PHASE-COHERENT DIGITAL-COMMUNICATIONS FOR UNDERWATER ACOUSTIC CHANNELS
PHASE-COHERENT DIGITAL-COMMUNICATIONS FOR UNDERWATER ACOUSTIC CHANNELS
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DOI：
10.1109/48.289455
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发表时间：
1994-01-01
影响因子：
4.1
通讯作者：
PROAKIS, JG
中科院分区：
文献类型：
--
作者：
STOJANOVIC, M;CATIPOVIC, JA;PROAKIS, JG
海洋信道中的高速相位相干通信由于大的多普勒起伏和扩展的时变多径的综合影响而变得困难。为了考虑这些影响，我们考虑一个接收器，执行最佳相位同步和信道均衡联合。由于在一些水声信道的符号间干扰跨越几十个符号间隔，使最佳的最大似然接收器不可接受的复杂性，我们使用一个次优的，但复杂度低，判决反馈均衡器。均方误差多参数优化的结果在一个自适应算法，这是一个组合的递归最小二乘和二阶数字相位和延迟锁定环。分数间隔均衡器的使用消除了显式的符号延迟tracking.The所提出的算法被施加到三种类型的水声信道的实验数据：远程深水，远程浅水，和短程浅水信道。使用的调制技术是4-和8-PSK。结果表明，在这些信道中实现功率有效的通信的可行性，并展示了相干联合收割机多个到达的能力，从而利用多径传播中固有的多样性。
High-speed phase coherent communications in the ocean channel are made difficult by the combined effects of large Doppler fluctuations and extended, time-varying multipath. In order to account for these effects, we consider a receiver which performs optimal phase synchronization and channel equalization jointly. Since the intersymbol interference in some underwater acoustic channels spans several tens of symbol intervals, making the optimal maximum-likelihood receiver unacceptably complex, we use a suboptimal, but low complexity, decision feedback equalizer. The mean squared error multiparameter optimization results in an adaptive algorithm which is a combination of recursive least squares and second-order digital phase and delay-locked loops. The use of a fractionally spaced equalizer eliminates the need for explicit symbol delay tracking.The proposed algorithm is applied to experimental data from three types of underwater acoustic channels: long-range deep water, long-range shallow water, and short-range shallow water channels. The modulation techniques used are 4- and 8-PSK. The results indicate the feasibility of achieving power-efficient communications in these channels and demonstrate the ability to coherently combine multiple arrivals, thus exploiting the diversity inherent in multipath propagation.