Wu Xisheng, Li Dong, Wu Yanbo, Zhu Min
Ocean Acoustic Technology Laboratory, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China.
Science and Technology on Sonar Laboratory, Hangzhou Applied Acoustic Research Institute, Hangzhou 310023, China.
J Acoust Soc Am. 2023 Jul 1;154(1):433-442. doi: 10.1121/10.0020272.
A probabilistic constellation shaping (PCS)-aided single-carrier transceiver is proposed to improve spectral efficiency for underwater acoustic (UWA) communications. At the transmitter, the information bits are input into a distribution matcher followed by a systematic binary encoder, which yields a sequence of sign bits with a uniform distribution and a sequence of amplitude bits with a non-uniform distribution. Based on these two sequences, the PCS is then realized by mapping coded bits onto a quadrature amplitude modulation constellation. At the receiver, an improved frequency-domain turbo equalizer based on the vector approximate message passing (VAMP) is proposed for the PCS-UWA communication system to eliminate the multipath interference. It exploits the a priori symbol probability information benefiting from the PCS at the beginning of the turbo iteration and over the self-iteration of the VAMP soft equalizer, improving the symbol detection performance. Finally, the first experimental demonstration of a deep-sea PCS-UWA communication system and numerical simulation of shallower water are presented. The experimental results reveal the PCS-UWA communication system significantly outperforms traditional systems with no PCS. Also, the proposed receiver is superior to the classical adaptive turbo equalizer based on the improved proportionate normalized least mean square algorithm even with data reuse.
提出了一种概率星座整形（PCS）辅助的单载波收发器，以提高水下声学（UWA）通信的频谱效率。在发射端，信息比特输入到一个分布匹配器，随后是一个系统二进制编码器，其产生具有均匀分布的符号比特序列和具有非均匀分布的幅度比特序列。基于这两个序列，然后通过将编码比特映射到正交幅度调制星座上来实现PCS。在接收端，针对PCS-UWA通信系统提出了一种基于向量近似消息传递（VAMP）的改进频域Turbo均衡器，以消除多径干扰。它利用了在Turbo迭代开始时以及VAMP软均衡器的自迭代过程中受益于PCS的先验符号概率信息，提高了符号检测性能。最后，给出了深海PCS-UWA通信系统的首次实验演示以及较浅水域的数值模拟。实验结果表明，PCS-UWA通信系统明显优于无PCS的传统系统。此外，即使在数据重用的情况下，所提出的接收机也优于基于改进比例归一化最小均方算法的经典自适应Turbo均衡器。
