As a generalized framework unifying the traditional orthogonal frequency-division multiplexing (OFDM) and single-carrier frequency-domain equalization (SC-FDE), orthogonal signal-division multiplexing (OSDM) has emerged as a promising modulation scheme for building reliable underwater acoustic communication (UAC) systems. However, given the temporal and spatial variability of acoustic links, the received changing signal strength can pose a serious performance-degrading factor for the actual OSDM systems. This paper resorts to the feedback-based adaptive power control (APC) and builds smart OSDM systems that can maintain the signal-to-noise ratio (SNR) of the received signal at a pre-specified level, thus affording substantial gains in either power savings or link quality improvement. We first introduce the underwater OSDM system and formulate its APC procedure. Then, an innovative solution for establishing an initial link with a more efficient initial power instead of the traditionally used maximum power of the transmitting transducer is presented. Next, we focus on the APC techniques and propose three different algorithms in both the fixed-step and variable-step categories. Finally, simulation results are presented to demonstrate the feasibility and effectiveness of the proposed OSDM-APC system.

作为统一传统正交频分复用（OFDM）和单载波频域均衡（SC-FDE）的通用框架，正交信号分复用（OSDM）已经成为建立可靠的水下声通信的一种有前途的调制方案。 （UAC）系统。但是，考虑到声学链路的时间和空间可变性，接收到的变化信号强度可能对实际OSDM系统造成严重的性能下降因素。本文采用基于反馈的自适应功率控制（APC）并构建了智能OSDM系统，该系统可以将接收信号的信噪比（SNR）维持在预定的水平，从而在任一种功率上均具有可观的收益节省或改善链接质量。我们首先介绍水下OSDM系统并制定其APC程序。然后，提出了一种创新的解决方案，该解决方案可以建立具有更高效率的初始功率而不是传统的发射换能器最大功率的初始链路。接下来，我们重点介绍APC技术，并在固定步长和可变步长类别中提出三种不同的算法。最后，仿真结果表明了所提出的OSDM-APC系统的可行性和有效性。