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CN112713913A - Matched filtering capture system and capture method in incoherent direct sequence spread spectrum system - Google Patents

Matched filtering capture system and capture method in incoherent direct sequence spread spectrum system Download PDF

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CN112713913A
CN112713913A CN202011537585.2A CN202011537585A CN112713913A CN 112713913 A CN112713913 A CN 112713913A CN 202011537585 A CN202011537585 A CN 202011537585A CN 112713913 A CN112713913 A CN 112713913A
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pseudocode
matched filter
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赵洪林
姜洪涛
张佳岩
马永奎
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Harbin Institute of Technology Shenzhen
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Abstract

A matched filtering capture system and a capture method in a non-coherent direct sequence spread spectrum system belong to the technical field of receiver pseudo code synchronization in spread spectrum communication. The invention solves the problem that the data hopping in the incoherent direct sequence spread spectrum system influences the synchronous acquisition. The parallel folding matched filter based on the SRL16 is used as an algorithm for pseudo code phase capturing, so that the use of hardware resources is greatly optimized; the N-path cache method is combined with the matched filter, so that the problem that the phase positions of the data information and the pseudo code are uncertain under the incoherent condition is solved, and the estimation of the data information flip jump position is more accurate. When the pseudo code is Gold code, the code length is 1023, the code rate is 3.069Mcps, the data information rate is 8kbps, and the modulation mode is BPSK, the pseudo code phase can be captured, and the search of errors not greater than 48 pseudo code chip length errors can be completed on the data information flip jump position. The invention can be applied to receiver pseudo code synchronization.

Description

Matched filtering capture system and capture method in incoherent direct sequence spread spectrum system
Technical Field
The invention belongs to the technical field of receiver pseudo code synchronization in spread spectrum communication, and particularly relates to a pseudo code synchronization acquisition method suitable for an incoherent direct sequence spread spectrum communication system.
Background
With the continuous progress of modern communication technology and aerospace measurement and control technology, aerospace measurement and control communication systems gradually develop towards the direction of being compatible with various data information rates, pseudo code rates and higher anti-interference performance, and a direct sequence spread spectrum technology is widely applied to good performances such as simultaneous measurement and control of a plurality of measurement and control targets or different measurement and control signals of the same measurement and control target, high-resolution ranging and the like by utilizing a code division multiple access technology due to excellent anti-interference performance, confidentiality and anti-interception performance. However, since the clocks generated by the baseband data and the pseudo code under the incoherent direct sequence spread spectrum system are non-homologous, the phase is not synchronized, and when the baseband data information is flipped and hopped at different positions in the pseudo code period, the correlation peak value under the conventional synchronization method is reduced to different degrees, so that the conventional direct sequence spread spectrum receiver is not applicable to the pseudo code synchronization operation method.
In the process of synchronous capture of a receiver, overcoming the influence of data information flip-flop is one of key technologies of synchronous processing of a non-coherent direct sequence spread spectrum communication system, common delay phase multiplication multiplies a received signal by a signal which is delayed by a certain code word and then conjugated to obtain a new signal to be processed, the influence of data information flip-flop can be eliminated, but noise power is increased after noise is processed in the same way, and the signal-to-noise ratio in the receiver is reduced. Another common method is a half-bit method, which performs correlation accumulation synchronization processing on adjacent received signals with a length of half baseband data, and because a segment of information is not affected by data information flip-flop, the influence can be overcome, but because the correlation accumulation length is half of the entire baseband data length, there is a processing loss of 3dB, and the correlation peak value is reduced by about half. Therefore, the problem of data information flip hopping is solved, and the problem is one of key problems of synchronous acquisition in the non-coherent direct sequence spread spectrum communication system.
Disclosure of Invention
The invention aims to solve the problem that data hopping in an incoherent direct sequence spread spectrum system influences synchronous acquisition, and provides a matched filtering acquisition system and an acquisition method in the incoherent direct sequence spread spectrum system.
The technical scheme adopted by the invention for solving the technical problems is as follows:
based on one aspect of the invention, a matched filtering capture system in an incoherent direct sequence spread spectrum system comprises a down-conversion module, a pseudo code cache module, a matched filter module, an incoherent accumulation module and a decision module; wherein:
the down-conversion module is used for processing the received BPSK intermediate frequency signal to obtain an in-phase signal and an orthogonal signal;
the pseudo code caching module is used for caching the local pseudo codes by N paths to obtain N paths of local pseudo code sequences;
the matched filter module is used for performing correlation accumulation processing on the N local pseudo code sequences and the in-phase signal and the orthogonal signal obtained by the down-conversion module to obtain a correlation accumulation processing result corresponding to each local pseudo code sequence;
the incoherent accumulation module is used for carrying out incoherent accumulation on a correlation accumulation processing result corresponding to each path of local pseudo code sequence to obtain an incoherent accumulation result corresponding to each path of local pseudo code sequence;
the number of the incoherent accumulation sections is selected to meet the requirement that the incoherent accumulation total length at least comprises a complete pseudo code period;
the judgment module is used for processing the maximum value of the incoherent accumulation result corresponding to the N paths of local pseudo code sequences, comparing the maximum value with a set threshold value until the maximum value is greater than the threshold value, and proving that the capturing of the pseudo code phase is finished.
Only when the initial position of the matched filtering correlation accumulation operation is close to the data information flip hopping position, a larger correlation result can be obtained, so that the maximum value can be selected from the corresponding N-path results obtained by incoherent accumulation to be sent to a judgment module and a threshold value for judgment, and whether the acquisition of the pseudo code phase of the received signal and the search of the data flip hopping position are finished or not can be judged.
Further, the down-conversion module is configured to process the received BPSK intermediate frequency signal to obtain an in-phase signal and an orthogonal signal; the specific process comprises the following steps:
the received BPSK intermediate frequency signal is multiplied by a cos signal generated by a local oscillator to obtain an in-phase signal, and the received BPSK intermediate frequency signal is multiplied by a sin signal generated by the local oscillator to obtain an orthogonal signal.
Furthermore, the initial phase difference of each two adjacent local pseudo code sequences cached by the pseudo code caching module
Figure BDA0002853579880000021
TDThe length of the baseband data information bit is N, and the number of the buffer branches is N.
Further, the matched filter module is a parallel folding matched filter based on the SRL 16.
Further, the SRL 16-based parallel folding matched filter comprises M SRL16 primitives,
Figure BDA0002853579880000022
wherein, TCIs the pseudo code symbol length, P is the folding rate, and Q is the oversampling rate.
Furthermore, the matched filter module is configured to perform correlation accumulation processing on the N local pseudo code sequences and the in-phase signal and the orthogonal signal obtained by the down-conversion module to obtain a correlation accumulation processing result corresponding to each local pseudo code sequence; the specific process comprises the following steps:
for any local pseudo code sequence of the cache, carrying out correlation accumulation operation on the in-phase signal and the local pseudo code sequence of the cache to obtain an in-phase signal correlation accumulation operation result, carrying out correlation accumulation operation on the orthogonal signal and the local pseudo code sequence of the cache to obtain an orthogonal signal correlation accumulation operation result, and carrying out square taking and adding processing on the in-phase signal correlation accumulation operation result and the orthogonal signal correlation accumulation operation result to obtain a correlation accumulation processing result corresponding to the local pseudo code sequence of the cache;
and after traversing each path of local pseudo code sequence, obtaining a relevant accumulation processing result corresponding to each path of local pseudo code sequence.
Based on another aspect of the present invention, a method for capturing a matched filter capture system in a non-coherent direct sequence spread spectrum system is specifically implemented by the following steps:
step one, after a received BPSK intermediate frequency signal is processed by a down-conversion module, an in-phase signal and an orthogonal signal are obtained;
step two, storing local pseudo codes in a ROM, then outputting the local pseudo codes in a reverse order, and caching the local pseudo codes output in the reverse order into an N-path local pseudo code sequence through a pseudo code caching module;
performing correlation accumulation processing on the N local pseudo code sequences and the in-phase signals and the orthogonal signals obtained by the down-conversion module by using a matched filter module to respectively obtain a correlation accumulation processing result corresponding to each local pseudo code sequence;
performing incoherent accumulation on a correlation accumulation processing result corresponding to each path of local pseudo code sequence by using an incoherent accumulation module to obtain an incoherent accumulation result corresponding to each path of local pseudo code sequence;
and fifthly, selecting a maximum value from the incoherent accumulation results corresponding to each path of local pseudo code sequence, sending the selected maximum value to a judgment module, and comparing the maximum value with a set threshold value by the judgment module to realize the capturing of the pseudo code phase.
Further, the specific process of the first step is as follows:
the received BPSK intermediate frequency signal is multiplied by a cos signal generated by a local oscillator to obtain an in-phase signal, and the received BPSK intermediate frequency signal is multiplied by a sin signal generated by the local oscillator to obtain an orthogonal signal.
Furthermore, in the N local pseudo code sequences, the initial phase difference between every two adjacent local pseudo code sequences
Figure BDA0002853579880000031
TDThe length of the baseband data information bit is N, and the number of the buffer branches is N.
Further, the matched filter module is a parallel folding matched filter based on the SRL 16.
Further, the SRL 16-based parallel folding matched filter comprises M SRL16 primitives,
Figure BDA0002853579880000032
wherein, TCIs the pseudo code symbol length, P is the folding rate, and Q is the oversampling rate.
Further, the specific process of the third step is as follows:
for any local pseudo code sequence of the cache, carrying out correlation accumulation operation on the in-phase signal and the local pseudo code sequence of the cache to obtain an in-phase signal correlation accumulation operation result, carrying out correlation accumulation operation on the orthogonal signal and the local pseudo code sequence of the cache to obtain an orthogonal signal correlation accumulation operation result, and carrying out square taking and adding processing on the in-phase signal correlation accumulation operation result and the orthogonal signal correlation accumulation operation result to obtain a correlation accumulation processing result corresponding to the local pseudo code sequence of the cache;
and after traversing each path of local pseudo code sequence, obtaining a relevant accumulation processing result corresponding to each path of local pseudo code sequence.
In order to utilize the good correlation characteristic of the pseudo code, a reasonable number of non-coherent accumulation sections is set so that the total length after the non-coherent accumulation contains at least one pseudo code period.
Furthermore, the working process of the parallel folding matched filter based on the SRL16 is as follows:
for cached N-path local pseudo code sequence
Figure BDA0002853579880000041
Figure BDA0002853579880000042
Respectively folded at a folding rate of P, wherein C0Is the first code element of the first path local pseudo code sequence,
Figure BDA0002853579880000043
is the end of the first local pseudo-code sequenceOne of the symbols is a symbol that is,
Figure BDA0002853579880000044
is the first code element of the second path of local pseudo code sequence,
Figure BDA0002853579880000045
for the last symbol of the second path of local pseudo-code sequence,
Figure BDA0002853579880000046
is the first code element of the Nth local pseudo code sequence,
Figure BDA0002853579880000047
the last code element of the Nth path of local pseudo code sequence;
for any path of local pseudo code sequence, loading a corresponding folded code word in each time slot of the path of local pseudo code sequence, and controlling a control logic to zero at an initial value of a 1 st time slot adder, wherein the initial value of a 2 nd time slot adder is a correlation accumulation sum of the 1 st time slot adder, …, and the initial value of a P th time slot adder is a correlation accumulation sum of a P-1 th time slot adder, and then extracting and accumulating the correlation accumulation sum of the P th time slot adder to obtain a correlation accumulation result corresponding to the path of local pseudo code sequence;
and in the same way, obtaining the correlation accumulation results corresponding to the N local pseudo code sequences respectively.
The invention has the beneficial effects that: the invention has proposed a matching filter in the incoherent direct sequence spread spectrum system and caught the system and catches the method, the invention is directed against Xilinx's hardware platform, adopt the parallel folding matched filter based on SRL16 as the algorithm that the pseudo-code phase catches, has greatly optimized the use of the hardware resource; the N-path cache method is combined with the matched filter, so that the problem that the phase positions of the data information and the pseudo code are uncertain under the incoherent condition is solved, compared with the current half-bit method, the correlation peak value is improved, and meanwhile, the estimation of the flip jump position of the data information is more accurate. When the algorithm of the invention is applied to the condition that the pseudo code is Gold code, the code length is 1023, the code rate is 3.069Mcps, the data information rate is 8kbps, and the modulation mode is BPSK, the acquisition of the pseudo code phase can be completed, and the search of the error which is not more than 48 pseudo code chip length errors can be completed on the data information flip jump position.
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FIG. 1 is a schematic diagram of an incoherent direct sequence spread spectrum process;
FIG. 2 is an overall framework diagram of the pseudo code acquisition method in a non-coherent direct sequence spread spectrum system of the present invention;
FIG. 3 is a block diagram of an SRL 16-based matched filter module with an N-way cache according to the present invention;
FIG. 4 is a timing diagram of the SRL16 based matched filter module process with N-way cache according to the present invention;
in the figure, clk _ sys: system operating clock, clk _ samp: sampling clock, clk _ data: data information generation clock, srl _ in: input data of 1 st SRL16 primitive, SRL _ out 1: output data of 1 st SRL16 primitive, SRL _ out 95: output data of 95 th SRL16 primitive;
fig. 5 is a schematic diagram of the whole capturing process of the matched filter with N-way cache according to the present invention.
Detailed Description
For the incoherent direct sequence spread spectrum system, the biggest difference with the conventional direct sequence spread spectrum system is that the baseband data information generating clock at the transmitting end is non-homologous with the pseudo code generating clock, the spreading diagram is shown in fig. 1, and no definite relation exists between the baseband data information and the pseudo code phase.
Fig. 2 presents an overall block diagram of the synchronization acquisition at the receiver end of the invention. The device mainly comprises a down-conversion module, a pseudo code cache module, a matched filter capturing module, a non-coherent accumulation module and a judgment module.
The down-conversion module is used for carrying out down-conversion processing on the received BPSK intermediate frequency signal, and multiplying the received intermediate frequency signal by a local carrier and a carrier of which the phase is shifted by 90 degrees respectively to obtain an in-phase signal and an orthogonal signal.
The down-conversion module is used for multiplying the intermediate frequency signal obtained after the down-conversion of the digital signal in the radio frequency chip by the local carrier and then combining the multiplication with the subsequent accumulation process to change the intermediate frequency signal into the baseband signal.
The pseudo code caching module is used for caching the local pseudo code by N paths, and the length of each path is the length T of transmitting baseband dataDDifference between two adjacent initial phases
Figure BDA0002853579880000051
The matched filtering module is used for respectively carrying out the same-phase and orthogonal signals obtained by the down-conversion module and the cached N paths with the length of TDThe pseudo code is subjected to correlation accumulation operation, and the two paths of correlation results are subjected to square-taking and adding processing.
The incoherent accumulation module is used for obtaining the length TDThe correlation results are accumulated to control the total accumulated operation length of each time to include at least one pseudo code period, so as to achieve the purpose of utilizing the good correlation property of the pseudo code.
And the judgment module is used for carrying out maximum value taking processing on the correlation result obtained after the incoherent accumulation, and judging the maximum value and the set threshold value.
The method of the invention realizes the capture of the pseudo code by the receiving end in the incoherent direct sequence spread spectrum system through the following steps:
firstly, multiplying the received intermediate frequency signal by a carrier generated by a local oscillator and the carrier with 90-degree phase shift thereof through a down-conversion module to obtain an in-phase signal and an orthogonal signal.
Step two, because the length of the baseband data information of the transmitting terminal is TDTherefore, N-path cache is carried out on the local pseudo code, and the initial phase difference of every two adjacent paths
Figure BDA0002853579880000052
Step three, the invention adopts the parallel folding matched filter based on SRL16 with N-path cache as shown in figure 3 to carry out local folding matched filter for the cached N-pathPseudo code
Figure BDA0002853579880000053
Wherein T isDFor data information bit length, TCFor code element length, respectively making folding with folding rate P, utilizing time division multiplexing idea to load correspondent code element in every time slot
Figure BDA0002853579880000061
And the control logic controls the first time slot adder to clear, and the initial values of other time slot adders are the accumulated sum of the last time slot.
In addition, due to the existence of the over-sampling rate, the corresponding time slots contributing to the correlation value are extracted and accumulated again to obtain the final correlation accumulation result corresponding to each path. As an example to illustrate the process, if the number of buffer branches is 4, the folding rate of the SRL 16-based parallel folding matched filter is set to 4, and the oversampling rate is set to 4, so that 4 × 4 is required to be 16 delays, the resource of SRL16 can be utilized to the maximum extent, in case of 8kbps baseband data information rate, 1023 Gold code length, 3.069Mbps code rate, and T correlation accumulation length is TDIf the width of the pseudo code word is 384, the first local pseudo code sequence is C0～C383The second path of local pseudo code sequence is C96～C479The third local pseudo code sequence is C192～C575The fourth local pseudo code sequence is C288～C671. The working sequence of the parallel folding matched filter based on the SRL16 is shown in fig. 4, because the folding rate is 4, the oversampling rate is 4, the selected working clock (clk _ sys) is 16 times of the baseband data information generating clock (clk _ data), after each data comes in and is delayed, correlation operation is respectively carried out with the local pseudo code of the 4-way cache, and because the folding rate is 4, in the 1 st time slot, the C in the local pseudo code word of the 4-way cache is respectively related with the C in the 1 st time slot0～C95/C96～C191/C192～C287/C288～C383Performing correlation operation, and performing correlation operation on C in the local pseudo code word cached in 4 ways at the 2 nd time slot96～C191/C192～C287/C288～C383/C384～C479Performing correlation operation, and performing correlation operation on the 3 rd time slot and C in the local pseudo code word cached in the 4 ways192～C287/C288～C383/C384～C479/C480～C575Performing correlation operation, and performing correlation operation with C in the local pseudo code word of the 4-way cache in the 4 th time slot288～C383/C384～C479/C480～C575/C576～C671And performing correlation operation, and extracting and accumulating the corresponding correlation accumulation sum of each sampling point to obtain a correlation value because the oversampling rate is 4.
The accumulation process plays a role of a low-pass filter, and high-frequency components in signals obtained by multiplying the received signals and the two local paths of carriers are filtered. In physical implementation, a Slice (Slice) composed of a lookup table (LUT) in an FPGA can be divided into two logic units (LCs), and when delay shift processing is performed, if a structure based on a D flip-flop (DFF) is adopted, one Slice can only be synthesized into two DFFs, so as to implement two delay units. And by adopting the SRL16 primitive provided by Xilinx, one Slice can be integrated into two SRLs 16, and at most 32 delay units can be realized, and in consideration of the above-mentioned optimization of SRLs 16 on resources, the design is realized by using a matched filter based on the SRL 16.
Step four, because the number of the pseudo code elements corresponding to the length of the data information does not contain a complete pseudo code period, the correlation accumulation processing performed in this way cannot utilize good correlation characteristics of the pseudo codes (m sequence, gold sequence, etc.), therefore, the correlation accumulation result obtained by the matched filter needs to be subjected to incoherent accumulation processing, the number of incoherent accumulation sections needs to meet the requirement that the final accumulated total length at least contains a complete period of the pseudo code, then the maximum value of the correlation results corresponding to the N paths is selected to be compared with the threshold value, as shown in fig. 5, if the maximum value is greater than the threshold value, the capturing of the pseudo code phase is proved to be completed, and meanwhile, only when the initial phase of the ith (i is greater than or equal to 1 and less than or equal to N) path in the N-path cache is close to the data information flip jump position, the correlation peak value obtained by the correlation accumulation is the maximum at this moment, the search for the data information flip transition position is also completed.
The above-described calculation examples of the present invention are merely to explain the calculation model and the calculation flow of the present invention in detail, and are not intended to limit the embodiments of the present invention. It will be apparent to those skilled in the art that other variations and modifications of the present invention can be made based on the above description, and it is not intended to be exhaustive or to limit the invention to the precise form disclosed, and all such modifications and variations are possible and contemplated as falling within the scope of the invention.

Claims (13)

1.一种非相干直扩系统中的匹配滤波捕获系统，其特征在于，所述系统包括下变频模块、伪码缓存模块、匹配滤波器模块、非相干累加模块和判决模块；其中：1. a matched filter capture system in a non-coherent direct expansion system, is characterized in that, described system comprises down-conversion module, pseudocode buffer module, matched filter module, non-coherent accumulation module and decision module; Wherein: 所述下变频模块用于将接收到的BPSK中频信号进行处理，得到同相信号和正交信号；The down-conversion module is used to process the received BPSK intermediate frequency signal to obtain an in-phase signal and a quadrature signal; 所述伪码缓存模块用于将本地伪码进行N路缓存，得到N路本地伪码序列；The pseudocode cache module is used to perform N-way caching of the local pseudocode to obtain N-way local pseudocode sequences; 所述匹配滤波器模块用于将N路本地伪码序列与下变频模块得到的同相信号和正交信号进行相关累加处理，得到每路本地伪码序列所对应的相关累加处理结果；The matched filter module is used to perform correlation accumulation processing on the in-phase signals and quadrature signals obtained by the N-way local pseudocode sequence and the down-conversion module, and obtain the correlation accumulation processing result corresponding to each local pseudocode sequence; 所述非相干累加模块用于将每路本地伪码序列所对应的相关累加处理结果进行非相干累加，得到每路本地伪码序列对应的非相干累加结果；The non-coherent accumulation module is used to non-coherently accumulate the correlation accumulation processing results corresponding to each local pseudocode sequence to obtain the incoherent accumulation result corresponding to each local pseudocode sequence; 所述判决模块用于对N路本地伪码序列对应的非相干累加结果取最大值处理，并将最大值与设置的阈值进行比较，直至最大值大于阈值时，则证明已经完成了对伪码相位的捕获。The decision module is used to process the maximum value of the non-coherent accumulation results corresponding to the N-way local pseudocode sequences, and compare the maximum value with the set threshold until the maximum value is greater than the threshold, which proves that the pseudocode has been completed. Phase capture. 2.根据权利要求1所述的一种非相干直扩系统中的匹配滤波捕获系统，其特征在于，所述下变频模块用于将接收到的BPSK中频信号进行处理，得到同相信号和正交信号；其具体过程为：2. the matched filter acquisition system in a kind of non-coherent direct spread system according to claim 1, is characterized in that, described down-conversion module is used for the BPSK intermediate frequency signal received to be processed, obtains in-phase signal and positive Cross signal; its specific process is: 将接收到的BPSK中频信号与本地振荡器产生的cos信号相乘得到同相信号，将接收到的BPSK中频信号与本地振荡器产生的sin信号相乘得到正交信号。The in-phase signal is obtained by multiplying the received BPSK intermediate frequency signal by the cos signal generated by the local oscillator, and the quadrature signal is obtained by multiplying the received BPSK intermediate frequency signal by the sin signal generated by the local oscillator. 3.根据权利要求2所述的一种非相干直扩系统中的匹配滤波捕获系统，其特征在于，所述伪码缓存模块缓存的每相邻两路本地伪码序列的起始相位相差
Figure FDA0002853579870000011
TD为基带数据信息比特长度，N为缓存支路数。3. the matched filter capture system in a kind of non-coherent direct spread system according to claim 2, it is characterized in that, the initial phase difference of every adjacent two-way local pseudo-code sequence buffered by described pseudo-code buffer module
Figure FDA0002853579870000011
TD is the baseband data information bit length, and N is the number of cache branches. 4.根据权利要求3所述的一种非相干直扩系统中的匹配滤波捕获系统，其特征在于，所述匹配滤波器模块为基于SRL16的并行折叠匹配滤波器。4 . The matched filter capture system in a non-coherent direct expansion system according to claim 3 , wherein the matched filter module is a parallel folded matched filter based on SRL16. 5 . 5.根据权利要求4所述的一种非相干直扩系统中的匹配滤波捕获系统，其特征在于，所述基于SRL16的并行折叠匹配滤波器包括M个SRL16原语，
Figure FDA0002853579870000012
其中，TC为伪码码元长度，P为折叠率，Q为过采样率。5. the matched filter capture system in a kind of non-coherent direct expansion system according to claim 4, is characterized in that, described parallel folding matched filter based on SRL16 comprises M SRL16 primitives,
Figure FDA0002853579870000012
Among them, T C is the length of the pseudo code symbol, P is the folding rate, and Q is the oversampling rate. 6.根据权利要求5所述的一种非相干直扩系统中的匹配滤波捕获系统，其特征在于，所述匹配滤波器模块用于将N路本地伪码序列与下变频模块得到的同相信号和正交信号进行相关累加处理，得到每路本地伪码序列所对应的相关累加处理结果；其具体过程为：6. the matched filter capture system in a kind of non-coherent direct spread system according to claim 5, is characterized in that, described matched filter module is used for the in-phase obtained by N-way local pseudocode sequence and down-conversion module The signal and the quadrature signal are subjected to correlation accumulation processing, and the correlation accumulation processing result corresponding to each local pseudocode sequence is obtained; the specific process is as follows: 对于缓存的任意一路本地伪码序列，将同相信号与该路本地伪码序列进行相关累加运算，得到同相信号相关累加运算结果，将正交信号与该路本地伪码序列进行相关累加运算，得到正交信号相关累加运算结果，将同相信号相关累加运算结果和正交信号相关累加运算结果进行取平方再相加的处理，得到该路本地伪码序列对应的相关累加处理结果；For any buffered local pseudo-code sequence, perform the correlation and accumulation operation on the in-phase signal and the local pseudo-code sequence to obtain the result of the in-phase signal correlation and accumulation operation, and perform the correlation and accumulation operation on the quadrature signal and the local pseudo-code sequence. , obtain the correlation accumulation operation result of the quadrature signal, and perform the processing of squaring and adding the in-phase signal correlation accumulation operation result and the quadrature signal correlation accumulation operation result to obtain the correlation accumulation processing result corresponding to the local pseudocode sequence of this road; 遍历完成各路本地伪码序列后，得到每路本地伪码序列对应的相关累加处理结果。After traversing each local pseudocode sequence, the correlation accumulation processing result corresponding to each local pseudocode sequence is obtained. 7.基于权利要求1所述的一种非相干直扩系统中的匹配滤波捕获系统的捕获方法，其特征在于，所述方法具体通过以下步骤实现：7. based on the capture method of the matched filter capture system in a kind of non-coherent direct expansion system according to claim 1, it is characterised in that the method is specifically realized by the following steps: 步骤一、接收到的BPSK中频信号经过下变频模块的处理后，得到同相信号和正交信号；Step 1: After the received BPSK intermediate frequency signal is processed by the down-conversion module, an in-phase signal and a quadrature signal are obtained; 步骤二、在ROM中存储本地伪码后进行倒序输出，通过伪码缓存模块将倒序输出的本地伪码缓存为N路本地伪码序列；Step 2: After storing the local pseudocodes in the ROM, perform reverse-order output, and cache the reversed-order output local pseudocodes as N-way local pseudocode sequences by the pseudocode cache module; 步骤三、利用匹配滤波器模块对N路本地伪码序列和下变频模块得到的同相信号和正交信号进行相关累加处理，分别得到每路本地伪码序列所对应的相关累加处理结果；Step 3, using the matched filter module to perform correlation accumulation processing on the in-phase signals and quadrature signals obtained by the N channels of local pseudocode sequences and the down-conversion module, and obtain the correlation accumulation processing results corresponding to each channel of local pseudocode sequences respectively; 步骤四、利用非相干累加模块对每路本地伪码序列所对应的相关累加处理结果进行非相干累加，得到每路本地伪码序列对应的非相干累加结果；Step 4, using the incoherent accumulation module to perform incoherent accumulation on the correlation accumulation processing results corresponding to each local pseudocode sequence, and obtain the incoherent accumulation result corresponding to each local pseudocode sequence; 步骤五、从每路本地伪码序列对应的非相干累加结果中选取出最大值，将选取出的最大值送入判决模块，判决模块将最大值与设置的阈值进行比较，实现对伪码相位的捕获。Step 5. Select the maximum value from the non-coherent accumulation results corresponding to each local pseudo-code sequence, and send the selected maximum value to the judgment module, and the judgment module compares the maximum value with the set threshold to realize the pseudo-code phase capture. 8.根据权利要求7所述的一种非相干直扩系统中的匹配滤波捕获系统的捕获方法，其特征在于，所述步骤一的具体过程为：8. the acquisition method of the matched filter acquisition system in a kind of non-coherent direct expansion system according to claim 7, is characterized in that, the concrete process of described step 1 is: 将接收到的BPSK中频信号与本地振荡器产生的cos信号相乘得到同相信号，将接收到的BPSK中频信号与本地振荡器产生的sin信号相乘得到正交信号。The in-phase signal is obtained by multiplying the received BPSK intermediate frequency signal by the cos signal generated by the local oscillator, and the quadrature signal is obtained by multiplying the received BPSK intermediate frequency signal by the sin signal generated by the local oscillator. 9.根据权利要求8所述的一种非相干直扩系统中的匹配滤波捕获系统的捕获方法，其特征在于，所述N路本地伪码序列中，每相邻两路本地伪码序列的起始相位相差
Figure FDA0002853579870000021
TD为基带数据信息比特长度，N为缓存支路数。9. the acquisition method of the matched filter acquisition system in a kind of non-coherent direct spread system according to claim 8, is characterized in that, in described N-way local pseudo-code sequence, every adjacent two-way local pseudo-code sequence start phase difference
Figure FDA0002853579870000021
TD is the baseband data information bit length, and N is the number of cache branches. 10.根据权利要求9所述的一种非相干直扩系统中的匹配滤波捕获系统的捕获方法，其特征在于，所述匹配滤波器模块为基于SRL16的并行折叠匹配滤波器。10 . The method for capturing a matched filter capture system in a non-coherent direct expansion system according to claim 9 , wherein the matched filter module is a parallel folded matched filter based on SRL16. 11 . 11.根据权利要求10所述的一种非相干直扩系统中的匹配滤波捕获系统的捕获方法，其特征在于，所述基于SRL16的并行折叠匹配滤波器包括M个SRL16原语，
Figure FDA0002853579870000022
其中，TC为伪码码元长度，P为折叠率，Q为过采样率。11. The capture method of the matched filter capture system in a non-coherent direct expansion system according to claim 10, wherein the parallel folded matched filter based on SRL16 comprises M SRL16 primitives,
Figure FDA0002853579870000022
Among them, T C is the length of the pseudo code symbol, P is the folding rate, and Q is the oversampling rate. 12.根据权利要求11所述的一种非相干直扩系统中的匹配滤波捕获系统的捕获方法，其特征在于，所述步骤三的具体过程为：12. The acquisition method of the matched filter acquisition system in a non-coherent direct expansion system according to claim 11, wherein the specific process of the step 3 is: 对于缓存的任意一路本地伪码序列，将同相信号与该路本地伪码序列进行相关累加运算，得到同相信号相关累加运算结果，将正交信号与该路本地伪码序列进行相关累加运算，得到正交信号相关累加运算结果，将同相信号相关累加运算结果和正交信号相关累加运算结果进行取平方再相加的处理，得到该路本地伪码序列对应的相关累加处理结果；For any buffered local pseudo-code sequence, perform the correlation and accumulation operation on the in-phase signal and the local pseudo-code sequence to obtain the result of the in-phase signal correlation and accumulation operation, and perform the correlation and accumulation operation on the quadrature signal and the local pseudo-code sequence. , obtain the correlation accumulation operation result of the quadrature signal, and perform the processing of squaring and adding the in-phase signal correlation accumulation operation result and the quadrature signal correlation accumulation operation result to obtain the correlation accumulation processing result corresponding to the local pseudocode sequence of this road; 遍历完成各路本地伪码序列后，得到每路本地伪码序列对应的相关累加处理结果。After traversing each local pseudocode sequence, the correlation accumulation processing result corresponding to each local pseudocode sequence is obtained. 13.根据权利要求12所述的一种非相干直扩系统中的匹配滤波捕获系统的捕获方法，其特征在于，所述基于SRL16的并行折叠匹配滤波器的工作过程为：13. the capture method of the matched filter capture system in a kind of non-coherent direct expansion system according to claim 12, it is characterized in that, the working process of the parallel folded matched filter based on SRL16 is: 对缓存的N路本地伪码序列
Figure FDA0002853579870000031
Figure FDA0002853579870000032
分别进行折叠率为P的折叠，其中，C0为第一路本地伪码序列的首个码元，
Figure FDA0002853579870000033
为第一路本地伪码序列的末个码元，
Figure FDA0002853579870000034
为第二路本地伪码序列的首个码元，
Figure FDA0002853579870000035
为第二路本地伪码序列的末个码元，
Figure FDA0002853579870000036
为第N路本地伪码序列的首个码元，
Figure FDA0002853579870000037
为第N路本地伪码序列的末个码元；N-way local pseudocode sequence for the cache
Figure FDA0002853579870000031
Figure FDA0002853579870000032
Perform folding with a folding rate of P respectively, where C 0 is the first symbol of the first local pseudocode sequence,
Figure FDA0002853579870000033
is the last symbol of the first local pseudocode sequence,
Figure FDA0002853579870000034
is the first symbol of the second local pseudocode sequence,
Figure FDA0002853579870000035
is the last symbol of the second local pseudocode sequence,
Figure FDA0002853579870000036
is the first symbol of the Nth local pseudocode sequence,
Figure FDA0002853579870000037
is the last symbol of the Nth local pseudocode sequence; 对于任意的一路本地伪码序列，在该路本地伪码序列的每一个时隙加载对应的折叠后的码字，控制逻辑控制在第1个时隙加法器初始值清零，第2个时隙加法器初始值为第1个时隙加法器的相关累加和，…，第P个时隙加法器初始值为第P-1个时隙加法器的相关累加和，再对第P个时隙加法器的相关累加和进行抽取再累加，得到该路本地伪码序列所对应的相关累加结果；For any local pseudocode sequence, load the corresponding folded codeword in each time slot of the local pseudocode sequence, the control logic controls the initial value of the adder to be cleared in the first time slot, and the second time slot The initial value of the slot adder is the relevant cumulative sum of the first slot adder, ..., the initial value of the P-th slot adder is the relevant cumulative sum of the P-1th slot adder, and then for the P-th time slot adder. The correlation accumulation sum of the slot adder is extracted and then accumulated to obtain the correlation accumulation result corresponding to the local pseudocode sequence of this road; 同理，分别得到N路本地伪码序列所对应的相关累加结果。Similarly, the correlation accumulation results corresponding to the N local pseudocode sequences are obtained respectively.
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