Coherent integration and detection algorithm for high-speed weak targets in OFDM sonar based on FrFT-Keystone motion compensation
A coherent integration algorithm for high-speed weak targets is proposed towards orthogonal frequency division multiplexing(OFDM)signals in underwater target detection.The algorithm solves the problem of insufficient coherent integration gain,which is caused by significant phase changes caused by target maneuvering under multi pulse integration and low signal to noise ratio(SNR)in underwater environments.The proposed algorithm utilizes fractional Fourier transform(FrFT)to estimate the motion parameters of the target and compensate for it,and combines Keystone transform(KT)to achieve multi pulse coherent integration for high-speed weak targets.Through theoretical derivation and simulation experiments,the results show that the proposed algorithm can effectively compensate for the phase shift between high-speed target pulses and achieve good energy integration effect in low SNR environments.
high-speed and weak targetcoherent integrationfractional Fourier transform(FrFT)Keystone transform(KT)