A system and method for correcting non-periodic pseudo-code in frequency-hopping communication

Abstract

The present invention provides a system and method for correcting aperiodic pseudocode in spread-hopping frequency communication, belonging to the field of wireless communication technology, and solving the problem of uncertain time delay of a traditional code extraction method for aperiodic pseudocode in a spread-hopping frequency communication system. The system comprises: a time code parsing module for parsing time code information; a time correction module for calculating the parsed time code information in combination with prior information output by control software, correction information output by a signal processing device, and a fixed code extraction delay to obtain a code extraction time correction value; a parameter setting module for calculating and sending a code extraction instruction to a pseudocode server based on a current time count and the code extraction time correction value; and a data storage module for buffering aperiodic pseudocode data stream output by the pseudocode server and outputting the data to a signal processing device. The present invention can improve the code extraction accuracy of the aperiodic pseudocode under high hopping speed conditions, and provide the signal processing device with a spread-hopping pseudocode data stream with high accuracy and good real-time performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communication, is applied to spread frequency hopping communication technology, and specifically relates to a system and method for correcting aperiodic pseudo code in spread frequency hopping communication. Background Art

[0002] In the field of wireless communications, spread spectrum communication technology has been widely used in military and civilian communication systems and has become a mainstream technology due to its advantages of good confidentiality, strong anti-interference ability and high spectrum efficiency. Spread spectrum communication is mainly categorized into direct sequence (DS), frequency hopping (FH), and time hopping (TH) spread spectrum technologies, depending on the spread spectrum method. DS spread spectrum offers the advantages of good communication concealment and robustness against multipath interference, but also suffers from limited processing gain, stringent synchronization requirements, and poor near-far effect. FH spread spectrum offers the advantages of good near-far characteristics, wide communication bandwidth, and avoidance of single-frequency interference, but also suffers from complex equipment during fast hopping and poor concealment during slow hopping. Compared to single-system spread spectrum technologies, hybrid direct spread / frequency hopping (DS / FH) spread spectrum technology, which adds FH spread spectrum to DS, combines the advantages of DS spread spectrum's good concealment and FH spread spectrum's good interference avoidance, overcoming the bottleneck of a single spread spectrum communication system and weak anti-interference and anti-interception capabilities. This technology enables communication equipment to have stronger security protection and self-survival capabilities in complex electromagnetic environments. Therefore, the spread frequency hopping communication system is of great significance in military and civilian fields such as aerospace measurement and control, electronic countermeasures, satellite communications and data links.

[0003] The high hopping rate of up to tens of thousands of hops in spread frequency hopping communication systems can further improve the confidentiality and anti-interception capabilities of the communication system, thereby preventing interference, deception, and destruction by other signals and providing stable and reliable communication quality. However, if the signal processing equipment is to accurately track the spread frequency hopping signal at high hopping rates, it is necessary to ensure that the local pseudo-code phase and the carrier phase are always highly synchronized between each hopping point. Therefore, the signal processing equipment must update the local spread frequency hopping pseudo-code in a short period of time, which is the primary condition for achieving signal synchronization. To make the spread frequency hopping signal more concealed and more anti-interference capable, the signal processing equipment usually uses a dedicated aperiodic spread frequency hopping pseudo-code server to store the direct spread frequency pseudo-code and the frequency hopping pseudo-code. Therefore, the code extraction accuracy and real-time processing of the aperiodic spread frequency hopping pseudo-code data stream will directly determine whether the spread frequency hopping communication system can achieve rapid synchronization.

[0004] In a spread-hopping frequency communication system, after receiving external standard time to synchronize local time, the time synchronization device generally uses the IRIG-B format time code, namely the B code, to encode the time information and pass it to the signal processing device; the signal processing device parses the time information provided by the time synchronization device, generates a code retrieval instruction, and sends the code retrieval instruction to the pseudo-code server. The pseudo-code server obtains the starting position of the spread-hopping pseudo-code based on the code retrieval instruction and starts to output the code. After the code retrieval is successful, it directly and continuously provides the signal processing device with a non-periodic spread-hopping pseudo-code data stream.

[0005] In traditional code retrieval methods, uncertain delays occur when parsing B-code time information and generating pseudocode server retrieval instructions. Furthermore, when the pseudocode server retrieves the code according to the retrieval instructions, uncertain delays are also caused due to inconsistent starting positions of the spread-hopping pseudocode. Therefore, traditional code retrieval methods generate large delays and uncertain time ambiguity during the retrieval process, which makes synchronization of direct-spread and frequency-hopping pseudocodes and carrier demodulation difficult, and therefore cannot meet the engineering requirements of spread-hopping frequency communication systems. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem of uncertain delay of the traditional code extraction method of the aperiodic pseudo code in the spread hopping frequency communication system, and therefore proposes a correction system and method; the present invention can improve the code extraction accuracy of the aperiodic pseudo code under high hopping rate conditions, thereby providing a high-precision and real-time spread hopping pseudo code data stream for signal processing equipment.

[0007] The present invention adopts the following technical solutions to achieve the purpose:

[0008] A frequency spread hopping communication non-periodic pseudo code correction system, the system comprising: a time code analysis module, a time correction module, a parameter setting module and a data storage module;

[0009] The time code parsing module is used to parse the time code information output by the time system equipment to obtain time information such as year, day, hour, minute, second, and second pulse;

[0010] The time correction module is used to calculate the parsed time code information based on the time information output by the time code parsing module, combined with the prior information output by the control software, the correction information output by the signal processing device, and the fixed code acquisition delay, to obtain the code acquisition time correction value;

[0011] The parameter setting module is used to calculate the code fetching instruction by using the current time count and the code fetching time correction value output by the time correction module, and send the code fetching instruction to the pseudo code server when the start output by the control software is valid;

[0012] The data storage module is used to perform data buffering processing on the non-periodic spread-jump pseudocode data stream output by the pseudocode server using a fixed code acquisition delay, and output the buffered spread-jump pseudocode data stream to the signal processing device.

[0013] The present invention also provides a method for correcting aperiodic pseudo-code in frequency spread hopping communication, the method comprising the following steps:

[0014] S1. Analyze the time code information output by the time system equipment to obtain the time information including year, day, hour, minute, second and second pulse;

[0015] S2. Calculate a code acquisition time correction value based on the time information, combined with the prior information output by the control software, the correction information output by the signal processing device, and the fixed code acquisition delay;

[0016] S3, using the current time count and the code fetching time correction value to calculate the code fetching instruction;

[0017] S4. When the start output by the control software is valid, the code fetching instruction is sent to the pseudo code server;

[0018] S5. Using a fixed code acquisition delay, perform data buffering processing on the non-periodic spread-hop pseudocode data stream output by the pseudocode server, and output the processed spread-hop pseudocode data stream to the signal processing device.

[0019] In summary, due to the adoption of this technical solution, compared with the traditional code acquisition method of non-periodic pseudo code in the spread hopping frequency communication system, the present invention has the following beneficial effects:

[0020] 1. High code acquisition accuracy. The time correction module of the present invention uses a high-frequency system processing clock to count the intra-hop time, eliminating the processing delay caused by module transmission and parameter calculation. Compared with traditional code acquisition methods, it can significantly improve the code acquisition accuracy of the non-periodic spread jump pseudocode.

[0021] 2. Good real-time correction performance. The time correction module of the present invention uses the time information output by the time code analysis module, combined with the prior information output by the control software, the correction information output by the signal processing device, and the fixed code acquisition delay to calculate the code acquisition time correction value. At the same time, the data storage module uses the fixed code acquisition delay to perform data buffering on the non-periodic spread jump pseudocode data stream. Compared with traditional code acquisition methods, the spread jump pseudocode data stream output by the correction system of the present invention has good real-time performance.

[0022] 3. Simple implementation structure. The present invention's time code analysis module, time correction module, and parameter setting module can be logically implemented using only multipliers, and the data storage module can be logically implemented using only a small amount of on-chip RAM. Compared with traditional code acquisition methods, this method requires less computational complexity and hardware processing resources, and its algorithm structure is simple and easy to implement, while significantly improving the technical effect. It can replace the traditional code acquisition technology of non-periodic pseudo-code in spread-frequency hopping communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structural principle of the system of the present invention;

[0024] Figure 2 Schematic diagram of the principle of B-code symbols of the time code analysis module in the present invention;

[0025] Figure 3 This is a schematic diagram of the time counting principle of the time correction module in the present invention;

[0026] Figure 4 Schematic diagram of the steps of the method of the present invention. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0029] This embodiment will provide a detailed description of the calibration system and the calibration method used in the system of the present invention.

[0030] like Figure 1 As shown, a frequency-hopping communication non-periodic pseudo-code correction system is provided, the system comprising: a time code analysis module, a time correction module, a parameter setting module and a data storage module;

[0031] The time code analysis module is used to analyze the time code information output by the time system equipment to obtain time information such as year, day, hour, minute, second and second pulse;

[0032] The time correction module is used to calculate the code acquisition time correction value based on the time information output by the time code analysis module, combined with the prior information output by the control software, the correction information output by the signal processing device and the fixed code acquisition delay;

[0033] The parameter setting module is used to calculate the code fetching instruction by using the current time count and the code fetching time correction value output by the time correction module, and send the code fetching instruction to the pseudo code server when the start output by the control software is valid;

[0034] The data storage module is used to buffer the cycle-free, spread-hop pseudocode data stream output by the pseudocode server using a fixed code acquisition delay, and then output the buffered spread-hop pseudocode data stream to the signal processing device. The following details the functions of each module in the system and the calibration methods used.

[0035] Please see Figure 2 As shown in the figure, the time code parsing module parses the time code information output by the time system device to obtain time information such as year, day, hour, minute, second, and second pulse. In this embodiment, the time code information uses the IRIG-B format time code, referred to as B code. The time code information is arranged in a format of one frame per second, with each frame consisting of 10 fields. The 10 fields are divided into fields P0 to P9, each field containing 10 code elements.

[0036] In this embodiment, the time code analysis module uses pulse width modulation to divide 10 code elements into three categories: P code element, 1 code element, and 0 code element. The duration of each code element is 10 ms, and the high-level pulse durations of the P code element, 1 code element, and 0 code element are 8 ms, 5 ms, and 2 ms, respectively. The time code analysis module uses the system processing clock to count high-level pulses and clear low-level pulses to determine the three code elements. Two consecutive P code elements mark the beginning of each frame of time code information. The time code analysis module outputs a second pulse. When the second pulse is valid, it outputs the current time information, such as year, day, hour, second, and second pulse, in the form of fields. Among them, field P0 represents second information, field P1 represents minute information, field P2 represents hour information, field P3 represents day information, and field P4 represents year information.

[0037] Please see Figure 3 As shown in FIG, the time correction module counts the time in seconds, the number of hops, and the code chips according to the time information output by the time code analysis module when the second pulse output by the time code analysis module is valid.

[0038] In this embodiment, when the second pulse output by the time code analysis module is valid, the time correction module first clears the count and then processes the clock f through the system. sys Start counting and get the real-time time t0 in seconds. Then calculate the current time t in seconds by using the real-time time t0 in seconds. cnt, frequency hopping pseudo code H n The frequency hopping count n and the DS-PS code C n m The chip count m.

[0039] Then, the time correction module uses the time count t in seconds cnt , frequency hopping pseudo code H n The frequency hopping count n and the DS-PS code C n m The chip count m is combined with the prior information output by the control software, the correction information output by the signal processing device and the fixed code acquisition delay to calculate the code acquisition time correction amount.

[0040] In this embodiment, the a priori information output by the control software includes: a priori hop count offset H pre , the frequency hopping frequency is f hopp , and its correction accuracy is t hopp =1 / f hopp The correction information output by the signal processing device includes: frequency hopping count offset H adj and direct expansion code chip offset R adj , the direct spread pseudo code frequency is R code , and its correction accuracy is t code =1 / R code .

[0041] The time correction module counts the time in seconds t cnt , frequency hopping count n and chip count m, and the prior information output by the control software, the correction information output by the signal processing device and the fixed code acquisition delay t max Directly accumulate and calculate the code acquisition time correction; the code acquisition time correction includes the second time count correction Δt cnt , frequency hopping count correction amount Δn and chip count correction amount Δm.

[0042] In the parameter setting module, the current time count and the code time correction value output by the time correction module are used to calculate the code instruction, and when the start output by the control software is valid, the code instruction is sent to the pseudo code server. In this embodiment, the code instruction includes the year information t in the time information output by the time code analysis module. year , Tianxin t day , time information hour and second information t sec , and the second time count correction value Δt in the code time correction value output by the time correction module cnt , frequency hopping count correction amount Δn and chip count correction amount Δm.

[0043] In the data storage module, a fixed code acquisition delay is used to buffer the non-periodic extended jump pseudo code data stream output by the pseudo code server, and the buffered extended jump pseudo code data stream is output to the signal processing device. In this embodiment, when the start output by the control software is valid, the code acquisition delay count t delay , write the non-periodic jump pseudo code data stream output by the pseudo code server into the internal data buffer memory; when the code acquisition delay count t delay Exceeding the fixed code acquisition delay t max When the signal processing device is used, the expanded jump pseudo code data stream is read from the internal data buffer memory, and the expanded jump pseudo code data stream after data buffering is output to the signal processing device.

[0044] The non-periodic pseudo code fetching correction method in the frequency hopping communication system performed by each module in the above system can be summarized as the following method steps, which can be referred to Figure 4 Instructions:

[0045] S1. Analyze the time code information output by the time system equipment to obtain the time information including year, day, hour, minute, second and second pulse;

[0046] S2. Calculate the code acquisition time correction value based on the time information, combined with the prior information output by the control software, the correction information output by the signal processing device, and the fixed code acquisition delay;

[0047] S3, using the current time count and the code fetching time correction value to calculate the code fetching instruction;

[0048] S4. When the start output by the control software is valid, a code fetching instruction is sent to the pseudo code server;

[0049] S5. Using a fixed code acquisition delay, perform data buffering processing on the non-periodic spread-hop pseudocode data stream output by the pseudocode server, and output the processed spread-hop pseudocode data stream to the signal processing device.

[0050] Next, the code acquisition method disclosed in this embodiment is analyzed and explained with a specific example: Taking a non-periodic spread hopping pseudo code server of a certain type of spread hopping frequency communication system as an example, the time code information of its time system equipment adopts B code, and the system processing clock f in this embodiment sys is 240MHz, the frequency hopping frequency of the spread hopping signal is f hopp The DSSS frequency is 20,000 hops per second. code 10Mcps, fixed code acquisition delay t max 50ms is selected; after testing, the system modules of this embodiment improve the code acquisition accuracy of the non-periodic pseudocode and expanded jump pseudocode to the microsecond level under high jump rate conditions according to their correction function mode, thereby providing the signal processing equipment with a high-precision and real-time expanded jump pseudocode data stream.

Claims

1. A frequency spread hopping communication non-periodic pseudo code correction system, characterized in that: The system includes: a time code analysis module, a time correction module, a parameter setting module and a data storage module; The time code parsing module is used to parse the time code information; The time correction module is used to calculate the parsed time code information based on the prior information output by the control software, the correction information output by the signal processing device, and the fixed code acquisition delay to obtain the code acquisition time correction value; The parameter setting module is used to calculate and send a code retrieval instruction to the pseudo code server using the current time count and the code retrieval time correction value; The data storage module is used to perform data buffering processing on the non-periodic spread-jump pseudocode data stream output by the pseudocode server, and output the processed spread-jump pseudocode data stream to the signal processing device.

2. The system for correcting aperiodic pseudo-code in frequency spread hopping communication according to claim 1, wherein: The time code parsing module is used to parse the time code information in B code format output by the time system equipment to obtain time information, wherein the time information includes year, day, hour, minute, second and second pulse; the time code parsing module is also used to convert the time code information into three code elements including P code element, 1 code element and 0 code element in a pulse width modulation manner, and the duration of each code element is 10ms; wherein the high level duration of the pulse of the P code element, 1 code element and 0 code element is 8ms, 5ms and 2ms respectively; the time code parsing module is also used to process the system clock f sys The three code elements are judged by counting the high level of pulses and clearing the low level. Two consecutive P code elements mark the beginning of a frame of time code information. The time code analysis module is also used to output a second pulse at the beginning of each frame of time code information, and when the second pulse is valid, output the time information represented by different fields in the time code information in B code format.

3. The system for correcting aperiodic pseudo-code in frequency spread hopping communication according to claim 2, wherein: The time correction module is used to count the time in seconds, the number of hops and the number of chips according to the time information output by the time code analysis module when the second pulse output by the time code analysis module is valid; the time correction module is also used to clear the count when the second pulse output by the time code analysis module is valid, and then process the clock f through the system. sys Start counting and get the real-time time t0 in seconds. Then calculate the current time t in seconds by using the real-time time t0 in seconds. cnt , frequency hopping pseudo code H n The frequency hopping count n and the DS-PS code C n m The chip count m.

4. The system for correcting aperiodic pseudo-code in frequency spread hopping communication according to claim 3, wherein: The time correction module is also used to obtain the time count t in seconds. cnt , frequency hopping count n and chip count m, combined with the prior information output by the control software, the correction information output by the signal processing device and the fixed code acquisition delay, the code acquisition time correction amount is calculated; The prior information includes the prior hop count offset H pre , the frequency hopping frequency is f hopp , the correction accuracy is t hopp =1 / f hopp ; The correction information includes the frequency hopping count offset H adj and direct expansion code chip offset R adj , the direct spread pseudo code frequency is R code , the correction accuracy is t code =1 / R code ; The time correction module is also used to count the time in seconds t cnt , frequency hopping count n and chip count m, and the prior information, the correction information and the fixed code delay t max Directly accumulate and calculate the code acquisition time correction value; the code acquisition time correction value includes the second time count correction value Δt cnt , frequency hopping count correction amount Δn and chip count correction amount Δm.

5. The system for correcting aperiodic pseudo-code in frequency spread hopping communication according to claim 4, characterized in that: The parameter setting module is used to calculate the code acquisition instruction based on the current time count and the code acquisition time correction value output by the time correction module, and send the code acquisition instruction to the pseudo code server when the start output by the control software is valid; the code acquisition instruction includes the year information t in the time information output by the time code analysis module year , Tianxin t day , time information hour and second information t sec The code fetch instruction also includes the second time count correction value Δt in the code fetch time correction value output by the time correction module cnt , frequency hopping count correction amount Δn and chip count correction amount Δm.

6. The system for correcting aperiodic pseudo-code in frequency spread hopping communication according to claim 5, characterized in that: The data storage module is used to use a fixed code acquisition delay to perform data buffering on the non-periodic extended jump pseudo code data stream output by the pseudo code server, and output the buffered extended jump pseudo code data stream to the signal processing device; the data storage module is also used to start the code acquisition delay count t when the start output of the control software is valid delay , write the non-periodic jump pseudo code data stream output by the pseudo code server into the internal data buffer memory; the data storage module is also used to, when the code delay count t delay Exceeding the fixed code acquisition delay t max When the signal processing device is used, the expanded jump pseudo code data stream is read from the internal data buffer memory, and the expanded jump pseudo code data stream after data buffering is output to the signal processing device.

7. A method for correcting aperiodic pseudo-code in frequency spread hopping communication, characterized in that: The steps include: S1. Analyze the time code information output by the time system equipment to obtain the time information including year, day, hour, minute, second and second pulse; S2. Calculate a code acquisition time correction value based on the time information, combined with the prior information output by the control software, the correction information output by the signal processing device, and the fixed code acquisition delay; S3, using the current time count and the code fetching time correction value to calculate the code fetching instruction; S4. When the start output by the control software is valid, the code fetching instruction is sent to the pseudo code server; S5. Using a fixed code acquisition delay, perform data buffering processing on the non-periodic spread-hop pseudocode data stream output by the pseudocode server, and output the processed spread-hop pseudocode data stream to the signal processing device.

8. The method for correcting aperiodic pseudo-code in frequency spread hopping communication according to claim 7, wherein: In step S1, the time code information adopts the B code format, and the time code information is set to 10 fields per frame and divided into fields P0 to P9, each field containing 10 code elements; the code elements are divided into three categories using pulse width modulation, namely P code elements, 1 code elements and 0 code elements, the time length of each code element is 10ms, and the high level duration of the pulse of P code elements, 1 code elements and 0 code elements is 8ms, 5ms and 2ms respectively; the system processes the clock f sys The three code elements are distinguished by counting high-level pulses and clearing low-level pulses. Two consecutive P code elements mark the beginning of each frame of the time code information; then the second pulse is output. When the second pulse is valid, the fields of the current moment are output, where field P0 represents second information, field P1 represents minute information, field P2 represents hour information, field P3 represents day information, and field P4 represents year information.

9. The method for correcting aperiodic pseudo-code in frequency spread hopping communication according to claim 8, wherein: In step S2, when the second pulse in step S1 is valid, the count is first cleared, and then the system processes the clock f sys , start counting and get the real time in seconds t0, calculate the current time in seconds t0 by the real time in seconds cnt , frequency hopping pseudo code H n The frequency hopping count n and the DS-PS code C n m The chip count m; Then, the a priori information output by the control software, the correction information output by the signal processing device and the fixed code delay t max Directly add up and calculate the code acquisition time correction amount.

10. The method for correcting aperiodic pseudo-code in frequency spread hopping communication according to claim 9, wherein: In step S4, when the start signal output by the control software is valid, the code acquisition delay count t delay , write the non-periodic jump pseudo code data stream output by the pseudo code server into the internal data buffer memory used for data buffer processing; when the code acquisition delay count t delay Exceeding the fixed code acquisition delay t max When the signal processing device is used, the expanded jump pseudo code data stream is read from the internal data buffer memory, and the expanded jump pseudo code data stream after data buffering is output to the signal processing device.

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