Naval Research Laboratory, Washington, DC 20375, USA.
J Acoust Soc Am. 2011 Oct;130(4):1995-2002. doi: 10.1121/1.3632078.
The performance of underwater acoustic communications, such as the output signal-to-noise ratio (OSNR), is generally dependent on the channel specifics, hence a channel model is normally required as the performance of the channel equalizer depends on the number of tap coefficients used (e.g., a sparse equalizer) which are different for different oceans having different multipath arrivals. This letter presents theoretical arguments, and experimental data from different oceans that suggest that the increase of OSNR with the number of diverse receivers (in terms of the effective number of receivers) and the decrease of OSNR with the channel-estimation error follow a universal relationship using the time-reversal or correlation-based equalizer, despite the fact that the channels have very different properties. The reason is due to the fact that the OSNR is a function of the q function, the auto-correlation of the received impulse responses summed over all receiver channels, and the q function is approximately the same for all shallow waters given a sufficient (≥4-6) number of receivers.
水下声通信的性能，如输出信噪比（OSNR），通常取决于信道特性，因此通常需要信道模型，因为信道均衡器的性能取决于所使用的抽头系数数量（例如，稀疏均衡器），不同的海洋具有不同的多径到达，这些系数数量也不同。本函件提出了理论论证和来自不同海洋的实验数据，表明使用时间反转或基于相关的均衡器，随着不同接收器数量（以有效接收器数量表示）的增加，OSNR 会增加，而随着信道估计误差的增加，OSNR 会减小，这与信道具有非常不同的特性的事实相矛盾。原因是 OSNR 是 q 函数的函数，q 函数是所有接收通道上接收脉冲响应的自相关的函数，并且对于给定足够数量（≥4-6）的接收器，q 函数对于所有浅水域几乎都是相同的。
