Title :
Iterative equalization for underwater acoustic channels potentiality for the TPIDENT system
Author :
Labat, Joel ; Lapierre, G. ; Trubuil, Joel
Author_Institution :
ENST Bretagne, Brest, France
Abstract :
This paper deals with blind adaptive equalization for short burst communication system. Until now, blind adaptive equalizers have been mainly dedicated to continuous data stream applications because of their supposedly well-known slow convergence. The aim of the paper is twofold. It intends both to combat this latter idea and to stress the relevance of the blind approach, under two mild conditions of sufficient burst length and channel stationarity. In some cases, conventional results of equalization are not adequate. This paper proposes two different techniques for improving the performance of equalization processing. For that purpose, the blind decision feedback equalizer introduced in [J. Labat, et al., 2001] is combined with an iterative procedure and operates on both direct and time reverse sequences. Performances are illustrated with examples of 4-PSK short bursts and underwater acoustic signals. The results are very convincing since, at a low computational cost, the challenge of recovering all the data has now been taken up.
Keywords :
adaptive equalisers; decision feedback equalisers; oceanographic techniques; underwater acoustic communication; underwater sound; TPIDENT system; blind adaptive equalization; blind decision feedback equalizer; burst communication system; burst length; channel stationarity; data stream application; direct-time reverse sequence; equalization processing performance; iterative equalization; iterative procedure; latter idea; mild condition; slow convergence; underwater acoustic channel; underwater acoustic signal; Adaptive equalizers; Additive white noise; Blind equalizers; Convergence; Decision feedback equalizers; Delay estimation; Finite impulse response filter; Maximum likelihood estimation; Stress; Underwater acoustics;
Conference_Titel :
OCEANS 2003. Proceedings
Conference_Location :
San Diego, CA, USA
Print_ISBN :
0-933957-30-0
DOI :
10.1109/OCEANS.2003.178098