主要研究了多输入多输出正交频分复用水声通信中的峰均功率比抑制技术。针对传统选择性映射算法(Selective Mapping,SLM)需要将所选加扰相位序列的序号作为边带信息传递给接收端的缺点,提出了一种改进SLM算法,从判决反馈的角度设计图样检测器对所选加扰相位序列的序号进行判断,节约了边带信息传输,克服了传统SLM算法系统的误比特率性能依赖于边带信息准确性的问题,提高了系统的频带利用率。通过仿真验证,改进SLM方法能在不损失峰均功率比抑制性能的前提下,在接收端能够准确地解算出所选择的加扰相位序列序号,实现无边带信息传输的可靠水声通信。
This paper studies the peak-to-average power ratio reduction methods for Multiple-input Multiple-output Orthogonal Frequency Division Multiplexing(MIMO-OFDM) system in underwater acoustic communication. An improved selected mapping(SLM) method without side information is proposed to overcome the disadvantages of the conventional SLM algorithm, which needs transmitting the serial number of selected scrambling phase sequence as side information. A pattern detector based on the decision feedback is designed at the receiver to find out the serial number of selected scrambling phase sequence. Therefore, the proposed method does not need to reserve bits for submitting side information, resulting in an increase of the data rate. Furthermore, unlike the conventional SLM algorithm, the improved SLM method has no dependence on the side information. Simulations show that the proposed method could offer better performances of bit error rate under the premise of without losing PAPR reduction performance. The serial number of selected scrambling phase sequence could be calculated accurately by the pattern detector at the receiver, and a reliable underwater acoustic communication without a transmission of side information could be achieved.