College of Earth, Ocean, and Environment, University of Delaware, 114 Robinson Hall, Newark, Delaware 19716, USA.
J Acoust Soc Am. 2012 Jan;131(1):281-91. doi: 10.1121/1.3664085.
Multiple-input/multiple-output (MIMO) techniques can lead to significant improvements of underwater acoustic communication capabilities. In this paper, receivers based on time reversal processing are developed for high frequency underwater MIMO channels. Time reversal followed by a single channel decision feedback equalizer, aided by frequent channel updates, is used to compensate for the time-varying inter-symbol interference. A parallel interference cancellation method is incorporated to suppress the co-channel interference in the MIMO system. The receiver performance is demonstrated by a 2008 shallow water experiment in Kauai, Hawaii. In the experiment, high frequency MIMO signals centered at 16 kHz were transmitted every hour during a 35 h period from an 8-element source array to a wide aperture 16-element vertical receiving array at 4 km range. The interference cancellation method is shown to generate significant performance enhancement, on average 2-4 dB in the output signal-to-noise ratio per data stream, throughout the 35 h MIMO transmissions. Further, communication performance and achieved data rates exhibit significant changes over the 35 h period as a result of stratification of the water column.
多输入多输出（MIMO）技术可以显著提高水声通信能力。本文针对高频水声 MIMO 信道，开发了基于时反处理的接收机。采用时反处理结合单通道判决反馈均衡器，并通过频繁的信道更新来补偿时变符号间干扰。同时，采用并行干扰消除方法来抑制 MIMO 系统中的同信道干扰。通过在夏威夷考艾岛进行的 2008 年浅海实验，验证了该接收机的性能。在该实验中，8 元发射源阵在 4km 的距离内向宽孔径 16 元垂直接收阵以 16kHz 的中心频率，每小时发送高频 MIMO 信号，持续 35 小时。干扰消除方法可在整个 35 小时的 MIMO 传输中，平均每个数据流提供 2-4dB 的输出信噪比增益。此外，由于水柱分层，通信性能和实现的数据速率在 35 小时的周期内发生显著变化。
