Comparison of matched filter and dechirp processing used in Linear Frequency Modulation

Abstract

Linear Frequency Modulation (LFM) is an important wideband signal, which is widely used in radar system. Both matched filter and dechirp processing can realize pulse compression of LFM, and then get high resolution target range profile. Matched filter has strong anti-noise ability; it can also achieve accurate pulse compression under seriously noisy environment. Dechirp processing can reduce the sample rate of AD efficiently, but the anti-noise ability is not as good as matched filter. This paper analyzes the algorithms of matched filter and dechirp processing which are used in LFM, then simulates the pulse compression to get high resolution target one-dimension range profile under different signal to noise ratio (SNR). The simulation results indicate that matched filter has strong anti-noise ability, dechirp processing has advantage in sample rate of data processing by hardware. This work can provide the theory basis and guidance to select the best pulse compression method under different scenes.