基于信号空间扩展方法降低OFDM系统的PAPR

Reducing peak to average power ratio of OFDM system based on signal space expansion

在分析降低正交频分复用(OFDM)系统峰均功率比(PAPR)研究进展的基础上,通过减少OFDM调制方案中使用的载波数和选择不同的载波频率进行组合使信号空间得以扩展,然后,利用穷举法选择较低PAPR的组合与发送信号建立映射关系,从而降低整个OFDM系统的PAPR,仿真研究表明该方法能有效降低OFDM系统的PAPR.针对载波数较大系统运算量较大的问题,提出了由子载波数较小系统采用模块化结构搭建子载波数较大系统的方法,与穷举法相比,该方法对子载波数较大系统不是最优的,但特别适用于信息速率自适应的OFDM系统.

Related research progress on reducing the peak to average power ratio (PAPR) of the orthogonal frequency division multiplexing (OFDM) system is firstly introduced. The signal space is expanded by combined decreasing practical sub-carrier number and choosing different sub-carrier frequencies. Then the selected optimal PAPR combinations by the exhausted approach are mapped to the sending signals so that the total OFDM system has the lowest PAPR. The computer simulation results indicate that the method can efficiently overcome the high PAPR problem in OFDM system. To solve the problem of large calculation quantity for large sub-carrier number system, the blocking construction from small sub-carrier number to large sub-carrier number is proposed. Although it is not optimal for the large sub-carrier number system, the proposed method is particularly adapted to the adaptive information rate OFDM system.