Title :
ML-based receivers for underwater networks using OFDM signals with strong nonlinear distortion effects
Author :
Guerreiro, Joao ; Dinis, Rui ; Montezuma, Paulo
Author_Institution :
DEE, FCT Univ. Nova de Lisboa, Monte de Caparica, Portugal
fDate :
Oct. 29 2012-Nov. 1 2012
Abstract :
Underwater networks present considerable opportunities as well as technical challenges. Due to severe nature of the underwater acoustic channel, the use of OFDM signals (Orthogonal Frequency Division Multiplexing) with reduced envelope fluctuations is strongly recommendable. Although iterative clipping and filtering techniques are the most efficient way of reducing the envelope fluctuations of OFDM signals, they introduce significant nonlinear distortion effects that lead to performance degradation. In this paper we consider the ML (Maximum-Likelihood) detection of underwater OFDM signals with strong nonlinear distortion effects. It is shown that the nonlinear distortion does not necessarily mean significant performance degradation and, in fact, the ML performance could even be better than the performance with ideal, linear transmitters. We also present sub-optimum ML-based receivers that allow remarkable performance improvements, being able to reduce significantly the gap between the ML performance and the performance of conventional OFDM receivers.
Keywords :
OFDM modulation; maximum likelihood detection; nonlinear distortion; radio receivers; underwater acoustic communication; ML-based receivers; envelope fluctuations; filtering techniques; iterative clipping; linear transmitters; maximum-likelihood detection; orthogonal frequency division multiplexing; strong nonlinear distortion effects; underwater OFDM signals; underwater acoustic channel; underwater networks; AWGN channels; Bit error rate; Complexity theory; Frequency domain analysis; Nonlinear distortion; OFDM; Receivers; OFDM signals; Underwater communications; clipping and filtering; maximum-likelihood detection; nonlinear distortion; sub-optimum receivers;
Conference_Titel :
MILITARY COMMUNICATIONS CONFERENCE, 2012 - MILCOM 2012
Conference_Location :
Orlando, FL
Print_ISBN :
978-1-4673-1729-0
DOI :
10.1109/MILCOM.2012.6415761