US 20020097779 A1 Abstract An orthogonal complex spreading method for a multichannel and an apparatus thereof are disclosed. The method includes the steps of complex-summing α
_{n1}W_{M,n1}X_{n1 }which is obtained by multiplying an orthogonal Hadamard sequence W_{M,n1 }by a first data X_{n1 }of a n-th block and α _{n2}W_{M,n2}X_{n2 }which is obtained by multiplying an orthogonal Hadamard sequence W_{1,n2 }by a second data X_{n2 }of a n-th block; complex-multiplying α_{n1}W_{M,n1}X_{n1}+jα_{n2}W_{M,n2}X_{n2 }which is summed in the complex type and W_{M,n3}+jPW_{M,n4 }of the complex type using a complex multiplier and outputting as an in-phase information and quadrature phase information; and summing only in-phase information outputted from a plurality of blocks and only quadrature phase information outputted therefrom and spreading the same using a spreading code. Claims(40) 1. An orthogonal complex spreading method for a multichannel, comprising the steps of:
complex-summing α _{n1}W_{M,n1}X_{n1 }which is obtained by multiplying an orthogonal Hadamard sequence W_{M,n1 }by a first data X_{n1}, and gain α_{n1}, of a n-th block and α_{n2}W_{M,n2}X_{n2 }which is obtained by multiplying an orthogonal Hadamard sequence W_{M,n2 }by a second data X_{n2 }and gain α_{n2 }of a n-th block; complex-multiplying α _{n1}W_{M,n1}X_{n1}+jα_{n2}W_{M,n2}X_{n2 }which is summed in the complex type and W_{M,n3}+jW_{M,n4 }of the complex type using a complex multiplier and outputting as an in-phase information and quadrature phase information; and summing only in-phase information outputted from a plurality of blocks and only quadrature phase information outputted therefrom and spreading the same using a spreading code. 2. The method of 3. The method of 4. The method of 5. The method of _{k−1 }in a M×M (M=4) Hadamard matrix, and in the case of one block, α_{11}W_{0}X_{11}+j_{α} _{12}W_{2}X_{12 }and W_{0}+jW_{1 }is complex-multiplied based on W_{M,11}=W_{0}, W_{M,12}=W_{2 }and W_{M,13}=W_{0}, W_{M,14}=W_{1. } 6. The method of _{11}W_{0} _{X} _{11}+jα_{12}W_{4}X_{12 }and W_{0}+jW_{1}, are complex-multiplied based on M=8 and W_{M,12}=W_{4. } 7. The method of _{k−1 }in a M×M (M is a natural number) Hadamard matrix, and α_{n1}W_{0}X_{n1}+jα_{n2}W_{2p}X_{n2 }and W_{2n−2}+jW_{2n−1 are complex-multiplied based on W} _{M,n1}=W_{0}, W_{M,n2}=W_{2p }(where p represents a predetermined number in a range from 0 to (M/2)−1) and W_{M,n3}=W_{2n−2}, W_{M,n4}=W_{2n−1 }(where n represents a n-th block number). 8. The method of _{k−1 }in a M×M (M=8) Hadamard matrix and complex-multiplying α_{11}W_{0}X_{11}+jα_{12}W_{4}X_{12 }and W_{0}+jW_{1 }based on W_{M,11}=W_{0}, W_{M,12}=W_{4}, W_{M,13}=W_{0}, W_{M,14 }=W_{1}, and a resultant value which is obtained by complex-multiplying α_{21}W_{0}X_{21}+jα_{22}W_{4}X_{22 }and W_{2}+jW_{3 }based on W_{M,21}=W_{0}, W_{M,22}=W_{4}, W_{M,23}=W_{2}, W_{M,24}=W_{3 }are summed. 9. The method of _{11}W_{0}X_{11}+jα_{12}W_{6}X_{12 }and W_{0}+jW_{1 }based on W_{M,12}=W_{6}, and α_{21}W_{0}X_{21}+jα_{22}W_{6 }X_{22 }and W_{2}+jW_{3 }are summed. 10. An orthogonal complex spreading apparatus, comprising:
a plurality of complex multiplication blocks for distributing the data of the multichannel and complex signal α _{n1}W_{M,n1}X_{n1}+jα_{n2}W_{M,n2}X_{n2 }of which α_{n1}W_{M,n1}X_{n1 }which is obtained by multiplying the orthogonal Hadamard sequence W_{M,n1 }with the first data X_{n1 }of the n-th block and the gain α_{n1 }and α_{n2}W_{M,n2}X_{n2 }which is obtained by multiplying the orthogonal Hadamard sequence W_{M,n2 }with the second data X_{n2 }of the n-th block and the gain α_{n2 }are constituents, are complex-multiplied by W_{M,n3}+jW_{M,n4 }using the complex multiplier; a summing unit for summing only the in-phase information outputted from each block of the plurality of the complex multiplication blocks and summing only the quadrature phase information outputted from each block of the plurality of the complex multiplicator blocks; and a spreading unit for multiplying the in-phase information and the quadrature phase information which are summed by the summing unit by the spreading code and outputting an I channel and a Q channel. 11. The apparatus of 12. The apparatus of a first multiplier for multiplying the first data X _{n1 }of a corresponding block by the orthogonal Hadamard sequence W_{M,n1; } a second multiplier for multiplying the output signal from the first multiplier by the gain α _{n1; } a third multiplier for multiplying the second data X _{n2 }by the orthogonal Hadamard sequence W_{M,n2; } a fourth multiplier for multiplying the output signal from the third multiplier by the gain α _{n2; } fifth and sixth multipliers for multiplying the output signal α _{n1}W_{M,n1}X_{n1 }from the second multiplier and the output signal α_{n2}W_{M,n2}X_{n2 }from the fourth multiplier by the orthogonal Hadamard sequence W_{M,n3; } seventh and eighth multipliers for multiplying the output signal α _{n1}W_{M,n1}X_{n1 }from the second multiplier and the output signal α_{n2}W_{M,n2}X_{n2 }from the fourth multiplier by the orthogonal Hadamard sequence W_{M,n4; } a first adder for summing the output signal (ac) from the fifth multiplier and the minus output signal (−bd) from the eighth multiplier and outputting an in-phase information (ac−bd); and a second adder for summing the output signal (bc) from the sixth multiplier and the output signal (ad) from the seventh multiplier and outputting a quadrature phase information (bc+ad). 13. The apparatus of 14. A permutated orthogonal complex spreading method for a multichannel, comprising the steps of:
complex-summing α _{n1}W_{M,n1}X_{n1 }which is obtained by multiplying a predetermined orthogonal Hadamard sequence W_{M,n1 }by a data X_{n1 }and a gain α_{n1 }and α_{n2}W_{M,n2}X_{n2 }which is obtained by multiplying the orthogonal Hadamard sequence W_{M,n2 }of the second block by a predetermined data X_{n2 }and a gain α_{n2 }in the first block during a multichannel data distribution; summing only the in-phase information based on the output signals from a plurality of other channels from two blocks and summing only the quadrature phase information; and complex-multiplying which are summed in the complex type and W _{M,I}+jPW_{M,Q }which are formed of P representing a predetermined sequence or a spreading code or a predetermined integer using a complex multiplier and W_{M,I }and W_{M,Q }which are the orthogonal Hadamard sequences, and outputs the signal as an in-phase information and a quadrature phase information. 15. The method of 16. The method of 17. The method of _{k−l based on the M×M Hadamard matrix, the conditions W} _{M,I}=W_{0}, W_{M,Q}=W_{2q+1 }(where q represents a predetermined number in a range from 0 to (M/2)−1) are obtained, and a predetermined spreading code for P is configured so that consecutive two sequences have the identical values. 18. The method of 19. The method of 20. The method of _{k−1}, based on the M×M (M=4) Hadamard matrix, and in the case that two data are transmitted, the conditions W_{M} _{M,11}=W_{0}, W_{M,12}=W_{2}, and W_{M,I}=W_{0}, W_{M,Q}=W_{1 }are determined for thereby complex-multiplying α_{11}W_{0}X_{11}+jα_{12}W_{2}X_{12 }and W_{0}+jPW_{1. } 21. The method of _{11}W_{0}X_{11}+jα_{12}W_{4}X_{12 }and W_{0}+jPW_{1 }are complex-multiplied based on M=8 and W_{M,12}=W_{4. } 22. The method of _{k−1 }based on the M×M Hadamard matrix, the conditions W_{M,n1}=W_{0}, W_{M,n2}=W_{2q+1 }(where q represents a predetermined number in a range from 0 to (M/2)−1) are obtained and the conditions W_{M,I}=W_{0}, W_{M,Q}=W_{1 }(where n represent a n-th block number) for thereby complex-multiplying α_{n1}W_{0}X_{n1}+jα_{n2}W_{2q}X_{n2 }and W_{0}+jPW_{1. } 23. The method of 24. The method of a first multiplier for multiplying the first data X _{n1 }of a corresponding block by the gain α_{n1; } a second multiplier for multiplying the output signal from the first multiplier by the orthogonal Hadamard sequence W _{M,n1; } a third multiplier for multiplying the second data X _{n2 }by the gain α_{n2; } a fourth multiplier for multiplying the output signal from the third multiplier by the orthogonal Hadamard sequence W _{M,n2; } fifth and sixth multipliers for multiplying the output signal α _{n1}W_{M,n1}X_{n1 }from the second multiplier and the output signal α_{n2}W_{M,n2}X_{n2 }from the fourth multiplier by the orthogonal Hadamard sequence W_{M,I; } seventh and eighth multipliers for multiplying the output signal α _{n1}W_{M,n1}X_{n1 }from the second multiplier and the output signal α_{n2}W_{M,n2}X_{n2 }from the fourth multiplier by the orthogonal Hadamard sequence W_{M,Q; } a first adder for summing the output signal (ac) from the fifth multiplier and the minus output signal (−bd) from the eighth multiplier and outputting an in-phase information (ac−bd); and a second adder for summing the output signal (bc) from the sixth multiplier and the output signal (ad) from the seventh multiplier and outputting a quadrature phase information (bc+ad). 25. The apparatus of 26. A permutated orthogonal complex spreading apparatus for a multichannel, comprising:
first and second Hadamard sequence multipliers for allocating the multichannel to a predetermined number of channels, splitting the same into two groups and outputting α _{n1}W_{M,n1}X_{n1 }which is obtained by multiplying the data X_{n1 }of each channel by the gain α_{n2 }and the orthogonal Hadamard sequence W_{M,n1}; a first adder for outputting which is obtained by summing the output signals from the first Hadamard sequence multiplier; a second adder for outputting which is obtained by summing the output signals from the second Hadamard sequence multiplier; a complex multiplier or receiving the output signal from the first adder and the output signal from the second adder in the complex form of and complex-multiplying W _{M,I}+jPW_{M,Q }which consist of the orthogonal Hadamard code W_{M,I}, and the permutaed orthogonal Hadamard code PW_{M,Q }that W_{M,Q }and a predetermined sequence P are complex-multiplied; a spreading unit for multiplying the output signal from the complex multiplier by the spreading code; a filter for filtering the output signal from the spreading unit; and a modulator for multiplying and modulating the modulation carrier wave, summing the in-phase signal and the quadrature phase signal and outputting a modulation signal of the real number. 27. The method of _{k−1 }based on the M×M (M=8) Hadamard matrix, and W_{M,11}=W_{0}, W_{M,12}=W_{4}, W_{M,21}=W_{2}, and W_{M,1}=W_{0}, W_{M,Q}=W_{1 }are determined, and the summed value which is obtained by summing α_{11}W_{0}X_{11}+jα_{12}W_{4}X_{12}, and α_{21}W_{2}X_{21 }is complex-multiplied by W_{0}+jPW_{1. } 28. The method of _{k−1}, based on the M×M Hadamard matrix, and W_{M,11}=W_{0}, W_{M,12}=W_{2 }and W_{M,I}=W_{0}, W_{M,Q}W_{1 }are determined based on M=8 , and the summed value which is obtained by summing α_{11}W_{0}X_{11}+jα_{12}W_{4}X_{12 }and α_{21}W_{8}X_{21 }is complex-multiplied by W_{0}+jPW_{1 }based on M=16. 29. The method of _{k−1}, based on the M×M (M=8) Hadamard matrix, and W_{M,11}=W_{0}, W_{M,12}=W_{4}, W_{M,21}=W_{2}, W_{M,31}=W_{6}, and W_{M,I}=W_{0}, W_{M,Q}=W_{1 }are determined, and the summed value which is obtained by summing α_{11}W_{0}X_{11}+jα_{12}W_{4}X_{12}, α_{21}W_{2}X_{21 }and α_{31}W_{6}X_{31 }is complex-multiplied by W_{0}+jPW_{1. } 30. The method of _{k−1 }based on the M×M Hadamard matrix, and W_{11,11}=W_{0}, W_{M,12}=W_{4}, W_{M,31}=W_{2}, W_{M,I}=W, W,=W_{1 }are determined based on M=8 and W_{M,21}=W_{8 }is determined based on M=16, and the summed value which is obtained by summing α_{11}W and is complex-multiplied by W_{0}+jPW_{1. } 31. The method of _{k-1 }based on the M×M (M=8) Hadamard matrix, and W_{M,11}=W_{0 }W_{M,12}=W_{4}, W_{M,21}=W_{2},W F,31 =W 1 W l W, 1 and Wk, =W,, WM, CW_{1 }are determined, and the summed value which is obtained by summing α_{11}W_{0}X_{11}α_{12}W_{4}X_{12 }is complex-multiplied by W_{21}+jPW_{1. } 32. The method of _{M,12}=W_{4}, W_{M,21}=W_{2}, M,31 W 6 t W_{M,22}=W_{3}, and W_{14}=W_{0}, W_{M,Q}=W_{1 }are determined, and the summed value which is obtained by summing α_{11}W_{3}X_{11}+jα_{12}W_{4}X_{12}, α_{21}W_{8}X_{22}+ja ?,W _{3}X 22 and aX _{31}W 6 X 31 is complex-multiplied by W_{0}+jPW_{1. } 33. The method of _{k}31 based on the M×M Hadamard matrix, and W_{M,11}=W_{0}, W_{M,12}=W_{4 }W_{M,31}=W_{2}, W_{M,22}=W_{6}, and W_{M,I}=W_{0}, W_{M,Q}=W_{1 }are determined based on M=8 and W_{M,21}=W_{8 }is determined based on M=16, and the summed value which is obtained by summing α_{11}W_{0}X_{11}+jα_{12}W_{4}X_{12},α_{21}W_{8}X_{21}+jα_{22}W_{6}X_{22 }and α_{31}W_{2}X_{31 }is complex-multiplied W_{0}+jPW_{1. } 34. The method of _{n1 }and a gain α_{n2 }are the identical gain in order to remove the phase dependency by an interference occurring in a multipath of a self signal and an interference occurring by other users. 35. The method of _{n1 }and a gain α_{n2 }are the identical gain in order to remove the phase dependency by an interference occurring in a multipath of a self signal and an interference occurring by other users. 36. The method of 37. The method of _{k−1 and a sequence vector of the m-th column or row is set to W} _{m }the first M/2 or the last M/2 is obtained from the vector W_{k−1 }and the last M/2 or the first M/2 is obtained from W_{m−1}, so that the combined orthogonal Hadamard vector is set to W_{, and the summed value of α} _{11}W_{0}X_{11}+jα_{12}W_{4//1}X_{12 }and W_{0}+jPW_{1//4 }are complex-multiplied based on W_{M,11}=W_{0}, W_{M,12}=W_{4//1}, and W_{M,I}=W_{0}, W_{M,Q}=W_{1//4}, 38. The method of _{k−1 }and a sequence vector of the m-th column or row is set to W_{m }the first M/2 or the last M/2 is obtained from the vector W_{k−1}, and the last M/2 or the first M/2 is obtained from W_{m−1 }, so that the combined orthogonal Hadamard vector is set to W_{and the summed value of α} _{11}W_{0}X_{11}+jα_{12}W_{4//1}X_{12 }and α_{21}W_{2}X_{21 }and W_{0}+jPW_{1//4 }are complex-multiplied based on W_{M,11}=W_{0}, W_{M,12}=W_{4//1}, W_{M,21}=W_{2}, and W_{M,I}=W_{0}, W_{M,Q}=W_{1//4}. 39. The method of _{k−1}, and a sequence vector of the m-th column or row is set to W_{m}, the first M/2 or the last M/2 is obtained from the vector W_{k−1}, and the last M/2 or the first M/2 is obtained from W_{m−1}, so that the combined orthogonal Hadamard vector is set to W_{k−1//m−1}, and the summed value of α_{11}W_{0}X_{11}+jαand W_{0}+jPW_{1//2 }are complex-multiplied based on W_{M,11}=W_{0}, W_{M,12}=W_{2//1}, and W_{M,I } 40. The method of _{k−1}, and a sequence vector of the m-th column or row is set to W_{m}, the first M/2 or the last M/2 is obtained from the vector W_{k−1}, and the last M/2 or the first M/2 is obtained from W_{m−1}, so that the combined orthogonal Hadamard vector is set to W_{k−1//m−1}, and the summed value of α_{11}W_{0}X_{11}+jα_{12}W_{2//1}X_{12 }and α_{21}W_{4}X_{21 }and W_{0}+jPW_{1//2 }are complex-multiplied based on W_{M,11}=W_{0}, W_{M,12}=W_{2//1}, W_{M,21}=W_{4}, and W_{M,I}=W_{0}, W_{M,Q}=W_{1//2}.Description [0001] 1. Field of the Invention [0002] The present invention relates to an improved orthogonal complex spreading method and apparatus for multiple channels. The invention is capable of the following: [0003] decreasing a peak power-to-average power ratio by introducing an orthogonal complex spreading structure and spreading input signals using a spreading code; implementing a structure capable of spreading complex output signals using a spreading code by adapting a permuted orthogonal complex spreading structure for a complex-type multi-channel input signal with respect to the summed values; and decreasing a phase dependency of an interference based on a multipath component (when there is an one chip difference) of a self signal, which is a problem that is not overcome by a permuted complex spreading modulation method, nor by a combination of an orthogonal Hadamard sequence. [0004] 2. Description of the Prior Art [0005] In the area of mobile communication systems, it is well known in the art that linear and non-linear distortions affect power amplifiers. The statistical characteristic of a peak power-to-average power ratio has a predetermined interrelationship for non-linear distortion. [0006] The third order non-linear distortion, which is one of the factors affecting the power amplifier, causes an inter-modulation problem in an adjacent frequency channel. The inter-modulation problem created by a high peak amplitude, which increases the adjacent channel power (ACP), so that there is a predetermined limit for selecting the amplifier. In particular, the Code Division Multiple Access (CDMA) system requires a very strict condition with respect to linearity of a power amplifier. Therefore, the above-described condition is a very important factor. [0007] In accordance with International Standards 97 and 98, the FCC stipulates a condition on the adjacent channel power (ACP). In order to satisfy the above-described condition, the bias of the Radio Frequency (RF) power amplifier has to be limited. [0008] According to the current IMT-2000 system standard recommendation, a plurality of CDMA channels are recommended. In case a plurality of channels are provided, the peak power-to-average power ratio is considered an important factor for increasing the efficiency of the modulation method. [0009] The IMT-2000, which is a third generation mobile communication system, has received a lot of attention as the next generation communication system following the digital cellular system, personal communication system, and etc. The IMT-2000 will be commercially available as a wireless communication system, which has a high capacity and performance for supporting various multimedia services and international roaming services, etc. [0010] Many countries have proposed utilizing IMT-2000 systems that would require high data transmission rates for internet service or electronic commercial activity. This is directly related to the power efficiency of a RF amplifier. [0011] The IMT-2000 modulation method based on CDMA technology is classified as a pilot channel and symbol method. The pilot channel method is directed to the CDMA ONE introduced in North America. The pilot symbol method is directed to the NTT-DOCOMO and ARIB proposal introduced in Japan and to the FMA2 proposal introduced in Europe. [0012]FIG. 1 illustrates a prior art complex spreading method based on a CDMA ONE method. [0013] The CDMA ONE is implemented by using a complex spreading method. The pilot channel and the fundamental channel spread by a Walsh code [0014] As shown, the signals from a fundamental channel [0015] In a summing unit [0016] The in-phase and quadrature-phase information are then multiplied by a PN [0017]FIG. 2A is a view illustrating a constellation of signals in a phase domain before pulse shaping in a prior art CDMA ONE method and FIG. 2B is a view illustrating a constellation of signals in a phase domain after shaping in prior art CDMA ONE method. [0018] In the CDMA ONE, the left and right information, namely, the in-phase information (I channel) and the upper and lower information, namely, the quadrature-phase information (Q channel) pass through the actual pulse-shaping filter thereby causing a peak power. [0019] In view of the crest factor and the statistical distribution of the power amplitude, the peak power is generated in a vertical direction so that the problems such as irregular spreading of code and crosstalk occur. [0020] Accordingly, it is an object of the present invention to provide an orthogonal complex spreading method and apparatus for multiple channels that overcomes the aforementioned problems encountered in the prior art. [0021] The peak power-to-average power ratio is important in IMT-2000 system since the CDMA system requires a strict condition for linearity of a power amplifier. In particular, the IMT-2000 system provides multiple channels, which transmit signals simultaneously, and the peak power-to-average power ratio is related to the efficiency of the modulation method. [0022] It is another object of the present invention to provide an orthogonal complex spreading method and apparatus for multiple channels, which have an excellent power efficiency compared with the complex spreading methods introduced in the CDMA-ONE of the United States and the W-CDMA. Additionally, the invention is capable of resolving a power unbalance problem of an in-phase and quadrature-phase channel as well as the complex spreading method. [0023] It is still another object of the present invention to provide an orthogonal complex spreading method and apparatus for multiple channels, which is capable of maintaining a stable low peak power-to-average power ratio. [0024] Additionally, in the present invention a spreading operation is implemented as follows: multiplying predetermined channel data among data of a multichannel by an orthogonal Hadamard sequence and a gain; multiplying data of another channel by an orthogonal Hadamard sequence and a gain; summing the information of the two channels in complex type; multiplying the summed information of the complex type by the orthogonal Hadamard sequence of the orthogonal type; obtaining a complex type; summing a plurality of channel information of the complex type in the above-described manner; and multiplying the information of the complex type of the multichannel by a spreading code sequence. [0025] Furthermore, it is an object of the present invention to decrease the probability that the power drops to zero by doing the following: preventing the FIR filter input state from exceeding 90° in an earlier sample state; increasing the power efficiency and decreasing the consumption of bias power for a back-off of the power amplifier; and saving the power of a battery. [0026] It is still another object of the present invention to provide an orthogonal complex spreading method and apparatus for a multichannel, which is capable of implementing a Permuted Orthogonal Complex QPSK (POCQPSK) which is another modulation method that has a power efficiency similar with the Orthogonal Complex QPSK (OCQPSK). [0027] In order to achieve the above objects, there is an orthogonal complex spreading method that is provided for a multichannel which includes the following steps: [0028] complex-summing α [0029] In order to achieve the above objects, there is provided an orthogonal complex spreading apparatus according to a one embodiment of the present invention which includes the following: a plurality of complex multiplication blocks for distributing the data of the multichannel and complex-multiplying α [0030] In order to achieve the above objects, there is provided an orthogonal complex spreading apparatus according to another embodiment of the present invention, which includes the following: first and second Hadamard sequence multipliers for allocating the multichannel to a predetermined number of channels, splitting the same into two groups and outputting α [0031] [0032] which is obtained by summing the output signals from the first Hadamard sequence multiplier; a second adder for outputting [0033] [0034] which is obtained by summing the output signals from the second Hadamard sequence multiplier; a complex multiplier for receiving the output signal from the first and second adder in the complex form of [0035] [0036] and complex-multiplying W [0037] Additional advantages, objects and other features of the invention will be set forth in the description which follows and will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. [0038] The present invention will become more fully understood from the detailed description given below and the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: [0039]FIG. 1 is a block diagram illustrating a prior art multichannel complex spreading method of a CDMA ONE method; [0040]FIG. 2A is a view illustrating a constellation of signals in a phase domain before pulse shaping in a prior art CDMA ONE method; [0041]FIG. 2B is a view illustrating a constellation of signals in a phase domain after pulse shaping in a prior art CDMA ONE method; [0042]FIG. 4 is a block diagram illustrating a multi-channel orthogonal complex spreading apparatus in accordance with one embodiment of the present invention; [0043]FIG. 5A is a circuit diagram illustrating the complex multiplier of FIG. 4; [0044]FIG. 5B is a circuit diagram illustrating the summing unit and spreading unit of FIG. 4; [0045]FIG. 5C is a circuit diagram illustrating another embodiment of the spreading unit of FIG. 4; [0046]FIG. 5D is a circuit diagram illustrating the filter and modulator of FIG. 4; [0047]FIG. 6A is a view illustrating a constellation of signals in a phase domain before pulse shaping in an OCQPSK according to the present invention; [0048]FIG. 6B is a view illustrating a constellation of signals in a phase domain after pulse shaping in an OCQPSK in accordance with the present invention; [0049]FIG. 7 is a view illustrating a statistical distribution characteristic of power peak occurrences with respect to an average power between the prior art and the present invention; [0050]FIG. 8 illustrates an example of an orthogonal Hadamard sequence in accordance with the present invention; [0051]FIG. 9 is a circuit diagram illustrating a multichannel permuted orthogonal complex spreading apparatus in accordance with another embodiment of the present invention; [0052]FIG. 10 is a circuit diagram illustrating the complex multiplier of FIG. 8; [0053]FIG. 11 is a circuit diagram illustrating a multichannel permuted orthogonal complex spreading apparatus with two input channels in accordance with the present invention; [0054]FIG. 12 is a circuit diagram illustrating a multichannel permuted orthogonal complex spreading apparatus with three input channels in accordance with the present invention; [0055]FIG. 13A is a circuit diagram illustrating a multichannel permuted orthogonal complex spreading apparatus for a QPSK having a high transmission rate with the present invention; [0056]FIG. 13B is a circuit diagram illustrating a multichannel permuted orthogonal complex spreading apparatus with four input channels in accordance with the present invention; [0057]FIG. 14A is a circuit diagram illustrating a multichannel permuted orthogonal complex spreading apparatus for a multimedia service in accordance with the present invention; [0058]FIG. 14B is a circuit diagram illustrating a multichannel permuted orthogonal complex spreading apparatus with five input channels in accordance with the present invention; [0059]FIG. 15A is a phase trajectory view of an OCQPSK according to the present invention; [0060]FIG. 15B is a phase trajectory view of a POCQPSK according to the present invention; and [0061]FIG. 15C is a phase trajectory view of a prior art complex spreading method. [0062] The complex summing unit and complex multiplier, according to the present invention, will be explained with reference to the accompanying drawings. In the present invention, assuming that two complex number (a+jb) and (c+jd) are used, where a, b, c and d represent predetermined real numbers, a complex summing unit outputs (a+c)+j(b+d) and a complex multiplier outputs ((a×c)-(b×d))+j((b×c)+(a×d)). The following items are defined for the invention: a spreading code sequence is defined as SC; information data is defined as X [0063] The data X [0064]FIG. 4 is a block diagram illustrating a multichannel orthogonal complex spreading apparatus, in accordance with one embodiment of the present invention. [0065] As shown therein, there is provided a plurality of complex multipliers [0066] As shown in FIG. 4, the first complex multiplier [0067] In addition, the n-th complex multiplier [0068] The complex multiplication data outputted from the n-number of the complex multipliers are summed at the summing unit [0069] The above-described function will be explained as follows: [0070] [0071] K represents a predetermined integer greater than or equal to 1; and n represents an integer greater than or equal to 1 and less than K and is identical with the index of each complex multiplier. [0072] In FIG. 5A, the complex multiplier includes the following: a first multiplier [0073] The first and second multipliers [0074] Referring back to FIG. 4, the first complex multiplier [0075] In addition, FIG. 5B is a circuit diagram illustrating the summing and spreading unit of FIG. 4 and FIG. 5C is a circuit diagram illustrating another embodiment of the spreading unit of FIG. 4. [0076] As shown therein, the summing unit [0077] The spreading unit [0078] In FIG. 5C, the spreading unit [0079] In the summing unit [0080] In FIG. 5D, the filter [0081] In the present invention, the orthogonal Hadamard sequences may be replaced by a Walsh code or other orthogonal code. [0082]FIG. 8 illustrates a 8×8 Hadamard matrix as an example of the Hadamard or Walsh code. The sequence vector of a k-th column or row is set to W [0083] In order to enhance the efficiency of the present invention, the orthogonal Hadamard sequence by which multiplies each channel data is multiplied, is determined as follows. In the M×M Hadamard matrix, the sequence vector of the k-th column or row is set to W [0084] In FIG. 4, if only the first complex multipliers are used, then, only two channels are complex-multiplied, so that it can be determined that W [0085] If the two complex multipliers are used in FIG. 4 it can be determined that W [0086] Additionally, if spreading is implemented by using the SC, as shown in FIG. 5, one spreading code may be used. However, two spreading codes SC [0087] In order to achieve the objects of the present invention, the combined orthogonal Hadamard sequence may be used instead of the orthogonal Hadamard sequence thereby removing phase dependency based on the interference generated in the multiple paths of self-signal and the interference other users. [0088] If the sequence vector of the k-th column or row is set to W [0089] In the case of three channels, the summed value of α [0090] In addition, in the case of two channels, to the summed value of α [0091] In addition, in the case of three channels, the summed value of α [0092] Therefore, the cases of two and three channels have been explained. The two and three channels may be selectively used in accordance with the difference of the impulse response characteristic of the pulse shaping band pass filter. [0093]FIG. 6A is a view illustrating a constellation of signals in a phase domain before pulse shaping in the OCQPSK in accordance with the present invention. FIG. 6B is a view of a constellation of signals in a phase domain after pulse shaping in an OCQPSK of FIG. 6A. FIG. 7 is a view illustrating a statistical distribution characteristic of power peak occurrences with respect to an average power between the prior art CDMA ONE and the present invention. The embodiment of FIG. 6A is similar to FIG. 2A. However, there is a difference in the signals after the pulse shaping. In FIG. 6B, the range of the upper and lower information (Q channel) and the left and right information (I channel) are saturated to their respective limits. This causes the difference of the statistical distribution of the peak power-to-average power. [0094]FIG. 7 illustrates the peak power-to-average power ratio based on the result of the actual simulation between the present invention and the prior art. In order to provide identical conditions, the power level of the control or signal channel is set to the same the same power level of the communication channel (Fundamental channel, Supplemental channel; or In-phase channel, the Quadrature channel). Additionally, the power level of the pilot channel is set lower than the power level of the communication channel by 4dB. In the above-described condition, the statistical distributions of the peak power-to-average power are compared. [0095] In case of OCQPSK, in accordance with the present invention, the comparison is implemented by using the first complex multiplier [0096] In the case of OCQPSK, the probability that the instantaneous power exceeds the average power value (0 dB) by 4 dB is 0.03%, and in the case of CDMA ONE, it is 0.9%. Therefore, the present invention has a very excellent characteristic with respect to the power efficiency and as a new modulation method, it reduces the crosstalk interference problem. [0097]FIG. 9 illustrates a POCQPSK in accordance with the present invention. As shown therein, one or a plurality of channels are combined and complex-multiplied by the permuted orthogonal Hadamard code and then are spread by the spreading code. [0098] In FIG. 9, the following items are provided: first and second Hadamard sequence multipliers [0099] [0100] which is obtained by summing the output signals from the first Hadamard sequence multiplier [0101] [0102] which is obtained by summing the output signals from the second Hadamard sequence multiplier [0103] [0104] and complex multiplying the received signal by W [0105] Additionally, in FIG. 9 the construction of the spreading unit [0106] In the first orthogonal Hadamard sequence multiplier [0107] The first adder [0108] [0109] In the second orthogonal Hadamard sequence multiplier [0110] The second adder [0111] [0112] The signal outputted from the first adder [0113] [0114] from the first and second adders [0115] The spreading unit [0116] [0117] where K represents an integer greater than or equal to 1. [0118]FIG. 10 illustrates an embodiment where two channel data are complex-multiplied. Channel data X [0119] As shown, the orthogonal Hadamard sequence multiplier includes the following: [0120] a first multiplier [0121] The complex multiplier [0122] Therefore, the first and second multipliers [0123] The first adder [0124]FIG. 10 illustrates the complex multiplier [0125] The in-phase and quadrature phase information is spread by the spreading unit [0126] The embodiment as shown in FIG. 9 is identical to FIG. 4 instead of orthogonal Hadamard sequence, Walsh code or other orthogonal code may be used. In addition, in the orthogonal Hadamard sequence of each channel, the sequence vector of the k-th column or row is set to W [0127]FIG. 11 illustrates an embodiment of a permuted orthogonal complex spreading apparatus with two input channels. In this case, the data of two channels, namely, the pilot channel and the data of traffic channels are multiplied by the gain and orthogonal Hadamard sequence. The two channel signals are then inputted into the complex multiplier [0128]FIG. 12 illustrates an embodiment of a permuted orthogonal complex spreading apparatus with three input channels. The pilot channel and signaling channel are allocated to the first orthogonal Hadamard sequence multiplier [0129]FIG. 13A illustrates an embodiment of a permuted orthogonal complex spreading apparatus with four input channels. In FIG. 13B, the system may be constructed so that the input data (traffic [0130]FIG. 14A and 14B illustrate an embodiment of a permuted orthogonal complex spreading apparatus with five input channels. [0131] In FIG. 14B, when the data (Traffic) is separated into two channel data (Traffic [0132]FIG. 15A is a phase trajectory view of an OCQPSK, according to the present invention. FIG. 15B is a phase trajectory view of a POCQPSK, according to the present invention. FIG. 15C is a phase trajectory view of a complex spreading method, according to PN complex spreading method of the prior art. [0133] The shapes of the trajectories around the zero point are different when comparing FIGS. 15A, 15B and [0134]FIG. 7 illustrates a statistical distribution of a peak power-to-average power ratio of the CDMA ONE method compared to the OCQPSK and POSQPSK methods. [0135] In order to provide the identical condition the following has to occur: power level of the signal channel is controlled to be the same as the power level of the communication channel; power level of the pilot channel is controlled to be lower than the power level of the communication channel by 4dB. [0136] In the case of the POCQPSK, in the first block [0137] For example, the probability that the instantaneous power exceeds the average power value (0dB) by 4dB is 0.1% based on POCQPSK, and the complex spreading method is 2%. Therefore, in view of the power efficiency, the method in accordance with the present invention, is a new modulation method having excellent characteristics. [0138] As described above, in the OCQPSK in accordance with the present invention, the first data and the second data are multiplied by the gain and orthogonal code, and the resultant values are complex-summned, and the complex summed value is complex-multiplied by a complex type orthogonal code. A method is utilized where the information of the multichannel of the identical structure is summed and then spread. Therefore, this method statistically reduces the peak power-to-average power ratio to the desired range. [0139] Additionally, in the POCQPSK the data of the first block and the data of the second block are multiplied by the gain and the orthogonal code, respectively, and the permuted orthogonal spreading code of the complex type is complex-multiplied and then spread. Therefore, this method statistically reduces the peak power-to-average power ratio to the desired range. Utilizing the combined orthogonal Hadamard sequence, it is possible to decrease the phase dependency based in multichannel and multi-user interference. [0140] Although, the preferred embodiments of the present invention have been disclosed for illustrative purposes those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as recited in the accompanying claims. Referenced by
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