Asynchronous multiuser reception for OFDM in underwater acoustic communications
Asynchronous multiuser reception for OFDM in underwater acoustic communications
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DOI：
10.1109/oceans-yeosu.2012.6263506
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发表时间：
2012-05
期刊：
影响因子：
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通讯作者：
Zhaohui Wang;Shengli Zhou;J. Catipovic;Peter Willett
中科院分区：
文献类型：
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作者：
Zhaohui Wang;Shengli Zhou;J. Catipovic;Peter Willett
近年来，点到点水声通信技术取得了显著的进展，人们对多用户通信的应用也越来越感兴趣，而多用户通信的异步特性对多用户通信提出了巨大的挑战。提出了一种水声信道中正交频分复用（OFDM）传输的时间异步多用户接收方法。接收到的数据突发被分段并以重叠的方式分配给多个处理单元，其中处理单元的长度取决于OFDM块级上用户之间的最大复用。采用干扰消除来减少重叠处理单元之间的块间干扰。在每个处理单元内，来自多个用户的残留块间干扰被聚合为可以被参数化的一个外部干扰。多用户信道估计，数据检测和干扰缓解，然后进行迭代的方式。对于异步多用户传输，仿真和实验结果清楚地表明了用户之间的最大相对延迟对接收机性能的影响。
Recently significant progress has been made on point-to-point underwater acoustic communications, and the interest has grown on the application of those techniques in multiuser communication settings, where the asynchronous nature of multiuser communication poses a grand challenge. This paper develops a time-asynchronous multiuser reception approach for orthogonal frequency division multiplexing (OFDM) transmissions in underwater acoustic channels. The received data burst is segmented and apportioned to multiple processing units in an overlapped fashion, where the length of the processing unit depends on the maximum asynchronism among users on the OFDM block level. Interference cancellation is adopted to reduce the interblock interference between overlapped processing units. Within each processing unit, the residual inter-block interference from multiple users is aggregated as one external interference which can be parameterized. Multiuser channel estimation, data detection, and interference mitigation are then carried out in an iterative fashion. With asynchronous multiuser transmissions, simulation and experimental results clearly demonstrate the impact of the maximum relative delay among users on the receiver performance.