An Algorithm to Improve SNR of Target Detection by Coherent Synthesis of Multi-Frequency Signals

Abstract

In order to solve the problem that the signal to noise ratio(SNR) is too low when the weak communication signal is used as the external radiation source to detect the target, this paper intends to use the coherent synthesis of multi-carrier frequency signals to improve the detection SNR. Firstly, the moving target detection (MTD) algorithm in radar signal processing is introduced, and a single communication signal with very low SNR is coherently accumulated for a long time, and the signal form is transformed into a simple Sinc function. Therefore, it is not necessary to consider the different modulation modes, different signal codes, phase changes and other information between multiple signals, and only need to complete the phase compensation at the peak point in the two-dimensional processing results to obtain the coherent processing gain of multiple signals with different SNR and different carrier frequencies. The statistical results of simulation data show that the calculation accuracy of coherent synthesis gain of signals with different SNR can reach 0.1dB. Field experiment results prove the feasibility and accuracy of the proposed algorithm.