使用非线性变换降低正交频分复用的峰均比

Reducing the peak-to-average power ratio of OFDM by exploiting nonlinear transform

针对正交频分复用(OFDM)所具有的高峰均比问题,提出了一种简单有效的降低峰均比的非线性变换方法。通过把OFDM信号看作随机变量,从概率统计的角度出发提出了一种新的非线性变换。经过非线性变换,将OFDM信号幅度的概率分布改变为近似的均匀分布,从而压缩了信号的动态范围,有效地降低了峰均比;在加性高斯信道下,获得了较好的误码率性能。数据仿真验证了所提出方法的有效性。

A simple but effective scheme to reduce the high peak-to-average power ratio （PAPR） of OFDM is presented. By taking the OFDM time domain signal as a random variable, a new nonlinear transform is derived based on probability and statistics. After nonlinear transform, the signal amplitude＇s statistic distribution becomes approximately uniform, then the signal＇s dynamic range is reduced and the PAPR is decreased efficiently. In case of the additive white Gaussian noise channel, the proposed scheme achieves a better performance on code error rate than that of conventional companding method. The effectiveness of the proposed scheme is demonstrated by simulations.