WO2004052038A1

WO2004052038A1 - A multiuser receiving means of uplink dedicated physical channel in wcdma system

Info

Publication number: WO2004052038A1
Application number: PCT/CN2003/000631
Authority: WO
Inventors: Limei Wei; Guolin Wang; Yu Jin
Original assignee: Huawei Technologies Co., Ltd
Priority date: 2002-12-05
Filing date: 2003-08-05
Publication date: 2004-06-17
Also published as: CN100382469C; CN1505294A; AU2003248236A1

Abstract

The invention discloses a multiuser receiving means of a uplink dedicated physical channel in WCDMA system, which involves the multiuser detection technique in WCDMA cell mobile communication system the multiuser detection technique is an enhanced technique of CDMA system, which applies of double weighting parallel interference cancellation and its simply method in order to greatly enhance the capability of the traditional method of parallel interference cancellation. The invention applies the simple method of double weighting parallel interference cancellation to receive signal in a uplink dedicated physical channel, which greatly enhances the receiving capability of uplink dedicated physical channel.

Description

Multipurpose receiver for uplink dedicated physical channel in WCDMA system TECHNICAL FIELD

The present invention relates to a communication system, and in particular, to a multi-user detection technology for a base station in a Wideband Code Division Multiple Access (WCDMA) cellular mobile communication system.

Background technique

The 3GPP protocol brings together a full set of standards for WCDMA systems. According to the 3GPP protocol, the information bits of the dedicated physical data channel (DPDCH) in the uplink dedicated physical channel are first channel-encoded, and then binary phase-shift keying (BPSK) mapping and spreading are performed. The information bits of the dedicated physical control channel (DPCCH) are directly subjected to BPSK mapping and spreading. The spread DPDCH channel chip and DPCCH channel chip form two data channels, I and Q, and perform scrambling processing together. The scrambled I and Q chips are pulse-formed respectively, and then sent to the base station through carrier modulation. In 3GPP's 25.104, 25.944, and 25.212 protocols, a channel coding scheme for a DPDCH channel in an uplink dedicated physical channel is specified. For the methods of spreading, scrambling, pulse shaping, and modulation of the uplink dedicated physical channel, see 3GPP's 25.213 protocol.

The above is the process in which the user terminal (UE) in the WCDMA system sends a bit on the uplink dedicated physical channel. The bits transmitted by the UE on the uplink dedicated physical channel at the base station side of the WCDMA system are received according to the following process:

Figure 1 shows a single-user RAKE receiving device for the uplink dedicated physical channel. As shown in FIG. 1, the received signal of the antenna is first demodulated and matched filtered to obtain Baseband signal; multipath search is performed on the baseband signal to obtain multipath delay information. The baseband signal and the multipath delay information enter the DPDCH processing channel and the DPCCH processing channel at the same time. The DPCCH processing channel performs DPCCH despreading, channel estimation, and RAKE combining on the baseband signal according to the multipath delay information, and sends the DPCCH RAKE combining result to the TFCI decoding unit 101 and the DPCCH hard decision unit 102. The TFCI decoding unit 101 decodes the RAKE combining result of the DPCCH to obtain a DPDCH spreading factor, and sends the spreading factor to the DPDCH despreading unit 104. DPCCH hard decision unit 102.

The information bits of the DPCCH channel are obtained.

The DPDCH processing channel performs DPDCH despreading, DPDCH RAKE combining on the baseband signal according to the multipath delay information and the DPDCH spreading factor, and sends the RAKE combined result of the DPDCH channel to the decoder 103 for decoding. The decoder 103 decodes the RAKE combining result of the DPDCH to obtain the information bits of the DPDCH channel. The decoding of the DPDCH channel is the reverse of the DPDCH channel coding. This is the RAKE receiving process of the information bits of the uplink dedicated physical channel in the WCDMA system.

WCDMA systems are interference-limited systems. Multiple access interference has limited the further improvement of WCDMA system capacity. The performance of traditional RAKE receiver decreases with the increase of the number of users and the distance effect. Multi-user detection technology is an enhanced technology to overcome the impact of multiple-access interference and increase the capacity of WCDMA systems. It performs joint detection on multiple user signals, thereby minimizing the impact of multiple-access interference on receiver performance and increasing system capacity.

Verdu proposed the best multi-user detector in 1986, but this detector is complicated and difficult to apply. In the sub-optimal multi-user detection method, document [1] is a two-layer weighted parallel interference cancellation algorithm with patent application number 01132754. The weighted parallel interference cancellation method performs better. Document [2] is a simplified algorithm of the double-layer weighted parallel interference cancellation algorithm with patent application number 01135527. 1. The proposed simplified method reduces the improvement of implementing complex methods while maintaining the performance of the double-layer weighted parallel interference cancellation method. , Not only minimizes the cost of symbol-level decision, but also can make up for the deviation of user signal estimation in the statistical sense, and greatly improves the severity of traditional parallel interference cancellation methods.

dagger.

In this paper, a simplified method of double-layer weighted parallel interference cancellation method is applied to a receiving device of an uplink dedicated physical channel, and a multi-user receiving device of the uplink dedicated physical channel is proposed.

Summary of the Invention

An object of the present invention is to provide a multi-user receiving device for an uplink dedicated physical channel in a WCDMA system. The device has higher performance than a conventional single-user RAKE receiving device, and greatly improves the receiving performance of the uplink dedicated physical channel.

A multi-user receiving device for an uplink dedicated channel in a WCDMA system, comprising: a demodulation and matched filter for demodulating and matching filtering a received signal of an antenna to output a baseband signal;

A multipath searcher group is composed of a multipath searcher, which is used to perform multipath search on the demodulated and matched filtered baseband signals. Each searcher is responsible for searching the path delay information of one user and outputting the information of all users. Multipath delay information, which is a positive integer greater than 1. The first level of parallel interference cancellation (PIC) structure is composed of Γ user signal processing units and an interference cancellation unit, and each user corresponds to a user signal processing unit. The first The input of the first-level PIC structure is composed of the baseband signal and the multipath delay information of all users. The baseband signal enters the signal processing unit of the user in parallel, and the multipath delay information of each user enters the corresponding user signal. The processing unit outputs the power control instruction, symbol-level regeneration signal, and chip-level regeneration signal of each user after corresponding processing, wherein the power control instructions of all users are respectively fed back to the transmitting end of the corresponding user via the downlink, and the baseband signal And the chip-level regeneration signal of all users enters the interference cancellation unit to process the residual signal;

The last-stage PIC structure includes Γ user signal processing units, and each user corresponds to a user-signal processing unit. The input of the last-stage PIC structure is the multipath delay information of all Γ users, and the upper-stage PIC structure. The output residual signal and the symbol-level reproduced signals of all users are composed. The residual signal output by the upper-level PIC structure is input into the signal processing unit of each user in parallel, and the multipath delay information of the Γ users and the The symbol-level reproduced signals of all the Γ users output by the first-level PIC structure processing enter the corresponding user signal processing units, respectively, and perform corresponding processing.

The present invention also includes an intermediate-stage PIC structure, which is any level of PIC structure located between the first-stage PIC structure and the last-stage PIC structure. Each user corresponds to a user signal processing unit. The input of the intermediate-level PIC structure consists of the baseband signal, the multipath delay information of all Γ users, and the residual signals output by the processing of its upper-level PIC structure and all users. Composed of symbol-level reproduced signals, where the residual signal processed by the previous-stage PIC structure enters the signal processing unit of each user in parallel, and the multipath delay information of each user and all K users output by the higher-level PIC structure are processed Symbol-level regeneration signals The user signal processing unit outputs the symbol-level reproduced signal and chip-level reproduced signal of each user through corresponding processing, wherein the baseband signal and the chip-level reproduced signal of all users enter the interference cancellation unit to process the residual signal.

The number of intermediate-stage PIC structures can be determined as required. One or more intermediate-stage PIC structures can be used, or the intermediate-stage PIC structure can be omitted.

The structure of all the user signal processing units in the first-level PIC structure is completely the same, and completes the same functions. The user signal processing unit includes:

Dedicated physical control channel (DPCCH) despreading unit. The DPCCH despreading unit performs multipathing on the input baseband signal according to the spreading code of the DPCCH channel, which is the product of the DPCCH channel code and the scrambling code, and the input multipath delay information. Despread, and output the multipath despread result; channel estimation unit, obtain the channel estimation result of each path from the despread result of each path of the input DPCCH channel, and output it; power control unit, each of the input DPCCH channel A power control instruction is obtained as a result of the path despreading, and is used as an output of the PIC structure of this level, and is fed back to the transmitting end of the user. The noise power estimation unit obtains the noise power of the DPCCH channel from the despread results of the input DPCCH channels. The estimated results and output them;

The RAKE combining unit of the DPCCH channel is configured to perform de-channel modulation and RAKE combining on the input DPCCH despreading result in combination with the input channel estimation result, and output the combined result;

'A transmission format combination indication (TFCI) decoding unit, configured to perform TFCI decoding on the RAKE combined result of the input DPCCH channel, obtain a spreading factor of the DPDCH channel, and output it; Dedicated physical data channel (DPDCH) despreading unit, the DPDCH despreading unit is based on the spreading code of the DPDCH channel, that is, the product of the DPDCH channel code and the scrambling code, and the input multipath delay information and the DPDCH channel after TFCI decoding Multipath despreading of the input baseband signal, and output the multipath despreading result;

The RAKE combining unit of the DPDCH channel is configured to perform de-channel modulation and RAKE combining on the input DPDCH despreading result in combination with the input channel estimation result, and output the combined result;

The DPDCH soft decision and soft decision weighting unit obtains the soft decision for each symbol of the DPDCH from the RAKE combining result of the DPDCH channel and the estimation result of the noise power of the input signal, and then outputs the result after weighting the soft decision; DPCCH soft decision and soft decision The weighting unit obtains the soft decision of each symbol of the DPCCH from the RAKE combining result of the DPCCH channel and the estimation result of the noise power of the input signal, and then outputs the result after weighting the soft decision;

A signal reproduction unit, which obtains the user's symbol-level reproduction signal and chip-level reproduction signal from the DPDCH channel soft-decision weighting result, the DPCCH channel soft-decision weighting result, and the user's multipath delay information, and reproduces the chip-level reproduction signal The signal is sent to the interference cancellation unit in the PIC structure of this stage, and the symbol-level reproduction signal is sent to the signal processing unit of the same user in the next stage PIC structure.

The structures of all f user signal processing units in the last-stage PIC structure are completely the same, and perform exactly the same functions. The user signal processing unit includes:

DPDCH despreading unit, which is the product of the spreading code of the DPDCH channel, that is, the product of the DPDCH channel code and the 4 code, and the input multipath delay information and the DPDCH channel. A spreading factor, which performs multipath despreading on the input baseband signal, and outputs the multipath despreading result; a DPCCH despreading unit, which is based on the spreading code of the DPCCH channel, which is the product of the DPCCH channel code and the scrambling code, And input multipath delay information, perform multipath despreading on the input baseband signal, and output a multipath despread result;

A channel estimation unit that obtains channel estimation results for each path from the despread results of each path of the input DPCCH channel, and outputs them; two symbol correction units for combining the input-level user-symbol-regenerated signals to the input DPCCH respectively The channel despreading result and the DPDCH channel despreading result are subjected to symbol correction, and the symbol correction results are output respectively; the RAKE combining unit of the DPDCH channel and the RAKE combining unit of the DPCCH channel are used for combining the input channel estimation results to the input The symbol correction result of the DPCCH channel and the symbol correction result of the DPDCH channel are subjected to de-channel modulation and RAKE order, and the results are output respectively; a channel decoder for channel decoding the RAKE combined result of the input DPDCH channel to obtain a DPDCH channel Sent information bits; a hard decision unit, configured to perform a hard decision on the RAKE combining result of the input DPCCH channel, to obtain the information bits sent by the DPCCH channel.

The structures of all the Γ user signal processing units in the intermediate-level PIC structure are completely the same, and perform exactly the same functions. The user signal processing units include:

DPDCH despreading unit, the DPDCH despreading unit performs multi-processing on the input baseband signal according to the spreading code of the DPDCH channel, which is the product of the DPDCH channel code and the scrambling code, and the input multipath delay information and the spreading factor of the DPDCH channel. The DPCCH despreading unit is based on the spreading code of the DPCCH channel, which is the product of the DPCCH channel code and the scrambling code, and the input multipath delay information. Baseband signal Multipath despreading, and output multipath despreading results;

The channel estimation unit obtains the channel estimation results of each path from the input despreading results of the DPCCH channel and outputs them; the noise power estimation unit obtains the noise power of the DPCCH channel from the input DPCCH channel despreading results of the paths. The estimated results and output them;

Two symbol correction units, which are used to perform symbol correction on the input DPCCH despread result and DPDCH despread result in combination with the input user's symbol-level regeneration signal, and output the symbol correction results respectively; RAKE combining unit and DPCCH of the DPDCH channel The channel RAKE combining unit is configured to perform de-channel modulation and RAKE combining on the input DPDCH symbol correction result and DPCCH symbol correction result in combination with the input channel estimation result, and output the results respectively;

A signal reproduction unit, which obtains the user's symbol-level reproduction signal and chip-level reproduction signal from the DPDCH channel soft-decision weighting result, the DPCCH channel soft-decision weighting result, and the user's multipath delay information, and reproduces the chip-level reproduction signal The signal is sent to the interference cancellation unit in the PIC structure of this level, and the symbol-level reproduction signal is sent to the signal processing unit of the same user in the PIC structure of the subsequent level. The interference cancellation unit includes: a signal summing device for summing chip-level regeneration signals of each user input, and then outputting the summation result; a shaping and matching filter unit for summing the input signal, that is, the summation result Perform shaping filtering and matching filtering, and output the filtering result; a residual calculation unit, configured to subtract the input filtering result from the input baseband signal to obtain a residual signal, and use the residual signal as the PIC of the current stage The output signal is sent to the user signal processing unit of each user in the next PIC structure in parallel.

The PIC structure of the last stage and the PIC structure of the middle stage further include a spreading factor calculation unit for calculating a spreading factor of the DPDCH channel of the present stage. The spreading factor calculation unit includes a TFCI decoding unit, which is used to TFCI decode the RAKE combined result of the input DPCCH channel to obtain the spreading factor of the DPDCH channel, and sends the spreading factor of the DPDCH channel to the DPDCH despreading unit.

The spreading factor of the DPDCH channel of the DPDCH despreading unit in the middle-stage PIC structure and the last-stage PIC structure can use the spreading factor of the DPDCH despreading unit in the previous-stage PIC structure, or it can be spread by the current stage. Provided by factor calculation unit.

The present invention applies a simplified method of a double-layer weighted parallel interference cancellation method to a receiving device for an uplink dedicated physical channel to obtain a multi-user receiving device. The double-weighted parallel interference cancellation method is a simplified method that reduces the implementation complexity while maintaining the performance of the double-layer weighted parallel interference cancellation method. In this way, the device can greatly improve the reception performance of the uplink dedicated physical channel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an existing uplink dedicated physical channel single-user RAKE receiving apparatus; FIG. 2 is a schematic diagram of an uplink dedicated physical channel multi-user receiving apparatus of the present invention; 3 is a schematic diagram of a first-level PIC structure in an uplink dedicated physical channel multi-user receiving device according to the present invention;

4 is a schematic structural diagram of an intermediate stage PIC in an uplink dedicated physical channel multi-user receiving device according to the present invention;

FIG. 5 is the last stage in the uplink dedicated physical channel multi-user receiving device of the present invention

PIC structure diagram.

detailed description

The invention is further described below with reference to the drawings and embodiments.

FIG. 2 shows an uplink dedicated physical channel multi-user receiving device according to the present invention. As shown in FIG. 2, the received signal of the antenna passes through the demodulation and matched filter 201 to obtain the baseband signal, and the baseband signal is sent to the multipath searcher group 205, the first-stage PIC structure 202 and the middle-stage PIC structure 203 at the same time.

The multipath searcher group 205 searches to obtain the path delay information of each user, and sends the path delay information of all users to the first-stage PIC structure 202, the middle-stage PIC structure 203, and the last-stage PIC structure 204 at the same time. As shown in FIG. 2, the baseband signal enters the multipath searcher group 205, and it is assumed that the system has Γ users, and the multipath searcher group 205 has a multipath searcher. Each user corresponds to a multipath searcher, where is a positive integer greater than 1.

Processing of the first level PIC structure

FIG. 3 shows the first-stage PIC structure in the uplink dedicated physical channel multi-user receiving device of the present invention. The first-stage PIC structure 202 is composed of Γ user signal processing units 300 and an interference cancellation unit 320. Each user corresponds to a user signal processing unit 300. As shown in FIG. 3, the baseband signals entering the first-stage PIC structure 202 enter each The signal processing unit 300 of the user enters the multi-path delay information of each user entering the first-stage PIC structure 202 into the signal processing unit 300 of the corresponding user. The signal processing unit 300 of each user performs exactly the same function.

The baseband signal and the user's multipath delay information entering the user signal processing unit 300 enter the DPDCH processing channel and the DPCCH processing channel, respectively.

The DPCCH despreading unit 302 performs multipath despreading on the input baseband signal according to the spreading code of the DPCCH channel, that is, the product of the DPCCH channel code and the scrambling code, and the input multipath delay information, and sends the multipath despread result to the To the channel estimation unit 304, the power control unit 303, the noise power estimation unit 308, and the RAKE combining unit 307 of the DPCCH channel.

The channel estimation unit 304 obtains the channel estimates of each path from the despread results of the DPCCH paths, and sends the channel estimation results to the RAKE combining unit 305 of the DPDCH channel and the RAKE combining unit 307 of the DPCCH channel at the same time.

The power control unit 303 obtains a power control instruction from the despreading result of each path of the input DPCCH channel, and uses the power control instruction as an output of the first-stage PIC, and feeds it back to the transmitting end of the user.

The noise power estimation unit 308 obtains an estimation of the noise power of the DPCCH channel from the despread results of the DPCCH paths, and sends the estimation result of the noise power to the DPDCH soft decision and soft decision weighting unit 309 and the DPCCH soft decision and soft decision weighting unit at the same time. 310.

The RAKE combining unit 307 of the DPCCH channel is used to combine the input channel estimation results to dechannelize and RAKE combine the input DPCCH despread results, and send the combined results to the DPCCH soft decision and soft decision weighting unit 310 and TFCI interpreter, respectively. Code unit 306. The TFCI decoding unit 306 is configured to perform TFCI decoding on the RAKE combined result of the input DPCCH channel to obtain a spreading factor of the DPDCH channel, and send the spreading factor to the DPDCH despreading unit 301.

The DPDCH despreading unit 301 performs multipath despreading on the baseband signal according to the spreading code of the DPDCH channel, which is the product of the DPDCH channel code and the scrambling code, and the input multipath delay information and the spreading factor obtained after TFCI decoding. And send the multipath despreading result to the RAKE combining unit 305 of the DPDCH channel.

The RAKE combining unit 305 of the DPDCH is configured to perform de-channel modulation and RAKE combining on the DPDCH despreading result in combination with the input channel estimation result, and send the combined result to the DPDCH soft decision and soft decision weighting unit 309.

The DPDCH soft decision and soft decision weighting unit 309 obtains the soft decision for each symbol of the DPDCH by combining the results of the DPDCH RAKE and the estimation result of the noise power, and then performs soft decision weighting. The DPCCH soft decision and soft decision weighting unit 310 obtains the soft decision for each symbol of the DPCCH from the RAKE combining result of the DPCCH and the estimation result of the noise power, and then performs soft decision weighting. DPDCH channel soft decision weighted weights and DPCCH channel soft decision weighted weights can take different values. When calculating the soft decision of a DPDCH channel, the noise power of the DPDCH channel must first be calculated from the estimation of the noise power of the DPCCH channel.

The signal regeneration unit 311 obtains the user's symbol-level reproduction signal and chip-level reproduction signal from the DPDCH channel soft decision result, the DPCCH channel soft decision result, and the user's path delay information, and sends the chip-level regeneration signal to the interference pair. Cancellation unit 320; sends the symbol-level reproduction signal to the symbol correction sub-unit of the signal processing unit 400 of the same user in the intermediate-stage PIC structure 203. The chip-level regeneration signal of the user can be expressed as (1), and the user The symbol-level reproduced signals of the DPDCH channel and the DPCCH channel of the J-th path can be respectively expressed as (2) and (3):

g> (/)-τη)) ρ (ΐ― nT _h

τ _; · /)) _Q)

sg (^ = A _i! ∑ _∞ p ^ p (t-nT _h ) (2)

Where is the number of paths; 7 is the path number, / = l, .., ...,; is the channel estimation value for the / th user ’s path, provided by the channel estimation unit; W is the time for the #th user ’s path. Delay; Represents the user / spreading code. /-'ίί ^(λ) and / ^£) are the weighted results of the DPDCH and DPCCH channels in the r-th level PIC structure, respectively; represents the amplitude ratio of the DPCCH channel to the DPDCH channel; 0 represents a rectangular pulse with a period T _b , When ^ [0, T _b ], P (0 = l; when [0, Γ], _P ) = 0; .s W is the channel code of the DPDCH channel, is the channel code of the DPCCH channel, and) is the user / Scrambling code.

The chip-level reproduced signals and baseband signals of all users enter the signal summing device 321 in the interference cancellation unit 320. The signal summing device 321 sums up the chip-level reproduced signals of each user input, and then sends the summed result to the shaping and matching filtering unit 322. The shaping and matching filtering unit 322 performs shaping filtering and matching filtering on the input signal. The shaping filter is the same as the shaping filter used in the uplink dedicated physical channel modulation part. The matched filter is the matched filter used at the receiving end of the uplink dedicated physical channel. The filtering result is sent to a residual calculation unit 323. The baseband signal also enters the residual calculation unit. The residual calculation unit 323 subtracts the filtering result from the baseband signal to obtain a residual signal, and sends the residual signal as an output signal of the current level PIC to the next level PIC structure. In the next level PIC structure, the signals are parallelized Signal processing unit for each user. For the first-stage PIC structure of the present invention, the spreading factor obtained by TFCI decoding may be used only by the current-stage PIC structure, or may be transmitted to the subsequent-stage PIC structure for use by the DPDCH despreading unit in the subsequent PIC structure.

Intermediate level P I C structure processing

The structure of the middle-level PIC is exactly the same. The second-level PIC structure is taken as an example to explain the processing process of the middle-level PIC structure.

FIG. 4 shows an intermediate PIC structure in an uplink dedicated physical channel multi-user receiving device of the present invention. The residual signal obtained by the first-stage PIC structure 202, the symbol-level reproduction signal of each user, and the path delay information of each user enter the intermediate-stage PIC structure 203. The intermediate PIC structure 203 is still composed of if user signal processing units 400 and an interference cancellation unit 420. Each user has a user signal processing unit 400. The user signal processing unit 400 of each user performs exactly the same function.

As shown in FIG. 4, in the intermediate-level PIC structure 203, the input signals of the user's signal processing unit 400 are: a residual signal, a symbol-level reproduction signal of the user, and path delay information of the user.

The user's signal processing unit 400 first sends the user's multipath delay information and the residual signal to the DPDCH channel processing channel and the DPCCH channel processing channel simultaneously.

The DPDCH despreading unit 401 performs multipath despreading on the input residual signal according to the spreading code of the DPDCH channel, which is the product of the DPDCH channel code and the scrambling code, and the input multipath delay information and the spreading factor of the DPDCH channel. The despreading result is sent to the symbol correction unit 405 of the DPDCH channel; the DPCCH despreading unit 402 is based on the spreading code of the DPCCH channel, which is the product of the DPCCH channel code and the scrambling code, and the input multipath delay information. Difference signal Multipath despreading is performed, and the despreading results are sent to a channel estimation unit 403, a noise power estimation unit 404, and a symbol correction unit 406 of the DPCCH channel.

The channel estimation unit 403 obtains the channel estimates of the paths from the despread results of the DPCCH paths, and sends the channel estimation results to the RAKE combining unit 407 of the DPDCH channel and the RAKE combining unit 408 of the DPCCH channel at the same time.

The noise power estimation unit 404 obtains an estimation of the noise power of the DPCCH channel from the despread results of the paths of the input DPCCH channel, and sends the estimation results of the noise power to the two subsequent soft decision and soft decision weighting units simultaneously.

The symbol correction unit 405 of the DPDCH channel performs symbol-level correction on the despread result of the input DPDCH channel, that is, the despread result of a certain path of the DPDCH channel is added to the symbol-level regeneration signal of the path. The symbol correction unit 406 of the DPCCH channel performs symbol-level correction on the despreading result of the input DPCCH channel, that is, the despreading result of a certain path of the DPCCH channel is added to the symbol-level reproduced signal of the path.

The RAKE combining unit 407 of the DPDCH channel and the RAKE combining unit 408 of the DPCCH channel perform dechannel modulation and multipath combining on the DPDCH symbol correction result and the DPCCH symbol correction result, respectively, and send the combined results to the DPDCH soft decision and soft decision weighting, respectively. Unit 409 and DPCCH soft decision and soft decision weighting unit 410.

The DPDCH soft decision and soft decision weighting unit 409 obtains the soft decision for each symbol of the DPDCH from the RAKE combining result of the input signal, that is, the DPDCH channel, and the noise power estimation result, and then performs soft decision weighting; The input signal, that is, the RAKE combining result of the DPCCH channel and the estimation result of the noise power, obtains a soft decision for each symbol of the DPCCH, and then performs soft decision weighting. DPDCH channel soft The weight of the decision weight and the weight of the DPCCH channel soft decision weight can take different values. However, the weight of the soft decision weight of the DPDCH at this level is greater than the weight of the soft decision weight of the previous level. The same is true for the weighted soft decision weights of the DPCCH channel.

The signal reproduction unit 411 obtains the user's symbol-level reproduction signal and chip-level reproduction signal from the DPDCH channel soft decision result, the DPCCH channel soft decision result, and the user's path delay information, and sends the chip-level reproduction signal to the interference pair. The cancellation unit 420; sends the symbol-level reproduction signal to the symbol correction sub-unit of the signal processing unit of the same user in the subsequent-stage PIC structure 204.

The chip-level reproduction signals and baseband signals of all users enter the signal summing device 421 in the interference cancellation unit 420. The signal summing device 421 sums the chip-level reproduction signals of the respective users inputted, and then sends the result of the summation to the shaping and matching filtering unit 422. The shaping and matching filtering unit 422 performs shaping filtering and matching filtering on the input signal. The filtered result is sent to the residual calculation unit 423. The baseband signal also enters the residual calculation unit. The residual calculation unit 423 subtracts the filtering result from the baseband signal to obtain a residual signal, and sends the residual signal as the output signal of the current level PIC to the next level PIC structure. In the next level PIC structure, the signals are parallelized Signal processing unit for each user.

The despreading unit of the DPDCH needs to know the spreading factor of the DPDCH. The spreading factor can be a spreading factor obtained by TFCI decoding in the first-level PIC structure, or it can be obtained by a spreading factor calculation unit of the current-level PIC. The spreading factor calculation unit 430 of the PIC at this level includes a TFCI decoder 431, and performs TFCI decoding on the RAKE combining result of the DPCCH channel to obtain the spreading factor of the DPDCH channel. After the interference cancellation of the previous-stage PIC structure, the signal-to-noise ratio of the MKE combining result of the DPCCH channel in the current-stage PIC structure should be higher than that of the previous-stage PIC. The signal-to-noise ratio of the RAKE combining result of the DPCCH channel in the structure is high, so the bit error rate of the spreading factor obtained by the TFCI decoding at this level will be smaller. Therefore, in this stage, the spreading factor calculation unit 430 is used, and the spreading factor obtained by the unit is used to perform despreading of the DPDCH, which is more beneficial to user detection. However, TFCI decoding not only increases complexity but also increases latency. Can determine whether to use the spreading factor calculation unit at this stage according to needs.

Subsequent intermediate-level PIC structures perform the same operation.

Processing of the last PIC structure

FIG. 5 shows the last-stage PIC structure in the uplink dedicated physical channel multi-user receiving device of the present invention. The last-stage PIC structure 204 is composed of? User signal processing units 500. The user's signal processing unit 500 is shown in FIG. 5.

The input of the signal processing unit 500 is the residual signal and the symbol-level reproduction signal obtained in the previous stage, and the multipath delay information. The user signal processing unit 500 first sends the multipath delay information and the residual signal to the DPDCH processing channel and the DPCCH processing channel, respectively.

The DPDCH despreading unit 501 performs multipath despreading on the input residual signal according to the spreading code of the DPDCH channel, which is the product of the DPDCH channel code and the scrambling code, and the input multipath delay information and the spreading factor of the DPDCH channel. The despreading result is sent to the symbol correction unit 504 of the DPDCH channel; the DPCCH despreading unit 502 is based on the spreading code of the DPCCH channel, which is the product of the DPCCH channel code and the scrambling code, and the input multipath delay information. The difference signal is multi-path despread, and the despread result is sent to the channel estimation unit 503 and the symbol correction unit 505 of the DPCCH channel.

The channel estimation unit 503 obtains the channel estimates of the paths from the despread results of the DPCCH paths, and sends the channel estimation results to the RAKE combining unit 506 of the DPDCH channel at the same time. RAKE combining unit 507 of the DPCCH channel.

The symbol correction unit 504 of the DPDCH channel performs symbol level correction on the despread result of the input DPDCH channel, that is, the despread result of a certain path of the DPDCH channel is added to the symbol-level regeneration signal of the path. The symbol correction unit 505 of the DPCCH channel performs symbol level correction on the despread result of the input DPCCH channel, that is, the despread result of a certain path of the DPCCH channel is added to the symbol-level reproduced signal of the path.

The RAKE combining unit 506 of the DPDCH channel and the RAKE combining unit 507 of the DPCCH channel perform dechannel modulation and multipath combining on the DPDCH symbol correction result and the DPCCH symbol correction result, respectively, in combination with the channel estimation results. The combined result of the DPDCH channel is sent to the channel decoder 508 of the DPDCH channel, and the combined result of the DPCCH channel is sent to the hard decision unit 509 of the DPCCH channel.

The channel decoder 508 performs channel decoding on the input signal to obtain information bits transmitted by the DPDCH channel.

The hard decision unit 509 performs a hard decision on the input signal to obtain the information bits sent by the DPCCH channel.

The despreading unit 501 of the DPDCH needs to know the spreading factor of the DPDCH. The spreading factor can be the spreading factor obtained by TFCI decoding in the previous-stage PIC structure, or it can be obtained by the spreading factor calculation unit 510 of the current-stage PIC. You can determine whether to use the spreading factor calculation unit at this level as needed.

The number of stages of the PIC structure can be determined as required. Either the first and last PIC structures can be used, or more PIC structures can be used.

Claims

Rights request

A multi-user receiving device for an uplink dedicated channel in a wideband code division multiple access (WC plane A) system, characterized in that the multi-user receiving device includes:

Demodulation and matched filter for demodulating and matching filtering the received signal of the antenna to output the baseband signal;

A multipath searcher group is composed of a multipath searcher, which is used to perform multipath search on the demodulated and matched filtered baseband signals. Each searcher is responsible for searching the path delay information of one user and outputting the information of all users. Multipath delay information, which is a positive integer greater than 1. The first level of parallel interference cancellation (PIC) structure is composed of r user signal processing units and one interference cancellation unit, and each user corresponds to a user signal processing unit. The input of the first-stage PIC structure is composed of the baseband signal and multipath delay information of all Γ users, where the baseband signal enters the signal processing unit of the user in parallel, and the multipath delay of each user The information enters the corresponding user signal processing unit respectively, and after corresponding processing, the power control instructions, symbol-level regeneration signals, and chip-level regeneration signals of each user are output, and the power control instructions of all f users are respectively fed back to the corresponding ones via the downlink. The transmitting end of the user, and the baseband signal and the chip-level regeneration signal of all users enter the interference cancellation unit. Outputting a residual signal;

The last-stage PIC structure includes f user signal processing units, and each user corresponds to a user-signal processing unit. The input of the last-stage PIC structure is multipath delay information of all f users and the upper-stage PIC. The residual signals output by the structure processing and the symbol-level reproduced signals of all users are composed, wherein the residual signals output by the upper-level PIC structure processing enter the signal processing units of the f users in parallel, The path delay information and the symbol-level reproduced signals of all users outputted from the processing performed by the upper-level PIC structure enter the corresponding user signal processing units for corresponding processing.

2. The multi-user receiving device according to claim 1, further comprising: the multi-user receiving device further comprising an intermediate-stage PIC structure, wherein the intermediate-stage PIC structure is located at the first-stage PIC structure and the last one. Any level PIC structure between two levels of PIC structures, it includes f user signal processing units and an interference cancellation unit, each user corresponds to a user signal processing unit, the input of the intermediate stage PIC structure is based on the baseband signal, all The multipath delay information of Γ users, and the residual signal processed by the upper-level PIC structure and the symbol-level reproduced signals of all users, where the residual signal processed and output by the upper-level PIC structure enters all Talk! The signal processing unit of each user, and the multipath delay information of each user and the symbol-level reproduction signals of all the users processed and output by the upper-level PIC structure enter the corresponding user signal processing unit, and output each user after corresponding processing. The symbol-level reproduced signal and chip-level reproduced signal, wherein the baseband signal and the chip-level reproduced signal of all users enter the interference cancellation unit to process the residual signal.

3. The multi-user receiving device according to claim 2, further characterized in that: the number of stages of the intermediate-stage PIC structure can be determined as required, and one or more intermediate-stage PIC structures can be used, or intermediate Level PIC structure.

4. The multi-user receiving device according to claim 1, further characterized in that the structures of all f user signal processing units in the first-stage PIC structure are completely the same, and complete the same functions, and the user signals The processing unit includes:

A dedicated physical control channel (DPCCH) despreading unit, and the DPCCH despreading unit root According to the spreading code of the DPCCH channel, which is the product of the DPCCH channel code and the scrambling code, and the input multipath delay information, multipath despreading is performed on the input baseband signal, and the multipath despreading result is output; the channel estimation unit is Despread results of each path of the input DPCCH channel to obtain channel estimation results of each path, and output them;

The power control unit obtains a power control instruction from the despread results of the paths of the input DPCCH channel, and uses the power control instruction as an output of the first-stage PIC structure, and feeds it back to the transmitting end of the user;

The noise power estimation unit obtains an estimation result of the noise power of the DPCCH channel from the input despreading result of each path of the DPCCH channel, and outputs it;

A transmission format combination indication (TFCI) decoding unit, configured to perform TFCI decoding on the RAKE combined result of the input DPCCH channel, obtain a spreading factor of the DPDCH channel, and output it;

Dedicated physical data channel (DPDCH) despreading unit, the DPDCH despreading unit is based on the spreading code of the DPDCH channel, that is, the product of the DPDCH channel code and the scrambling code, and the input multipath delay information and the TFCI decoded DPDCH Spreading factor of the channel, performing multipath despreading on the input baseband signal, and outputting the multipath despreading result;

The RAKE combining unit of the DPDCH channel is configured to perform de-channel modulation and RAKE combining on the input DPDCH despreading result in combination with the input channel estimation result, and output the combined result; The DPDCH soft decision and soft decision weighting unit obtains the soft decision for each symbol of the DPDCH from the RAKE combining result of the DPDCH channel and the estimation result of the noise power of the input signal, and then performs soft decision weighting to output the result;

The DPCCH soft decision and soft decision weighting unit obtains the soft decision for each symbol of the DPCCH from the input signal, ie, the RAKE combining result of the DPCCH channel and the estimation result of the noise power, and then performs soft decision weighting to output the result;

A signal regeneration unit, which obtains a user's symbol-level reproduction signal and chip-level reproduction signal from a DPDCH channel soft decision weighting result, a DPCCH channel soft decision weighting result, and a user's multipath delay information, and The reproduction signal is sent to the interference cancellation unit in the first-stage PIC structure, and the symbol-level reproduction signal is sent to the signal processing unit of the same user in the next-stage PIC structure.

5. The multi-user receiving device according to claim 1, further characterized in that the structures of all f user signal processing units in the last-stage PIC structure are completely the same, and complete the same functions, and the user signals The processing unit includes:

A DPDCH despreading unit, which is based on the spreading code of the DPDCH channel, that is, the product of the DPDCH channel code and the scrambling code, and the input multipath delay information and the spreading factor of the DPDCH channel to the input residual signal Perform multipath despreading, and output the result of multipath despreading; a DPCCH despreading unit, the DPCCH despreading unit ^ according to the spreading code of the DPCCH channel, which is the product of the DPCCH channel code and the scrambling code, and the input multipath delay Information, multipath despread the input residual signal, and output the multipath despread result;

A channel estimation unit, which obtains channel estimation results of each path from the despread results of each path of the input DPCCH channel, and outputs them; Two symbol correction units, configured to perform symbol correction on the despread result of the input DPCCH channel and the despread result of the DPDCH channel in combination with the symbol-level reproduced signal of the input user, and output positive sign results respectively;

The RAKE combining unit of the DPDCH channel and the RAKE combining unit of the DPCCH channel are used to perform de-channel modulation and RAKE combining on the input DPDCH channel symbol correction result and the DPCCH channel symbol correction result in combination with the input channel estimation result, and separately combine Result output

A channel decoder, configured to perform channel decoding on the RAKE combined result of the input DPDCH channel to obtain the information bits sent by the DPDCH channel;

A hard decision device is used to perform a hard decision on the RAKE combining result of the input DPCCH channel to obtain the information bits sent by the DPCCH channel.

6. The multi-user receiving device according to claim 2, further characterized in that the structures of all the user signal processing units in the intermediate-stage PIC structure are completely the same, complete the same functions, and the user signal processing unit Including:

A DPDCH despreading unit, which is based on the spreading code of the DPDCH channel, that is, the product of the DPDCH channel code and the scrambling code, and the input multipath delay information and the spreading factor of the DPDCH channel to the input residual signal Perform multipath despreading, and output a multipath despreading result; a DPCCH despreading unit, the DPCCH despreading unit is based on a spreading code of the DPCCH channel, which is a product of a DPCCH channel code and a scrambling code, and input multipath delay information , Performing multi-path despreading on the input residual signal, and outputting the multi-path despreading result;

A channel estimation unit, which obtains channel estimation results of each path from the despread results of each path of the input DPCCH channel, and outputs them; The noise power estimation unit obtains an estimation result of the noise power of the DPCCH channel from the despread results of the paths of the input DPCCH channel, and outputs the result.

Two symbol correction units, which are used to perform symbol correction on the input DPCCH despread result and DPDCH despread result in combination with the input user-level reproduced signal, and output the symbol correction results respectively;

The DPDCH soft decision and soft decision weighting unit is composed of the input signal, namely, the DPDCH channel.

The RAKE combining result and the noise power estimation result are used to obtain a soft decision for each symbol of the DPDCH, and then the soft decision is weighted and the result is output;

The DPCCH soft decision and soft decision weighting unit obtains a soft decision for each symbol of the DPCCH from the RAKE combining result of the DPCCH channel and the estimation result of the noise power of the input signal, and then performs soft decision weighting to output the result;

A signal regeneration unit, which obtains a user's symbol-level reproduction signal and chip-level reproduction signal from a DPDCH channel soft decision weighting result, a DPCCH channel soft decision weighting result, and a user's multipath delay information, and The reproduced signal is sent to the interference cancellation unit in the PIC structure of the current stage, and the symbol-level reproduced signal is sent to the signal processing unit of the same user in the latter-stage PIC structure.

7. The multi-user receiving device according to claim 1 or 2, further characterized in that the interference cancellation unit comprises: A signal summing device, configured to sum input chip-level regeneration signals of each user, and then output the summation result;

A shaping and matching filtering unit, configured to perform shaping filtering and matching filtering on the summing result of the signal summing device, and output the filtering result;

A residual calculation unit, configured to subtract the filtering result of the shaping and matching filtering unit from the input baseband signal to obtain a residual signal, and send the residual signal as an output signal of the current level PIC to the next parallel User signal processing unit for each user in the PIC structure.

8. The multi-user receiving apparatus according to claim 1, further comprising: the last-stage PIC structure further comprises a spreading factor calculation unit, configured to calculate a spreading factor of a DPDCH channel of the current stage.

9. The multi-user receiving device according to claim 2, further comprising: the intermediate-stage PIC structure further comprises a spreading factor calculation unit, configured to calculate a spreading factor of a DPDCH channel of the current stage.

10. The multi-user receiving device according to claim 8 or 9, further characterized in that the spreading factor calculation unit comprises a TFCI decoding unit, configured to perform TFCI decoding on the RAKE combining result of the input DPCCH channel. The spreading factor of the DPDCH channel, and the spreading factor of the DPDCH channel is sent to the DPDCH despreading unit.

11. The multi-user receiving device according to claim 5 or 6, further comprising: spreading the channel of the DPDCH despreading unit in the intermediate-stage PIC structure and the last-stage PIC structure. The factor can use the spreading factor of the DPDCH despreading unit in the PIC structure at the upper level, or it can be provided by the spreading factor calculation unit at the current level.