No. ______ (Attorney Docket Number 18577US02) filed on even date herewith;
U.S. patent application Ser. No. ______ (Attorney Docket Number 18578US02) filed on even date herewith;
U.S. patent application Ser. No. ______ (Attorney Docket Number 18579US02) filed on even date herewith;
U.S. patent application Ser. No. ______ (Attorney Docket Number 18580US02) filed on even date herewith;
U.S. patent application Ser. No. ______ (Attorney Docket Number 18581US02) filed on even date herewith;
U.S. patent application Ser. No. ______ (Attorney Docket Number 18590US02) filed on even date herewith; and
U.S. patent application Ser. No. ______ (Attorney Docket Number 18591US02) filed on even date herewith.
Each of the above stated applications is hereby incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

Certain embodiments of the invention relate to multi-standard systems. More specifically, certain embodiments of the invention relate to a method and system for integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS).

BACKGROUND OF THE INVENTION

A direct digital frequency synthesizer (DDFS) is a digitally-controlled signal generator that may vary the output signal frequency over a large range of frequencies, based on a single fixed-frequency precision reference clock. In addition, a DDFS is also phase-tunable. In essence, within the DDFS, discrete amplitude levels are input to a digital-to-analog converter (DAC) at a sampling rate determined by the fixed-frequency reference clock. The output of the DDFS may provide a signal whose shape may depend on the sequence of discrete amplitude levels that are input to the DAC at the constant sampling rate. The DDFS is particularly well suited as a frequency generator that outputs a sine or other periodic waveforms over a large range of frequencies, from almost DC to approximately half the fixed-frequency reference clock frequency.
A DDFS offers a larger range of operating frequencies and requires no feedback loop, thereby providing near instantaneous phase and frequency changes, avoiding overshooting, undershooting and settling time issues associated with other analog systems. A DDFS may provide precise digitally-controlled frequency and/or phase changes without signal discontinuities.
With the popularity of portable electronic devices and wireless devices that support audio applications, there is a growing need to provide a simple and complete solution for audio communications applications. For example, some users may utilize Bluetooth-enabled devices, such as headphones and/or speakers, to allow them to communicate audio data with their wireless handset while freeing to perform other activities. Other users may have portable electronic devices that may enable them to play stored audio content and/or receive audio content via broadcast communication, for example.
However, integrating multiple audio communication technologies into a single device may be costly. Combining a plurality of different communication services into a portable electronic device or a wireless device may require separate processing hardware and/or separate processing software. Moreover, coordinating the reception and/or transmission of data to and/or from the portable electronic device or a wireless device that uses FM transceivers may require significant processing overhead that may impose certain operation restrictions and/or design challenges.
Furthermore, simultaneous use of a plurality of radios in a handheld may result in significant increases in power consumption. Power being a precious commodity in most wireless mobile devices, combining devices such as a Bluetooth radio and a FM radio requires careful design and implementation in order to minimize battery usage. Additional overhead such as sophisticated power monitoring and power management techniques are required in order to maximize battery life.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.

BRIEF SUMMARY OF THE INVENTION

A method and/or system for integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS), substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.
These and other advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a block diagram of an exemplary FM transmitter that communicates with handheld devices that utilize a single chip with integrated Bluetooth and FM radios, in accordance with an embodiment of the invention.

FIG. 1B is a block diagram of an exemplary FM receiver that communicates with handheld devices that utilize a single chip with integrated Bluetooth and FM radios, in accordance with an embodiment of the invention.

FIG. 1C is a block diagram of an exemplary single chip with integrated Bluetooth and FM radios that supports FM processing and an external device that supports Bluetooth processing, in accordance with an embodiment of the invention.

FIG. 1D is a block diagram of an exemplary single chip with integrated Bluetooth and FM radios and an external device that supports Bluetooth and FM processing, in accordance with an embodiment of the invention.

FIG. 1E is a block diagram that illustrates an exemplary single integrated circuit (IC) that supports FM and Bluetooth radio operations, in accordance with an embodiment of the invention.

FIG. 2A is an exemplary block diagram of integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS), in accordance with an embodiment of the invention.

FIG. 2B is an exemplary block diagram of another embodiment of integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS), in accordance with an embodiment of the invention.

FIG. 2C is an exemplary block diagram of another embodiment of integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS), in accordance with an embodiment of the invention.

FIG. 2D is a block diagram illustrating an exemplary DDFS, in accordance with an embodiment of the invention.

FIG. 3 is a flowchart illustrating exemplary steps for integration of Bluetooth and FM local oscillator generation in a single unit using a DDFS, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain embodiments of the invention may be found in a method and system for integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS). Aspects of the method and system may comprise generating a clock signal f_LOat a particular frequency in a chip that handles communication of Bluetooth signals and FM signals. The generated clock signal f_LOmay be divided to produce a frequency divided clock signal f_DIV, which may be mixed with the generated clock signal f_LOto enable transmission and/or reception of Bluetooth signals. The generated clock signal f_LOor the frequency divided clock signal f_DIVmay be selected for clocking one or more direct digital frequency synthesizers (DDFSs) to enable transmission and/or reception of the FM signals.
FIG. 1A is a block diagram of an exemplary FM transmitter that communicates with handheld devices that utilize a single chip with integrated Bluetooth and FM radios, in accordance with an embodiment of the invention. Referring to FIG. 1A, there is shown an FM transmitter 102, a cellular phone 104 a, a smart phone 104 b, a computer 104 c, and an exemplary FM and Bluetooth-equipped device 104 d. The FM transmitter 102 may be implemented as part of a radio station or other broadcasting device, for example. Each of the cellular phone 104 a, the smart phone 104 b, the computer 104 c, and the exemplary FM and Bluetooth-equipped device 104 d may comprise a single chip 106 with integrated Bluetooth and FM radios for supporting FM and Bluetooth data communications. The FM transmitter 102 may enable communication of FM audio data to the devices shown in FIG. 1A by utilizing the single chip 106. Each of the devices in FIG. 1A may comprise and/or may be communicatively coupled to a listening device 108 such as a speaker, a headset, or an earphone, for example.
The cellular phone 104 a may be enabled to receive an FM transmission signal from the FM transmitter 102. The user of the cellular phone 104 a may then listen to the transmission via the listening device 108. The cellular phone 104 a may comprise a “one-touch” programming feature that enables pulling up specifically desired broadcasts, like weather, sports, stock quotes, or news, for example. The smart phone 104 b may be enabled to receive an FM transmission signal from the FM transmitter 102. The user of the smart phone 104 b may then listen to the transmission via the listening device 108.
The computer 104 c may be a desktop, laptop, notebook, tablet, and a PDA, for example. The computer 104 c may be enabled to receive an FM transmission signal from the FM transmitter 102. The user of the computer 104 c may then listen to the transmission via the listening device 108. The computer 104 c may comprise software menus that configure listening options and enable quick access to favorite options, for example. In one embodiment of the invention, the computer 104 c may utilize an atomic clock FM signal for precise timing applications, such as scientific applications, for example. While a cellular phone, a smart phone, computing devices, and other devices have been shown in FIG. 1A, the single chip 106 may be utilized in a plurality of other devices and/or systems that receive and use Bluetooth and/or FM signals.
A clock signal f_LOmay be generated at a particular frequency in the single chip 106 that handles communication of Bluetooth signals and FM signals. The generated clock signal f_LOmay be utilized for clocking one or more direct digital frequency synthesizers (DDFSs) to enable transmission of the FM signals.
FIG. 1B is a block diagram of an exemplary FM receiver that communicates with handheld devices that utilize a single chip with integrated Bluetooth and FM radios, in accordance with an embodiment of the invention. Referring to FIG. 1B, there is shown an FM receiver 110, the cellular phone 104 a, the smart phone 104 b, the computer 104 c, and the exemplary FM and Bluetooth-equipped device 104 d. In this regard, the FM receiver 110 may comprise and/or may be communicatively coupled to a listening device 108. A device equipped with the Bluetooth and FM transceivers, such as the single chip 106, may be able to broadcast its respective signal to a “deadband” of an FM receiver for use by the associated audio system. For example, a cellphone or a smart phone, such as the cellular phone 104 a and the smart phone 104 b, may transmit a telephone call for listening over the audio system of an automobile, via usage of a deadband area of the car's FM stereo system. One advantage may be the universal ability to use this feature with all automobiles equipped simply with an FM radio with few, if any, other external FM transmission devices or connections being required.
In another example, a computer, such as the computer 104 c, may comprise an MP3 player or another digital music format player and may broadcast a signal to the deadband of an FM receiver in a home stereo system. The music on the computer may then be listened to on a standard FM receiver with few, if any, other external FM transmission devices or connections. While a cellular phone, a smart phone, and computing devices have been shown, a single chip that combines a Bluetooth and FM transceiver and/or receiver may be utilized in a plurality of other devices and/or systems that receive and use an FM signal.
A clock signal f_LOmay be generated at a particular frequency in the single chip 106 that handles communication of Bluetooth signals and FM signals. The generated clock signal f_LOmay be utilized for clocking one or more direct digital frequency synthesizers (DDFSs) to enable reception of the FM signals.
FIG. 1C is a block diagram of an exemplary single chip with integrated Bluetooth and FM radios that supports FM processing and an external device that supports Bluetooth processing, in accordance with an embodiment of the invention. Referring to FIG. 1C, there is shown a single chip 112 a that supports Bluetooth and FM radio operations and an external device 114. The single chip 112 a may comprise an integrated Bluetooth radio 116, an integrated FM receiver 118, an integrated FM transmitter 121 and an integrated processor 120. The Bluetooth radio 116 may comprise suitable logic, circuitry, and/or code that enable Bluetooth signal communication via the single chip 112 a. In this regard, the Bluetooth radio 116 may support audio signals or communication. The FM receiver 118 may comprise suitable logic, circuitry, and/or code that enable FM signal communication via the single chip 112 a.
The integrated processor 120 may comprise suitable logic, circuitry, and/or code that may enable processing of the FM data received by the FM receiver 118. Moreover, the integrated processor 120 may enable processing of FM data to be transmitted by the FM receiver 118 when the FM receiver 118 comprises transmission capabilities. The external device 114 may comprise a baseband processor 122. The baseband processor 122 may comprise suitable logic, circuitry, and/or code that may enable processing of Bluetooth data received by the Bluetooth radio 116. Moreover, the baseband processor 122 may enable processing of Bluetooth data to be transmitted by the Bluetooth radio 116. In this regard, the Bluetooth radio 116 may communicate with the baseband processor 122 via the external device 114. The Bluetooth radio 116 may communicate with the integrated processor 120. The FM transmitter 121 may comprise suitable logic, circuitry, and/or that may enable transmission of FM signals via appropriate broadcast channels, for example.
FIG. 1D is a block diagram of an exemplary single chip with integrated Bluetooth and FM radios and an external device that supports Bluetooth and FM processing, in accordance with an embodiment of the invention. Referring to FIG. 1D, there is shown a single chip 112 b that supports Bluetooth and FM radio operations and an external device 114. The single chip 112 b may comprise the Bluetooth radio 116, FM receive radio 118, and FM transmit radio 123. The Bluetooth radio 116, the FM receive radio 118 and FM transmit radio 123 may be integrated into the single chip 112 b. The external device 114 may comprise a baseband processor 122. The baseband processor 122 may comprise suitable logic, circuitry, and/or code that may enable processing of Bluetooth data received by the Bluetooth radio 116 and/or processing of Bluetooth data to be transmitted by the Bluetooth radio 116. In this regard, the Bluetooth radio 116 may communicate with the baseband processor 122 via the external device 114. Moreover, the baseband processor 122 may comprise suitable logic, circuitry, and/or code that may enable processing of the FM data received by the FM receive radio 118. The baseband processor 122 may enable processing FM data to be transmitted by the FM transmit radio 123. In this regard, the FM receive radio 118 and the FM transmit radio 123 may communicate with the baseband processor 122 via the external device 114.
FIG. 1E is a block diagram that illustrates an exemplary single radio chip that supports FM and Bluetooth radio operations, in accordance with an embodiment of the invention. Referring to FIG. 1F, there is shown a mobile phone 150 that may comprise a FM/Bluetooth coexistence antenna system 152 and a single chip FM/Bluetooth (FM/BT) radio device 154. The single chip FM/BT radio device 154 may comprise a FM radio portion 156 and a Bluetooth radio portion 158. The single chip FM/BT radio device 154 may be implemented based on a system-on-chip (SOC) architecture, for example.
The FM/Bluetooth coexistence antenna system 152 may comprise suitable hardware, logic, and/or circuitry that may be enabled to provide FM and Bluetooth communication between external devices and a coexistence terminal. The FM/Bluetooth coexistence antenna system 152 may comprise at least one antenna for the transmission and reception of FM and Bluetooth packet traffic.
The FM radio portion 156 may comprise suitable logic, circuitry, and/or code that may be enabled to process FM packets for communication. The FM radio portion 156 may be enabled to transfer and/or receive FM packets and/or information to the FM/Bluetooth coexistence antenna system 152 via a single transmit/receive (Tx/Rx) port. In some instances, the transmit port (Tx) may be implemented separately from the receive port (Rx). The FM radio portion 156 may also be enabled to generate signals that control at least a portion of the operation of the FM/Bluetooth coexistence antenna system 152. Firmware operating in the FM radio portion 156 may be utilized to schedule and/or control FM packet communication, for example.
The FM radio portion 156 may also be enabled to receive and/or transmit priority signals 160. The priority signals 160 may be utilized to schedule and/or control the collaborative operation of the FM radio portion 156 and the Bluetooth radio portion 158. The Bluetooth radio portion 158 may comprise suitable logic, circuitry, and/or code that may be enabled to process Bluetooth protocol packets for communication. The Bluetooth radio portion 158 may be enabled to transfer and/or receive Bluetooth protocol packets and/or information to the FM/Bluetooth coexistence antenna system 152 via a single transmit/receive (Tx/Rx) port. In some instances, the transmit port (Tx) may be implemented separately from the receive port (Rx). The Bluetooth radio portion 158 may also be enabled to generate signals that control at least a portion of the operation of the FM/Bluetooth coexistence antenna system 152. Firmware operating in the Bluetooth radio portion 158 may be utilized to schedule and/or control Bluetooth packet communication. The Bluetooth radio portion 158 may also be enabled to receive and/or transmit priority signals 160. A portion of the operations supported by the FM radio portion 156 and a portion of the operations supported by the Bluetooth radio portion 158 may be performed by common logic, circuitry, and/or code.
In some instances, at least a portion of either the FM radio portion 156 or the Bluetooth radio portion 158 may be disabled and the wireless terminal may operate in a single-communication mode, that is, coexistence may be disabled. When at least a portion of the FM radio portion 156 is disabled, the FM/Bluetooth coexistence antenna system 152 may utilize a default configuration to support Bluetooth communication. When at least a portion of the Bluetooth radio portion 158 is disabled, the FM/Bluetooth coexistence antenna system 152 may utilize a default configuration to support FM communication.
In accordance with an embodiment of the invention, a clock signal f_LOmay be generated at a particular frequency in the single chip FM/BT radio device 154 that handles communication of Bluetooth signals and FM signals. The generated clock signal f_LOmay be divided to produce a frequency divided clock signal f_DIV, which may be mixed with the generated clock signal f_LOto enable transmission and/or reception of Bluetooth signals. The generated clock signal f_LOor the frequency divided clock signal f_DIVmay be selected for clocking one or more direct digital frequency synthesizers (DDFSs) to enable transmission and/or reception of the FM signals.
FIG. 2A is an exemplary block diagram of integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS), in accordance with an embodiment of the invention. Referring to FIG. 2A, there is shown a communication system 200. The communication system 200 comprises a FM transceiver 202, a Bluetooth transceiver 204, a processor 240, a local oscillator generation unit (LOGEN) 206, and a coupler 234 coupled to an antenna 244. The FM transceiver 202 may comprise a FM receiver 232 and a FM transmitter 230. The Bluetooth transceiver 204 may comprise a Bluetooth receiver 208 and a Bluetooth transmitter 210. The LOGEN 206 may comprise a filter 236, a digital to analog converter (DAC) 238 a direct digital frequency synthesizer (DDFS) 242, a voltage controlled oscillator (VCO) 212, a plurality of loop amplifiers 216, 218, 226, and 228, a plurality of mixers 222 and 224, a fractional synthesizer 214, and a divider 220.
The LOGEN 206 may comprise suitable logic, circuitry, and/or code that may be enabled to generate a Bluetooth clock signal f_BTcomprising an in-phase (I) component f_BT _— _Iand a quadrature-phase (Q) component f_BT _— _Q. The I component and Q component signals may be communicated to the Bluetooth receiver 208 and the Bluetooth transmitter 210. The frequency of the generated Bluetooth clock signal f_BTto the Bluetooth receiver 208 and the Bluetooth transmitter 210 may be about 2.4 GHz, for example, and may be enabled to clock one or more of the Bluetooth receiver 208 and the Bluetooth transmitter 210. The LOGEN 206 may also be enabled to generate an I component and a Q component output signal, f_FM _— _Iand f_FM _— _Qrespectively to the FM transceiver 202. The I and Q component signals, f_FM _— _Iand f_FM _— _Qrespectively may be communicated to the FM receiver 232 and the FM transmitter 230. The frequency of the generated FM clock signal f_FMto the FM receiver 232 and the FM transmitter 230 may be about 78-100 MHz, for example, and may be enabled to clock one or more of the FM receiver 232 and the FM transmitter 230.
The VCO 212 may comprise suitable logic, circuitry, and/or code that may be enabled to generate a clock signal f_LOat a particular frequency that may be N times the frequency of the reference oscillator, Nf₀, for example, where f₀is the frequency of the reference oscillator. For example, the VCO 212 may be enabled to generate a 1.6 GHz clock signal.
The loop amplifier 216 may comprise suitable logic, circuitry, and/or code that may be enabled to amplify the generated clock signal f_LOreceived from the VCO 212. The loop amplifier 216 may be enabled to generate an amplified output signal to the plurality of mixers 222 and 224, and the divider 220. The loop amplifier 218 may comprise suitable logic, circuitry, and/or code that may be enabled to amplify a received signal from the loop amplifier 216 and generate an amplified output signal to the fractional synthesizer 214.
The fractional synthesizer 214 may comprise suitable logic, circuitry, and/or code that may be enabled to divide the output of the VCO 212 by N, for example, to match the frequency of a reference oscillator. The fractional synthesizer 214 may be programmable to synthesize a plurality of closely spaced frequencies, which enables it to be utilized in applications such as in commercial wireless applications with multiple channels, for example. In an embodiment, the fractional synthesizer 214 may be enabled to adjust a clock signal f_LOgenerated by the VCO 212 without affecting the Bluetooth clock signals f_BTcommunicated to the Bluetooth transceiver 204.
The divider 220 may comprise suitable logic, circuitry, and/or code that may be enabled to divide a frequency of a received input signal into one or more signals with different frequencies. For example, the divider 220 may be enabled to receive a 1.6 GHz input signal from the loop amplifier 222 and generate two 800 MHz output signals, for example, to the plurality of mixers 222 and 224. The divider 220 may be enabled to generate an output clock signal f_DIVby dividing a frequency of the generated clock signal f_LO.
The mixer 222 may comprise suitable logic, circuitry, and/or code that may be enabled to mix the received input signals from the loop amplifier 216 and the divider 220 and generate an output signal to the loop amplifier 226. For example, the mixer 222 may be enabled to mix a 1.6 GHz input signal from the loop amplifier 216 and a 800 MHz input signal from the divider 220 and generate a 2.4 GHz output signal to the loop amplifier 226. The loop amplifier 226 may be enabled to amplify the received input signal from the mixer 222 and generate an amplified output signal to one or more of the Bluetooth receiver 208 and the Bluetooth transmitter 210. For example, the loop amplifier 226 may be enabled to generate the Q component f_BT _— _Qof the amplified output signal to one or more of the Bluetooth receiver 208 and the Bluetooth transmitter 210.
The mixer 224 may comprise suitable logic, circuitry, and/or code that may be enabled to mix the received input signals from the loop amplifier 216 and the divider 220 and generate an output signal to the loop amplifier 228. For example, the mixer 224 may be enabled to mix a 1.6 GHz input signal from the loop amplifier 216 and a 800 MHz input signal from the divider 220 and generate a 2.4 GHz output signal to the loop amplifier 228. The loop amplifier 228 may be enabled to amplify the received input signal from the mixer 224 and generate an amplified output signal to one or more of the Bluetooth receiver 208 and the Bluetooth transmitter 210. For example, the loop amplifier 228 may be enabled to generate the I component f_BT _— _Iof the amplified output signal to one or more of the Bluetooth receiver 208 and the Bluetooth transmitter 210.
In operation, the fractional synthesizer 214 may be enabled to generate a control signal, which may be utilized by the VCO 212 to generate a clock signal f_LO. In an exemplary embodiment of the invention, the frequency of the clock signal, f_LO, may be about 1.6 GHz. The fractional synthesizer 214 may utilize the clock signal, f_LOto adjust a subsequent control signal communicated to the VCO 212. The clock signal, f_LO, may be communicated to a divider 220, which may implement frequency division on the received signal f_LO. The divider 220 may generate an output clock signal, f_DIVcomprising in-phase (I) component frequency division signal, f_DIV _— _I, and a quadrature-phase (Q) component frequency division signal, f_DIV _— _Q. In an exemplary embodiment of the invention:
$\begin{matrix} f_{DIV_I} = f_{DIV_Q} = \frac{f_{LO}}{2} & [1] \end{matrix}$
The mixer 224 may be enabled to mix the signals, f_LOand f_DIV _— _I, and generate a signal f_BT _— _I. The mixer 222 may mix the signals, f_LOand f_DIV _— _Q, and generate a signal f_BT _— _Q. In an exemplary embodiment of the invention, the frequencies of the signals f_BT _— _Iand f_BT _— _Qmay be represented as follows:
f _BT _— _I =f _LO +f _DIV _— _I [2]
and
f _BT _— _Q =f _LO +f _DIV _— _Q [3]
The signals f_BT _— _Iand f_BT _— _Qmay be communicated to the Bluetooth receiver 208 and/or to the Bluetooth transmitter 210. In an exemplary embodiment of the invention, the frequency of the signals f_BT _— _Iand f_BT _— _Qmay be about 2.4 GHz.
In an embodiment of the invention, the clock signal f_LOmay be communicated to the DDFS 242. The DDFS 242 may comprise suitable logic, circuitry and/or code that may enable reception of the clock signal f_LOand generate a sequence of binary numbers. The process of converting the clock signal f_LOinput signal to a sequence of binary numbers may comprise analog to digital conversion (ADC) whereby each distinct voltage, current and/or power level associated with the received clock signal, f_LOmay be represented as a binary number selected from a plurality of binary numbers. Conversely, each binary number may correspond to a range of voltage, current and/or power levels in the received clock signal f_LO. An exemplary clock signal, f_LOmay be a sinusoidal signal for which the corresponding period may be equal to the inverse of the frequency, (1/f_LO).
The number of binary numbers may be determined by the number of bits, b, in the binary number representation. Each binary number may comprise a least significant bit (LSB) and a most significant bit (MSB). In an exemplary numerical representation, each of binary numbers may have a value within the range 0 to 2^b−1. The operation of the DDFS 242 may be such that a period of the received clock signal, f_LOmay be converted to a binary sequence 0, 1, . . . , 2^b−1, wherein upon reaching the value 2^b−1 the next number in the binary sequence may be 0 with the sequence continuing. The set of numbers from 0 to 2^b−1 may represent a period of the binary sequence. The DDFS 242 may receive a frequency word input signal, f_Word, from the processor 240 upon which the value of b may be determined. Consequently, the period of the sequence of binary numbers generated by the DDFS may be programmable based on the f_Wordinput signal.
The DAC 238 may comprise suitable logic, circuitry and/or code that may enable generation of an analog output signal based on a received sequence of input binary numbers. The DAC 238 may be enabled to generate a corresponding analog voltage level for each input binary number. The number of distinct analog voltage levels may be equal to the number of distinct binary numbers in the input sequence.
The filter 238 may comprise suitable logic, circuitry and/or code that may enable low pass filtering (LPF) of signal components contained in a received input signal. The filter 238 may enable smoothing of the received input signal to attenuate amplitudes for undesirable frequency components contained in the received input signal. The filter 238 may generate a signal, f_FM, having a frequency in the FM frequency band. In an exemplary embodiment of the invention, the range of frequencies for the signal f_FMmay be between about 78 MHz and 100 MHz, for example. The signal f_FMmay be a quadrature signal comprising I and Q signal components, f_FM _— _Iand f_FM _— _Qrespectively. The 78-100 MHz I and Q signals may be communicated to an FM transmitter 230 and/or an FM receiver 232.
In an exemplary embodiment of the invention, the FM transmitter 230 and the FM receiver 232 may be coupled to an antenna 244 via a bidirectional coupler 234. The bidirectional coupler 234 may couple the antenna to the FM receiver 232 at a given time instant, such that the FM receiver 232 signal may receive signals via the antenna 244. The bidirectional coupler 234 may couple the antenna to the FM transmitter 230 at a different time instant under the control of a different f_Wordto the DDFS 242, such that the FM transmitter 230 signal may transmit signals via the antenna 244. In another exemplary embodiment of the invention, the FM transmitter 230 may be coupled to a transmitting antenna 245 b, while the FM receiver 232 may be coupled to a receiving antenna 245 a.
In operation, the value f_Wordmay be selected to maintain an approximately constant frequency for the signal f_FMdespite changes that may occur in the signal f_LO, which may occur due to frequency hopping in the Bluetooth communication signal.
FIG. 2B is an exemplary block diagram of another embodiment illustrating integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS), in accordance with an embodiment of the invention. Referring to FIG. 2B, there is shown a communication system 200. The communication system 200 comprises a FM transceiver 202, a Bluetooth transceiver 204, a processor 240, a local oscillator generation unit (LOGEN) 206, and a coupler 234 coupled to an antenna 244. The FM transceiver 202 may comprise a FM receiver 232 and a FM transmitter 230. The Bluetooth transceiver 204 may comprise a Bluetooth receiver 208 and a Bluetooth transmitter 210. The LOGEN 206 may comprise a filter 236, a digital to analog converter (DAC) 238, a direct digital frequency synthesizer (DDFS) 242, a voltage controlled oscillator (VCO) 212, a plurality of loop amplifiers 216, 218, 226, and 228, a plurality of mixers 222 and 224, a fractional synthesizer 214, and a divider 220. The various components of FIG. 2B may be substantially as described in FIG. 2A
In operation, the fractional synthesizer 214 may be enabled to generate a control signal, which may be utilized by the VCO 212 to generate a clock signal. In an exemplary embodiment of the invention, the frequency of the clock signal, f_LO, may be about 1.6 GHz. The fractional synthesizer 214 may utilize the clock signal, f_LOto adjust a subsequent control signal communicated to the VCO 212. The clock signal, f_LO, may be communicated to a divider 220, which may implement frequency division on the received signal f_LO. The divider 220 may generate an in-phase (I) component frequency division signal, f_DIV _— _I, and a quadrature-phase (Q) component frequency division signal, f_DIV _— _Q. In an exemplary embodiment of the invention:
$\begin{matrix} f_{DIV_I} = f_{DIV_Q} = \frac{f_{LO}}{2} & [1] \end{matrix}$
The mixer 224 may be enabled to receive the signals, f_LOand f_DIV _— _I, and generate a signal f_BT _— _I. The mixer 222 may receive the signals, f_LOand f_DIV _— _Q, and generate a signal f_BT _— _Q. In an exemplary embodiment of the invention, the frequencies of the signals f_BT _— _Iand f_BT _— _Qmay be represented as follows:
f _BT _— _I =f _LO +f _DIV _— _I [2]
and
f _BT _— _Q =f _LO =f _DIV _— _Q [3]
The signals f_BT _— _Iand f_BT _— _Qmay be communicated to the Bluetooth receiver 208 and/or to the Bluetooth transmitter 210. In an exemplary embodiment of the invention, the frequency of the signals f_BT _— _Iand f_BT _— _Qmay be about 2.4 GHz.
In another embodiment of the invention, the signal f_DIV _— _Ior the signal f_DIV _— _Qmay be communicated to the DDFS 242. The DDFS 242 may comprise suitable logic, circuitry and/or code that may enable reception of the f_DIV _— _Ior f_DIV _— _Qinput signal and subsequent generation of a sequence of binary numbers. The process of converting the f_DIV _— _Ior f_DIV _— _Qinput signal to a sequence of binary numbers may comprise analog to digital conversion (ADC) whereby each distinct voltage, current and/or power level associated with the received f_DIV _— _Ior f_DIV _— _Qsignal may be represented as a binary number selected from a plurality of binary numbers. Conversely, each binary number may correspond to a range of voltage, current and/or power levels in the received f_DIV _— _Ior f_DIV _— _Qsignal.
In an embodiment of the invention, f_DIV _— _Ior f_DIV _— _Qmay be a sinusoidal signal for which the corresponding period may be equal to the inverse of the frequency, (1/f_DIV _— _I) or (1/f_DIV _— _Q). The number of binary numbers in the plurality may be determined by the number of bits, b, contained in the binary number representation. Each binary number may comprise a least significant bit (LSB) and a most significant bit (MSB). In an exemplary numerical representation, each of the binary numbers may have a value within the range 0 to 2^b−1. The operation of the DDFS 242 may be such that a period of the received f_DIV _— _Ior f_DIV _— _Qsignal may be converted to binary sequence 0, 1, . . . , 2^b−1, wherein upon reaching the value 2^b−1 the next number in the binary sequence may be 0 with the sequence continuing. The set of numbers from 0 to 2^b−1 may represent a period of the binary sequence. The DDFS 242 may receive a frequency word input signal, f_Word, from the processor 240 upon which the value of b may be determined. Consequently, the period of the sequence of binary numbers generated by the DDFS 242 may be programmable based on the f_Wordinput signal.
FIG. 2C is an exemplary block diagram of another embodiment illustrating integration of Bluetooth and FM local oscillator generation in a single unit using a direct digital frequency synthesizer (DDFS), in accordance with an embodiment of the invention. Referring to FIG. 2C, there is shown a communication system 200. The communication system 200 comprises a FM transceiver 202, a Bluetooth transceiver 204, a processor 240, a local oscillator generation unit (LOGEN) 206, and a coupler 234 coupled to an antenna 244. The FM transceiver 202 may comprise a FM receiver 232 and a FM transmitter 230. The Bluetooth transceiver 204 may comprise a Bluetooth receiver 208 and a Bluetooth transmitter 210. The LOGEN 206 may comprise a filter 236, a digital to analog converter (DAC) 238, a direct digital frequency synthesizer (DDFS) 242, a voltage controlled oscillator (VCO) 212, a plurality of loop amplifiers 216, 218, 226, and 228, a plurality of mixers 222 and 224, a fractional synthesizer 214, a divider 220 and a multiplexer 221. The various components of FIG. 2C may be substantially as described in FIG. 2A.
The clock signal f_LOmay be generated at a particular frequency, for example, at 1.6 GHz in a chip capable of handling communication of Bluetooth signals and FM signals. The divider 220 may be enabled to divide the generated clock signal f_LOto produce a frequency divided clock signal f_DIV, which may be mixed with the generated clock signal f_LOto enable transmission and/or reception of Bluetooth signals. The multiplexer 221 may be enabled to select the generated clock signal f_LOor the frequency divided clock signal f_DIVfor clocking one or more direct digital frequency synthesizers (DDFSs) 242 to enable transmission and/or reception of the FM signals based on a select signal received from the processor 240. The generated clock signal f_LOor the frequency divided clock signal f_DIVmay be enabled to clock at least one of the DDFSs 242 to enable the transmission and/or reception of the FM signals.
FIG. 2D is a block diagram illustrating an exemplary direct digital frequency synthesizer (DDFS), in accordance with an embodiment of the invention. Referring to FIG. 2D, there is shown a DDFS 250, a clock 252 and a DDFS controller 254. The DDFS 250 may be a digitally-controlled signal generator that may vary the analog output signal g(t) over a large range of frequencies, based on a single fixed-frequency precision reference clock, for example, clock 252. Notwithstanding, the DDFS 250 may also be phase-tunable. The digital input signal d(t) may comprise control information regarding the frequency and/or phase of the analog output signal g(t) that may be generated as a function of the digital input signal d(t). The clock 252 may provide a reference clock that may be N times higher than the frequency fc of the generated output signal g(t). The DDFS controller 254 may generate a variable frequency analog output signal g(t) by utilizing the clock 252 and the digital input signal d(t).
FIG. 3 is a flowchart illustrating exemplary steps for integration of Bluetooth and FM local oscillator generation in a single unit using a DDFS, in accordance with an embodiment of the invention. Referring to FIG. 3, exemplary steps may begin at step 300. In step 302, a VCO may generate a clock signal f_LOat a particular frequency, for example, 1.6 GHz utilizing a fractional synthesizer. In step 304, a frequency divided clock signal f_DIVmay be generated by dividing a frequency of the generated clock signal f_LO. In step 306, a Bluetooth clock signal f_BTmay be generated by mixing the generated clock signal f_LOwith the frequency divided clock signal f_DIV. In step 308, the generated Bluetooth clock signal f_BTmay be utilized to enable the transmission and/or reception of the Bluetooth communication signals. In step 310, the generated clock signal f_LOor the generated frequency divided clock signal f_DIVmay be communicated to the DDFS. In step 312, the DDFS may enable modification of a frequency of the generated clock signal f_LOor the generated frequency divided clock signal f_DIVbased on a received control word f_WORD. In step 314, a FM clock signal f_FMmay be generated utilizing the generated clock signal f_LOor the generated frequency divided clock signal f_DIVto enable the transmission and/or reception of FM communication signals. Control then passes to end step 316.
In accordance with an embodiment of the invention, a method and system for integration of Bluetooth and FM local oscillator generation in a single unit using a DDFS may include generating a clock signal f_LOat a particular frequency in a chip that handles communication of Bluetooth signals and FM signals. The generated clock signal f_LOmay be divided to produce a frequency divided clock signal f_DIV, which may be mixed with the generated clock signal f_LOto enable transmission and/or reception of Bluetooth signals. The generated clock signal f_LOor the frequency divided clock signal f_DIVmay be selected by a multiplexer 221 for clocking one or more direct digital frequency synthesizers (DDFSs) 242 to enable transmission and/or reception of the FM signals. The generated clock signal f_LOor the frequency divided clock signal f_DIVmay be enabled to clock at least one of the DDFSs 242 to enable the transmission and/or reception of the FM signals.
A Bluetooth clock signal f_BTmaybe generated by mixing the generated clock signal f_LOwith the produced frequency divided clock signal f_DIV. The generated Bluetooth clock signal f_BTmay comprise an in phase (I) component f_BT _— _Iand a quadrature phase (Q) component f_BT _— _Q. The generated Bluetooth clock signal f_BTmay enable transmission and/or reception of the Bluetooth signals. A FM clock signal f_FMmay be generated to enable the transmission and/or reception of the FM signals via one or more DDFSs 242. The generated FM clock signal f_FMmay comprise an in phase (I) component f_FM _— _Iand a quadrature phase (Q) component f_FM _— _Q. The clock signal f_LOmay be generated at the particular frequency, for example, at 1.6 GHz utilizing one or more of: a voltage controlled oscillator (VCO) 212 and a fractional synthesizer 214. The transmission and/or reception of the FM signals may be controlled via a bi-directional coupler 234. The DDFS 242 may be enabled to modify the frequency of the selected clock signal f_LOor the frequency divided clock signal f_DIVbased on a received control word f_WORD. The processor 240 may be enabled to adjust the received control word f_WORDto compensate for changes in the generated clock signal.
Another embodiment of the invention may provide a machine-readable storage, having stored thereon, a computer program having at least one code section executable by a machine, thereby causing the machine to perform the steps as described above for integration of Bluetooth and FM local oscillator generation in a single unit using a DDFS.
Accordingly, the present invention may be realized in hardware, software, or a combination of hardware and software. The present invention may be realized in a centralized fashion in at least one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware and software may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
The present invention may also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form.
While the present invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A method for communicating signals, the method comprising:

in a chip that handles communication of Bluetooth signals and FM signals:

generating a clock signal at a particular frequency;

dividing said generated clock signal to produce a frequency divided clock signal, which is mixed with said generated clock signal to enable transmission of said Bluetooth signals or reception of said Bluetooth signals; and

selecting said generated clock signal or said frequency divided clock signal for clocking one or more direct digital frequency synthesizers (DDFSs) to enable transmission of said FM signals or reception of said FM signals.

2. The method according claim 1, comprising clocking via said generated clock signal or said frequency divided clock signal, at least one of said DDFSs to enable said transmission of said FM signals or said reception of said FM signals.

3. The method according to claim 1, comprising generating a Bluetooth clock signal by mixing said generated clock signal with said produced frequency divided clock signal.

4. The method according claim 3, wherein said generated Bluetooth clock signal comprises an in phase (I) component and a quadrature phase (Q) component.

5. The method according claim 3, wherein said generated Bluetooth clock signal enables said transmission of said Bluetooth signals or said reception of said Bluetooth signals.

6. The method according to claim 1, comprising generating a FM clock signal to enable said transmission of said FM signals or said reception of said FM signals via said one or more DDFSs.

7. The method according claim 6, wherein said generated FM clock signal comprises an in phase (I) component and a quadrature phase (Q) component.

8. The method according to claim 1, comprising generating said clock signal at said particular frequency utilizing one or more of: a voltage controlled oscillator (VCO) and a fractional synthesizer.

9. The method according to claim 1, comprising controlling said transmission of said FM signals or said reception of said FM signals via a bidirectional coupler.

10. The method according to claim 1, comprising modifying a frequency of said selected said generated clock signal or said frequency divided clock signal based on a received control word.

11. The method according to claim 10, comprising adjusting said received control word to compensate for changes in said generated clock signal.

12. A system for communicating signals, the system comprising:

one or more circuits in a chip that handles communication of Bluetooth signals and FM signals, wherein said one or more circuits enable generation of a clock signal at a particular frequency;

said one or more circuits enable division of said generated clock signal to produce a frequency divided clock signal, which is mixed with said generated clock signal to enable transmission of said Bluetooth signals or reception of said Bluetooth signals; and

said one or more circuits enable selection of said generated clock signal or said frequency divided clock signal for clocking one or more direct digital frequency synthesizers (DDFSs) to enable transmission of said FM signals or reception of said FM signals.

13. The system according claim 12, wherein said one or more circuits enable clocking via said generated clock signal or said frequency divided clock signal, at least one of said DDFSs to enable said transmission of said FM signals or said reception of said FM signals.

14. The system according claim 12, wherein said one or more circuits enable generation of a Bluetooth clock signal by mixing said generated clock signal with said produced frequency divided clock signal.

15. The system according claim 14, wherein said generated Bluetooth clock signal comprises an in phase (I) component and a quadrature phase (Q) component.

16. The system according claim 14, wherein said generated Bluetooth clock signal enables said transmission of said Bluetooth signals or said reception of said Bluetooth signals.

17. The system according to claim 12, wherein said one or more circuits enable generation of a FM clock signal to enable said transmission of said FM signals or said reception of said FM signals via said one or more DDFSs.

18. The system according claim 17, wherein said generated FM clock signal comprises an in phase (I) component and a quadrature phase (Q) component.

19. The system according to claim 12, wherein said one or more circuits enable generation of said clock signal at said particular frequency utilizing one or more of: a voltage controlled oscillator (VCO) and a fractional synthesizer.

20. The system according to claim 12, wherein said one or more circuits enable controlling of said transmission of said FM signals or said reception of said FM signals via a bidirectional coupler.

21. The system according to claim 12, wherein said one or more circuits enable modification of a frequency of said selected said generated clock signal or said frequency divided clock signal based on a received control word.

22. The system according to claim 21, wherein said one or more circuits enable adjusting of said received control word to compensate for changes in said generated clock signal.