JP4818951B2 - Carrier reproduction circuit and receiver - Google Patents

Description

  The present invention relates to a carrier recovery circuit and a receiving apparatus in a direct spread communication system, and in particular, a carrier recovery circuit in an M-ary / SS (M-ary / Spread Spectrum) communication system. And a receiving apparatus.

  2. Description of the Related Art In recent years, spread spectrum (SS) communication systems have attracted attention as one of systems for transmitting images, sounds, data, and the like in mobile communication systems and satellite communication systems. The SS communication method includes a direct spreading (DS) method and a frequency hopping (FH) method. The DS system is a system in which communication is performed by spread spectrum of an information signal by directly multiplying the information signal by a pseudo-noise (PN) sequence that is much wider than that of the information signal.

Among the DS systems, the M-ary / SS (M-ary / Spread Spectrum) system prepares 2 ^K code sequences (orthogonal code sequences) that are orthogonal to each other (K is a natural number). In other words, one orthogonal code sequence is selected for each K-bit transmission data, and the signal is transmitted by directly spreading the selected orthogonal code sequence. The M-ary / SS system is a transmission system suitable for increasing the information transmission speed because K-bit information transmission can be performed in one period of the orthogonal code sequence while realizing spread spectrum. Hereinafter, this value of K is referred to as a modulation multilevel number.

  In the DS system, a plurality of signals spread by different spreading codes are code-multiplexed and transmitted in parallel to increase the information transmission rate (see, for example, Patent Document 1 below). In order to increase the information transmission rate, it is desirable to use the M-ary / SS system and to perform such code multiplexing.

  Hereinafter, a receiving apparatus in a conventional direct spreading communication system described in Patent Document 1 will be described. The receiving apparatus of Patent Document 1 below is based on the premise that a multiplexed RF (Radio Frequency) signal obtained by performing spread spectrum modulation, code multiplexing, and frequency conversion on one synchronization dedicated channel and N data channels is received. Yes. First, in the receiving apparatus disclosed in Patent Document 1 below, the receiving antenna receives the multiplexed RF signal, and the RF amplifier unit amplifies the power of the multiplexed RF signal. Then, the quasi-synchronous detection unit converts the power-amplified multiplexed RF signal into a baseband signal having a chip rate frequency band by performing frequency conversion.

  Next, the code synchronization unit performs a correlation operation between the baseband signal generated by the quasi-synchronous detection unit and the synchronization dedicated spreading code PN-0 generated by the spreading code generation unit. Then, spreading code synchronization and clock synchronization are established for the received signal using the correlation calculation result, and a code synchronization signal and a clock signal are output.

  After the code synchronization is established, the spread code generator generates a spread code group (a total of (N + 1) spread codes including one synchronization dedicated channel and N data channels) having the same clock and phase based on the clock signal and the code synchronization signal. ). Then, the carrier reproduction unit performs despreading processing on the baseband signal frequency-converted by the quasi-synchronous detection unit, using the code-synchronized dedicated dedicated spreading code PN-0 generated by the spreading code generation unit. Next, the carrier reproduction unit estimates the carrier phase from the despread result, and outputs the estimation result as a reproduced carrier signal.

  Next, the N baseband demodulation units generate a baseband signal after carrier phase correction using the reproduced carrier signal generated by the carrier recovery unit and the baseband signal frequency-converted by the quasi-synchronous detection unit. . The n-th (n = 1,..., N) baseband demodulator outputs the spread code PN that is output from the spread code generator for the baseband signal after the carrier phase correction and has established code synchronization. -N is used to perform despreading processing, and data demodulation is performed using the despreading result. Finally, the parallel / serial conversion unit converts the demodulated data output from the N baseband demodulation units into serial data in a predetermined order and outputs the serial data as demodulated data.

JP-A-8-167864

  However, according to the above-described conventional technique, a demodulated data is extracted by providing a synchronization-dedicated channel and performing carrier reproduction using the synchronization-dedicated channel. For this reason, a synchronization dedicated channel that does not perform data transmission is required, and there is a problem that transmission efficiency deteriorates.

  On the other hand, in order to avoid the above-described deterioration in transmission efficiency, it is conceivable to perform carrier regeneration without using a synchronization dedicated channel. In the M-ary / SS transmission, when carrier recovery is performed without using a synchronization dedicated channel, the following processing is performed.

For example, when demodulating a signal having a modulation multi-level number K transmitted by the M-ary / SS system, a partial despreading result (hereinafter referred to as a partial correlation value) obtained by dividing a spreading code into 2 ^K pieces is obtained. Generate ^2K pieces. Then, 2 ^K orthogonal correlation values indicating the correlation between the partial correlation value and 2 ^K orthogonal code sequences are obtained. Since 2 ^K code sequences used in M-ary / SS transmission are orthogonal to each other, one orthogonal corresponding to a transmission data sequence in units of K bits out of 2 ^K orthogonal correlation values. Only the correlation value is a significant value including the modulation component, and the remaining (2 ^K −1) orthogonal correlation values are only the noise component. When demodulating a signal having a modulation multi-level number K transmitted by the M-ary / SS system without using a dedicated channel for synchronization, an orthogonal correlation value used for carrier regeneration is obtained from 2 ^K orthogonal correlation values. It is necessary to select.

  However, when selecting the above-mentioned orthogonal correlation value, there is a possibility that the orthogonal correlation value of only the noise component is erroneously selected in a state where the SN ratio of the received signal is poor. In this case, the carrier reproduction unit generates a carrier reproduction signal using the orthogonal correlation value of only the misselected noise component. For this reason, there is a problem that the estimation accuracy of the reproduced carrier signal is deteriorated and the quality of the demodulated data is deteriorated.

  The present invention has been made in view of the above, and a carrier regeneration circuit and a receiver for performing carrier regeneration with high accuracy on a signal transmitted by the M-ary / SS system without using a dedicated channel for synchronization. The object is to obtain a device.

  In order to solve the above-described problems and achieve the object, the present invention receives a multiplexed signal obtained by further channel-multiplexing an M-ary / SS (M-ary spread spectrum) modulated signal and multiplexing the received signal. In a receiving apparatus that performs carrier phase correction on a baseband signal obtained by frequency-converting a signal, a carrier that generates a reproduction carrier signal for performing the carrier phase correction based on a partial correlation value between the baseband signal and a spread code A reproduction circuit, for each channel, obtains a sum of squares of a real part and an imaginary part of an orthogonal correlation value which is a correlation value between the partial correlation value and an orthogonal sequence group used for M-ary / SS modulation, Maximum orthogonal correlation value selection means for selecting an orthogonal correlation value that maximizes the sum of squares, and the maximum orthogonal correlation values for a predetermined number of channels equal to or less than the maximum number of channels to be code-multiplexed are added, and the addition is performed. Adding means for generating a reproduced carrier signal based on a result, characterized in that it comprises a.

  According to the present invention, carrier recovery is performed by adding orthogonal correlation values of a plurality of channels in the carrier recovery circuit. For this reason, the probability of erroneous selection by the carrier reproduction unit is reduced, the carrier estimation accuracy is improved, and high-quality demodulated data can be generated for signals transmitted by the M-ary / SS system without using a dedicated channel for synchronization. There is an effect that it can be obtained.

  Embodiments of a carrier recovery circuit and a receiving apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
1 is a diagram illustrating a functional configuration example of a first embodiment of a receiving device according to the present invention. As shown in FIG. 1, the receiving apparatus according to the present embodiment includes a receiving antenna 1 that receives a multiplexed RF signal (Radio Frequency) transmitted from a transmitting apparatus, and an RF (Radio Frequency) amplification that amplifies the received multiplexed signal. Unit 2, a quasi-synchronous detection unit 3 that generates a baseband signal having a frequency band of a chip rate by frequency-converting the amplified multiplexed signal, and a phase correction unit 4 that performs phase correction on the baseband signal, A partial correlation value calculation unit 5 that obtains a partial correlation value by performing a partial correlation calculation between the spreading code used by the transmission device and the phase-corrected baseband signal, and a symbol clock synchronized with the spreading code period based on the partial correlation value A code synchronizer 6 that generates a delay, delay correctors 7-1 to 7-N (N is the number of data channels) for performing delay correction on the partial correlation values, and a symbol clock rise for each symbol period. Latches 8-1 to 8 -N that send partial correlation values after delay correction at the same timing, and matrix multipliers 9-1 to obtain orthogonal correlation values based on partial correlation values after delay correction output from the latches and 9-N, a carrier recovery unit 10, a data demodulation unit 11-1 to 11-N to generate a parallel demodulated data K bits by performing a maximum likelihood determination with respect to 2 ^K pieces of quadrature correlation values, the parallel demodulation And a parallel-serial converter 12 that converts data into serial data.

In the present embodiment, in transmission processing, after M-ary / SS modulation is performed using the same spreading code for all data channels, a multiplexed signal that is multiplexed with a different delay amount is assigned to each data channel. It is assumed that the receiving device receives. In this embodiment, it is assumed that the spreading code and the delay amount (for each channel) used in the transmission processing are determined in advance, and the receiving apparatus holds these. In the receiving apparatus, it is assumed that the delay amount is held in association with the channel number for each channel. In M-ary / SS modulation, 2 ^K (K is a natural number) orthogonal code sequences (orthogonal code sequences) are prepared, and one orthogonal code sequence is selected for each K-bit transmission data. The selected orthogonal code sequence is directly spread using a spreading code. In the present embodiment, it is assumed that the correspondence between these 2 ^K orthogonal code sequences used in transmission processing and the transmission data and the orthogonal code sequences is determined in advance. ^{Assume that K} orthogonal code sequences and correspondence between transmission data and orthogonal code sequences are retained.

  Next, the operation of the receiving apparatus according to this embodiment will be described. In the receiving apparatus of the present embodiment, first, the receiving antenna 1 receives the multiplexed signal and outputs it to the RF amplification unit 2. The RF amplifier 2 amplifies the power of the multiplexed signal and outputs it to the quasi-synchronous detector 3. The quasi-synchronous detection unit 3 frequency-converts the power-amplified multiplexed signal, generates a baseband signal having a complex value in the chip rate frequency band, and outputs the baseband signal to the phase correction unit 4.

  The phase correction unit 4 outputs a signal obtained by rotating the baseband signal output from the quasi-synchronous detection unit 3 in the opposite direction to the phase of the reproduction carrier signal generated by the carrier reproduction unit 10, thereby generating a baseband signal. The carrier phase is corrected for the signal. The reproduction carrier signal generation process of the carrier reproduction unit 10 will be described later.

Next, the partial correlation value calculation unit 5 performs partial correlation calculation between the spread code and the phase-corrected baseband signal output from the phase correction unit 4 using the held spread code. Specifically, in the present embodiment, one symbol length (one spreading code period) is divided into 2 ^K blocks to perform partial correlation calculation, and 2 ^K partial correlation values are transmitted to the code synchronization unit 6 and the delay. Output to the correction units 7-1 to 7-N, respectively. The partial correlation value has a complex value.

Next, the code synchronization unit 6 detects the start timing of the spread code period of the spread code multiplied by the received signal based on the 2 ^K partial correlation values output from the partial correlation value calculation unit 5, and starts this start A clock having a symbol period synchronized with the timing (hereinafter referred to as a symbol clock) is generated. At this time, the start timing of the spread code period is synchronized with the rising edge timing of the symbol clock. As a method for detecting the start timing of the spreading code period, for example, it may be detected as the timing at which the sum of the square sums of 2 ^K partial correlation values is maximized within the spreading code period.

Next, the delay correction unit 7-n (n = 1,..., N) has N pieces of delay based on the delay amount (delay amount given in the transmission process) corresponding to the held nth data channel. The timing is adjusted so that the start timings of the symbol periods are aligned in all the data channels, and 2 ^K partial correlation values are output. For example, assuming that the delay amount of the _nth data channel is tan seconds and the data output timing when the delay amount is “0” is t seconds later, the delay correction unit 7-n sets the partial correlation value to (t and outputs it to the -ta _n) seconds later. Next, the latches 8-n (n = 1,..., N) extract the 2 ^K partial correlation values output from the delay correction unit 7-n at the timing of the rising edge of the symbol clock for each symbol period. To do.

Next, matrix multiplication unit 9-n (n = 1, ..., N) is 2 performs a 2 ^K number of partial correlation value and 2 ^K pieces each orthogonal code sequence output from the latch 8-n correlation calculation ^K correlation values (hereinafter referred to as orthogonal correlation values) are obtained. For example, an orthogonal code sequence having a code length of 2 ^K bits used in M-ary / SS modulation of transmission processing is set to a matrix f _i (i = 1,..., 2 ^K ) having 1 column and 2 ^K rows, and H = 2 ^K and to time, and _{(f 1 f 2 ... f H} ) 2 K rows 2 ^K columns matrix matrix a by arranging the 2 ^K number of orthogonal code sequences in the row direction as. Then, determine the first row 2 ^K columns of the matrix of the partial correlation values as elements in each column, and the matrix A, of 2 ^K number of orthogonal correlation value by performing multiplication. Since the partial correlation value is a complex number, the orthogonal correlation value is also a complex number.

Next, the data demodulating unit 11-n (n = 1,..., N) performs maximum likelihood determination on the 2 ^K orthogonal correlation values output from the matrix multiplying unit 9-n, and obtains K bits. Generate demodulated data. Since the data demodulation units 11-1 to 11-N perform the demodulation processing, N pieces of parallel data are generated. The parallel-serial conversion unit 12 performs parallel-serial conversion on the total (K × N) bits of parallel demodulated data output from the data demodulation units 11-1 to 11-N, thereby generating one series of demodulated data.

Next, the reproduction carrier signal generation process of the carrier reproduction unit 10 of the present embodiment will be described. FIG. 2-1 is a diagram illustrating a functional configuration example of the carrier reproducing unit 10 according to the present embodiment. As illustrated in FIG. 2A, the carrier reproducing unit 10 according to the present embodiment obtains the square sum of the real part and the imaginary part of 2 ^K orthogonal correlation values, and the orthogonal correlation that maximizes the square sum. The maximum power orthogonal correlation value selection units 20-1 to 20-N that output values as error signals and the error signals output from the maximum power orthogonal correlation value selection units 20-1 to 20-N are all added to form a combined error An adder 21 that generates a signal, an averaging unit 22 that calculates a time average value of the combined error signal, an arctangent calculation unit 23 that calculates a declination from the time average value and outputs it as a carrier phase error, and a carrier phase error And an integrator 24 that integrates and outputs a reproduced carrier signal. Here, the adder 21, the averaging unit 22, the arctangent calculator 23, and the integrator 24 are provided, but all are integrated, or two or three of these are integrated. You may comprise so that it may become.

In the carrier recovery unit 10, first, the maximum power orthogonal correlation value selection unit 20-n (n = 1,..., N) applies the 2 ^K orthogonal correlation values output from the matrix multiplication unit 0-n. , ((Square of real part) + (square of imaginary part)) is calculated, and an orthogonal correlation value that maximizes ((square of real part) + (square of imaginary part)) is selected. The selected orthogonal correlation value is output as an error signal. In the following, this ((square of real part) + (square of imaginary part)) process is called power calculation process, and ((square of real part) + (square of imaginary part)) is called power. .

  Next, the adding unit 21 adds the error signals output from the maximum power orthogonal correlation value selecting units 20-n to generate a combined error signal. When N = 1, the adding unit 21 outputs the error signal output from the maximum power orthogonal correlation value selecting unit 20-1 as it is as a combined error signal. Next, the averaging unit 22 averages the combined error signal output from the adding unit 21 in the time direction for each symbol period. This averaging is performed in order to improve the S / N ratio, but may not be performed when a sufficient S / N ratio is obtained. Moreover, there is no restriction | limiting in the time which performs averaging, What is necessary is just to set according to a communication system.

  Next, the arctangent calculation unit 23 calculates the declination of the time-averaged combined error signal having a complex value and outputs it as a carrier phase error. Then, the integrator 24 integrates the carrier phase error output from the arctangent calculation unit 23 and outputs it to the phase correction unit 4 as a reproduced carrier signal (the phase of the carrier signal).

  Note that the code synchronization unit 6 according to the present embodiment obtains the start timing for the spreading code period of the data channel subjected to M-ary / SS modulation, but other than the data channel subjected to M-ary / SS modulation. If the channel (hereinafter referred to as another channel) is multiplexed in synchronization with the code period of the data channel subjected to M-ary / SS modulation, the start timing of the spreading code period of this other channel is obtained. Thus, a symbol clock synchronized with the start timing with respect to the spreading code period of the data channel subjected to M-ary / SS modulation may be generated.

  In this embodiment, the rising edge of the symbol clock is generated in accordance with the timing of the code synchronization. However, the latches 8-1 to 8-N have the timing of the code synchronization and the rising edge of the symbol clock. If the partial correlation value at the timing of code synchronization is extracted by shifting the time difference (phase difference) for extraction, the clock phase of the symbol clock may be arbitrary.

  In the carrier reproducing unit 10 having the configuration example illustrated in FIG. 2A, the arc tangent calculation unit 23 performs an arc tangent calculation after the averaging unit 22 to convert it into phase information. Thus, the arc tangent calculating unit 23 is deleted, and the arc tangent calculating units 23a-1 to 23a-N are arranged between the maximum power orthogonal correlation value selecting units 20-1 to 20-N and the adding unit 21, and the arc tangent calculation is performed. The process may be performed before the addition process. In this case, the arc tangent calculators 23a-1 to 23a-N obtain the declination of the maximum power orthogonal correlation value input to each and output it to the adder 21 as an error phase amount. The processing of the adding unit 21 is the same as the configuration example of FIG. 2A except that the addition target is the phase error amount instead of the orthogonal correlation value. The process of the averaging unit 22 is the same as the configuration example of FIG. 2A except that the averaging target is the phase error amount and the output destination is the integrator 24 instead of the arctangent calculation unit 23. The integrator 24 uses the averaged phase error amount output from the averaging unit 22 as a carrier phase error and performs integration in the same manner as in the configuration example of FIG.

  Further, as shown in FIG. 2-3, the averaging unit 22 and the arc tangent calculating unit 23 are deleted from the functional configuration example of FIG. 2A, and the arc tangent calculating unit 23b, By adding the averaging unit 22a, the order of arc tangent calculation and averaging may be reversed. In this case, the arc tangent calculation unit 23b calculates the declination of the combined error signal output from the addition unit 21, outputs it as a phase error amount to the averaging unit 22a, calculates the time average value of the phase error amount, and integrates the integrator. 24. The processing of the integrator 24 is integrated in the same manner as the integrator 24 in the configuration example of FIG. 2A using the averaged phase error amount output from the averaging unit 22a as the carrier phase error.

Further, in the carrier recovery unit 10 of the configuration example illustrated in FIG. 2A, the maximum power orthogonal correlation value selection unit 20-n (n = 1,..., N) performs power calculation processing of the orthogonal correlation value, After obtaining the orthogonal correlation value that maximizes the power value, the adding unit 21 performs addition processing for N channels. As shown in FIG. 3, the maximum power orthogonal correlation value selecting units 20-1 to 20-N are performed. , In-phase addition / maximum power quadrature correlation value selection unit 25 may be provided instead of the addition unit 21, and the order of the addition process and the maximum power selection process may be switched. In this case, the in-phase addition / maximum power quadrature correlation value selection unit 25 extracts an arbitrary one from 2 ^K quadrature correlation values of each data channel, and adds the extracted N quadrature correlation values. This extraction and addition is performed for all ^2KN combinations. Then, among these addition results, the addition result that maximizes ((the square of the real part) + (the square of the imaginary part)) is output to the averaging unit 22 as a combined error signal. The processing of the averaging unit 22, the arc tangent calculating unit 23, and the integrator 24 is the same as the processing of the averaging unit 22, arc tangent calculating unit 23, and integrator 24 in the configuration example of FIG.

  In the configuration example of FIG. 3, the number of addition operations increases, but the in-phase addition process is performed before the power calculation process, so the SN ratio of the addition result is improved. Therefore, in the example of FIG. 3, the probability of erroneous selection of the addition result is reduced due to the improvement of the SN ratio, and compared with the configuration example of the carrier reproducing unit 10 illustrated in FIGS. The probability that the error signal is only a noise component is reduced, and the reproduced carrier signal can be calculated with higher accuracy.

  Similarly to the case of FIG. 2-3, the arc tangent calculation unit 23 and the averaging unit 22 are deleted from the configuration example of FIG. 3, and the arc tangent calculation unit 23b and the averaging unit 22a are added to calculate the arc tangent calculation. And the order of averaging may be reversed. In this case, the arc tangent calculation unit 23b obtains the declination of the combined error signal output from the in-phase addition / maximum power quadrature correlation value selection unit 25, and outputs it to the averaging unit 22a as the combined phase error, and the averaging unit 22a Performs the process of averaging the composite phase error in the time direction. The integrator 24 performs integration in the same manner as in the configuration example of FIG. 2A using the time averaged combined phase error as the carrier phase error.

  In addition, in the configuration example of the carrier reproducing unit 10 in FIGS. 2-1 to 3, the adding unit 21 performs the adding process for N channels, but the number of channels to be added is P (P May be a natural number equal to or less than N). Further, in the addition processing of the in-phase addition / maximum power quadrature correlation value selection unit 25 in FIG. 3, the addition for N channels is performed, but a predetermined amount for P (P is a natural number equal to or less than N) channels is added. May be. In the case of P <N, compared with the carrier reproducing unit 10 shown in FIGS. 2-1 to 2-3 or FIG. 3, the effect of improving the accuracy of carrier reproduction is reduced, but the circuit scale can be reduced. it can. Therefore, P may be selected in consideration of the circuit scale and the demand for higher accuracy of carrier reproduction. In addition, not all of the maximum number of channels N are always used. In such a case, the number of channels to be used is P, and when the number of channels to be used changes, P depends on the number of channels. The setting value may be changed.

  As described above, in the carrier reproduction unit 10 according to the present embodiment, the addition unit 21 generates a combined error signal for the reception signal multiplexed with the N-channel M-ary / SS modulated signals. Thus, a reproduced carrier signal is generated using the combined error signal. This combined error signal can increase the expected value of the number of channels including signal components to N times that of an error signal generated from a signal of only one data channel. For this reason, the probability that the combined error signal is only a noise component is reduced, and the reproduced carrier signal can be calculated with high accuracy without using a channel dedicated to synchronization. Further, in the receiving apparatus of the present embodiment, demodulation processing is performed using a highly accurate reproduced carrier signal in the above-described carrier reproducing circuit, so that high-quality demodulated data can be obtained. Furthermore, in the receiving apparatus according to the present embodiment, it is possible to prevent a decrease in transmission efficiency due to insertion of a dedicated synchronization channel.

Embodiment 2. FIG.
FIG. 4 is a diagram illustrating a functional configuration example of the second embodiment of the receiving device according to the present invention. As illustrated in FIG. 4, the receiving apparatus of the present embodiment deletes the delay correction units 7-1 to 7-N from the receiving apparatus of the first embodiment, and replaces the partial correlation value calculating unit 5 with the partial correlation values. Calculation units 5a-1 to 5a-N are provided. Components having the same functions as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the first embodiment, the reception apparatus that receives the signal multiplexed by multiplying the N-channel signal by the same spreading code and adding different delay amounts to each channel is shown. Receives a code-multiplexed signal without adding a delay amount to each channel by multiplying each channel by a different spreading code. It is assumed that the spreading code for each channel is determined in advance and held by the receiving apparatus.

The operation of this embodiment will be described. Only the parts different from the first embodiment will be described below. The processing up to the phase correction unit 4 is the same as in the first embodiment, but the phase correction unit 4 outputs the baseband signals after phase correction to the partial correlation value calculation units 5a-1 to 5a-N, respectively. Next, the partial correlation value calculation units 5a-1 to 5a-N calculate partial correlation values between the spread code and the baseband signal after phase correction, using the spread code corresponding to each channel. Specifically, in the present embodiment, one symbol length is divided into 2 ^K blocks to perform partial correlation calculation, and 2 ^K partial correlation values correspond to the code synchronization unit 6 and the same channel number. Outputs to the latches 8-1 to 8-N, respectively. Other operations are the same as those in the first embodiment.

  As described above, in the present embodiment, the partial correlation value calculation units 5a-1 to 5a-N calculate the partial correlation values using the spreading codes corresponding to the respective channels. Further, the carrier reproducing unit 10 of the present embodiment has the same configuration as the carrier reproducing unit 10 of the first embodiment. For this reason, even when receiving a signal spread by a different spreading code for each channel, the receiving apparatus of the present embodiment can obtain the same effects as those of the first embodiment.

Embodiment 3 FIG.
FIG. 5 is a diagram illustrating an example of a functional configuration of the receiving apparatus according to the third embodiment of the present invention. As shown in FIG. 5, the receiving apparatus according to the present embodiment replaces carrier reproducing section 10 and data demodulating sections 11-1 to 11-N of the receiving apparatus according to the first embodiment with carrier reproducing section 10a and data demodulating section. Parts 11a-1 to 11a-N. Components having the same functions as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The receiving apparatus according to the first embodiment feeds back the reproduced carrier signal calculated by the carrier reproducing unit 10 to the phase correcting unit 4. However, in the present embodiment, as shown in FIG. Yes. FIG. 6 is a diagram illustrating a functional configuration example of the carrier reproducing unit 10a according to the present embodiment. As shown in FIG. 6, the carrier reproducing unit 10a has a configuration in which the integrator 24 is deleted from the carrier reproducing unit 10 shown in FIG. 2-1 of the first embodiment. Components having the same functions as those in FIG. 2-1 of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

Next, the operation of the present embodiment will be described. Only the parts different from the first embodiment will be described below. In the first embodiment, the partial correlation value calculation unit 5 performs the partial correlation calculation of the baseband signal after the phase correction and the spread code, but in this embodiment, the baseband signal before the phase correction and the spread code are processed. Although the point which performs a partial correlation calculation differs, it is the same as that of Embodiment 1 except it. Further, the carrier reproduction unit 10a outputs the output of the arctangent calculation unit 23 as a reproduction carrier signal to the data demodulation units 11a-1 to 11a-N. Then, the data demodulator 11a-n (n = 1,..., N) regenerates the carrier for the 2 ^K orthogonal correlation values output from the matrix multiplier 9-n (n = 1,..., N). After performing phase correction based on the phase indicated by the signal, maximum likelihood determination is performed and K-bit parallel demodulated data is output. Other operations are the same as those in the first embodiment.

  As described above, in the present embodiment, the phase correction unit 4 of the first embodiment is deleted, the reproduced carrier signals are output to the data demodulation units 11a-1 to 11a-N, and the data demodulation units 11a-1 to 11a are output. -N performs the maximum likelihood determination after phase correction and outputs K-bit parallel demodulated data. For this reason, it is not necessary to provide the phase correction part 4, and a structure can be simplified from Embodiment 1, and the effect similar to Embodiment 1 can be acquired.

Embodiment 4 FIG.
FIG. 7-1 is a diagram illustrating a functional configuration example of the fourth embodiment of the carrier reproducing unit 10b according to the present invention. The configuration of the receiving apparatus of the present embodiment is the same as that of the receiving apparatus of the first embodiment except that the reproduction carrier unit 10 of the first embodiment is replaced with the carrier reproducing unit 10b. As shown in FIG. 7A, the carrier reproducing unit 10 of the present embodiment adds a nonlinear processing unit 26 to the carrier reproducing unit 10 shown in FIG. 2-3 of the first embodiment. These are the same as the carrier reproducing unit 10 shown in FIG. Components having the same functions as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  7-2 and 7-3 are diagrams illustrating another configuration example of the present embodiment. Here, first, the configuration example of FIG. 7-1 will be described, and the configuration examples of FIGS. 7-2 and 7-3 will be described later. Also in the present embodiment, as in the first embodiment, after M-ary / SS modulation is performed using the same spreading code for all channels, a different delay amount is given to each data channel and multiplexed. It is assumed that a multiplexed signal is received. In the present embodiment, the carrier reproduction unit 10b performs the averaging process in the time direction after performing the non-linear process on the combined error signal or the deviation angle of the combined error signal. In comparison, a more accurate reproduced carrier signal is generated.

  Subsequently, the operation of the carrier reproducing unit 10b according to the present embodiment will be described with reference to FIG. Hereinafter, a different part from Embodiment 1 is demonstrated. The nonlinear processing unit 26 of the carrier reproducing unit 10b according to the present embodiment performs nonlinear processing on the phase error amount output from the arctangent calculation unit 23b, and outputs the phase amount after nonlinear processing to the averaging unit. As the nonlinear processing of the present embodiment, for example, a threshold value α [rad] is determined in advance, and a limiter processing that limits the maximum absolute value of the output signal with α [rad] as shown in FIG. Alternatively, as shown in FIG. 8B, when the absolute value of the input signal is larger than α [rad], a process of outputting 0 [rad] is assumed.

  The averaging unit 22a averages the composite error phase that has been nonlinearly processed instead of the phase error amount. Other than that, the averaging unit 22a is the same as the averaging unit 22a in the configuration example of FIG. 2-3 of the first embodiment. is there. The processing of the integrator 24 is the same as that of the configuration example of FIG. Other operations in the receiving apparatus are the same as those in the first embodiment.

  The phase error amount has a value in the vicinity of 0 [rad] when the reproduced carrier signal (carrier phase) is sufficiently drawn by feedback control and has a signal component. In the present embodiment, by performing nonlinear processing on the phase error amount as described above, even when the phase error amount is only a noise component and has a random phase amount, the combined error phase after the nonlinear processing is obtained. Can be suppressed to a small value as compared with the first embodiment. For this reason, in this embodiment, it is possible to reduce jitter characteristics as compared with the reproduction carrier signal generated in the first embodiment, and it is possible to generate a reproduction carrier signal with higher accuracy. In particular, when the value of the number of channels P to be added by the adder 21 (P is a natural number equal to or less than N) is reduced, there is a high possibility that the combined error phase is generated from only noise components. The effect of reducing the jitter characteristics of the reproduced carrier signal is increased. In particular, even when P = 1, it is possible to improve the accuracy of the reproduced carrier signal as compared with a conventional receiver that does not perform channel addition.

  Note that the threshold value α used in the nonlinear processing unit 26 is a value with the passage of time, for example, a relatively large value at the time of feedback control pull-in of the reproduction carrier signal and a relatively small value after the feedback control signal pull-in of the reproduction carrier signal. By changing, it is possible to achieve both the feedback control pull-in of the reproduced carrier signal in a short time and the high accuracy of the reproduced carrier signal after the pull-in. In this case, for example, a counter that resets at the start of the operation of the carrier reproducing unit 10a and counts up for each symbol may be used, and the value of α may be appropriately changed according to the counter value.

  In FIG. 7A, the non-linear processing unit 26 is arranged between the arctangent calculation unit 23b and the averaging unit 22a. However, as shown in FIG. Nonlinear processing units 26 a-1 to 26 a -N may be provided between the power orthogonal correlation value selection unit 20-n (n = 1,..., N) and the addition unit 21. In this case, the non-linear processing units 26a-1 to 26a-N need to perform non-linear processing on complex orthogonal correlation values instead of phase amounts. For example, the threshold β is set in advance only for the imaginary component, and the orthogonal correlation values are determined. Is limited to a range within the threshold β. In this way, by limiting the orthogonal correlation value, the output of the integrator 24 can be limited in the same manner as in FIG. In this case, the adder 21 and the arctangent calculator 23b input and process the orthogonal correlation value after the nonlinear process, but the other processes are the same as in the configuration example of FIG. is there. The processing of the integrator 24 is the same as the configuration example of FIG.

  Further, as shown in FIG. 7C, the nonlinear processing unit 26 in the configuration example of FIG. 7-1 may be deleted, and a nonlinear processing unit 26b may be provided between the adding unit 21 and the arctangent calculation unit 23b. . Also in this case, the non-linear processing unit 26b performs non-linear processing on complex values in the same manner as the non-linear processing units 26a-1 to 26a-N in the configuration example of FIG. The process of the arc tangent calculation unit 23b is the same as the configuration example of FIG. 7A except that the orthogonal correlation value after the nonlinear process becomes the input value. About the process of the averaging part 22a and the integrator 24, it is the same as that of the structural example of FIGS.

  In this embodiment, the nonlinear processing unit 26 is added to FIG. 2-3. However, as shown in FIG. 9, the nonlinear processing unit 26 is added to the configuration example of FIG. 3 of the first embodiment. Also good. In FIG. 9, the non-linear processing unit 26 is arranged between the inverse operation unit 23 b and the averaging unit 22 a. However, as in FIG. You may make it arrange | position in front of the reverse operation part 23b.

  In the configuration example of FIGS. 7-1 to 7-3, the non-linear processing unit 26 is added to FIG. 2-3 of the first embodiment, but the configuration example of FIG. 2-1 or FIG. A non-linear processing unit 26 may be added. When the nonlinear processing unit 26 is added to the configuration example of FIG. 2A, the nonlinear processing unit 26 may be disposed between the arctangent calculation unit 23 and the integrator 24. In the case of adding the non-linear processing unit 26 to the configuration example of FIG. 2B, it may be arranged between the adding unit 21 and the averaging unit 22.

  In FIG. 9, the arc tangent calculation unit 23b is arranged between the in-phase addition / maximum power orthogonal correlation value selection unit 25 and the nonlinear processing unit 26, but between the nonlinear processing unit 26 and the averaging unit 22a, or Alternatively, it may be arranged between the averaging unit 22a and the integrator 24. In this case, as in the examples of FIGS. 7-2 and 7-3, the nonlinear processing unit 26 performs nonlinear processing on the orthogonal correlation value. Further, in the case of arranging between the non-linear processing unit 26 and the averaging unit 22a, the input value to the arc tangent calculation unit 23b becomes the orthogonal correlation value after the non-linear processing. In the processing in the case of being arranged between the averaging unit 22a and the integrator 24, the input value to the arc tangent calculation unit 23b becomes the averaged orthogonal correlation value. Other processes are the same as those in the configuration example of FIG.

  In the present embodiment, the carrier reproducing unit 10 of the receiving apparatus of the first embodiment is replaced with the carrier reproducing unit 10b. However, the carrier reproducing unit 10 of the receiving apparatus of the second embodiment is replaced with the carrier reproducing unit 10b. You may make it change. Further, the carrier regeneration unit 10a of the receiving apparatus according to the third embodiment may be replaced with a carrier reproduction unit 10b according to the present embodiment in which the integrator 24 is deleted.

  As described above, in the present embodiment, the carrier phase error range is limited by performing nonlinear processing in the carrier reproducing unit 10b. For this reason, compared with Embodiment 1, the jitter characteristic of a carrier reproduction signal can be improved, and higher quality demodulated data can be obtained.

Embodiment 5 FIG.
FIG. 10 is a diagram illustrating an example of a functional configuration of the receiving apparatus according to the fifth embodiment of the present invention. As shown in FIG. 10, the receiving apparatus according to the present embodiment adds transmission rate information extracting section 27 to the receiving apparatus according to the first embodiment, and carrier reproducing section 10 and data demodulating section of the receiving apparatus according to the first embodiment. 11 is provided with a carrier reproducing unit 10c and data demodulating units 11b-1 to 11b-N. Components having the same functions as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the receiving apparatus according to the present embodiment, the modulation multilevel number and the data channel multiplexing number are determined by the adaptive modulation operation, and the M-ary / SS modulation is performed using the modulation multilevel number and the same spreading code for all channels. Is performed, the data channels corresponding to the number of multiplexed data channels are given different delay amounts and receive multiplexed multiplexed signals. Here, the adaptive modulation operation refers to an operation of changing the transmission rate according to the transmission path condition and determining the modulation multi-value number and the data channel multiplexing number based on the transmission rate information indicating the transmission rate. Therefore, the modulation multi-level number and the data channel multiplexing number vary according to the transmission path state. In this embodiment, it is assumed that transmission rate information is code-multiplexed with the received signal. Also, the correspondence between the modulation multi-level number and the data channel multiplexing number for the transmission rate information is predetermined and is assumed to be held by the receiving apparatus of this embodiment.

  Next, the operation of the present embodiment will be described. Hereinafter, a different part from Embodiment 1 is demonstrated. The operations of the reception antenna 1, the RF amplification unit 2, and the quasi-synchronous detection unit 3 are the same as those in the first embodiment. The phase correction unit 4 performs the phase correction processing in the same manner as in the first embodiment, and then outputs the baseband signal after the phase correction to the partial correlation value calculation unit 5 and the transmission rate information extraction unit 27. The transmission rate information extraction unit 27 performs despreading processing and data demodulation processing to extract transmission rate information from the baseband signal after phase correction, and performs carrier reproduction unit 10c and data demodulation units 11b-1 to 11b-N. , Output to the parallel-serial converter 12a.

  The operations of the partial correlation value calculation unit 5, the code synchronization unit 6, the delay correction units 7-1 to 7-N, the latches 8-1 to 8-N, and the matrix multiplication units 9-1 to 9-N are the same as those in the first embodiment. It is the same. As will be described later, the carrier reproducing unit 10c obtains the modulation multilevel number and the data channel multiplexing number from the transmission rate information, and generates a reproduction carrier signal according to the modulation multilevel number and the data channel multiplexing number.

  The data demodulation unit 11b-n (n = 1,..., N) obtains a modulation multilevel number J (J is a natural number equal to or less than K) based on the transmission rate information, and performs data demodulation processing according to the modulation multilevel number. To output J-bit parallel demodulated data. The parallel-serial converter 12a obtains the modulation multilevel number J and the data channel multiplexing number I (I is a natural number equal to or less than N) based on the transmission rate information, and the J and I from the data demodulation units 11b-1 to 11b-N. Significant parallel demodulated data corresponding to is selected, and the selected parallel demodulated data is subjected to parallel-serial conversion to generate one series of demodulated data. Here, the priority of data channel allocation is determined in advance on the transmission side and the reception side, and if the number of multiplexed data channels is known, a significant channel number (used for data transmission) is unique. It is assumed that the correspondence is held by the receiving apparatus.

  FIG. 11 is a diagram illustrating a functional configuration example of the carrier reproducing unit 10c according to the present embodiment. As shown in FIG. 11, the carrier reproducing unit 10c of the present embodiment replaces the adding unit 21 of the configuration example shown in FIG. 2-1 of the first embodiment with an adding unit 21a. This is the same as the carrier reproducing unit 10 of the first embodiment. Components having the same functions as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

Subsequently, the operation of the carrier reproducing unit 10c of the present embodiment will be described. The maximum power orthogonal correlation value selection unit 20-n (n = 1,..., N) of the carrier reproduction unit 10c obtains the modulation multilevel number J based on the transmission rate information. The maximum power orthogonal correlation value selection unit 20-n selects 2 ^J significant orthogonal correlation values from the 2 ^K orthogonal correlation values input from the matrix multiplication unit 9-n, and 2 ^J The orthogonal correlation value having the maximum power is selected from the significant orthogonal correlation values, and is output as an error signal. Here, the data positions of significant 2 ^J orthogonal correlation values out of 2 ^K orthogonal correlation values are determined in advance according to the value of J, and when J is determined, 2 ^J unique values are determined. It is assumed that the orthogonal correlation value can be selected.

  Next, the adding unit 21a obtains the data channel multiplexing number I based on the transmission rate information and adds error signals for the I channels to generate a combined error signal. Other processing is the same as that of the configuration example of FIG.

  In the above description, the case where the modulation multilevel number and the data channel multiplexing number are time-varying in the adaptive modulation operation is shown. However, only one of the modulation multilevel number and the data channel multiplexing number is time-varying. Even when one of them is a fixed value, it can be similarly received by the receiving apparatus of this embodiment. In that case, when the modulation multilevel number is a fixed value, the modulation multilevel number of the fixed value is used instead of the modulation multilevel number based on the transmission rate information, and the data channel multiplexing number is fixed. In this case, the fixed number of data channel multiplexes may be used instead of the number of data channel multiplexes based on the transmission rate information.

In addition, in the functional configuration example of FIG. 11, the carrier recovery unit 10 c adds the correlation value having the maximum power for each data channel after the maximum power orthogonal correlation value selection unit 20-1 to 20 -N obtains the correlation value. Although the addition process is performed by the unit 21a, the order of the addition process and the maximum power selection process can be switched as in FIG. 3 of the first embodiment. FIG. 12 shows a functional configuration example of the carrier reproducing unit 10c when the order of the addition process and the maximum power selection process is switched. The functional configuration example of FIG. 12 is the same as the functional configuration example of FIG. 3 except that the in-phase addition / maximum power quadrature correlation value selection unit 25 of the functional configuration example of FIG. 3 is replaced with an in-phase addition / maximum power quadrature correlation value selection unit 25a. It is the same. The in-phase addition / maximum power orthogonal correlation value selection unit 25a obtains the data channel multiplexing number I and the modulation multilevel number J based on the transmission rate information. Then, 2 ^J significant orthogonal correlation values are selected from the 2 ^K orthogonal correlation values input from the matrix multiplication unit 9-n, and the orthogonal correlation values for I channels are added in any combination. Then, the addition result that maximizes the power of the addition result is output as a combined error signal. The operations of the averaging unit 22, arctangent calculation unit 23, and integrator 24 are the same as those in the functional configuration example of FIG.

  Note that the nonlinear processing unit 26 described in the second embodiment may be added to the carrier reproducing unit 10c of the present embodiment. FIG. 13 is a diagram illustrating a functional configuration example in which a non-linear processing unit 26 is added to the carrier reproducing unit 10c of the present embodiment. Further, the nonlinear processing unit 26 shown in the second embodiment may be added to the carrier reproducing unit 10c shown in FIG. FIG. 14 is a diagram illustrating a functional configuration example in which a nonlinear processing unit 26 is added to the carrier reproducing unit 10c illustrated in FIG. The operation of the nonlinear processing unit 26 is the same as that in the second embodiment.

  Further, the carrier recovery unit 10c uses the maximum power orthogonal correlation value selection units 20-1 to 20-N and the addition unit 21 of FIGS. 2-2, 2-3, 7-2, and 7-3 as the maximum power orthogonality. The correlation value selecting units 20a-1 to 20a-N and the adding unit 21a may be replaced.

  In the present embodiment, FIG. 10 shows a receiving apparatus for a signal that is code-multiplexed by adding different delay amounts to each M-ary / SS modulated data channel. When receiving signals that are generated using different spreading codes and code-multiplexed without adding a delay amount to this data channel, the functional configuration example shown in FIG. 15 may be used. The receiving apparatus shown in FIG. 15 adds a transmission rate information extracting unit 27 to the receiving apparatus of the functional configuration example shown in FIG. 4 of the third embodiment, and converts the data demodulating units 11-1 to 11-N into the data demodulating unit 11b-. 1 to 11b-N. The function of each part is the same as that of the same reference numerals described in the third embodiment or the present embodiment.

  As described above, in this embodiment, the transmission rate information extraction unit 27 extracts the transmission rate information in a system that performs an adaptive modulation operation in which the number of modulation multi-levels and the number of multiplexed data channels varies with time based on the transmission rate information. Then, the carrier reproducing unit 10c obtains the modulation multi-value number and the data channel multiplexing number based on the transmission rate information, and performs carrier reproduction according to the obtained modulation multi-value number and data channel multiplexing number. Therefore, even in a system that performs an adaptive modulation operation, it is possible to generate a highly accurate reproduced carrier signal without providing a synchronization channel as in the carrier reproduction circuit of the first embodiment.

  As described above, the carrier reproducing apparatus and the receiving apparatus according to the present invention are useful for a direct spreading communication system, and are particularly suitable for an M-ary / SS communication system.

It is a figure which shows the function structural example of Embodiment 1 of the receiver concerning this invention. 3 is a diagram illustrating a functional configuration example of a carrier reproducing unit according to Embodiment 1. FIG. 6 is a diagram illustrating another functional configuration example of the carrier reproducing unit according to Embodiment 1. FIG. 6 is a diagram illustrating another functional configuration example of the carrier reproducing unit according to Embodiment 1. FIG. 6 is a diagram illustrating a functional configuration example in which the order of addition processing and maximum power selection processing of the carrier reproduction unit according to Embodiment 1 is switched. FIG. 6 is a diagram illustrating a functional configuration example of a receiving apparatus according to Embodiment 2. FIG. FIG. 10 is a diagram illustrating a functional configuration example of a receiving device according to a third embodiment. FIG. 10 is a diagram illustrating a functional configuration example of a carrier reproducing unit according to a third embodiment. FIG. 10 is a diagram illustrating a functional configuration example of a carrier reproducing unit according to a fourth embodiment. FIG. 10 is a diagram illustrating another functional configuration example of the carrier reproducing unit according to the fourth embodiment. FIG. 10 is a diagram illustrating another functional configuration example of the carrier reproducing unit according to the fourth embodiment. It is a figure for demonstrating a nonlinear process. It is a figure for demonstrating the nonlinear process of a complex number. FIG. 4 is a diagram in which a nonlinear processing unit is added to the carrier reproduction unit of the first embodiment. FIG. 10 is a diagram illustrating a functional configuration example of a receiving device according to a fifth embodiment. FIG. 10 is a diagram illustrating a functional configuration example of a carrier reproducing unit according to a fifth embodiment. It is a figure which shows the function structural example of the carrier reproduction | regeneration part at the time of switching the order of an addition process and a maximum power selection process. FIG. 10 is a diagram illustrating a functional configuration example in which a nonlinear processing unit is added to the carrier reproducing unit of the fifth embodiment. It is a figure which shows the function structural example which added the nonlinear process part to the carrier reproduction | regeneration part of FIG. It is a figure which shows the function structural example which added the transmission rate information extraction part of Embodiment 5 to the receiver of Embodiment 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reception antenna 2 RF amplification part 3 Quasi-synchronous detection part 4 Phase correction part 5,5a-1-5a-N Partial correlation value calculation part 6 Code synchronization part 7-1-7-N delay correction part 8-1-8- N latch 9-1 to 9-N matrix multiplication unit 10, 10a, 10b, 10c carrier reproduction unit 11-1 to 11-N, 11a-1 to 11a-N, 11b-1 to 11b-N data demodulation unit 12, 12a Parallel-serial conversion unit 20-1 to 20-N Maximum power orthogonal correlation value selection unit 21, 21a Addition unit 22, 22a Averaging unit 23, 23a-1 to 23a-N, 23b Inverse tangent calculation unit 24 Integrator 25, 25a In-phase addition / maximum power quadrature correlation value selection unit 26, 26a-1 to 26a-N Nonlinear processing unit 27 Transmission rate information extraction unit

Claims (15)

A receiving apparatus that receives a multiplexed signal obtained by further channel-code-multiplexing an M-ary / SS (M-ary spread spectrum) modulated signal and performs carrier phase correction on a baseband signal obtained by frequency-converting the multiplexed signal. A carrier recovery circuit for generating a playback carrier signal for performing the carrier phase correction based on a partial correlation value between a baseband signal and a spreading code,
For each channel, the square sum of the real part and the imaginary part of the orthogonal correlation value, which is the correlation value between the partial correlation value and the orthogonal sequence group used for M-ary / SS modulation, is obtained, and the square sum is maximized. Maximum orthogonal correlation value selection means for selecting the orthogonal correlation value to be
Adding means for adding the maximum orthogonal correlation value for a predetermined number of channels equal to or less than the maximum number of channels to be code-multiplexed, and generating a regenerated carrier signal based on the addition result;
A carrier reproduction circuit comprising: The maximum orthogonal correlation value selection means obtains a modulation multilevel number based on transmission rate information indicating a transmission rate that is changed according to a transmission path condition, and calculates an orthogonal correlation value corresponding to the orthogonal sequence group of the modulation multilevel number. Make the above selection,
2. The carrier reproduction circuit according to claim 1, wherein the adding means obtains the number of multiplexed data channels based on the transmission rate information, and sets the predetermined number of channels to a value equal to or less than the number of multiplexed data channels. In a receiving apparatus that receives a multiplexed signal obtained by further code-multiplexing an M-ary / SS (M-ary spread spectrum) modulated signal and performs carrier phase correction on a baseband signal obtained by frequency-converting the multiplexed signal. A carrier recovery circuit for generating a playback carrier signal for performing the carrier phase correction based on a partial correlation value between the baseband signal and a spreading code,
For each channel of a predetermined number of channels, one of the orthogonal correlation values, which is a correlation value between the partial correlation value and the orthogonal sequence group used for M-ary / SS modulation, is selected and selected for each channel. The orthogonal correlation values are added for the predetermined number of channels to obtain the square sum of the real part and the imaginary part of the addition result, and further, the process of obtaining the square sum is performed for the orthogonal correlation values of all combinations, Thereafter, an addition means for selecting the addition result that maximizes the obtained sum of squares and generating a reproduced carrier signal based on the selected addition result;
A carrier reproduction circuit comprising:   The adding means obtains a modulation multi-level number based on transmission rate information indicating a transmission rate changed according to a transmission path condition, and selects the correlation multi-level number corresponding to the orthogonal sequence group corresponding to the modulation multi-level number. 4. The carrier recovery circuit according to claim 3, further comprising: obtaining a number of multiplexed data channels based on the transmission rate information, and setting the predetermined number of channels to a value equal to or less than the number of multiplexed data channels.   5. The adding means according to claim 1, wherein the adding means calculates a deviation angle of the addition result, obtains a carrier phase error based on the deviation angle, and generates a reproduction carrier signal based on the carrier phase error. The carrier reproduction circuit according to one.   6. The addition processing according to claim 5, wherein in the addition processing, nonlinear processing is performed so that an absolute value of the declination is within a predetermined threshold, and a reproduced carrier signal is generated based on the value after the processing. Carrier regeneration circuit.   The predetermined threshold value α [rad] is set to a value not less than 0 [rad] and not more than π [rad]. In the nonlinear processing, when the declination exceeds α [rad], the declination is set to α [rad]. 7. The carrier reproduction circuit according to claim 6, wherein when the declination is smaller than-[alpha] [rad], the declination is set to-[alpha] [rad].   A predetermined threshold value α [rad] is set to a value not less than 0 [rad] and not more than π [rad], and in the nonlinear processing, when the declination exceeds α [rad] or the declination is less than −α [rad]. The carrier reproduction circuit according to claim 6, wherein when the angle is small, the deviation angle is set to 0 [rad]. A counter that resets at the start of carrier regeneration circuit operation and counts up for each symbol.
Further comprising
9. The carrier reproduction circuit according to claim 7, wherein the threshold value α is changed based on a count value output from the counter.   The carrier regeneration circuit according to any one of claims 5 to 9, wherein the adding means uses the carrier phase error as a time average value of the declination.   11. The carrier reproducing circuit according to claim 5, wherein the adding unit integrates the carrier phase error to generate a reproduced carrier signal. A M-ary / SS (M-ary spread spectrum) modulated signal is a receiving device that receives a multiplexed signal that is channel code multiplexed with a different delay amount added to each channel,
The carrier regeneration circuit according to any one of claims 1 to 11,
Phase correction means for performing carrier phase correction of a baseband signal obtained by frequency-converting a multiplexed signal based on the reproduced carrier signal output from the carrier reproduction circuit;
A partial correlation value calculating means for obtaining a partial correlation value between a baseband signal after carrier phase correction and a spread code;
Delay correction means for correcting the delay amount for the partial correlation value for each channel;
For each channel, an orthogonal correlation value calculating unit that calculates an orthogonal correlation value that is a correlation between the partial correlation value after delay correction and an orthogonal sequence group used in M-ary / SS modulation, and outputs the orthogonal correlation value to the carrier recovery circuit When,
Data demodulating means for generating demodulated data by performing maximum likelihood determination based on the orthogonal correlation value for each channel;
Parallel-serial conversion means for rearranging the demodulated data for each channel in series;
A receiving apparatus comprising: A receiving apparatus that receives a multiplexed signal in which a signal modulated by M-ary / SS (M-ary spread spectrum) using a different spreading code for each channel is further channel code multiplexed,
The carrier regeneration circuit according to any one of claims 1 to 11,
Phase correction means for performing carrier phase correction of a baseband signal obtained by frequency-converting a multiplexed signal based on the reproduced carrier signal output from the carrier reproduction circuit;
For each channel, partial correlation value calculating means for obtaining a partial correlation value between the baseband signal after carrier phase correction and the spreading code;
For each channel, an orthogonal correlation value calculating unit that calculates an orthogonal correlation value that is a correlation between the partial correlation value and an orthogonal sequence group used in M-ary / SS modulation, and outputs the orthogonal correlation value to the carrier recovery circuit;
Data demodulating means for generating demodulated data by performing maximum likelihood determination based on the orthogonal correlation value for each channel;
Parallel-serial conversion means for rearranging the demodulated data for each channel in series;
A receiving apparatus comprising: A receiving apparatus for receiving a multiplexed signal obtained by further channel-multiplexing an M-ary / SS (M-ary spread spectrum) modulated signal,
A carrier regeneration circuit according to any one of claims 1 to 10,
A partial correlation value calculating means for obtaining a partial correlation value between a baseband signal obtained by frequency-converting a multiplexed signal and a spreading code;
For each channel, an orthogonal correlation value calculating unit that calculates an orthogonal correlation value that is a correlation between the partial correlation value and an orthogonal sequence group used in M-ary / SS modulation, and outputs the orthogonal correlation value to the carrier recovery circuit;
Data demodulation for generating demodulated data by performing carrier phase correction of the orthogonal correlation value based on the recovered carrier signal output from the carrier recovery circuit for each channel and performing maximum likelihood determination based on the corrected orthogonal correlation value Means,
Parallel-serial conversion means for rearranging the demodulated data for each channel in series;
A receiving apparatus comprising: Transmission rate information indicating a transmission rate is code-multiplexed, a modulation multi-level number and a data channel multiplexing number are determined based on the transmission rate information, and M-ary / SS (M-ary spread spectrum) is determined based on the modulation multi-level number. A receiving apparatus for receiving a multiplexed signal in which a modulated signal is further channel code multiplexed by the number of data channel multiplexing,
The carrier regeneration circuit according to claim 2 or 4,
Transmission rate extraction means for extracting transmission rate information from the multiplexed signal;
Phase correction means for performing carrier phase correction of a baseband signal obtained by frequency-converting a multiplexed signal based on the reproduced carrier signal output from the carrier reproduction circuit;
A partial correlation value calculating means for obtaining a partial correlation value between a baseband signal after carrier phase correction and a spread code;
Delay correction means for correcting the delay amount for the partial correlation value for each channel;
For each channel, an orthogonal correlation value calculating unit that calculates an orthogonal correlation value that is a correlation between the partial correlation value after delay correction and an orthogonal sequence group used in M-ary / SS modulation, and outputs the orthogonal correlation value to the carrier recovery circuit When,
A modulation multi-level number and a data channel multiplex number are obtained based on the transmission rate information, and a maximum likelihood determination is performed for each channel corresponding to the data channel multiplex number based on the orthogonal correlation value and the modulation multi-level number. Data demodulating means for generating demodulated data by
Parallel-serial conversion means for rearranging the demodulated data for each channel in series;
A receiving apparatus comprising:

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