SYSTEM-IDENTIFICATION USING CHIRP SIGNALS AND TIME-VARIANT FILTERS INTHE JOINT TIME-FREQUENCY DOMAIN

In this paper, we propose a novel method to identify an unknown linear time invariant (LTI) system in low signal-to-noise ratio (SNR) enviro nment, The method is based on transmitting chirp signals for the trans mitter and using linear time-variant filters in the joint time-frequen cy (TF) domain for the receiver to reduce noise before identification, Due to the TF localization property of chirp signals, a large amount of additive white noise can be reduced, and therefore, SNR before iden tification can be significantly increased. This, however, cannot be ac hieved in the conventional methods, where pseudo-random signals are us ed, and therefore, noise reduction techniques do not apply, Our simula tion results indicate that the method proposed in this paper outperfor ms the conventional methods significantly in low SNR environment, This paper provides a good application of time-frequency analysis and synt hesis.