Method for improving signal-to-interference ratio of phase coded signal

Abstract

The invention discloses a method for improving a signal-to-interference ratio of a phase coded signal, and belongs to the field of signal processing. The method comprises: in a first step, carrying out speed separation and compensation to solve pulse pressure primary-to-secondary ratio loss caused by target speeds, wherein the target speeds can correspond to Doppler frequency shifts, i.e., acquiring and storing data of units at the same distance in N adjacent transmission periods and carrying out N-point FFT calculation to obtain N pieces of channel data so as to separate different speed targets into different channels, and carrying out Doppler compensation on each channel, wherein a compensation value of an nth path is n*fr / N+m*fr, fr represents a transmission pulse repetition frequency and m represents folding times by which a target Doppler frequency corresponds to fr; in a second step, carrying out channel noise reduction to solve signal-to-interference ratio loss caused by noise,i.e., designing a high-stopband suppression filter so as to filter out out-of-band noise in an effective signal of each channel; and in a third step, mismatching a pulse pressure and selecting large outputs so as to further improve the signal-to-interference ratio, i.e., designing a phase coded mismatched filter by utilizing a least square method, and selecting the large outputs for multiple pathsof data after mismatching the pulse pressure to obtain final output values.

Description

technical field [0001] The invention relates to signal processing technology, in particular to a method for improving signal-to-interference ratio. Background technique [0002] First, the phase-encoded master-slave ratio is sensitive to phase changes. The coding pattern characteristics of phase coding are reflected by phase changes. Taking four-phase coding as an example, four phases represent four kinds of symbol information, and every time the phase changes by 90 degrees, the symbol information it represents changes once. The Doppler frequency shift of the moving target will affect the phase of the phase encoding, which will be converted into a change of the symbol information and change the code pattern of the echo, thereby reducing the correlation between the echo and the pulse pressure coefficient and affecting the signal-to-interference ratio of the pulse pressure . Secondly, noise interference reduces the signal-to-interference ratio; high-power noise interference ...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a method for improving the signal-to-interference ratio of phase-coded signals, thereby solving 1. the decline of the phase-coded signal-to-interference ratio caused by Doppler frequency shift, 2. the impact of noise on the signal-to-interference ratio of phase-coded signals, and 3. traditional four-phase The code matches the pulse pressure, the primary and secondary ratio is not high, three problems

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