High-precision rapid time-frequency difference estimation method under same-frequency interference

By using segmented spectrum correlation function and time domain offset technology in passive positioning, the cyclic frequency value and correlation function received by the receiving station are calculated, and the high-precision estimation of the time-frequency difference parameters are solved. The time-frequency difference under homofrequency interference is solved The problem of low parameter estimation accuracy reduces the computational complexity and meets the timeliness of passive positioning engineering.

CN119312000APending Publication Date: 2025-01-14CHINA ACADEMY OF SPACE TECHNOLOGY
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Patent Information

Application Number
CN202411224708.5
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-09-03
Publication Date
2025-01-14

AI Technical Summary

Technical Problem

The existing passive positioning technology is difficult to achieve high-precision fast time-frequency difference parameter estimation in the environment of homogeneous interference, especially in multi-station collaborative positioning, with a large number of signals and complex spectrum overlap. The existing method is under low signal-to-noise ratio. The parameter estimation accuracy is poor, and the baseline length limits the positioning accuracy.

Method used

The segmented spectrum correlation function is used to calculate the cyclic frequency value of the target signal received by the receiving station, and the coarse cyclic autocorrelation and cross-correlation functions are calculated through large-scale time domain offset, and the time-frequency difference fuzzy function diagram is obtained, and the spectral peak search is performed to obtain the coarse estimation. value, adjust the time difference search range, calculate the fine cyclic autocorrelation and cross-correlation functions, and realize high-precision estimation of time and frequency difference parameters.

Benefits of technology

Effectively separate the target signal from the same frequency interference signal, realize high-precision estimation of time-frequency difference parameters, reduce calculation complexity, and meet the timeliness requirements of passive positioning engineering.

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Abstract

The invention provides a high-precision rapid time-frequency difference estimation method under same-frequency interference, and the method comprises the steps: calculating a cyclic frequency value of a first receiving station through collecting the receiving data of the first receiving station and a second receiving station for the same target on the ground; respectively performing large-scale time domain offset on the received data of the first receiving station and the second receiving station, and calculating a coarse cyclic autocorrelation function of the first receiving station and a coarse cyclic cross-correlation function of the first receiving station and the second receiving station based on the cyclic frequency value, calculating a time-frequency difference coarse estimation value based on the coarse cycle self-correlation function and the coarse cycle cross-correlation function; and according to the time-frequency difference coarse estimation value, adjusting a time difference search range, then calculating a corresponding fine cyclic autocorrelation function and a fine cyclic cross-correlation function, and finally obtaining a time-frequency difference estimation value based on the fine cyclic autocorrelation function and the fine cyclic cross-correlation function. Therefore, high-precision estimation of the time-frequency difference parameter can be realized, and the calculation efficiency is effectively improved.
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