WO2011038600A1

WO2011038600A1 - Method and device for multi-path search in code division multiple access system

Info

Publication number: WO2011038600A1
Application number: PCT/CN2010/074634
Authority: WO
Inventors: 闫晓伟
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-09-30
Filing date: 2010-06-28
Publication date: 2011-04-07
Also published as: CN101667848B; CN101667848A

Abstract

A method for a multi-path search in a Code Division Multiple Access system is disclosed. The method comprises: computing the coherent integration and the non-coherent integration of both a Dedicated Physical Control Channel (DPCCH) and an Enhanced Dedicated Physical Control Channel (E-DPCCH) to obtain a correlation function of the DPCCH and a correlation function of the E-DPCCH; computing or selecting, according to the correlation function of the DPCCH and the correlation function of the E-DPCCH, to obtain a final correlation function; then obtaining a multi-path set of the search through peak detection and interpolation. The multi-path set of the search is used for search window tracking to adjust the search window position, and is used in combination with a multi-path history set to obtain a final multi-path set. The final multi-path set is sent to a receiver. A multi-path searcher for a Code Division Multiple Access system is also disclosed. In the technical solution, a multi-path search is performed when a DPCCH and E-DPCCH are simultaneously present to overcome the disadvantages that occur in some cases when only a DPCCH is used to search, and to improve the overall performance of a searcher.

Description

Method and device for multipath search in code division multiple access system

Technical field

The present invention relates to the field of mobile communication technologies, and in particular, to a multipath search method and apparatus in a direct spread spectrum code division multiple access system.

Background technique

In the direct spread spectrum code division multiple access system, the uplink uses a pseudo-random sequence (Pseudorandom Noise, PN sequence) to scramble the spread spectrum signal to distinguish different users. If the local PN sequence generated by the wireless receiving end and the PN sequence of the received signal are completely synchronized, the received spread spectrum signal can be correctly despread. In order to complete the phase synchronization of the PN sequence of the received signal and effectively separate the multipath, it is necessary to correctly estimate the time delay between the transceivers and between the signals of the respective paths.

At present, pilot signals in a Dedicated Physical Control Channel (DPCCH) are usually used to estimate multipath delay, that is, using the received baseband signal and known scrambling codes and pilot symbols for different delays. Correlation, get a correlation function. The correlation function will have a peak when the correlation delay and multipath delay are the same, and find the peak in the correlation function waveform. If the peak value is greater than a certain threshold, the corresponding delay is the multipath delay.

Since the scrambling code and pilot symbols of the receiving end are known, it is related to the received baseband signal, and a more accurate correlation function can be obtained. In the Rel-6 version of the 3rd Generation Partnership Project (3GPP) and previous versions, the difference between the energy of the DPCCH and the total energy of each channel for High-Speed Uplink Packet Access (HSUPA) service The value is less than 15dB. However, in the 3GPP protocol Rel-7 and later, E-DPCCH is raised in the FRC8 Enhanced Dedicated Physical Control Channel (E-DPCCH) Boosting mode due to the introduction of a new fixed reference channel FRC8. And the energy of the Enhanced Dedicated Physical Data Channel (E-DPDCH). Due to the low energy of the DPCCH itself and the interference of other code channels due to the presence of multipath, the performance of searching with DPCCH in the FRC8 E-DPCCH Boosting mode is drastically deteriorated. After rigorous theoretical derivation and link simulation, it is found that continuing to use DPCCH search in FRC8 E-DPCCH Boosting mode can not meet the receiver's requirements for search multipath energy and accuracy, receiver nature. Can not meet the requirements of the 3GPP protocol.

Therefore, in order to improve the performance of the searcher in this mode and improve the demodulation performance of the receiver to better meet the requirements of the 3GPP protocol, a new search method is needed to distinguish it from the DPCCH alone. Multipath search method.

Summary of the invention

The technical problem to be solved by the present invention is to provide a multipath search method and apparatus in a code division multiple access system, perform multipath search in a scenario where DPCCH and E-DPCCH exist simultaneously, and overcome the use of DPCCH for searching alone. The disadvantages of these scenarios improve the overall performance of the searcher.

In order to solve the above problems, the present invention proposes a multipath searcher, comprising: a calculation correlation function module, a correlation function combiner, a peak detection module, a multipath interpolation module, a search window tracker and a multipath combining module, wherein:

The calculation correlation function module is set to: calculate a correlation function of the DPCCH according to the DPCCH, and calculate a correlation function of the E-DPCCH according to the E-DPCCH;

The correlation function combiner is set to: calculate or select a final correlation function according to the correlation function of the DPCCH and the correlation function of the E-DPCCH;

The peak detection module is configured to: dynamically calculate a peak threshold according to the final correlation function, and use the peak threshold to detect a peak to obtain multipath information with a precision of 0.5 chips; the multipath interpolation module is set to: the detected by the peak detection module Multipath information is interpolated to improve the accuracy of multipath, and multipath information after interpolation is obtained;

The search window tracker is set to: adjust the position of the search window according to the multipath information after the interpolation of the multipath search;

The multipath combining module is configured to: combine the interpolated multipath set and the historical multipath set output by the multipath interpolation module to obtain a final multipath set, and output the final multipath set to the receiver.

The calculation correlation function module includes: a calculation DPCCH correlation function sub-module, which is configured to: calculate a correlation function of the DPCCH according to the DPCCH; and calculate an E-DPCCH correlation function sub-module, which is set to: calculate E- according to the E-DPCCH The relevant function of DPCCH.

The calculating DPCCH correlation function sub-module comprises: a DPCCH coherent integrator, which is set to: The coherent integration of the DPCCH is calculated to obtain the DPCCH coherently accumulated symbol; and the DPCCH non-coherent integrator is set to: non-coherently accumulate the DPCCH coherently accumulated symbols, and the output is a correlation function of the DPCCH.

The DPCCH coherent integrator includes: a descrambling sub-module, configured to: descramble the received antenna data and the known scrambling code; and despread the sub-module, which is set to: the data after descrambling and the known DPCCH The spreading code is despread; the pilot depolarization submodule is configured to: depolarize the symbol after despreading with a known DPCCH pilot symbol; and coherently accumulate the submodule, which is set to: Several symbols after the sum are added to obtain the coherently accumulated symbols of the DPCCH.

The DPCCH incoherent integrator includes: an amplitude or power calculation sub-module configured to: calculate a magnitude or power for a symbol obtained by coherent accumulation of the DPCCH coherent integrator output; and a non-coherent accumulation sub-module configured to: The correlation function of the DPCCH is obtained by accumulating the amplitude or power results of several time slots.

The calculation E-DPCCH correlation function sub-module comprises: an E-DPCCH coherent integrator, which is configured to: calculate a coherent integration of the E-DPCCH, output a symbol obtained by coherent accumulation of the E-DPCCH; and an E-DPCCH non-coherent integrator The setting is: non-coherent accumulation of the E-DPCCH coherently accumulated symbols, and the output is a correlation function of the E-DPCCH.

The E-DPCCH coherent integrator includes: a descrambling sub-module, configured to: descramble the received antenna data and the known scrambling code; and despread the sub-module, which is set to: the data after the descrambling and Knowing the spreading code to perform despreading; the buffer submodule is set to: buffer the despread symbols and wait for the E-DPCCH decoding result; the symbol depolarization submodule is set to: after the decoding arrives, The symbol is depolarized by the E-DPCCH decoding buffer; and the coherent accumulation sub-module is set to: accumulate the symbols after the depolarization to obtain the E-DPCCH coherently accumulated symbols.

The E-DPCCH non-coherent integrator includes: an amplitude or power calculation sub-module configured to: calculate a magnitude or power for a symbol obtained by coherent accumulation of the E-DPCCH coherent integrator output; and a non-coherent accumulation sub-module, It is set to: Accumulate the amplitude or power results of several time slots to obtain the correlation function of the DPCCH.

The correlation function combiner includes: a first calculation submodule, a second calculation submodule, a comparison submodule, and an assignment submodule, The first calculation sub-module is set to: obtain a correlation function ADP-c of the DPCCH, and calculate a maximum value ADPmax-c and a mean value ADPmean c of the correlation function ADP-c according to the correlation function ADPc of the DPCCH;

The second calculation sub-module is set to: obtain the E-DPCCH correlation function ADP_ec, and calculate the maximum value ADPmax_ec and the mean ADPmean ec of the correlation function ADP_ec according to the correlation function ADP-ec of the E-DPCCH;

The comparison submodule is set to: Determine if the following formula is true:

ADPmax ec * ADPmean_c>ADPmax_c * ADPmean ec ,

If so, it indicates that the assignment submodule assigns ADP_ec to the final correlation function ADP_final; if not, it indicates that the assignment submodule assigns ADP_c to the final correlation function ADP_ final.

The interpolated multipath information output by the multipath interpolation module is multipath information of 1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip precision.

The invention also provides a multipath search method, comprising:

Step A. Perform coherent integration and non-coherent integration on DPCCH to obtain the correlation function of DPCCH, perform coherent integration and non-coherent integration on E-DPCCH to obtain the correlation function of E-DPCCH; Step B. According to the correlation function of DPCCH and E-DPCCH The correlation function is calculated or selected to obtain the final correlation function;

Step C. Calculate a peak threshold according to the final correlation function, and perform multipath information with a peak detection of 0.5 chip precision;

Step D. Interpolating the multipath with 0.5 chip precision to obtain the multipath information after interpolation; Step E. Adjusting the search window position according to the interpolated multipath information obtained in step D, and adjusting the search window position according to the floating state of the multipath ; as well as

Step F. Perform multipath combining on the multipath set and the historical multipath set of the search to obtain a final multipath set and output it to the receiver.

In the step A, the E-DPCCH is subjected to coherent integration and non-coherent integration to obtain E-DPCCH. The steps of the related function include:

A3. Calculating the coherent integration of the E-DPCCH by using a coherent integrator according to the antenna data, the scrambling code, the E-DPCCH spreading code, and the symbol after the E-DPCCH decoding, and outputting the symbol obtained by coherently accumulating the E-DPCCH;

A4. Using the incoherent integrator, the E-DPCCH coherently accumulated symbols are non-coherently accumulated, and the output is a correlation function of the E-DPCCH.

The step A3 includes:

De-scrambling the received antenna data and the known scrambling code;

Despreading the data after descrambling and the known spreading code;

Cache the despread symbols and wait for the E-DPCCH decoding result;

After the decoding arrives, the symbol decoded by the E-DPCCH decoding of the buffer symbol is added; and the symbols after the depolarization are accumulated to obtain the E-DPCCH coherently accumulated symbol.

The step A4 includes:

Calculating amplitude or power for the coherently accumulated symbols;

The correlation function of the DPCCH is obtained by accumulating the amplitude or power results of several time slots.

The step B includes:

Step B1:

Obtain the correlation function ADP c of DPCCH, calculate the maximum value of the correlation function ADP c according to the correlation function ADP c of DPCCH ADPmax - c and the mean ADPmean - c;

The E-DPCCH correlation function ADP_ec is obtained, and the maximum value of the correlation function ADP ec is calculated according to the correlation function ADP_ec of the E-DPCCH. ADPmax_ec and the mean ADPmean_ec; and Step B2: Comparison determines whether the following formula holds:

ADPmax ec * ADPmean_c>ADPmax_c * ADPmean ec ,

If so, assign ADP_ec to the final correlation function ADP_ final; if not, assign ADP_c to the final correlation function ADP_fmal.

In the step D, the interpolated multipath information is 1/4 chip, 1/8 chip, 1/16 chip. Or multipath information with 1/32 chip precision.

In contrast to the prior art, the present invention introduces a search for E-DPCCH, i.e., the multipath delay correlation function is computed using the results of E-DPCCH hard decision or decoding. The correlation function is combined with a multipath delay correlation function calculated using DPCCH pilot symbols to perform multipath searching to improve the peak-to-average ratio of the correlation function. This can overcome the drawbacks of using the DPCCH search alone in some scenarios (the DIR of the DPCCH is too low) to improve the performance of the search. This joint search technique is a required solution for the FRC8 E-DPCCH Boosting mode.

Compared with the pilot symbol calculation function of DPCCH alone, using the E-DPCCH hard decision or decoding result to calculate the correlation function can use more symbols for correlation calculation, which can improve the peak-to-average ratio of the correlation function. Furthermore, in some scenarios where the DPCCH search can meet the performance requirements and the energy of the E-DPCCH is higher than the energy of the DPCCH, the joint search can further improve the performance of the searcher.

Furthermore, the present invention also provides a method of calculating or selecting a final correlation function based on a DPCCH correlation function and an E-DPCCH correlation function. This method can ensure that the searcher can obtain better search performance even when the scenes are frequently switched. BRIEF abstract

Figure 1 is a block diagram of a multipath searcher that is now commonly used with DPCCH alone;

2 is a block diagram of a multipath searcher of the present invention in combination with DPCCH and E-DPCCH;

Figure 3 is a block diagram of the algorithm for calculating the DPCCH correlation function;

4 is a block diagram of an algorithm for calculating an E-DPCCH correlation function according to the present invention;

5 is a block diagram of a correlation function combiner in a multipath searcher of the present invention in combination with DPCCH and E-DPCCH;

6 is a search processing flow of the present invention using DPCCH and E-DPCCH in combination;

7 is a process flow of a method for calculating a final correlation function according to the present invention;

Figure 8 is the same receiver using the existing universal searcher (search only with DPCCH) and the present Simulation performance of the bright searcher under FRC3 PB3;

Figure 9 is a simulation performance of the same receiver using the existing universal searcher (search only with DPCCH) and the searcher of the present invention in combination with DPCCH and E-DPCCH in FRC8 E-DPCCH Boosting mode PB3.

Preferred embodiment of the invention

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for multipath searching in a code division multiple access system, and in particular, a method and apparatus for multipath searching by means of DPCCH and E-DPCCH in an HSUPA system. In some scenarios where the DPCCH energy is low, the DPCCH and E-DPCCH joint search are used to improve the peak-to-average ratio of the correlation function and the overall performance of the searcher.

As shown in FIG. 1 , a multi-path searcher that is commonly used for searching using DPCCH is displayed. The multipath searcher includes a calculation DPCCH correlation function module 101, a peak detection module 102, a multipath interpolation module 103, and a search window tracking. The unit 104, the multipath combining module 105. among them:

The DPCCH correlation function module 101 is configured to perform correlation calculation according to the received antenna data and the scrambling code, the DPCCH spreading code, and the DPCCH pilot symbol by using the coherent integrator a1, to obtain a coherent integration result of the DPCCH (complex form); The non-coherent integrator a2 calculates the amplitude or power of the coherent integration result of the DPCCH, and then accumulates the amplitude or power of several time slots to obtain the result of the DPCCH non-coherent integration, which is the correlation function of the DPCCH;

The peak detecting module 102 is configured to dynamically calculate a peak threshold, and detect a peak according to a correlation function of the DPCCH and a peak threshold to obtain multipath information with lower precision;

Multipath interpolation module 103: used to interpolate the detected peaks to improve the accuracy of multipath and obtain higher precision multipath information;

The search window tracker 104 is configured to adjust the position of the search window according to a certain algorithm according to the result of the multipath search to ensure that the search window can still capture the large diameter including the strongest path as the multipath drifts. Most multipaths;

Multipath merge module 105: used to merge the multipath set and the historical multipath set of the current search, The final multipath set is obtained and output to the receiver.

As shown in FIG. 2, a multipath searcher in which the DPCCH and the E-DPCCH of the present invention are jointly searched is shown. The combined multipath searcher includes a calculation correlation function module 201, a correlation function combiner 202, and a peak detection module 203. The multipath interpolation module 204, the search window tracker 205, and the multipath combining module 206. among them:

The calculation correlation function module 201 is configured to calculate a DPCCH correlation function according to the DPCCH and a correlation function of the E-DPCCH according to the E-DPCCH, and further divide into: calculating a DPCCH correlation function sub-module a and calculating an E-DPCCH correlation function. Module b;

Calculate the DPCCH correlation function sub-module a including: DPCCH coherent integrator al , used to calculate

Coherent integration of DPCCH; DPCCH non-coherent integrator a2, used for non-coherent accumulation of DPCCH coherently accumulated symbols, the output is a correlation function of DPCCH;

The E-DPCCH correlation function sub-module b is calculated to include: an E-DPCCH coherent integrator bl for calculating the coherent integration of the E-DPCCH; and an E-DPCCH non-coherent integrator b2 for performing the E-DPCCH coherently accumulated symbols Non-coherent accumulation, the output is the correlation function of E-DPCCH.

Correlation function combiner 202: for calculating or selecting a final correlation function according to a DPCCH correlation function and an E-DPCCH correlation function;

The peak detection module 203 is configured to dynamically calculate a peak threshold, and detect a peak according to the final correlation function and a peak threshold to obtain multipath information with lower precision, for example, multipath information with 0.5 chip precision;

The multipath interpolation module 204 is configured to perform interpolation on the multipath detected by the peak detecting module 203 to improve multipath accuracy, and obtain high precision multipath information, for example, interpolating multipath information with 0.5 chip precision. Obtain multipath information of 1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip precision;

The search window tracker 205 is configured to adjust the position of the search window according to a certain algorithm according to the result of the multipath search to ensure that the search window can still capture most of the multipath energy as the multipath drifts; There are many search window adjustment algorithms, which can be applied to the present invention, and will not be described again here. The multipath combining module 206 is configured to combine the currently detected multipath set and the historical multipath set to obtain a final multipath set and output to the receiver. When searching for the first time, there is no historical multipath information, no multipath merging; the second search, the result of the first search is taken as the historical multipath set, and the multipath set of the second search is merged to obtain the second The second final multipath set; the third search, merges the second final multipath set with the most historical multipath set, and the third searched multipath set to obtain the third final multipath set, and so on.

According to Fig. 1 and Fig. 2, and comparing with the above detailed description, it can be found that the difference between the two searchers lies in the calculation of the correlation function module 201 and the correlation function combiner 202, and the functions of the other modules are the same. Thus, the multipath searcher in which the DPCCH and the E-DPCCH are searched in conjunction with the present invention will be described in detail below with reference to Fig. 2, with particular emphasis on the calculation correlation function module 201 and the correlation function combiner 202.

The calculation correlation function module 201 is configured to calculate correlation functions of the DPCCH and the E-DPCCH. Including: Calculate the DPCCH correlation function sub-module a and calculate the E-DPCCH correlation function sub-module b.

(1) Calculate the DPCCH correlation function sub-module a, which is used to calculate the correlation function of the DPCCH. It also includes:

DPCCH coherent integrator al: is used to calculate the coherent integration of DPCCH. The input of DPCCH coherent integrator al includes antenna data, scrambling code, DPCCH spreading code, DPCCH pilot symbol, and the output is the symbol obtained by coherent accumulation of DPCCH.

DPCCH non-coherent integrator a2: used to perform non-coherent accumulation on the DPCCH coherently accumulated symbols (the amplitude or power is calculated for the coherently accumulated symbols, and then summed). The input of the DPCCH non-coherent integrator a2 is the coherently accumulated symbol of the DPCCH output of al, and the output is the correlation function of DPCCH.

DPCCH coherent integrator al and DPCCH non-coherent integrator a2 calculation DPCCH correlation function detailed processing shown in Figure 3:

In the DPCCH coherent integrator a1, first, the descrambling sub-module 301 descrambles the received antenna data and the known scrambling code; after descrambling, the despreading sub-module 302 spreads the data after descrambling and the known DPCCH. The code is despread; the pilot depolarization sub-module 303 uses the known symbols after despreading DPCCH pilot symbol depolarization processing; coherent accumulation sub-module 304 accumulates several symbols after depolarization to obtain DPCCH coherently accumulated symbols.

In the DPCCH non-coherent integrator a2, first, the amplitude or power calculation sub-module 305 calculates the amplitude or power for the coherently accumulated symbols of the coherent accumulation sub-module 304; then, the result of the non-coherent accumulation sub-module 306 for a number of time slots ( That is, the amplitude or power value) is accumulated to obtain the correlation function of the DPCCH.

(2) Calculate the E-DPCCH correlation function sub-module b, which is used to implement the E-DPCCH related function. It also includes:

The E-DPCCH coherent integrator bl is used to calculate the coherent integration of the E-DPCCH. The input includes antenna data, scrambling code, E-DPCCH spreading code, E-DPCCH hard decision or symbol after decoding, and the output is the symbol obtained after coherent accumulation of E-DPCCH. Since the hard decision or decoding of the E-DPCCH takes time, the data after despreading needs to be buffered first, waiting for the hard decision or decoding result of the E-DPCCH, and de-spreading the buffer by using the hard decision or decoding result of the E-DPCCH. The symbols afterwards are depolarized.

The E-DPCCH non-coherent integrator b2 is used to perform non-coherent accumulation of the symbols after the E-DPCCH coherent accumulation of the E-DPCCH coherent integrator bl. The input is the DPCCH coherently accumulated symbol of the bl output, and the output is the correlation function of the E-DPCCH.

E-DPCCH coherent integrator bl and E-DPCCH non-coherent integrator b2 calculation The detailed processing of the E-DPCCH correlation function is shown in Figure 4:

In the E-DPCCH coherent integrator bl, first, the descrambling sub-module 401 descrambles the received antenna data and the known scrambling code; after descrambling, the despreading sub-module 402 pairs the descrambled data and the known spreading The frequency code is despread; then, the buffer submodule 403 buffers the despread symbols, waits for the E-DPCCH hard decision or the decoding result; after the decoding arrives, the symbol depolarity submodule 404, and the cache symbol uses E- DPCCH hard decision or decoded symbol depolarization; after depolarization, coherent accumulation sub-module 405 accumulates several symbols after depolarization to obtain E-DPCCH coherently accumulated symbols.

In the E-DPCCH non-coherent integrator b2, the amplitude or power calculation sub-module 406 calculates the amplitude or power for the coherently accumulated symbols of the coherent accumulation sub-module 405; the non-coherent accumulation sub-module 407, the result for several time slots (ie The amplitude or power value is added to get the correlation function of DPCCH. The correlation function combiner 202 is configured to combine or select the correlation functions of the DPCCH and the E-DPCCH calculated by the calculation correlation function module 201 to obtain a final correlation function. The input includes DPCCH correlation function and E-DPCCH. The detailed processing procedure is shown in Figure 5, including:

a first calculation sub-module 501, configured to obtain a DPCCH correlation function ADP-c, and calculate a maximum value ADPmax c and a mean value ADPmean-c according to a correlation function ADPc of the DPCCH;

a second calculation sub-module 502, configured to obtain an E-DPCCH correlation function ADP_ec, and calculate a maximum value ADPmax ec and a mean value ADPmean_ec according to the correlation function ADP_ec of the E-DPCCH;

The comparison submodule 503 is configured to determine whether the following formula is true:

ADPmax ec * ADPmean_c>ADPmax_c * ADPmean ec ,

If so, the assignment sub-module 504 is instructed to assign ADP_ec to the final correlation function ADP_final; if not, the assignment sub-module 504 is assigned the ADP-c to the final correlation function ADP-fmal.

The peak detecting module 203 is configured to detect a peak value from the final correlation function selected by the correlation function combiner 202, that is, a delay position corresponding to the multipath. The input is the final correlation function obtained by the correlation function combiner 202, and the output is a multipath set of 0.5 chip precision.

The multipath interpolation module 204 is configured to further interpolate the multipath detected by the peak detecting module 203 to obtain more accurate multipath information. The input is a multipath set of 0.5 chip precision obtained by the peak detecting module 203, and the output is more accurate (for example, 1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip). Multipath collection.

The search window tracker 205 is configured to adjust the search window position according to the multipath information interpolated by the multipath interpolation module 204 to ensure that the search window can cover most of the multipath including the strongest path. The input is the multipath set information of high precision (for example, 1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip) obtained by interpolation by the multipath interpolation module 204, and the output is the search window position. The direction and size of the adjustment.

The multipath combining module 206 is configured to combine the multipath set obtained by the search and the historical multipath set And, the final multipath set is obtained, and the final multipath set is sent to the receiver and the like. The input is the multipath interpolation module 204 to obtain the multipath set and the historical multipath set of the current search, and the output is the final multipath set. When searching for the first time, there is no historical multipath information, no multipath merging; the second search, the result of the first search is taken as the historical multipath set, and the multipath set of the second search is merged to obtain the second The second final multipath set; the third search, merges the second final multipath set with the most historical multipath set, and the third searched multipath set to obtain the third final multipath set, and so on.

The method for performing multipath search by combining DPCCH and E-DPCCH of the present invention comprises the following steps: Step A. Perform coherent integration and non-coherent integration on DPCCH and E-DPCCH respectively, and calculate correlation function of DPCCH and correlation of E-DPCCH Function

Step B. Calculate or select the final correlation function according to the correlation function of DPCCH and the correlation function of E-DPCCH;

Step D. Interpolating the multipath with 0.5 chip precision to obtain an accuracy of 1/4 chip, 1/8 chip,

Multipath information for 1/16 chips or 1/32 chips;

Step E. Adjust the search window position according to the multipath information of the output of step D, which is 1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip, and adjust with the multipath drift state. Search window position; Step F. Perform multipath combining on the multipath set and the historical multipath set of the search to obtain the final multipath set and output to the receiver. The historical multipath set is the final multipath set of the last multipath set and then output, or the result of the previous multiple search multipath set merge.

As shown in Fig. 6, a specific embodiment of performing multipath search by combining DPCCH and E-DPCCH is shown. The processing flow for joint DPCCH and E-DPCCH multipath search based on the searcher shown in Fig. 2 is as follows:

Step 601: Receive antenna data;

Step 602: Calculate the DPCCH correlation function and the E-DPCCH correlation function separately, including steps 602a and 602b performed simultaneously:

Step 602a: pass DPCCH coherent integrator a1 and DPCCH incoherent integrator a2 Calculate the DPCCH correlation function;

The input of the DPCCH coherent integrator includes antenna data, scrambling code, DPCCH spreading code, DPCCH pilot symbol, and the output is a symbol obtained by coherent accumulation of DPCCH.

The DPCCH non-coherent integrator a2 performs non-coherent accumulation on the DPCCH coherently accumulated symbols (the amplitude or power is calculated for the coherently accumulated symbols, and then summed and summed), and the input is the DPCCH coherently accumulated symbol of the al output, and the output is The relevant function of DPCCH.

Step 602b: Calculate the E-DPCCH correlation function by the E-DPCCH coherent integrator bl and the E-DPCCH incoherent integrator b2;

The E-DPCCH coherent integrator bl is used to calculate the coherent integration of the E-DPCCH. The input includes antenna data, scrambling code, E-DPCCH spreading code, E-DPCCH hard decision or symbol after decoding, and the output is the symbol obtained by coherent accumulation of E-DPCCH. Note that because the hard decision or decoding of the E-DPCCH takes time, the data after despreading needs to be buffered first, waiting for the hard decision or decoding result of the E-DPCCH, and the hard decision of the E-DPCCH or the decoding result of the decoding result. The symbol after the expansion is depolarized.

The E-DPCCH non-coherent integrator b2 is used to perform non-coherent accumulation of the E-DPCCH coherently accumulated symbols. The input is the symbol of the DPCCH coherently accumulated by the bl output, and the output is the correlation function of the E-DPCCH.

Step 603: According to the DPCCH correlation function and the E-DPCCH correlation function, perform correlation function merging, calculation or selection to obtain a final correlation function; and a specific processing procedure for calculating the final correlation function is shown in FIG. 7 .

Step 604: Perform peak detection on the final correlation function, detect the peak value, and output multipath information of 0.5 chip precision;

Step 605: Perform multipath interpolation on the 0.5-chip precision multipath information output of the peak detection output to obtain higher precision (1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip) Multipath information of accuracy); Step 606: Multipath information of 1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip precision outputted by step 605, on the one hand as a search window tracker The input of 205 (ie, the input of the search window position adjustment), uses the obtained multipath information to perform search window adjustment according to a certain algorithm, determines the direction and size of the search window adjustment, and outputs the feedback of the search window adjustment to step 604, according to which the search is performed. The output value of the window adjustment adjusts the position of the search window; Step 607: Step 605 outputs multi-path information of 1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip precision, and on the other hand, as an input of multipath combining, according to the current search. The multipath information and the historical multipath information are multipath combined according to a certain algorithm to obtain the final multipath information;

Step 608: The final multipath information is output to the receiver for use, and the process ends.

As shown in FIG. 7, the specific processing flow for calculating the final correlation function in step 603 is shown, including:

Step 701a: Obtain a DPCCH correlation function ADP_c;

Step 702a: Calculate the maximum value ADPmax_c and the mean value ADPmean c according to the correlation function ADP-c of the DPCCH;

Step 701b: Obtain an E-DPCCH correlation function ADP_ec;

Step 702b: Calculate the maximum value ADPmax_ec and the mean ADPmean ec according to the correlation function ADP_ec of the E-DPCCH;

The first branches of the above steps 701a, 702a are sequentially executed, and the second branches of steps 701b, 702b are sequentially executed: and the two branches are simultaneously executed.

Step 703: Determine whether ADPmax - ec * ADPmean - c > ADPmax - c * ADPmean - ec is established, if the step 704 is established, otherwise go to step 705;

Step 704: Assign ADP_ec to the final correlation function ADP_ final;

Step 705: Assign ADP-c to the final correlation function ADP_fmal.

Figure 8 is a simulation performance of the same receiver using the existing universal searcher (search only with DPCCH) and the searcher of the present invention for multipath searching under FRC3 PB3. As can be seen from Figure 8, the performance of the two searchers is comparable, that is, in the scenario where some existing searchers can meet the performance requirements, the searcher of the present invention can also meet the performance requirements, and the performance is comparable to the performance of the existing searcher.

Figure 9 is a simulation performance of the same receiver using the existing universal searcher (search only with DPCCH) and the searcher of the present invention for multipath search in conjunction with DPCCH and E-DPCCH in FRC8 E-DPCCH Boosting mode PB3. As can be seen from Fig. 9, in some special scenarios such as the FRC8 E-DPCCH Boosting mode, the performance of the existing searcher deteriorates greatly and cannot meet the performance requirements; and the searcher of the present invention can satisfactorily meet the performance requirements.

The above is only the embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Where is the spirit and principle of the present invention Any modifications, equivalent substitutions, improvements, etc., are intended to be included within the scope of the appended claims.

One of ordinary skill in the art will appreciate that all or a portion of the steps above may be accomplished by a program to instruct the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

Industrial applicability

Furthermore, the present invention also provides a method of calculating or selecting a final correlation function based on a DPCCH correlation function and an E-DPCCH correlation function. This method can ensure that the searcher can obtain better search performance even when the scenes are frequently switched.

Claims

Claim

A multipath searcher comprising: a computational correlation function module, a correlation function combiner, a peak value detection module, a multipath interpolation module, a search window tracker, and a multipath merge module, wherein:

The calculation correlation function module is configured to: calculate a correlation function of the DPCCH according to a dedicated physical control channel (DPCCH), and calculate a correlation function of the E-DPCCH according to the enhanced dedicated physical control channel (E-DPCCH);

The correlation function combiner is configured to: calculate or select a final correlation function according to a correlation function of the DPCCH and a correlation function of the E-DPCCH;

The peak detection module is configured to: dynamically calculate a peak threshold according to the final correlation function, and use the peak threshold to detect a peak to obtain multipath information with 0.5 chip precision;

The multipath interpolation module is configured to: interpolate multipath information detected by the peak detection module, improve multipath accuracy, and obtain interpolated multipath information;

The search window tracker is configured to: adjust the position of the search window according to the interpolated multipath information of the multipath search;

2. The multipath searcher of claim 1, wherein the calculation correlation function module comprises: a calculation DPCCH correlation function submodule, configured to: calculate a correlation function of the DPCCH according to the DPCCH;

The E-DPCCH correlation function sub-module is calculated, which is set as: Calculate the correlation function of the E-DPCCH according to the E-DPCCH.

3. The multipath searcher according to claim 2, wherein the calculating the E-DPCCH related function submodule comprises:

E-DPCCH coherent integrator, which is set to: Calculate the coherent integration of the E-DPCCH, output

Symbol obtained after coherent accumulation of E-DPCCH;

E-DPCCH non-coherent integrator, which is set to: Consistently accumulate the symbols after E-DPCCH Line non-coherent accumulation, the output is the correlation function of E-DPCCH.

4. The multipath searcher of claim 2, wherein the E-DPCCH coherent integrator comprises:

a descrambling sub-module, configured to descramble the received antenna data and the known scrambling code; the despreading submodule is configured to: despread the descrambled data and the known spreading code; the buffer submodule , which is set to: buffer the despread symbols, wait for the E-DPCCH hard decision or the decoding result;

a symbol depolarization sub-module, which is configured to: de-polarize the symbol of the hard-decision or decoding of the E-DPCCH for the cache symbol after the hard decision or the decoding result arrives;

A coherent accumulation submodule, which is set to: accumulate several symbols after depolarization

E-DPCCH coherently accumulated symbols.

The multipath searcher according to claim 2 or 3, wherein the E-DPCCH non-coherent integrator comprises:

An amplitude or power calculation sub-module configured to: calculate a magnitude or power for a symbol obtained by coherent accumulation of the E-DPCCH coherent integrator output;

A non-coherent accumulation sub-module, which is set to: accumulate the amplitude or power results of a number of time slots to obtain a correlation function of the DPCCH.

The multipath searcher according to claim 1, wherein the correlation function combiner comprises: a first calculation submodule, a second calculation submodule, a comparison submodule, and an assignment submodule, the first computation sub The module is set to: Get the DPCCH related function ADP c, according to

The correlation function of DPCCH ADP—c calculates the maximum value of the correlation function ADP— c ADPmax— c and the mean ADPmean c;

The second calculation submodule is configured to: obtain an E-DPCCH correlation function ADP_ec, and calculate a maximum value ADPmax_ec and a mean ADPmean ec of the correlation function ADP_ec according to the correlation function ADP_ec of the E-DPCCH;

The comparison submodule is set to: determine whether the following formula is true:

ADPmax ec*ADPmean c>ADPmax c*ADPmean ec, If so, the assignment sub-module is instructed to assign ADP_ec to the final correlation function ADP_final; if not, the assignment sub-module is instructed to assign ADP-c to the final correlation function ADP_fmal.

7. The multipath searcher according to claim 1, wherein the multipath information output by the multipath interpolation module is 1/4 chip, 1/8 chip, 1/16 chip or 1/32 code. Multipath information for slice precision.

8. A method of multipath searching, comprising:

Step A. Perform coherent integration and non-coherent integration calculation on the dedicated physical control channel (DPCCH) to obtain the correlation function of DPCCH, and perform coherent integration and non-coherent integration on the enhanced dedicated physical control channel (E-DPCCH) to obtain the correlation function of E-DPCCH. ;

Step D. Interpolating the multipath with 0.5 chip precision to obtain multipath information;

Step E. Perform search window tracking according to the multipath information obtained in step D, and dynamically adjust the search window position as the multipath drifts;

9. The method of claim 8 wherein

In the step A, the steps of performing coherent integration and non-coherent integration on the E-DPCCH to obtain the correlation function of the E-DPCCH include:

A3. Calculate the coherent integration of the E-DPCCH by using a coherent integrator according to the antenna data, the scrambling code, the E-DPCCH spreading code, the E-DPCCH hard decision or the symbol after decoding, and output the symbol obtained by coherently accumulating the E-DPCCH. ;

The method of claim 9, wherein the step A3 comprises: De-scrambling the received antenna data and the known scrambling code;

Despreading the data after descrambling and the known spreading code;

Cache the despread symbols, wait for the E-DPCCH hard decision or the decoding result; after the hard decision or decoding arrives, de-polarize the symbols obtained by hard-deciding or decoding the E-DPCCH for the buffer symbols;

The symbols after the depolarization are accumulated to obtain the coherently accumulated symbols of the E-DPCCH.

The method according to claim 9 or 10, wherein the step A4 comprises: calculating amplitude or power for the coherently accumulated symbols;

12. The method of claim 8, wherein the step B comprises:

Step B1:

ADPmax ec * ADPmean_c>ADPmax_c * ADPmean ec ,

13. The method according to claim 8, wherein the multipath information obtained in the step D is

Multipath information of 1/4 chip, 1/8 chip, 1/16 chip or 1/32 chip precision.