Department of Electrical and Computer Engineering, University of Connecticut, 371 Fairfield Road, Unit 2157, Storrs, Connecticut 06269, USA.
J Acoust Soc Am. 2012 Jun;131(6):4672-9. doi: 10.1121/1.4707460.
There are no commonly-agreed mathematical models for the input-output relationship of underwater acoustic channels. For each path in a time-varying multipath channel within a short period of time (e.g., one short data block), this paper proposes to use one polynomial to approximate the amplitude variation and another polynomial up to the first order to approximate the delay variation within a block duration. Under such a channel parameterization, the discrete-time channel input- output relationship tailored to zero-padded orthogonal-frequency-division-multiplexing (OFDM) transmissions is then derived, based on which an OFDM receiver is validated using experimental data collected during the 2008 Surface Processes and Acoustic Communications Experiment. For channels with a short coherence time, the numerical results show that incorporating both the amplitude and delay variations improves the system performance.
水下声信道的输入-输出关系尚无通用的数学模型。对于时变多径信道中的每条路径，在短时间内（例如，一个短数据块），本文建议使用一个多项式来近似幅度变化，另一个多项式近似至一阶来近似块持续时间内的延迟变化。在这样的信道参数化下，然后推导出针对零填充正交频分复用（OFDM）传输的离散时间信道输入-输出关系，在此基础上，使用 2008 年表面过程和声通信实验期间收集的实验数据验证了 OFDM 接收器。对于相干时间较短的信道，数值结果表明，同时考虑幅度和延迟变化可以提高系统性能。
