基于星座恢复法降低PAPR的性能分析

Performance Analysis for Reducing PAPR Based on Constellation Restoration

提出了一种新的降低峰均功率比(Peak-to-average ratio,PAPR)的方法——星座恢复法。在发送端采用软件削波限幅的方法来降低系统的峰均比,其系统结构简单、且可根据系统的要求灵活地改变PAPR值;在接收端根据调制信号的星座特性恢复出被限幅数据的实际值,从而减小了信号的畸变,提高了系统的误码性能。为了使星座恢复法更具实用性,对其算法进行了简化,从而大大地减少了系统的运算量。理论分析和仿真结果表明:与选择性映射法(Selective mapping,SLM)相比,基于星座恢复法的正交频分复用(Orthogonal frequency divisionmultiplexing,OFDM)系统,其误码性能得到了明显的改善,算法较简单,且无需额外信道来传送附加信息。

A new method of reducing peak-to-average ratio（PAPR） based on constellation restoration is presented.In the transmitter,the method of soft clipping is used to reduce the PAPR of orthogonal frequency division multiplexing system.The system structure is simple,and the PAPR value can be changed according to the requirement of the system.In the receiver,the actual value of the clipped data is recovered according to the constellation characteristics of modulated signal.Thus,the signal distortion is weakened,and the error performance is improved.To make the method of constellation restoration more practical,a simplified algorithm is proposed.Theoretical analysis and simulation results show that compared with SLM,the bit error rate performance of the orthogonal frequency division multiplexing（OFDM） system based on constellation restoration is significantly improved,the algorithm is relatively simple,and no additional channel is needed to transmit additional information.