基于软限幅法降低峰均比的性能分析

Analysis of PAPR Reduction Based on Soft-clipping

在正交频分复用技术(OFDM)系统接收到的信号较弱的情况下,为了获得较好的系统误码率,OFDM系统峰均功率比的设定值应较小。此时,采用选择性映射和部分传输序列法虽然能够有效地降低OFDM系统的峰均功率比,但是,其效果并不理想,且算法较复杂。为此,提出了软限幅法来降低OFDM系统的峰均功率比。理论分析和仿真结果表明,在峰均功率比取值较小的情况下,采用软限幅法的OFDM系统具有较好地误码率性能,且易于实现。

For the weak received signal in OFDM system,the set value for PAPR （peak-to-average power ratio） should be smaller,thus to obtain better BER.At this point,the selective mapping and partial transmit sequence method could effectively reduce peak-to-average power ratio.However,this method could not achieve satisfactory result,and the algorithm is fairly complex.So the soft-clipping method is proposed to reduce PAPR of the OFDM system.Theoretical analysis and simulation results show that when the PAPR value is relatively small,the OFDM system based on soft-clipping method would have better BER performance,and is easy in implementation.