Improved prewhitening method for linear frequency modulation reverberation using dechirping transformation

Abstract

This letter presents an autoregressive (AR) prewhitener for linear frequency modulation (LFM) reverberation to enhance the target signal. The proposed method uses a dechirping transformation to inversely compensate the frequency chirp rate of the LFM and give the LFM reverberation a stationary frequency property in each data block. The left or right beam signal adjacent to the current beam is then used as the reference signal, and the frequency response of each data block modeled using the AR coefficients. Finally, these coefficients are used to implement the inverse filter and efficiently prewhiten the LFM reverberation of the current beam.