一种基于门限的改进OFDM信号压扩方案

为了降低OFDM信号的高峰均功率比,在削波技术简单直接的基础上,应用压扩技术,提出了 一种基于门限的降低峰均功率比的改进压扩方案。门限压扩方案在发射端对幅值低于门限值的小幅度 信号不进行变换,而幅值高于门限值的大幅度信号则利用对数的压缩特性进行压缩。在接收端引入一个 简单的门限判决过程,将被压缩的信号从接收信号中识别出来,然后用相应的解压缩过程将被压缩的信 号恢复为原始信号。仿真结果表明,与削波技术和传统的压扩技术相比,门限压扩以较小的系统复杂度 获得了峰均比性能的改善。

Threshold-based Companding Scheme of OFDM Signals

For the effect of PAPR of OFDM signals reduction, an improved companding scheme was proposed based on threshold. The scheme uses the companding technique based on the simple clipping technique. In this scheme, using the compressing characteristic of logarithm function, the signals whose amplitudes are higher than the threshold value are compressed on the transmitter. A corresponding expanding process is implemented on the receiver after the compressed signals are distinguished from the received signals. Simulation results show that compared with clipping and the traditional companding techniques, threshold-based companding scheme can effectively improve the performance of PAPR with low complexity.