CN-119834830-B - High dynamic stable tracking method for non-spread spectrum continuous wave signal

CN119834830BCN 119834830 BCN119834830 BCN 119834830BCN-119834830-B

Abstract

The invention belongs to the technical field of wireless communication, and particularly discloses a high-dynamic stable tracking method of a non-spread spectrum continuous wave signal. The method comprises the steps of obtaining a digital signal based on ADC sampling, carrying out digital frequency conversion on all sampling points of a current symbol according to a current estimated frequency result to obtain a digital baseband signal, carrying out multi-stage downsampling to obtain a digital baseband signal under 4 times of oversampling, carrying out matched filtering processing on the digital baseband signal under 4 times of oversampling, determining an output result of a preset position in matched filtering output as an optimal sampling point to be used as the output of a tracking loop, carrying out timing error estimation according to the output result of matched filtering, adjusting sampling deviation of next-section data by utilizing the timing error estimation result, obtaining a phase discrimination value according to the optimal sampling point, and adjusting digital frequency conversion of the next-section data by utilizing the phase discrimination value. The technical problem that continuous stable tracking cannot be carried out on the non-spread spectrum continuous wave signal in a high dynamic scene is solved.

Inventors

MA ZHIRU
YANG JIAN
ZHU XIAOQING
ZHANG QIANNAN
SHANG JIADONG
YANG CHUNJING

Assignees

北京遥感设备研究所

Dates

Publication Date: 20260508
Application Date: 20241230

Claims (8)

1. A method for high dynamic stability tracking of a non-spread spectrum continuous wave signal, comprising: obtaining a digital signal based on ADC sampling, and carrying out digital frequency conversion on all sampling points of a current symbol according to a current estimated frequency result to obtain a digital baseband signal; Obtaining a digital baseband signal under 4 times of oversampling through multistage downsampling, carrying out matched filtering processing on the digital baseband signal under 4 times of oversampling, and determining an output result of a preset position in matched filtering output as an optimal sampling point to be used as the output of a tracking loop; The method comprises the steps of carrying out timing error estimation according to the output result of matched filtering, utilizing the timing error estimation result to adjust the sampling deviation of the next section of data, obtaining an phase discrimination value according to an optimal sampling point, utilizing the phase discrimination value to adjust the digital frequency conversion of the next section of data, carrying out timing error estimation according to the output result of matched filtering, utilizing the timing error estimation result to adjust the sampling deviation of the next section of data, acquiring a normalized symbol timing error estimation result, utilizing x i to represent the output of a matched filter, and adopting a normalized symbol timing error estimation formula as follows: Calculating the sampling deviation of the next segment of data according to the timing error estimation result, and determining the corresponding address adjustment quantity, wherein a specific calculation formula is as follows: the value range of n is (b+1) multiplied by 1024, n is less than or equal to (b+2) multiplied by 1024-1, and the OSR represents the oversampling multiple of the received signal.
2. The method of high dynamic stability tracking of a non-spread spectrum continuous wave signal according to claim 1, further comprising, after obtaining the digital signal based on ADC sampling: Caching the digital signal obtained by ADC sampling in a RAM, wherein each time a sampling point is input, the address of the RAM stock is added by one; the corresponding sample points are read from the RAM.
3. The method of high dynamic stability tracking of a non-spread spectrum continuous wave signal according to claim 2, wherein reading the corresponding sample point from the RAM comprises: determining a start address of a first sampling point of a first symbol, and determining a preset number of continuous sampling points as one symbol based on the start address; And updating the address information of the current sampling point according to the address of the previous symbol sampling point and the timing error estimation result, and reading the corresponding sampling point from the RAM.
4. The method for high dynamic stability tracking of non-spread spectrum continuous wave signal according to claim 1, wherein the step of obtaining the digital baseband signal at 4 times of oversampling through multi-stage downsampling comprises: And gradually reducing the sampling rate of the digital baseband signal by a preset multiple, and reducing the sampling rate to 4 times of the symbol rate through the downsampling of the multi-stage preset multiple to obtain the digital baseband signal under 4 times of oversampling.
5. The method of high dynamic stability tracking of a non-spread spectrum continuous wave signal according to claim 4, wherein gradually reducing the sampling rate of the digital baseband signal by a preset multiple comprises: obtaining a first filtering result obtained after inputting a preset number of sampling points into the current symbol according to the sampling points of the current symbol; Performing convolution operation when the current sampling point outputs a filtering result; and outputting a filtering result every time a preset number of sampling points are input from the second segment data of the current symbol.
6. The method of high dynamic stability tracking of non-spread spectrum continuous wave signals according to claim 1, wherein obtaining a phase discrimination value according to an optimal sampling point and adjusting digital frequency conversion of next segment of data using the phase discrimination value comprises: inputting the optimal sampling point into a phase discriminator to obtain a phase discrimination value; and inputting the phase discrimination value into a loop filter, and controlling the digital variable frequency of the next section of data by using the frequency offset estimation value output by the loop filter.
7. The method of high dynamic stability tracking of a non-spread spectrum continuous wave signal according to claim 6, wherein inputting the optimal sampling point into a phase discriminator to obtain a phase discrimination value comprises: And inputting the optimal sampling point into an arctan arc tangent phase discriminator, compensating the phase discrimination result, and compensating again after the loop is locked to obtain the phase discrimination value for eliminating burst phase discrimination errors.
8. A high dynamic stability tracking system for a non-spread spectrum continuous wave signal for implementing the high dynamic stability tracking method for a non-spread spectrum continuous wave signal as claimed in claim 1, comprising: the digital frequency conversion module is used for obtaining a digital signal based on ADC sampling, and carrying out digital frequency conversion on all sampling points of a current symbol according to a current estimated frequency result to obtain a digital baseband signal; the matched filtering module is used for obtaining a digital baseband signal under 4 times of oversampling through multistage downsampling, carrying out matched filtering processing on the digital baseband signal under 4 times of oversampling, and determining an output result of a preset position in matched filtering output as an optimal sampling point to be used as the output of a tracking loop; the timing error estimation module is used for carrying out timing error estimation according to the output result of the matched filtering and adjusting the sampling deviation of the next section of data by utilizing the timing error estimation result; the phase discriminator module is used for obtaining a phase discrimination value according to the optimal sampling point and adjusting the digital frequency conversion of the next section of data by utilizing the phase discrimination value.

Description

High dynamic stable tracking method for non-spread spectrum continuous wave signal Technical Field The invention belongs to the technical field of wireless communication, and particularly relates to a high-dynamic stable tracking method of a non-spread spectrum continuous wave signal. Background The relative motion between the two communicating parties can bring about the doppler effect. Along with the increase of the relative motion speed and the acceleration between the two parties, the Doppler frequency offset and the frequency offset acceleration of the received signal are increased, and meanwhile, the code offset of the two parties also changes. The code bias is related to the relative motion and the crystal vibration inconsistency of the receiving party and the transmitting party. If the receiver cannot accurately and stably track the frequency offset and the code offset change of the received signal, demodulation of the receiver can be affected, and even communication faults or interruption can be caused. At present, the common high-dynamic tracking method is mostly based on a spread spectrum system, the core idea is that a carrier ring assists a code ring, and NCO estimated by the carrier ring is fed back to the code ring to assist the code ring to eliminate the influence caused by high dynamic. The carrier loop includes a phase-locked loop, a frequency-locked loop, etc. However, the non-spread spectrum system cannot recover the original information using the code tracking loop, and thus cannot use the above algorithm. The common carrier synchronization algorithm of the non-spread spectrum system is mainly used for assuming that the frequency offset is unchanged in a period of time, and is suitable for the situation that the residual frequency is far smaller than the symbol rate. For a high dynamic scene, the frequency offset of a received signal is far greater than the symbol rate, and the current algorithm cannot ensure stable tracking of a non-spread spectrum continuous wave signal in the high dynamic scene. Disclosure of Invention The invention aims to provide a high-dynamic stable tracking method of a non-spread spectrum continuous wave signal, which aims to solve the technical problem that the non-spread spectrum continuous wave signal cannot be continuously and stably tracked in a high-dynamic scene. In order to achieve the above purpose, the invention adopts the following technical scheme: A high dynamic stable tracking method for non-spread spectrum continuous wave signal includes obtaining digital signal based on ADC sampling, carrying out digital frequency conversion on all sampling points of current symbol according to current estimated frequency result to obtain digital baseband signal, carrying out multi-stage down sampling to obtain digital baseband signal under 4 times of over sampling, carrying out matched filtering treatment on digital baseband signal under 4 times of over sampling, determining output result of preset position in matched filtering output as optimal sampling point to be used as output of tracking loop, carrying out timing error estimation according to output result of matched filtering, utilizing timing error estimation result to adjust sampling deviation of next section of data, obtaining phase discrimination value according to optimal sampling point, and utilizing phase discrimination value to adjust digital frequency conversion of next section of data. A high-dynamic stable tracking system of non-spread spectrum continuous wave signals comprises a digital frequency conversion module, a matched filtering module, a timing error estimation module and a phase discriminator module, wherein the digital frequency conversion module is used for obtaining digital signals based on ADC sampling and carrying out digital frequency conversion on all sampling points of a current symbol according to a current estimated frequency result, the matched filtering module is used for obtaining digital baseband signals under 4 times of oversampling through multistage downsampling and carrying out matched filtering processing on the digital baseband signals under 4 times of oversampling, an output result of a preset position in matched filtering output is determined to be an optimal sampling point and is used as output of a tracking loop, the timing error estimation module is used for carrying out timing error estimation according to the output result of matched filtering and utilizing the timing error estimation result to adjust sampling deviation of next section of data, and the phase discriminator module is used for obtaining a phase discrimination value according to the optimal sampling point and utilizing the phase discrimination value to adjust digital frequency conversion of next section of data. A computer readable storage medium having a computer program stored therein, wherein the computer program is configured to perform the above-described method of high dynamic stability trac