Spread spectrum communication multi-target capturing-to-tracking fast channel matching method, device and system

Abstract

The invention discloses a spread spectrum communication multi-target capturing-to-tracking fast channel matching method, device and system, and belongs to the field of wireless communication, and the method comprises the steps: S1, obtaining capturing and tracking parameters, and initializing channel matching parameters; s2, identifying the same target from capturing / tracking parameters based on a code load consistency criterion to perform channel matching; s3, channel allocation is carried out on capturing and tracking parameters of different targets based on the criterion of capturing after tracking; and S4, resolving and correcting the pseudo code phase in the channel matching parameters. The method solves the problem of channel matching between multi-target pseudo code capturing and code load tracking of a receiving terminal of a spread spectrum communication system, has the advantages of capturing and tracking dynamic decoupling, high code load matching precision and good channel processing timeliness, and can realize fast channel matching processing of multi-target pseudo code capturing and code load tracking of same-frequency same-code spread spectrum signals.

Description

Technical Field

[0001] The present invention relates to the field of wireless communications, and more specifically, to a method, device and system for fast channel matching of multi-target capture and tracking in spread spectrum communications. Background Art

[0002] Spread spectrum communication has been widely used in wireless communication, satellite navigation, aerospace and other fields due to its many advantages such as strong anti-interference and anti-interception capabilities, high spectrum utilization, code division multiple access communication, and high ranging and speed measurement accuracy. In the engineering application of spread spectrum communication system, due to factors such as uncertain transmission and reception time, channel transmission delay, and complex interference, the pseudo code phase difference between the local pseudo code sequence and the received signal is in a random and uncertain state. At the same time, due to the influence of the Doppler effect between transmission and reception and the instability of the device clock, there is a large frequency offset between the carrier frequency of the local carrier and the received signal. In order to realize the coherent demodulation of the spread spectrum communication system, the receiving terminal must perform high-precision real-time synchronization of the pseudo code phase / carrier frequency. Pseudo code capture (coarse synchronization) and code carrier tracking (fine synchronization) are important links in the baseband processing of the receiving terminal. How to accurately, quickly and efficiently realize the state transfer from the pseudo code capture link to the code carrier tracking link, target confirmation and pull-in synchronization has become the key core technology of the baseband processing of the receiving terminal of the spread spectrum communication system.

[0003] Pseudo-code capture performs a two-dimensional time-frequency search on the pseudo-code phase / carrier frequency of the received signal to obtain rough code-carrying parameters. Code-carrying tracking uses a tracking loop that combines a code loop and a carrier loop based on the rough code-carrying parameters obtained by capture, and operates periodically and continuously in the form of closed-loop feedback to achieve long-term stable synchronization of the pseudo-code phase / carrier frequency of the received signal. In traditional spread spectrum communication systems, code division multiple access (different pseudo-code sequences are configured for different targets) is used for multi-target communication. After the receiving terminal captures a target signal, it directly enters the corresponding receiving channel for code-carrying tracking. However, due to the limited number of pseudo-code sequences, the spread spectrum communication system of large-scale targets often uses the same pseudo-code sequence for spread spectrum modulation. The pseudo-code capture of the receiving terminal will detect one or more targets at a certain moment, but it is impossible to perform effective target identification through code division multiple access. The pseudo-code capture information of multiple targets must be matched with the code-carrying tracking parameters for the receiving channel. Otherwise, the confusion of the capture / tracking parameters of the receiving channel will directly lead to the failure of the receiving terminal.

[0004] The traditional receiving terminal does not perform channel matching for pseudocode capture and code carrier tracking. After pseudocode capture, it directly enters the corresponding receiving channel for code carrier tracking, performs bit synchronization, frame synchronization, decoding and other processing after long-term synchronization locking, parses the data bit stream information of the current receiving channel, and then identifies the target based on the number, position, speed and other information of the target corresponding to the current receiving channel. Therefore, the traditional method has a large number of receiving channels and they are repeatedly occupied on a large scale for a long time, resulting in high resource complexity of the receiving terminal, low channel utilization efficiency, and poor channel processing timeliness. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a method, device and system for fast channel matching of multi-target capture and tracking in spread spectrum communication, which has the advantages of good channel processing timeliness, high code-carrier matching accuracy and wide application range, and can realize fast channel matching processing of multi-target pseudo-code capture and code-carrier tracking of spread spectrum signals with the same frequency and code.

[0006] The object of the present invention is achieved through the following solutions:

[0007] A fast channel matching method for multi-target capture and tracking in spread spectrum communication, comprising the following steps:

[0008] S1: Get capture and tracking parameters, and initialize channel matching parameters;

[0009] S2: Channel matching based on the code consistency criterion to identify the same target from the acquisition / tracking parameters;

[0010] S3: Channel allocation of capture / tracking parameters for different targets based on the principle of tracking first and capturing later;

[0011] S4: Calculate and correct the pseudo code phase in the channel matching parameters.

[0012] Furthermore, in step S1, the acquisition of capture / tracking parameters specifically includes the following sub-steps:

[0013] Obtain the M capture parameters output by the pseudo code capture device at time t1; the M capture parameters specifically include: capture state s a,m , pseudo code phase τ a,m and the carrier Doppler frequency shift f a,m ; Where m is the capture parameter index, satisfying m∈(1,2,…,M);

[0014] And, obtaining N tracking parameters output by the code carrier tracking device at time t1; the N tracking parameters specifically include: tracking state s t,n , pseudo code phase τ t,n and the carrier Doppler frequency shift f t,n; Where n is the tracking parameter index, satisfying n∈(1,2,…,N).

[0015] Furthermore, the capture state s a,m is valid or invalid; the tracking status s t,n Idle or Converging.

[0016] Furthermore, in step S1, the initialization of channel matching parameters specifically includes the following sub-steps:

[0017] Initialize N matching parameters, the N matching parameters specifically include: matching state s p,n is idle, pseudo code phase τ p,n =0, pseudo code phase correction value δτ p,n is 0, carrier Doppler frequency shift f p,n is 0, the matching counters np and mp are initialized to 1, and n p ∈(1,2,…,N),m p ∈(1,2,…,M).

[0018] Further, in step S2, the identification of the same target from the capture / tracking parameters based on the code-carrying consistency criterion for channel matching specifically includes the following sub-steps:

[0019] S2.1: When the nth p Tracking Status When it is idle, if n p ≥N when n p =1, then go to step S3, otherwise n p =n p +1, repeat S2.1; when the nth p Tracking Status When convergence, match counter m p =1, go to step S2.2;

[0020] S2.2: When the mth p Capture Status If m is invalid, p ≥M when m p =1, return to step S2.1, otherwise m p =m p +1, repeat step S2.2; when the mth p Capture Status If it is valid, go to step S2.3;

[0021] S2.3: The nth p The tracking parameters and the mth p Capture parameters to make code consistency judgment;

[0022] S2.4: nth p Matching status For nth p Tracking Status and n p =n p +1, return to step S2.1.

[0023] Further, in step S2.3, the nth p The tracking parameters and the mth p The capture parameters are used to make a code-carrying consistency judgment, which specifically includes the following sub-steps:

[0024] When the information contained in the two codes is consistent, and Among them, τ thr is the pseudo code phase decision threshold, f thr is the carrier Doppler frequency shift decision threshold, the nth p Matching status For switching, pseudo code phase for Carrier Doppler shift for At the same time, the mth p Capture Status Convert to invalid, n p =n p +1, return to step S2.1;

[0025] When the code load is not consistent, that is, or If m p ≥M when m p =1, go to step S2.4, otherwise m p =m p +1, enter and return to step S2.2.

[0026] Further, in step S3, the channel allocation of the capture / tracking parameters of different targets based on the criterion of tracking first and capturing later specifically includes the following sub-steps:

[0027] S3.1: When the nth p Matching status When switching or converging, if n p ≥N when n p =1, go to step S4, otherwise n p =n p +1, repeat step S3.1; when the nth p Matching status When idle, match counter m p =1, go to step S3.2;

[0028] S3.2: When the mth p Capture Status If m is invalid, p ≥M when n p =1, return to step S3.1, otherwise m p =m p +1, repeat step S3.2; when the mth p Capture Status If it is valid, go to step S3.3;

[0029] S3.3: nth p Matching status For switching, pseudo code phase for Carrier Doppler shift for At the same time, the mth p Capture Status Convert to invalid, n p =n p +1, return to step S3.1.

[0030] Furthermore, in step S4, the pseudo code phase in the channel matching parameter is calculated and corrected, which specifically includes the following sub-steps:

[0031] Get the current time t2 and get the channel matching processing time t p = t2-t1, combined with the carrier Doppler frequency shift f of the nth matching channel p,n , using the formula τ p,n =(1+f p,n / R RF )×R c ×t p , and the pseudo code phase correction value τ of the nth matching channel is obtained by solving p,n , where R RF is the RF frequency, R c is the spreading pseudo code rate.

[0032] A fast channel matching device for multi-target capture and tracking in spread spectrum communication comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is loaded by the processor, any of the above methods is executed.

[0033] A spread spectrum communication multi-target capture-to-track fast channel matching system comprises the spread spectrum communication multi-target capture-to-track fast channel matching device as described above.

[0034] The beneficial effects of the present invention include:

[0035] (1) Dynamic decoupling of capture and tracking. The present invention is based on step S2: identifying the same target from the capture / tracking parameters for channel matching based on the code-carrier consistency criterion, and step S3: allocating channels for the capture and tracking parameters of different targets based on the tracking-before-capture criterion, so as to achieve dynamic decoupling processing of concurrent channels between multi-target detection and capture and multi-channel code-carrier tracking. Compared with traditional methods, the present invention has the low-complexity fast receiving and processing capability for large-capacity concurrent users.

[0036] (2) High code-carrier matching accuracy. Step S4 of the present invention: solve and correct the pseudo-code phase in the channel matching parameters, that is, calculate the channel matching processing time in real time, and solve and correct the pseudo-code phase in the matching channel in combination with the carrier Doppler frequency shift in the matching channel, thereby eliminating the code rate offset formed by the Doppler effect and causing the pseudo-code phase slip during the channel matching process. At the same time, the microsecond-level channel matching time reduces the carrier frequency error caused by the dynamic frequency change. Compared with the traditional method, the present invention has higher pseudo-code phase / carrier frequency matching accuracy.

[0037] (3) Good channel processing time efficiency. The program code of the spread spectrum communication multi-target capture and tracking fast channel matching device designed by the present invention is stored in the memory of the signal processing platform and is directly executed when the software is loaded. It can be fully digitally implemented based on development platforms such as FPGA and GPU, or can be implemented by language programming using processing chips such as DSP and ARM. The high-frequency processing of hundreds of MHz makes the channel matching of dozens or even hundreds of concurrent users only take a few microseconds. Compared with the traditional method, the present invention has better channel processing time efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1 A schematic diagram of a processing flow of a method according to an embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of the processing flow of step S2 in the method of the embodiment of the present invention;

[0041] Figure 3 It is a schematic diagram of the processing flow of step S3 in the method of the embodiment of the present invention. DETAILED DESCRIPTION

[0042] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0043] The present invention aims to propose the following solution to the problem of channel matching between multi-target pseudo code capture and code carrier tracking in a receiving terminal of a spread spectrum communication system.

[0044] See also Figure 1 In a first aspect, according to the present invention, in a preferred embodiment, a fast channel matching method for multi-target acquisition and tracking in spread spectrum communication is provided, which specifically comprises the following steps:

[0045] S1: Get capture / tracking parameters and initialize channel matching parameters;

[0046] S2: Channel matching based on the code consistency criterion to identify the same target from the acquisition / tracking parameters;

[0047] S3: Channel allocation of capture / tracking parameters for different targets based on the principle of tracking first and capturing later;

[0048] S4: Calculate and correct the pseudo code phase in the channel matching parameters.

[0049] In further other embodiments, step S1 specifically includes the following sub-steps:

[0050] When the capture parameters are valid, execute the following substeps:

[0051] Get the M capture parameters output by the pseudo code capture device at time t1, including: capture state s a,m (valid, invalid), pseudo code phase τ a,m , carrier Doppler frequency shift f a,m , where m is the capture parameter index, satisfying m∈(1,2,…,M);

[0052] Get the N tracking parameters output by the code carrier tracking device at time t1, including: tracking status s t,n (idle, convergence), pseudo code phase τ t,n , carrier Doppler frequency shift f t,n , where n is the tracking parameter index, satisfying n∈(1,2,…,N);

[0053] Initialize N matching parameters, including: matching status s p,n is idle, pseudo code phase τ p,n =0, pseudo code phase correction value δτ p,n is 0, carrier Doppler frequency shift f p,n is 0, matching counter n p 、mp Initialized to 1, satisfying n p ∈(1,2,…,N),m p ∈(1,2,…,M).

[0054] In further other embodiments, see Figure 2 Step S2 specifically includes the following sub-steps:

[0055] S2.1: When the nth p Tracking Status When it is idle, if n p ≥N when n p =1, enter S3, otherwise n p =n p +1, repeat S2.1; when the nth p Tracking Status When convergence, match counter m p =1, enter S2.2.

[0056] S2.2: When the mth p Capture Status If m is invalid, p ≥M when m p =1, return to S2.1, otherwise m p =m p +1, repeat S2.2; when the mth p Capture Status When it is valid, enter S2.3.

[0057] S2.3: nth p The tracking parameters and the mth p The capture parameters are used to determine the consistency of the code. Further, when the code information of the two is consistent, that is, and Among them, τ thr is the pseudo code phase decision threshold, f thr is the carrier Doppler frequency shift decision threshold, the nth p Matching status For switching, pseudo code phase for Carrier Doppler shift for At the same time, the mth p Capture Status Convert to invalid, n p =n p +1, return to S2.1; when the code is not consistent, that is, or If m p ≥M when m p =1, enter S2.4, otherwise mp =m p +1, enter and return to S2.2.

[0058] S2.4: nth p Matching status For nth p Tracking Status and n p =n p +1, return to S2.1.

[0059] In further other embodiments, see Figure 3 Step S3 specifically includes the following sub-steps:

[0060] S3.1: When the nth p Matching status When switching or converging, if n p ≥N when n p =1, enter S4, otherwise n p =n p +1, repeat S3.1; when the nth p Matching status When idle, match counter m p =1, enter S3.2.

[0061] S3.2: When the mth p Capture Status If m is invalid, p ≥M when n p =1, return to S3.1, otherwise m p =m p +1, repeat S3.2; when the mth p Capture Status When it is valid, enter S3.3.

[0062] S3.3: nth p Matching status For switching, pseudo code phase for Carrier Doppler shift for At the same time, the mth p Capture Status Convert to invalid, n p =n p +1, back to S3.1.

[0063] In further other embodiments, step S4 specifically includes the following sub-steps:

[0064] Get the current time t2 and get the channel matching processing time tp = t2-t1, combined with the carrier Doppler frequency shift f of the nth matching channel p,n , using the formula τ p,n =(1+f p,n / R RF )×R c ×t p , and the pseudo code phase correction value τ of the nth matching channel is obtained by solving p,n , where R RF is the RF frequency, R c is the spreading pseudo code rate.

[0065] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0066] According to one aspect of an embodiment of the present invention, a computer program product or a computer program is provided, the computer program product or the computer program includes a computer instruction, and the computer instruction is stored in a computer-readable storage medium. A processor of a computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the method provided in the above various optional implementations.

[0067] As another aspect, an embodiment of the present invention further provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the method described in the above embodiment.

Claims

1. A fast channel matching method for multi-target capture and tracking in spread spectrum communication, characterized in that: The following steps are involved: S1: Get capture and tracking parameters, and initialize channel matching parameters; S2: Channel matching based on the code consistency criterion to identify the same target from the acquisition / tracking parameters; S3: Channel allocation of capture / tracking parameters for different targets based on the principle of tracking first and capturing later; S4: Calculate and correct the pseudo code phase in the channel matching parameters.

2. The fast channel matching method for multi-target capture and tracking in spread spectrum communication according to claim 1, characterized in that: In step S1, the acquisition of capture / tracking parameters specifically includes the following sub-steps: Obtain the M capture parameters output by the pseudo code capture device at time t1; the M capture parameters specifically include: capture state s a,m , pseudo code phase τ a,m and the carrier Doppler frequency shift f a,m ; Where m is the capture parameter index, satisfying m∈(1,2,…,M); And, obtaining N tracking parameters output by the code carrier tracking device at time t1; the N tracking parameters specifically include: tracking state s t,n , pseudo code phase τ t,n and the carrier Doppler frequency shift f t,n ; Where n is the tracking parameter index, satisfying n∈(1,2,…,N).

3. The fast channel matching method for multi-target capture and tracking in spread spectrum communication according to claim 2, characterized in that: The capture state s a,m is valid or invalid; the tracking status s t,n Idle or Converging.

4. The fast channel matching method for multi-target capture and tracking in spread spectrum communication according to claim 3 is characterized in that: In step S1, the initialization of channel matching parameters specifically includes the following sub-steps: Initialize N matching parameters, the N matching parameters specifically include: matching state s p,n is idle, pseudo code phase τ p,n =0, pseudo code phase correction value δτ p,n is 0, carrier Doppler frequency shift f p,n is 0, matching counter n p 、m p Initialized to 1, and satisfy n p ∈(1,2,…,N),m p ∈(1,2,…,M).

5. The fast channel matching method for multi-target capture and tracking in spread spectrum communication according to claim 3, characterized in that: In step S2, the identification of the same target from the capture / tracking parameters based on the code-carrying consistency criterion for channel matching specifically includes the following sub-steps: S2.1: When the nth p Tracking Status When it is idle, if n p ≥N when n p =1, then go to step S3, otherwise n p =n p +1, repeat S2.1; when the nth p Tracking Status When convergence, match counter m p =1, go to step S2.2; S2.2: When the mth p Capture Status If m is invalid, p ≥M when m p =1, return to step S2.1, otherwise m p =m p +1, repeat step S2.2; when the mth p Capture Status If it is valid, go to step S2.3; S2.3: The nth p The tracking parameters and the mth p Capture parameters to make code consistency judgment; S2.4: nth p Matching status For nth p Tracking Status and n p =n p +1, return to step S2.

1.

6. The fast channel matching method for multi-target capture and tracking in spread spectrum communication according to claim 5, characterized in that: In step S2.3, the nth p The tracking parameters and the mth p The capture parameters are used to make a code-carrying consistency judgment, which specifically includes the following sub-steps: When the information contained in the two codes is consistent, and Among them, τ thr is the pseudo code phase decision threshold, f thr is the carrier Doppler frequency shift decision threshold, the nth p Matching status For switching, pseudo code phase for Carrier Doppler shift for At the same time, the mth p Capture Status Convert to invalid, n p =n p +1, return to step S2.1; When the code load is not consistent, that is, or If m p ≥M when m p =1, go to step S2.4, otherwise m p =m p +1, enter and return to step S2.

2.

7. The fast channel matching method for multi-target capture and tracking in spread spectrum communication according to claim 3, characterized in that: In step S3, the channel allocation of the capture / tracking parameters of different targets based on the principle of tracking first and capturing later is specifically comprised of the following sub-steps: S3.1: When the nth p Matching states t,np When switching or converging, if n p ≥N when n p =1, go to step S4, otherwise n p =n p +1, repeat step S3.1; when the nth p Matching states t,np When idle, match counter m p =1, go to step S3.2; S3.2: When the mth p Capture states a,mp If m is invalid, p ≥M when n p =1, return to step S3.1, otherwise m p =m p +1, repeat step S3.2; when the mth p Capture states a,mp If it is valid, go to step S3.3; S3.3: nth p Matching status For switching, pseudo code phase for Carrier Doppler shift for At the same time, the mth p Capture Status Convert to invalid, n p =n p +1, return to step S3.

1.

8. The fast channel matching method for multi-target capture and tracking in spread spectrum communication according to claim 3, characterized in that: In step S4, the pseudo code phase in the channel matching parameter is calculated and corrected, which specifically includes the following sub-steps: Get the current time t2 and get the channel matching processing time t p = t2-t1, combined with the carrier Doppler frequency shift f of the nth matching channel p,n , using the formula τ p,n =(1+f p,n / R RF )×R c ×t p , and the pseudo code phase correction value τ of the nth matching channel is obtained by solving p,n , where R RF is the RF frequency, R c is the spreading pseudo code rate.

9. A fast channel matching device for multi-target capture and tracking in spread spectrum communication, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is loaded by the processor, the method according to any one of claims 1 to 8 is executed.

10. A fast channel matching system for multi-target capture and tracking in spread spectrum communication, characterized in that: It includes the spread spectrum communication multi-target capture and tracking fast channel matching device as described in claim 9.

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