OFDM系统降低峰均比方法的研究

SLM(选择映射)技术是一种无失真降低OFDM(正交频分复用)信号峰均比的方法,它是一种很有效的方法。但是一般的SLM技术是在IFFT之后选择具有最小峰均比的序列,因此需要多个IF-FT模块,系统复杂度高。在改进的SLM技术中提出了一种基于比较序列随机性的判决算法,采用此算法可以在IFFT之前选择发送序列,从而只需要一个IFFT模块。通过仿真证明,这种判决算法可以在较小的计算量和复杂度条件下获得同原有SLM技术相同的降低峰均比性能。

Research on Peak-to-Average Power Ratio Reduction Scheme of OFDM Signal

SLM(Selected mapping) is an effective algorithm for the reduction of peak-to-average power ratio(PAPR) of OFDM(Orthogonal Frequeney Division Multiplexing) signal without distortion.In general,SLM selects the transmitted sequence with minimum PAPR after IFFT,so that the system needs some IFFTs operating in parallel and is very complex.An improved SLM technique,which adopts a simpler algorithm to select the transmitted sequence before IFFT by comparing randomness of sequences,is proposed.The system adopting the improved SLM technique only needs one IFFT.So it is with lower complexity.The simulation results show that the PAPR performance of the improved SLM technique with lower complexity is the same as that of the existing selected mapping technique.