OFDM系统中降低峰均功率比技术的研究

Research of Peak-to-Average Power Ratio Reduction in OFDM Systems

OFDM系统中信号存在峰均功率比(PAPR)较大的特性,通过信号预畸变技术降低系统的PAPR会导致系统误码率上升。针对压缩扩展变换法等信号预畸变技术进行研究,分析了压扩因子对系统PAPR和误码率性能的影响。采用在发射端对小信号扩展变换、同时对大信号进行压缩变换的方法对压缩扩展变换法进行了改进。仿真表明该方法降低OFDM信号的PAPR的同时,系统误码率劣化程度较小。

Signals in OFDM system have the character of high peak-to-average power ratio （PAPR）. The bit error rate（BER） will increase if the signal pre-distortion technology is used. The signal pre-distortion technology such as compression expansion transformation method has been discussed in this paper. The impact on the PAPR and the BER performance by the factor is analyzed. The performance of compression expansion transformation method is improved by expand the small signal while compress the large signal at transmitting terminal. The simulation shows that this method can achieve a lower degree of BER while reduce the PAPR of OFDM signals.