Direct spread receiver

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a direct sequence spread spectrum device used in a DS-CDMA (Direct Sequence --Code Division Multiple Access) system or the like using a pilot channel.

【0002】

[Conventional technology]

As a DS-CDMA system, there is a CDMA cellular telephone system (TIA IS95) standardized in North America. In this system, in the downlink, a pilot symbol is inserted into the pilot channel and transmitted, and the receiving side detects the carrier phase based on the received signal of this pilot channel and performs synchronous detection. FIG. 10 is a diagram showing a downlink configuration in a DS-CDMA system. 81 is a base station and 82 is a slave station. FIG. 11 is a schematic configuration diagram of a base station transmitter in a DS-CDMA system. In the code multiplier 91 of FIG. 11 (a), the transmission data 1 to N of the communication channels of users 1 to N and the data set to all 1 for the pilot channel are orthogonal generated by the orthogonal code generator 95. Each code is assigned and code-multiplexed, and is directly spread by multiplying the PN signal from the PN generator 96 in the multiplier 92, and multiplied by the reference frequency signal (carrier) of the reference frequency oscillator 97 in the multiplier 93. It is (modulated) and transmitted from the transmitting antenna 94.

【0003】

FIG. 11B shows a block configuration in which the transmission data n of the user n, which is input to the code multiplexing unit 91 of FIG. 11A, is generated. A redundant code (redundant bit for error detection) is added to the transmission information n of the user n in block units in the cyclic code conversion unit 101 for error detection. The slave station knows the reception quality of the transmitted data by decoding the error detection code corresponding to this. The output of the error detection coding unit is output to the convolutional coding unit 103 after a predetermined number of 0 bits are added to the encoder tail addition unit 102. The convolutional coding unit 103 performs convolutional coding, which is cleared at the end of one frame, and outputs it to the symbol repeating unit 104. In the symbol repetition unit 104, when the information transfer rate is slow, the transmission rate is adjusted to a constant value by repeatedly outputting the same symbol. As for the output of the symbol repeating unit 104, the block interleaving unit 105 outputs the transmission data n by rearranging the bit strings in order to enhance the correction capability for the burst error.

【0004】

FIG. 12 is a schematic configuration diagram of a slave station receiver in the DS-CDMA system. The signal received by the receiving antenna 110 is multiplied by the sinusoidal reference frequency signal of the reference frequency oscillator 112 in the multiplier 111 and converted into a baseband reception signal. The Rake reception method is adopted as a feature of the demodulator of the DS-CDMA system. Since the signal transmitted from the base station reaches the receiving antenna 110 through a plurality of paths, the received signal is a composite of a plurality of signals having different amplitudes, carrier phases, and delay times. The Rake reception method reverse-diffuses the baseband reception signal to separate it into the reception signals of paths 1 to K and combine them to the maximum ratio (Rake synthesis) to obtain one impulse response. C / N characteristics are improved.

【0005】

The baseband reception signal is output to the Rake reception unit 121 and the searcher unit 122. The baseband received signal is received by K fingers 118 in the Rake receiver 121.₁~118_KIs entered in. Each finger 118₁~118_KAre demodulators for the 1st to Kth paths, respectively. In the illustrated example, signals of up to K paths can be received. Each finger 118₁~118_KHas the same configuration.

【0006】

The baseband received signal is multiplied by the PN code output from the PN generator 114 in the multiplier 113 to be PN synchronized, and is output from the orthogonal code generator 117 in the multiplier 115. It is multiplied by the quadrature code of the communication channel of (hereinafter referred to as "user"), and is back-spread by integrating the received signal of this user's communication channel in the integrator 116 over a period of one symbol. Finger 118₁~118_KIs output to the synthesis circuit 119 from the back-diffused reception signal of the user's communication channel in the corresponding paths 1 to K.

【0007】

Here, the PN generator 114 and the orthogonal code generator 117 are supplied with timing signals for the respective paths 1 to K from the control unit 129 in the searcher unit 122 that estimates the impulse response. As a result, the PN generator 114 and the quadrature code generator 117 output the PN code and the quadrature code synchronized with the PN code and the quadrature code of the corresponding paths 1 to K, respectively.

【0008】

In the searcher unit 122, the baseband received signal is multiplied by the PN code output from the PN generator 124 in the multiplier 123 and the orthogonal code of the pilot channel output from the orthogonal code generator 126 in the multiplier 125. It is multiplied to separate the received signal of the pilot channel. Next, the received signal amplitude of the baseband of the pilot channel in one pass k and the phase with respect to the reference frequency signal are passed through a filter 128 that is integrated by one symbol in the integrator 127 and then averaged by a plurality of symbols. A reference signal W (k) representing (carrier phase) is created and output to the control unit 129. W (k) is a complex number and k = 1 ~ K. As paths 1 to K, K paths with high power are selected.

【0009】

The control unit 129 controls the timing of the PN generator 124 so that the PN code of the PN generator 124 is code-synchronized with the received signal, and is orthogonal so that the Walsh-Hadamard code of the orthogonal code generator 126 is code-synchronized with the received signal. Timing control of the code generator 126. The control unit 129 divides the time and generates K reference signals W (k) for K fingers. Also, by dividing the time, the K finger 118 of the Rake receiver 121₁~118_KThe timing signal is output to the PN generator 114 and the Walsh-Hadamard generator 117.

【0010】

In the synthesis circuit 119, each finger 118₁~118_KThe signal of the user's communication channel from is the phase offset of the received signal of the user's communication channel in each path 1 to K based on the reference signal W (k) obtained from the received signal of the pilot channel of each path 1 to K. Is removed to perform synchronous detection and Rake synthesis. The Rake-synthesized received signal is decoded by the decoding unit 120, and the desired data of the communication channel of the own station is output.

【0011】

In this way, the phase offset of the received signal of each path k is removed by estimating the impulse response of each path k using the back-diffused received signal of the pilot channel on which known data is transmitted. There is. Although not shown, the multiplier 111 shown in FIG. 12 is actually provided with two multipliers, and the signal received by the receiving antenna 110 is also multiplied by the orthogonal reference frequency signal orthogonal to the reference frequency signal. It is a received signal (usually represented by a complex number) of two series of basebands that are in phase and orthogonal to the reference frequency signal. Then, the subsequent processing is individually performed on the two series, and in the synthesis circuit 119, these two series become in-phase components and orthogonal components with respect to the phase of the reference frequency signal (carrier) and are synchronously detected.

【0012】

In general, when high-speed data transmission is performed by a DS-CDMA system, the chip rate naturally increases as the data rate increases. As the chip rate increases, the amount of interference due to multipath increases. As the number of multipaths increases, the Rake reception method can no longer prevent deterioration of transmission performance. When a composite of the arrival waves of the time-delayed paths 1 to K is received, when the arrival wave of a certain path k is reverse-diffused, the arrival waves of the other paths delayed in time become an interference signal. Therefore, the impulse response of one pass k contains the interference wave component generated by the cross-correlation with the incoming waves of the other pass. Therefore, if the impulse responses of paths 1 to K are Rake-synthesized, the transmission performance deteriorates.

【0013】

As the first conventional technology for eliminating such interference due to multipath, there is an interference canceling technology, for example, Wada et al. 1 "A study of a multi-user multi-stage interference canceller in a B5-140 DS-CDMA system" , Some are known at the Institute of Electronics, Information and Communication Engineers Society Conference (1998.9), and the applicant has applied for such an interference canceller (hereinafter referred to as "advanced technology") as Japanese Patent Application No. 10-236777.

【0014】

First, an accurate impulse response is estimated using a pilot channel or the like. Select K paths with large amplitude and set their values to W (k) (k = 1 ~ K). Among them, the path P having the maximum amplitude value is selected. Rake reception data is input to the first-stage interference canceller, and output data of the previous-stage interference canceller is input to the second-stage and subsequent interference cancellers. In addition, an interference replica for each user is generated using the spreading code and W (k) for each path other than the maximum amplitude path P. Interfering replicas of all users are subtracted from the received signal, backspreading is performed on the path P, and data for all users is detected. That is, W (k) is estimated in advance, and the radio wave propagation information is fixed after the estimation.

【0015】

In addition, as a second conventional technique for canceling interference signals by different methods, Sawahashi and two others, "Channel Estimate Sequentially Updated DS-CDMA Coherent Multistage Interference Canceller Using Pilots and Data Symbols", IEICE Technical Report 96 (354) ), Institute of Electronics, Information and Communication Engineers (1996-11) RCS96-100, p.9-16, etc. This is used in W-CDMA (Broadband CDMA) systems.

【0016】

This W-CDMA is a DS-CDMA system having a pilot symbol section in the frame. Interference is canceled one by one from the user with the highest power. Here, one user's channel estimation / interference generation unit Rake-synthesizes the back-spread signals for each of a plurality of multipaths to perform data judgment, and estimates the spread signals of each multipath from this judgment data. An interference replica is generated, the interference replica is canceled from the received back diffusion signal, and the interference replica is input to the above-mentioned channel estimation / interference generation unit.

【0017】

Further, the above-mentioned interference cancellation is performed in each stage i of the multi-stage (multi-stage configuration). In user k, the interference replica in i-stage for the user with higher power than user k and the interference replica in i-1 stage for other users with less power are removed, and each path of the own station is removed from the received signal. In each, the interference replicas other than the respective paths are removed, the impulse response in each path is estimated using the pilot symbol, and the back diffusion is performed based on the value. The back-diffused signal in each pass is Rake-synthesized. After synthesis, an interference replica is generated based on the decoded data and the estimated impulse response.

【0018】

The above-mentioned interference canceller needs to obtain reliable received data in advance. In order to improve the ability to cancel interference, it is necessary to increase the certainty of this received data. However, in the prior art, since the received data at the stage of digital demodulation is used in order to simplify the configuration, there is a limit in increasing the certainty of the received data. Conventionally, in IS-95, the transmission information has been convolutionally coded, and the receiving device has performed Viterbi decoding to output the received information with error correction. However, since the scale of the processing unit until the received information is obtained becomes very large and the processing time becomes long, it has not been considered to generate an interference replica from the received information. However, it was found that the ability to cancel interference is dramatically improved by using error-corrected received information. Further, even when the interference canceller uses the received data at the stage of digital demodulation, its processing time and power consumption are problems. In particular, in a multi-stage type interference canceller in which the error characteristics are improved by vertically connecting the interference cancellers in multiple stages, the processing time and power consumption increase according to the number of stages.

【0019】

The present invention has been made to solve the above-mentioned problems, but before explaining the present invention, the function of the interference canceller will be specifically explained by explaining the above-mentioned prior art. .. FIG. 13 is a basic block configuration diagram of the prior art. This is the case where a code-multiplexed channel sharing one PN code consists of one communication channel (one user) and one pilot channel. On the other hand, FIG. 12 shows a case where there are a plurality of code-multiplexed communication channels (users) sharing one PN code, so the premise is slightly different. explain.

【0020】

In this basic configuration, the impulse response is estimated, the reference signal W (k) representing this impulse response is fixed, and the output data DR is detected by the Rake receiving unit 121. Further, the maximum power path detector 131 selects the path P having the maximum power based on the reference signal W (k). In the interference canceller 133, the data output from the Rake receiving unit 121 is used as the initial reception data to generate a signal before synchronous detection and despreading in a path other than the path P where the power is maximized, and the pilot channel. Based on the known data of, generate the signals of the pilot channel before dedulation in the path other than the path P where the power is maximized, use these as the interference replicas, and subtract the interference replicas from the received signals. The data is rediscovered by performing dedulation and synchronous detection again on the path P with the highest power. In this way, the bit error rate is improved by removing the interference which is a factor of deterioration of the received signal quality.

【0021】

In the searcher unit 122 shown in FIG. 12, K high-power paths obtained by despreading the received signals of the pilot channels are selected, and the reference signals W (k) ( Output k = 1 ~ K). The maximum power path detector 131 shown in FIG. 14 selects the path P having the maximum power from the reference signal W (k) and outputs the value of P to the interference canceller 133.

【0022】

FIG. 16 is an operation explanatory view of the interference canceller 133 shown in FIG. The signal transmitted from the base station 1 passes through a plurality of paths and is received as a composite signal of signals having different delay times. The upper figure shows the impulse response by multipath. Select the path P that maximizes power, and virtually generate the received signal of the baseband before synchronous detection and dedulation in other paths based on the detection data and pilot channel data, and subtract this. The received signal is depopulated in the path P of the maximum power, and the canceled data of the interference signal as shown in the lower row is detected.

【0023】

It is presumed that the path P having the maximum power has a small proportion including the interference signal, and the paths excluding the path P are mainly interference signals. Then, the data DR of the communication channel of one user output from the Rake receiver 121 is used as the initial value, and from this, the reverse signal processing is performed to generate the signal before the synchronous detection and the reverse diffusion. .. At the same time, known data D of the pilot channel_pIt also generates a signal for the pilot channel before despreading based on. In this way, interference replicas in paths 1 to K excluding path P are generated. Then, when all the interference replicas of paths 1 to K excluding path P are subtracted from the received signal of the baseband, the received signal of the baseband of almost only path P is obtained.

【0024】

Therefore, the interference canceller 133 has an output data DR of one communication channel output from the Rake receiver 121 and a known data D of the pilot channel._pIs used to generate an interfering replica of K-1 paths excluding the maximum power path P. Then, the path P is back-spread again with respect to the received signal of the baseband from which the interference replica is removed from the received signal of the baseband. In this way, it is possible to reverse-diffuse the received signal in the baseband, which is almost the same as when it is assumed that only the incoming wave of a single path P is received. As a result, the received data DC of the communication channel from which the interference signal due to the cross-correlation of the paths has been removed can be obtained. The delay unit 132 compensates for the processing delay inside the Rake receiving unit 121 and the interference canceller 133.

【0025】

FIG. 14 is an internal configuration diagram of the interference canceller 133 shown in FIG. The one-user interference replica generator 135 generates interference replicas for K-1 paths, excluding path P, for the only communication channel used by only one user. Also, the interference replica generator of the pilot channel 135_pGenerates an interfering replica for K-1 paths for the pilot channel, excluding path P.

【0026】

15 (a) and 15 (b) are internal configuration diagrams of the interference replica generators 135 and 135p shown in FIG. 14, respectively. Interference replica generator for path 1 141₁The data DR output from the Rake receiver 121 is the reference signal W for path 1 in the multiplier 138.₁By multiplying by (1), it is returned to the signal before synchronous detection having the signal point phase and amplitude to which the carrier phase and amplitude of path 1 are given. Next, in multiplier 139, PN which is the PN code for path 1.₁(1) Further, in the multiplier 140, the quadrature code WS for the path 1 of one user.₁By multiplying each of (1) and spreading, it is returned to the baseband received signal before despreading, which has a time delay of pass 1, and an interference replica of pass 1 is generated. Interference replica generator for path 1 141₁There are K-1 signals except for path P, and these K-1 signals are added by the adder 142, and the output signal is the interference replica of paths 1 to K excluding path P. It becomes an output signal.

【0027】

Where W₁(k) (excluding k = 1 to K and k = P) is the reference signal output by the control unit 129 shown in FIG. 12, PN.₁(k) (excluding k = 1 to K and k = P) is the finger 118 shown in FIG._kPN code output by PN generator 114, Walsh-Hadamard WS₁(k) (excluding k = 1 to K and k = P) is the finger 118 shown in FIG._kIt is based on the one-user orthogonal code output by the orthogonal code generator 117 of. However, just as the baseband reception signal was delayed by the delay unit 132 in FIG. 13, the time delay is adjusted in consideration of the processing delay in the Rake receiving unit 121 and the processing delay inside the interference canceller 133. W₁(k), PN₁(k), WS₁(k) can be created by providing a delay unit similar to the delay unit 132 at each of the outputs of the control unit 129, the PN generator 114, and the orthogonal code generator 117 described above.

【0028】

Interference replica generator 135 for pilot channel, shown in Figure 15 (b)_pFor known data D of the pilot channel_pHowever, in the multiplier 138, the reference signal W for path 1₁By multiplying by (1), it becomes a signal having a signal point phase and amplitude to which the carrier phase and amplitude of path 1 are given. Next, in multiplier 139, PN which is the PN code for path 1.₁(1) Further, in the multiplier 140, the quadrature code WS with respect to the path 1 of the pilot channel.₁By multiplying each of (p, 1) and spreading, it is returned to the baseband received signal before despreading, which has a time delay of pass 1, and an interference replica of pass 1 is generated. Similar to FIG. 15 (a), the interference replica generator 141 for path 1₁There are K-1 signals except for path P, and these K-1 signals are added by the adder 142, and the output signal is the interference replica of paths 1 to K excluding path P. It becomes an output signal.

【0029】

Where W₁(k) (excluding k = 1 to K and k = P) is the reference signal output by the control unit 129 shown in FIG. 12, PN.₁(k) (excluding k = 1 to K and k = P) is the PN code (finger 118) output by the PN generator 124 of the searcher unit 122 shown in FIG._k(Matches the PN code output by the PN generator 114), Walsh-Hadamard WS₁(p, k) (excluding k = 1 to K, k = P) is based on the orthogonal code of the pilot channel output by the orthogonal code generator 126 of the searcher unit 122 shown in FIG. However, a time delay is provided to compensate for the processing delay in the Rake receiving unit 121, and the time delay is adjusted in consideration of the processing delay inside the interference canceller 133. W₁(k), PN₁(k), WS₁(p, k) can be created by providing a delay unit similar to the delay unit 132 at each of the outputs of the control unit 129, the PN generator 124, and the orthogonal code generator 126 described above.

【0030】

Let us return to FIG. 14 for explanation. In the adder 136, the output signal of the interference replica 135 is subtracted from the delayed baseband reception signal and input to the despreading unit 137 with respect to the path P. The back-diffusion portion 137 with respect to this path P is the finger portion 118 shown in FIG.₁~118_KIt has the same structure as the finger part of the path P inside. That is, the reference signal W for the path P₁(P), PN which is the PN code for path P₁(P) and one user's quadrature WS with respect to path P₁Using (P), the received signal of the baseband from which the interfering replica has been deleted is back-spread with respect to the path P, and the data is determined.

【0031】

This output data is the data of one user whose reception quality is improved by removing the interference due to cross-correlation. Reference signal W described above₁(P), PN code PN₁(P) and one user's orthogonal code WS₁(P) is the reference signal W of the path excluding the path P described above.₁(k), PN code PN₁(k) and one user's orthogonal code WS₁Similar to (k), a time delay is provided to compensate for the processing delay in the Rake receiving unit 121, and the time delay is adjusted in consideration of the processing delay inside the interference canceller 133.

【0032】

FIG. 17 is a block configuration diagram of the prior art in which a code-multiplexed channel sharing one PN code is composed of an N-user communication channel and one pilot channel. And the interference canceller corresponding to multiple users is the interference canceller 151 of the 1st to Mth stages.₁~151_MIt is connected vertically as. In this specific example, a plurality of interference cancellers are operated for a plurality of user 1 to N paths to eliminate interference, and a plurality of stages of interference cancellers are operated, and more probable data is detected. To. 1st stage interference canceller 151₁Inputs the data DR (1) to DR (N) output from the Rake receiver 146 as probable data, and also knows the pilot channel data D._pIs input, and more probable data DC (1,1) to DC (1, N) with the interference signal canceled is output.

【0033】

For the second and subsequent stages, the output data from the interference canceller in the previous stage becomes the input data of the interference canceller in the next stage, and the known data D of the pilot channel._pIs also entered. Interference canceller 151 at any stage₁~151_MAlso selects the same path P output from the maximum power path detector 131 (FIG. 13) as the maximum power path. Of the interference cancellers in each stage, the interference cancellers 151 in the 1st to (M-1) stages₁~151_M-1For, it is necessary to output the data of users 1 to N including the data of the own station (for example, user 1). That is, the interference canceller 151 in the 1st to (M-1) stages.₁~151_M-1For, a back-diffusion unit for users 1 to N is required.

【0034】

The above-mentioned direct spread receiver has been described on the premise of the CDMA cellular telephone system (TIA-IS95). However, this direct spread receiver is also applicable in W-CDMA systems. In the W-CDMA system, communication channels of multiple users are code-multiplexed, and a pilot symbol common to multiple communication channels is inserted in a certain time interval, and an impulse response is estimated based on this pilot symbol. By doing so, the reference signal W (k) is output.

【0035】

In W-CDMA, the section of the user communication channel and the section of the pilot channel are different in time, but when the multipath of the pilot channel enters the section of the user communication channel, the pilot channel is the user. Interference due to multipath cross-correlation with respect to the communication channel will be given. Therefore, by using the interference replica generation unit 135p of the pilot channel shown in FIG. 14, the interference caused by the pilot channel can be eliminated. However, originally, an interference replica of the pilot channel is generated even in the section of the pilot channel where the reception signal of the user communication channel does not exist. If the interference replica component in the section of this pilot channel is large, this may become a noise component and the transmission quality may deteriorate. Therefore, the output of the interference replica generation unit 135p of the pilot channel shown in FIG. 14 is output to the adder 136 via a switch unit (not shown). This switch unit is controlled by the control unit 129 to supply the interference replica of the pilot channel to the adder 136 only in the section of the user communication channel.

【0036】

[Problems to be Solved by the Invention]

An object of the present invention is to provide a direct diffusion receiving device that dramatically improves the quality of received information. Another object of the present invention is to provide a direct diffusion receiving device that reduces the power consumption of an interference canceller while maintaining the quality of received information.

【0037】

[Means for solving problems]

In the invention according to claim 1, the present invention receives a direct spreading signal in which transmission data is generated based on data in which transmission information is error-corrected and encoded, and the transmission data is directly spread. The receiving device includes initial data output means, error correction means, and interference canceling means. The initial data output means outputs initial received data based on a direct diffusion reception signal, and the error correction means After decoding the error correction code based on the initial reception data, the error correction coding is performed, and the interference canceling means is an interference signal included in the direct diffusion reception signal based on the output of the error correction means. The replica is generated, the replica is subtracted from the direct spread reception signal, and the received data in which the influence of the interference signal is reduced is output. Therefore, since interference cancellation is performed using the initial received data that has been error-corrected and the accuracy has been improved, the quality of the received information can be dramatically improved. As the interference canceling means, a one-stage interference canceller or a multi-stage interference canceller may be used. As the error correction code, for example, a convolutional code can be used, and the Viterbi decoding can be performed for the decoding.

【0038】

The invention according to claim 2 is a direct spread receiver that receives a direct spread signal in which transmission data is generated based on data in which transmission information is error-corrected and encoded, and the transmission data is directly spread. The initial data output means has an initial data output means, an error correction means, a plurality of series of interference canceling means, and a synthesis determination means, and the initial data output means receives the direct diffusion signal with an antenna corresponding to the plurality of series. , The initial reception data common to the respective series is output based on the direct diffusion reception signal of each series, and the error correction means performs error correction after decoding the error correction code based on the initial reception data. Encoding is performed, and the interference canceling means of each series generates a replica of the interference signal included in the direct spread reception signal of each series based on the output of the error correction means, and generates a replica of the interference signal included in the direct spread reception signal of each series. The replica is subtracted from the direct spread reception signal to output the reverse spread signal of each series in which the influence of the interference signal is reduced, and the synthesis determination means obtains a signal obtained by synthesizing the reverse spread signal of each series. It decodes and outputs the received data. Therefore, the quality of the received information is further improved as compared with the invention according to claim 1 due to the diversity effect due to the configuration of the receivers of a plurality of systems.

【0039】

The invention according to claim 3 is a direct diffusion receiver that receives a direct diffusion signal in which transmission data is generated based on data in which transmission information is error-corrected and encoded, and the transmission data is directly diffused. The initial data output means has an initial data output means, a plurality of stages of interference cancellers, and a plurality of stages of error correction means. The initial data output means outputs initial received data based on a direct spread reception signal, and the first stage. The interference canceller generated a replica of the interference signal included in the direct diffusion reception signal based on the initial reception data, and subtracted the replica from the direct diffusion reception signal to reduce the influence of the interference signal. The reception data is output, and the interference canceller in the second and subsequent stages generates a replica of the interference signal included in the direct diffusion reception signal based on the output of the error correction means in the previous stage, and from the direct diffusion reception signal. After subtracting the replica, the received data of the stage in which the influence of the interference signal is reduced is output, and the error correction means decodes the error correction code based on the output of the interference canceller of the stage. It performs error correction coding. Therefore, since the interference canceling means has a multi-stage configuration, the quality of the received information is further improved as compared with the invention according to claim 1.

【0040】

The invention according to claim 4 is a direct diffusion receiver that receives a direct diffusion signal in which transmission data is generated based on data in which transmission information is error-corrected and encoded, and the transmission data is directly diffused. The initial data output means has an initial data output means, a plurality of stages of interference cancellers, a plurality of stages of error correction means, and a plurality of stages of synthesis determination means, and the initial data output means is an antenna corresponding to the plurality of series. The direct diffusion signal is received, and the initial reception data for each series or the initial reception data common to each series is output based on the direct diffusion reception signal of each series, and the first stage The interference canceller of each series is an interference signal included in the direct diffusion reception signal of each series based on the initial reception data of each series or the initial reception data common to each series. A replica is generated, the replica is subtracted from the direct spread reception signal of each series, and the despread signal of each series of the first stage in which the influence of the interference signal is reduced is output, and the said in the first stage. The synthesis determination means decodes the signal obtained by synthesizing the reverse diffusion signals of each series of the first stage and outputs the received data of the first stage, and the interference canceller of each series of the second and subsequent stages is the previous stage. A replica of the interference signal included in the direct spread reception signal of each series is generated based on the output of the error correction means, and the replica is subtracted from the direct spread reception signal of each series to obtain the interference signal. The back-spreading signal of each series of the relevant stage in which the influence of the above is reduced is output, and the synthesis determination means of the second and subsequent stages decodes the combined signal of the back-spreading signal of each series of the relevant stage. The received data of the stage is output, and the error correction means performs error correction coding after decoding the error correction code based on the output of the synthesis determination means of the stage. Therefore, since the receiver configuration is a plurality of systems and the interference canceling means is a multi-stage configuration, the quality of the received information is further improved as compared with the invention according to claim 1.

【0041】

In the invention according to claim 5, the direct spreading receiver device receives a direct spreading signal in which transmission data is generated based on data in which transmission information is block error detection encoded and the transmission data is directly spread. The initial data output means has an initial data output means, an interference canceling means, an error detecting means, and an output selecting means. The initial data output means outputs initial received data based on a direct diffusion reception signal, and the interference canceling means. Generates a replica of the interference signal included in the direct diffusion reception signal based on the initial reception data, subtracts the replica from the direct diffusion reception signal, and obtains the reception data in which the influence of the interference signal is reduced. The error detection means outputs an error by decoding the error detection code based on the initial received data, and the output selection means detects an error in block units, and the output selection means responds to the detection result of the error detection means. It controls the operation / non-operation of the interference canceling means in the succeeding block, and selects reception information based on any one of the initial reception data and the output of the interference canceling means in the succeeding block. is there. Therefore, since the operation / non-operation of the interference canceling means is controlled according to the detection result of the error detecting means, the processing time of the receiving process is shortened and the power consumption of the receiving device is reduced while maintaining the quality of the received data at a predetermined level. Can be planned. The transmission information may be block error correction encoded after the block error detection coding, or may be block error detection coding before the block error correction coding. As the block error detection code, for example, a cyclic code can be used. As the interference canceling means, a one-stage interference canceller or a multi-stage interference canceller may be used.

【0042】

In the invention according to claim 6, the direct spreading receiver device receives a direct spreading signal in which transmission data is generated based on a data in which transmission information is block error detection coded and the transmission data is directly spread. The initial data output means has an initial data output means, a plurality of series of interference canceling means, a synthesis determination means, an error detection means, and an output selection means, and the initial data output means is the direct diffusion with an antenna corresponding to the plurality of series. The signal is received and the initial reception data common to each series is output based on the direct diffusion reception signal of each series, and the interference canceling means of each series is based on the initial reception data. A replica of the interference signal included in the direct spread reception signal of the series is generated, and the replica is subtracted from the direct spread reception signal of each series to obtain the reverse spread signal of each series in which the influence of the interference signal is reduced. Output, the synthesis determination means decodes the signal obtained by synthesizing the reverse diffusion signals of the respective series and outputs the received data, and the error detection means decodes the error detection code based on the initial reception data. By doing so, an error is detected in the block unit, and the output selection means controls the non-operation of the interference canceling means in the subsequent block according to the detection result of the error detecting means, and the subsequent operation / non-operation of the interference canceling means is performed. The reception information based on any one of the initial reception data and the output of the synthesis determination means in the block is selected. Therefore, the quality of the received information is further improved as compared with the invention according to claim 5 due to the diversity effect due to the configuration of the receivers of a plurality of systems.

【0043】

In the invention according to claim 7, the direct spreading receiver device receives a direct spreading signal in which transmission data is generated based on a data in which transmission information is block error detection coded and the transmission data is directly spread. It has an initial data output means, a multi-stage interference canceller, an error detection means, and an output selection means, and the initial data output means outputs initial received data based on a direct spread reception signal, and the first The interference canceller in the stage generates a replica of the interference signal included in the direct diffusion reception signal based on the initial reception data, and subtracts the replica from the direct diffusion reception signal to reduce the influence of the interference signal. The received data is output, and the interference canceller in the second and subsequent stages generates a replica of the interference signal included in the direct diffusion reception signal based on the output of the interference canceller in the previous stage, and the direct diffusion reception signal. By subtracting the replica from the data, the received data of the stage in which the influence of the interference signal is reduced is output, and the error detecting means outputs the interference canceller in accordance with the longitudinal operation of the plurality of stages of the interference canceller. An error is detected in block units by decoding an error detection code based on the received data, and the output selection means interferes in the plurality of stages in the subsequent block according to the error detection result of the error detection means. It controls the number of operation stages of the canceller and outputs reception information based on any one of the reception data in each stage. Therefore, since the interference canceling means has a multi-stage configuration, the quality of the received information is further improved as compared with the invention according to claim 5. Even in a multi-stage configuration, the number of operating stages of the interference canceling means is controlled according to the detection result of the error detecting means, so that the processing time of the receiving process can be shortened and the receiving device can be used while maintaining the quality of the received data at a predetermined level. Power consumption can be reduced.

【0044】

It controls the number of operating stages of the interference canceller in several stages and selects reception information based on any one of the received data in each stage. Therefore, since the receiver configuration is a plurality of systems and the interference canceling means is a multi-stage configuration, the quality of the received information is further improved as compared with the invention according to claim 5. Even in a multi-stage configuration, the number of operating stages of the interference canceling means is controlled according to the detection result of the error detecting means, so that the processing time of the receiving process can be shortened and the receiving device can be used while maintaining the quality of the received data at a predetermined level. Power consumption can be reduced.

【0045】

In the invention according to claim 9, the direct spreading receiver device receives a direct spreading signal in which transmission data is generated based on a data in which transmission information is block error detection coded and the transmission data is directly spread. It has an initial data output means, a multi-stage interference canceller, an error detection means, and an output selection means, and the initial data output means outputs initial received data based on a direct spread reception signal, and the first The interference canceller in the stage generates a replica of the interference signal included in the direct diffusion reception signal based on the initial reception data, and subtracts the replica from the direct diffusion reception signal to reduce the influence of the interference signal. The received data is output, and the interference cancellers in the second and subsequent stages generate a replica of the interference signal included in the direct diffusion reception signal based on the output of the interference canceller in the previous stage, and receive the direct diffusion reception. The replica is subtracted from the signal to output the received data of the stage in which the influence of the interference signal is reduced, and the error detecting means obtains the initial received data and the said initial received data in accordance with the longitudinal operation of the plurality of stages of the interference canceller. By decoding the error detection code based on the received data output by the interference canceller, an error is detected in block units, and the output selection means follows according to the error detection result of the error detection means. In the block, the operation / non-operation of the plurality of stages of interference cancellers and the number of operation stages are controlled, and reception information based on any one of the initial reception data and the reception data of each stage is selected. Therefore, in addition to controlling the number of operation stages of the interference canceller in the invention according to claim 7, it is possible to stop the operation of all the interference cancellers, further shorten the processing time of the reception process, and consume the power of the receiving device. Can be reduced.

【0046】

The received information based on any one of the received data of the above is selected. Therefore, in addition to controlling the number of operation stages of the interference canceller in the invention according to claim 8, it is possible to stop the operation of all the interference cancellers, further shorten the processing time of the reception process, and consume the power of the receiving device. Can be reduced.

【0047】

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a block configuration diagram for explaining the first embodiment of the present invention. As an example, the case where the code multiplex channel consists of one user and one pilot channel is shown. In the IS-95 CDMA system, as shown in Fig. 11 (b), the base station performs processing such as error detection coding, convolutional coding, block interleaving, etc., but here, a brief explanation will be given. In order to do so, only convolutional coding shall be performed. When executing with other processing, a processing block corresponding to the processing block on the transmitting side may be added to the receiver configuration of the slave station.

【0048】

In the figure, 1 is a Rake receiving unit, and for example, the Rake receiving unit 121 of FIG. 13 can be used. 2 is an intermediate error processing unit, 3 and 7 are Viterbi decoding units, 4 is a convolutional coding unit, and 5 is a direct diffusion reception signal dropped in the baseband according to the processing delay in the intermediate error processing unit 2 and the interference canceller 6. This is a delay unit for delaying the baseband reception signal. Reference numeral 6 denotes an interference canceller, and as an example, the interference canceller 133 shown in FIG. 13 can be used.

【0049】

The initial reception data output from the Rake reception unit 1 is subjected to error correction processing in the intermediate error processing unit 2, and is output to the interference canceller 6 as initial reception data with increased accuracy. The interference canceller 6 generates a replica of the interference signal included in the baseband reception signal output from the delay unit 5, subtracts this from the baseband reception signal, and bitabi the received data in which the influence of the interference signal is reduced. Output to the decoding unit 3. The Viterbi decoding unit 3 corrects errors in the received data and outputs the received information.

【0050】

The intermediate error processing unit 2 of this embodiment obtains error-corrected reception information from the initial reception data in the Viterbi decoding unit 3, and then performs convolutional coding again in the convolutional coding unit 4 to correct the error. Generate initial received data based on received information. As a result, the very probable initial reception data can be output to the interference canceller 6, so that the capability of the interference canceller 6 can be enhanced. By supplying the output of the interference canceller 6 to the Viterbi decoding unit 7, the reception information DC that matches the transmission information can be obtained. Since the above-mentioned Rake receiving unit 1 is for providing reliable initial reception data necessary for interference cancellation, it is replaced with this, for example, the direct diffusion reception signal of the baseband is despread, and among them, , It may be a despreading unit that decodes the despreading output of the path P that maximizes the power.

【0051】

FIG. 2 is a block configuration diagram for explaining a second embodiment of the present invention. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. 11 is an intermediate error processing unit, 12 and 13 are cyclic code decoding units, and 14 is a selection / control unit. This embodiment is based on the premise that a redundant bit is inserted into the transmission information on the transmitting side, cyclic coding is performed, and then convolutional coding is performed. The intermediate error processing unit 2 in the block diagram of FIG. 1 is replaced with the intermediate error processing unit 11. The output of the Viterbi decoding unit 3 is also output to the cyclic code decoding unit 12. Here, the presence or absence of an error is detected in block units, and if an error is not detected, the error flag ER = 0, and if an error is detected even with 1 bit, the error flag ER = 1. Also, the received information DR with the redundant bits removed is output. The output of the interference canceller 6 is the received information DC from which the redundant bits have been removed by the Viterbi decoding unit 7 and the cyclic code decoding unit 13. The cyclic code decoding unit 13 only needs to remove redundant bits, but may also output an error flag CR to monitor reception quality.

【0052】

When an error is not detected in a certain block (ER = 0), the selection / control unit 13 sets the received information DR as the output data Dout in the next block. At the same time, in the next block, the operation of the interference canceller 6 is stopped. On the other hand, when an error is detected in a certain block (ER = 1), the selection / control unit 13 cancels the interference in the next block and outputs the reception information DC with improved reception quality as output data Dout. ..

【0053】

The interference canceller 6 can be realized by a hardware circuit. By changing and controlling the number of operation stages of the interference canceller, it is possible to shorten the processing time of interference cancellation while maintaining the reception quality at a predetermined level. As a result, the power consumption of the hardware circuit of the interference canceller 6 can be reduced. In addition, the interference canceller can be realized by software using a CPU or DSP and an arithmetic processing program. In this case, the processing time can be shortened while maintaining the reception quality at a predetermined level, so that the processing load on the CPU or DSP can be reduced. In addition, the operation of the Viterbi decoding unit 7 and the like on the premise that the interference canceller 6 is operating can also be controlled to further reduce the power consumption.

【0054】

In the above description, the operation of the interference canceller 6 is controlled in units of one block, but the control is not limited to such control. For example, the appearance rate of blocks that detect errors is a predetermined rate E.₁When it becomes less than, the operation of the interference canceller 6 is stopped, and the predetermined ratio E again.₂(E₁<E₂) May be exceeded, the operation may be restarted. If there is a problem in the operation of the Viterbi decoding, interference canceller, etc. at the start of the operation, it is preferable to reduce the frequency of switching the operation.

【0055】

By controlling the operation of the interference canceller or the like in response to the detection of an error in block units, that is, according to the reception quality, the processing time and consumption of the interference canceller or the like are maintained while maintaining the reception quality at a predetermined level. It is possible to reduce the power consumption. It is also conceivable to use the received information DC as output data for the block in which an error is detected. However, in this case, since it is necessary for the delay unit 5 to delay the baseband signal by one data block or more, the power consumption by the buffer that realizes the delay unit 5 cannot be ignored.

【0056】

FIG. 3 is a block configuration diagram for explaining a third embodiment of the present invention. In the figure, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the intermediate error processing unit 11 in the block diagram of FIG. 2 is replaced with the intermediate error processing unit 21 on the premise that redundant bits are inserted into the transmission information on the transmitting side, cyclic coded, and then directly diffused. It is replaced with. Therefore, the output of the Rake receiving unit 1 is directly output to the interference canceller 6, and is also output to the cyclic code decoding unit 12. The cyclic code decoding unit 12 detects the presence or absence of an error in block units and outputs the received information DR from which redundant bits have been removed. The output of the interference canceller 6 is the received information DC from which the redundant bits have been removed by the cyclic code decoding unit 13. Since no error correction is performed, the reception quality has an error rate similar to that of the conventional technique, but the power consumption can be adaptively reduced according to the reception environment.

【0057】

FIG. 4 is a schematic diagram for explaining an example of the operation of the block configuration shown in FIG. 31 is the received data output by Rake receiving unit 1, 32 is the output DR of the intermediate error processing unit 21, 33 is the output of the interference canceller 6, 34 is the output DC of the cyclic code decoding unit 13, and 35 is the selection / control unit 14. Output data Dout. Initially, it is assumed that the interference canceller 6 is also operated. The selection / control unit 14 has a data buffer inside.

【0058】

In the first block, Dout = DR. The interference canceller 6 has stopped operating with respect to the block. The interference canceller 6 starts the operation when the block is input, but when ER = 0 is output after the end of the block, the interference canceller 6 stops the operation, and Dout = DR also in the next block. The interference canceller 6 starts the operation when the block is input, but when ER = 1 is output after the end of the block, the operation is continued and Dout = DC in the block. After the end of the block, when ER = 1 is output, the interference canceller 6 continues to operate, and Dout = DC also in the block. After the end of the block, when ER = 1 is output, the operation continues, and Dout = DC also in the block. The interference canceller 6 stops operating when ER = 0 is output after the end of the block, and Dout = DR in the block.

【0059】

As described above, when the cyclic code decoding unit 12 does not detect an error in a certain block, the selection / control unit 14 also uses the received information based on the output of the Rake receiving unit 1 as output data in the next block. On the other hand, when an error is detected, the selection / control unit 14 operates the interference canceller 6 in the next block and uses the received information based on this output as output data. When the error is no longer detected, the selection / control unit 14 uses the received information based on the output of the Rake receiving unit 1 as the output data in the next block, and stops the operation of the interference canceller. .. As a result, it is possible to output the received information in which the error is not detected, except that the block with the error is output at the time of switching, and the operation of the interference canceller is adaptive according to the detection of the error in the block unit. Power consumption can be reduced by deciding.

【0060】

The block error is not recovered by the interference canceller 6, but may be corrected by another method, for example, an automatic repeat request (ARQ). If the selection / control unit 14 does not have a buffer for the reception information of the user n, the blocks cannot be connected well at the time of selection switching, but it can be handled by ARQ. Note that the data in which the transmission information is convolutionally encoded as shown in FIG. 1 may be regarded as the transmission information in this embodiment. For example, it may be a case where redundant bits are added in block units after convolutional coding and cyclic coding is performed. The operation control of the interference canceller 6 is not limited to one block unit. Similar to the block configuration of FIG. 2, for example, the appearance rate of the block in which an error is detected is a predetermined rate E.₁When it becomes less than, the operation of the interference canceller 6 is stopped, and the predetermined ratio E again.₂(E₁<E₂) May be exceeded, the operation may be restarted.

【0061】

FIG. 5 is a block configuration diagram for explaining a fourth embodiment of the present invention. This embodiment has two receivers. The reference code is subscripted with a or b to distinguish between the first and second receivers. In the figure, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. 41a and 41b are receiving antennas, 42a and 42b are multipliers, 43a and 43b are reference frequency oscillators, 44a and 44b are Rake receivers, 45 and 49 are synthesis judgment units, 46a and 46b are delay units, and 47 are intermediate error processing. Part, 48 is an interference canceller, and 50 is a termination error processing part.

【0062】

Two receiving antennas are provided for diversity. For example, two receiving antennas are provided at a distance (space diversity). Alternatively, two identical directional antennas are provided with different antenna orientations (angle diversity). Alternatively, antennas with different directivity are used (angle diversity). The directivity characteristics and installation conditions of these antennas are used alone or in combination as appropriate to form two antennas.

【0063】

The signals received by the different receiving antennas 41a and 41b in this way are multiplied by the sinusoidal reference frequency signals of the reference frequency oscillators 43a and 43b in the multipliers 42a and 42b and converted into the direct spread reception signal of the baseband. .. The reference frequency oscillators 43a and 43b output sinusoidal reference frequency signals of the same frequency, and can share one reference frequency oscillator. This baseband reception signal is despread at the Rake receiving units 44a and 44b, and the despread signal is output.

【0064】

The Rake receivers 44a and 44b perform the same functions as the Rake receivers 1a and 1b shown in FIG. 1, but their output signal forms are different. The despread signal corresponding to the impulse response of the initial reception data at the stage immediately before decoding in the Rake reception units 44a and 44b to obtain the initial reception data is output. By synthesizing and judging the outputs of the two Rake receiving units 44a and 44b in the synthesis determination unit 45, the initial reception data becomes more accurate. The synthesis determination unit 45 performs a composition determination in the same manner as the composition determination unit 49 described later with reference to FIG.

【0065】

For the intermediate error processing unit 47, any of the intermediate error processing units 2, 11 and 21 shown in FIGS. 1 to 3 is used. When the intermediate error processing unit 2 or 11 is used, the error-corrected received data is obtained as the initial received data. When the intermediate error processing unit 11 or 21 is used, the output data is selected and the operation of the interference cancellers 48a and 48b is controlled. The two-series interference cancellers 6a and 6b generate a replica of the interference signal included in the direct spread reception signal based on the initial reception data output from the intermediate error processing unit 47, and subtract this replica from the direct spread reception signal. , Outputs a despread signal with reduced influence of interference signals. The delay units 46a and 46b are intermediate in the interference cancellers 48a and 48b by compensating for the processing delays in the Rake receiving units 44a and 44b, the synthesis determination unit 45, the intermediate error processing unit 47, and the interference cancellers 6a and 6b. The input timing of the output of the error processing unit 47 and the direct spread reception signal of the baseband is matched.

【0066】

The interference cancellers 48a and 48b are similar to the interference canceller 6 in FIG. 1 and the interference canceller 133 in FIG. 13 in the prior art. However, these have a built-in decoding unit for determining data. In this embodiment, since the data is determined by the subsequent synthesis determination unit 49, the interference cancellers 48a and 48b output the reverse diffusion signal at the stage immediately before determining the received data. This reverse diffusion signal corresponds to the impulse response of the received data determined by the interference canceller in the prior art. The synthesis determination unit 49 determines the received data by decoding the combined signal of the reverse diffusion signals output from the two series of interference cancellers 48a and 48b.

【0067】

The direct spread reception signals received from the antennas 41a and 41b of the two systems are independent. That is, it undergoes different multipath fading. Therefore, there is a high possibility that the direct spread reception signal without the output decrease due to the fading fluctuation can be received from either one, and the fading fluctuation becomes strong. Further, it is the multipliers 42a, 42b, etc. that convert the antennas 41a, 41b into the baseband received signal that affect the noise of the two receivers. If there are two receivers, the noise is independent for each system. Therefore, the influence of noise is averaged as compared with the case of one system.

【0068】

In the interference cancellers 48a and 48b, after removing the interference replica, the reverse diffusion signal immediately before the reception data is determined is output. As described above, an interference canceller is used based on the baseband signal in which independent noise is added to the received signals that have undergone independent multipath fading, and the output signals of the two systems are further combined and judged. As a result, this direct diffusion receiver is superior in the quality of received data to the performance of a single interference canceller alone. The bit error rate generally has a correlation with the average Eb / No when the signal power per bit is Eb and the noise power per 1 Hz is No, and the larger the Eb / No, the lower the bit error rate. When Gaussian noise is applied to the demodulator (static characteristics), the diversity effect has the effect of equivalently increasing Eb / No by 3 dB, so the same degree of improvement is expected in this embodiment as well.

【0069】

Note that you may use the Rake receiving unit 1 shown in FIG. 1, for example, which outputs the initial reception data to each of the above-mentioned Rake receiving units 44a and 44b. Each initial reception data may be input to each of the two intermediate error processing units 47 provided for each series, and the output thereof may be output to the interference cancellers 48a and 48b of the corresponding series. In this case, the intermediate error processing unit 2 shown in FIG. 1 is used as the intermediate error processing unit 47. In this case, since the very probable initial reception data can be output to the interference cancellers 48a and 48b, the capability of the interference canceller 6 can be enhanced. Also in this embodiment, the Rake receiving units 44a and 44b are replaced with, for example, a despreading unit that despreads the baseband reception signal and decodes the despreading output of the path P that maximizes the power. You may.

【0070】

FIG. 6 is an explanatory diagram of the synthesis determination unit 49 shown in FIG. FIG. 6 (a) is an explanatory diagram of the synthesis function, and FIG. 6 (b) is an explanatory diagram of the determination function. The in-phase component (I phase) and orthogonal component (Q phase) of the reverse diffusion signal output from the interference canceller 48a of the first receiver (system a) are set to (V)._1i, V_1q), And the common mode and orthogonal components of the reverse diffusion signal output from the interference canceller 48b of the second receiver (system b) are (V)._2i, V_2q), And the common mode and orthogonal components of the composite signal are (V)._0i, V_0q).

【0071】

The combined signal has a weight W for each of the reverse diffusion signals from the interference cancellers 48a and 48b of the first and second receivers._t1, W_t2Is created by adding. That is, V_0i= V_1i* W_t1+ V_2i* W_t2V_0q= V_1q* W_t1+ V_2q* W_t2And. Where the weight W_t1, W_t2As, for example W_t1= (V_1i²+ V_1q²) / {(V_1i+ V_2i)²+ (V_1q+ V_2q)²}^1/2W_t2= (V_2i²+ V_2q²) / {(V_1i+ V_2i)²+ (V_1q+ V_2q)²}^1/2And.

【0072】

Alternatively, the weight W_t1, W_t2As W_t1= (V_1i²+ V_1q²)^1/2/ {(V_1i+ V_2i)²+ (V_1q+ V_2q)²}^1/2W_t2= (V_2i²+ V_2q²)^1/2/ {(V_1i+ V_2i)²+ (V_1q+ V_2q)²}^1/2And. The value of each denominator is the length of the vector obtained by adding the reverse diffusion signals output from the interference cancellers 48a and 48b of the first and second receivers. As shown in Fig. 6 (b), in the case of 4-phase phase modulation, the above-mentioned composite signal (V)_0i, V_0q) Is in which quadrant on the IQ phase plane the received data is decoded.

【0073】

The terminal error processing unit 50 performs processing corresponding to the intermediate error processing unit 47. When the intermediate error processing units 2, 11 and 21 shown in FIGS. 1 to 3 are used as the intermediate error processing unit 47, the Viterbi decoding unit 7 and the Viterbi shown in FIGS. 1 to 3 are used as the termination error processing unit 50, respectively. The decoding unit 7, the cyclic code decoding unit 12, and the cyclic code decoding unit 13 are used.

【0074】

FIG. 7 is a block configuration diagram for explaining a fifth embodiment of the present invention. In this embodiment, as an example, it is premised that the number of users N is code-multiplexed, the interference canceling means is a multi-stage configuration, and a plurality of stages of interference cancellers are connected in cascade to operate. .. In the figure, 51 is the Rake receiver, 52,56 is the intermediate error processing unit, 53,55,57 is the delay unit, 54,58 is the interference canceller, 59 is the termination error processing unit, 60 is the error judgment / control unit, 61. Is the selection part. The Rake receiving unit 51 obtains initial reception data for each user 1 to N. For example, the Rake receiver 146 shown in FIG. 17 can be used. The interference canceller 54 outputs received data whose interference has been canceled for each user 1 to N. For example, the interference canceller 151 shown in FIG.₁Can be used. The interference canceller 58 in the final stage needs to cancel the interference only for the user n of this receiving device. For example, the interference canceller 151 shown in FIG. 17 needs to cancel the interference._MCan be used.

【0075】

When the intermediate error processing units 52 and 56 perform the same error correction processing as the intermediate error processing units 2 in FIG. 1 and the intermediate error processing unit 11 in FIG. 2, the Viterbi decoding and convolutional codes are used for each user 1 to N. To make it. The termination error processing unit 59 performs Viterbi decoding only on the received data of the user n of this receiving device, outputs the received information of the user n as DC (M, n), and uses this as the output data Dout. The error determination / control unit 60 and the selection unit 61 are not used.

【0076】

On the other hand, when performing error detection processing in the same manner as the intermediate error processing unit 11 in FIG. 2 and the intermediate error processing unit 21 in FIG. 3, the cyclic code is decoded only for the user n in block units of the user n. Detects an error and sets the error flags ER and EC (1) to 1. Alternatively, the cyclic code may be decoded for each user 1 to N, and the error flag ER may be set to 1 when a block error is detected even by one user. In any case, the reception information of the user n of this receiving device is output as DR (n) and DC (1, n). The terminal error processing unit 59 may also perform error detection in the same manner as in the intermediate stage.

【0077】

As each stage of the interference cancellers 54, ..., 58 operates in succession, the ability to cancel the interference improves, and the process advances to the stages of the intermediate error processing unit 52, 56, ..., and the terminal error processing unit 59. For each, more probable received data DR (n), DC (1, n), DC (2, n), ..., DC (M, n) can be output. Here, 1 to M are the number of stages of the interference canceller. The error determination / control unit 60 uses the error flags ER, EC (1), ..., EC (m), ... , EC (M-1) is input, and one of the received information DR (n), DC (1), ..., DC (m), ..., DC (M) is input to the selection unit 61. Is selected as the output data Dout. Various selection methods can be considered, but an example will be described here.

【0078】

FIG. 8 is a schematic diagram for explaining an example of the operation of the block configuration shown in FIG. 7. The number of stages will be described as M = 2. In the figure, 61 is the received data of the Rake receiving unit 51, 62 is the received information DR (n) output from the intermediate error processing unit 52, 63 is the output of the interference canceller 54, and 64 is the output DC of the intermediate error processing unit 56 ( 1, n) and 65 are the outputs of the interference canceller 58, 66 is the received information DC (M, n) output from the termination error processing unit 59, and 66 is the output data Dout output from the selection unit 61.

【0079】

In the block, Dout = DR (n). The interference canceller 54 has stopped operating with respect to the block. The interference canceller 54 starts the operation when the block is input, but stops the operation when ER = 0 is output after the end of the block, and Dout = DR (n) also in the next block. The interference canceller 54 starts operation when the block is input, but when ER = 1 is output after the end of the block, the operation continues, and Dout = DC (1, n) in the block. The interference canceller 58 starts operation when the block is input, but continues operation when ER = 1, EC (1) = 1 is output after the end of the block, and Dout = DC (M) in the block. , N). The interference canceller 56 starts operation when the block is input, but stops when ER = 1, EC (1) = 0 is output after the end of the block, and Dout = DC (1) in the block. , N). The interference canceller 56 starts the operation when the block is input, but stops the operation when ER = 0 is output after the end of the block, and Dout = DR (n) in the block.

【0080】

As described above, when an error is not detected in a certain block in a certain intermediate error processing unit, the received information of this stage is also used as output data in the next block. On the other hand, when an error is detected, in the next block, the interference canceller of the next stage is operated, and the received information of that stage is used as output data. When an error is no longer detected in the intermediate error processing section of the previous stage, in the next block, the received information of the stage closest to the first stage among the stages where this error is no longer detected is used as output data, and the subsequent stage Stop the operation of the interference canceller. As a result, it is possible to output the received information in which the error is not detected, except that the block with the error is output at the time of switching the stage, and according to the detection of the error in the block unit, that is, that is, The interference canceller processing time and power consumption can be reduced by adaptively determining the operation non-operation of the interference canceller and the number of operation stages according to the reception quality.

【0081】

Note that the error flag ER of the intermediate error processing unit 52 is not put in the error determination / control unit 60, and the reception information DR (n) output from the intermediate error processing unit 52 is not put in the selection unit 61, so that at least 1 The interference canceller 54 in the stage may be always operated to select the reception information whose interference has been canceled. Further, the intermediate error processing unit 52 may not perform error correction or may eliminate the intermediate error processing unit 52 itself.

【0082】

FIG. 9 is a block configuration diagram for explaining a sixth embodiment of the present invention. In this embodiment, as an example, it is premised that the number of users N is code-multiplexed, the interference canceling means is a multi-stage configuration, and a plurality of stages of interference cancellers are connected in cascade to operate. .. In the figure, the same parts as those in FIGS. 5 and 7 are designated by the same reference numerals and the description thereof will be omitted. The synthesis judgment unit 71 inputs the outputs of the Rake reception units 51a and 51b that obtain the initial reception data for each user 1 to N, performs a synthesis judgment for each user 1 to N, and causes the intermediate error processing unit 52 to perform the initial reception data. Is output. The synthesis judgment unit 72 inputs the outputs of the interference cancellers 54a and 54b that obtain the back diffusion signal for each user 1 to N, performs the synthesis judgment for each user 1 to N, and performs the synthesis judgment for each user 1 to N, and the intermediate error processing unit 56 is in the first stage. Output the received data. The synthesis determination unit 73 may perform the composition determination only for the user n of this receiving device.

【0083】

Similar to FIG. 7, as each stage of the interference canceller operates in succession, the ability to cancel the interference is improved, and each time the stage progresses to the stages of the intermediate error processing unit 52, 56, ..., and the terminal error processing unit 59. , More reliable received data can be output. Further, when the error determination / control unit 60 and the selection unit 61 are used, the processing time and power consumption can be reduced by adaptively determining the number of operation stages according to the detection of an error in blocks. it can. As in FIG. 7, at least the first-stage interference cancellers 54a and 54b may be always operated to select the reception information whose interference has been canceled. Further, the intermediate error processing unit 52 may not perform error correction or may eliminate the intermediate error processing unit 52 itself.

【0084】

In the above description, when the receiver configuration of a plurality of systems is used, two reception sequences are used, but a synthesis determination may be made by using a larger number of reception sequences. Further, the outputs of the receiving antennas of a plurality of systems are sequentially switched by the selection switch means, so that at least the receiving antennas are actually provided with a plurality of systems, but the subsequent processing blocks are made into one actual processing block. A plurality of series may be multiprocessed.

【0085】

In the above description, the interference cancellation that cancels the interference signal of the direct diffusion reception signal has been described. However, the interference canceller in the present invention is not limited to the interference canceller, as long as it is a canceller that removes from the received signal a signal that causes a decrease in the bit error rate of a general received signal including a direct spread reception signal. By replacing it with a canceller, the quality of received information can be dramatically improved.

【0086】

[Effect of the invention]

As is clear from the above description, the present invention has an effect that the quality of the received information can be dramatically improved because the interference is canceled by using the error-corrected initial received data. Further, the present invention has an effect that the processing time of the interference canceller can be shortened and the power consumption can be reduced while maintaining the quality of the received information. Further, a configuration having the above-mentioned two effects can be combined.

[Simple explanation of drawings]

[Figure 1]

It is a block block diagram for demonstrating the 1st Embodiment of this invention.

[Figure 2]

It is a block block diagram for demonstrating the 2nd Embodiment of this invention.

[Fig. 3]

It is a block block diagram for demonstrating the 3rd Embodiment of this invention.

[Fig. 4]

It is a schematic diagram for demonstrating an example of the operation of the block structure shown in FIG.

[Fig. 5]

It is a block block diagram for demonstrating the 4th Embodiment of this invention.

[Fig. 6]

It is explanatory drawing of the synthesis determination part shown in FIG.

[Fig. 7]

It is a block block diagram for demonstrating the 5th Embodiment of this invention.

[Fig. 8]

It is a schematic diagram for demonstrating an example of the operation of the block structure shown in FIG.

[Fig. 9]

It is a block block diagram for demonstrating the 6th Embodiment of this invention.

[Fig. 10]

It is a figure which shows the structure of the downlink in a DS-CDMA system.

[Fig. 11]

It is a schematic block diagram of the transmission device of a base station in a DS-CDMA system.

[Fig. 12]

It is a schematic block diagram of the receiving device of a slave station in a DS-CDMA system.

[Fig. 13]

It is a basic block block diagram of the prior art.

[Fig. 14]

It is an internal block diagram of the interference canceller shown in FIG.

[Fig. 15]

It is an internal block diagram of the interference replica generation part shown in FIG.

[Fig. 16]

It is operation explanatory drawing of the interference canceller shown in FIG.

[Fig. 17]

The code-multiplexed channel sharing one PN code is a block block diagram of the prior art consisting of an N-user communication channel and one pilot channel.

[Explanation of symbols]

1 Rake receiver, 2 intermediate error processing unit, 3,7 Viterbi decoding unit, 4 convolutional coding unit, 5 delay unit, 6 interference canceller, 11 intermediate error processing unit, 12,13 cyclic code decoding unit, 14 selection / control Department