The Impact of Estimation Error on Channel Estimation-Based Equalizer for UWA Channel

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Underwater acoustic channels are generally recognized as one of the most difficult communication media in use today. The ocean is a time and spatially varying propagation environment. The underwater acoustic propagation is best supported at low frequencies, and the bandwidth available for communication is extremely limited. The underwater acoustic communication differ from RF communication in two aspects: One is the long multipath delay time that containing ten to hundreds of symbols, and the other is the rapid time variation of underwater acoustic channel. The receiver structure that has been found useful in many applications is a decision-feedback equalizer(DFE). Due to the nature of the propagation channel, the required signal processing is often prohibitively complex, to reduce computational complexity of signal processing, the receiver structures that are matched to the physical channel characteristics are investigates. A channel estimation-based equalization which relies on an adaptive channel estimation to compute its parameters, this estimation is used to cancel the post-cursor ISI before the linear equalization. The impact of estimation error on the channel estimation-based equalizer are investigated.