Hopping time estimation algorithm of frequency hopping signal under impulse noise

Abstract

Aiming at the hopping time estimation problem of frequency hopping (FH) signals under alpha stable distributed noise, a hopping time estimation algorithm based on time-frequency pattern gradient sequence is proposed in this paper. Firstly, the FH signal model and the alpha stable distribution noise model are established according to the received signals; Secondly the fractional lower order SPWVD (FLOSPWVD) transform is used to suppress the impulse noise in the time frequency pattern, and a clear and reliable time frequency pattern is obtained by using the morphological filtering. Finally, the hopping time estimation of the frequency hopping signal is completed according to the jump of the gradient sequence of the time frequency graph.