过采样OFDM信号峰均功率比统计特性分析

Peak-to-Average Power Ratio of the Oversampling OFDM Signals

对连续正交频分复用信号所构成的随机过程进行分析,得到任意时刻之间信号相关性的解析表达式,并将其推广到任意过采样率情况下进行了讨论。随着过采样率增加,采样点之间相关性迅速上升,新增加采样点对信号峰值平均功率比的影响下降。分析和仿真结果表明,在过采样率为Nyquist采样率的2倍时,采样点之间可以近似满足相互独立同分布的关系,并得到此时信号峰值平均功率比概率分布的理论表达式。

The OFDM signal is analyzed as a continuous stochastic processes and the closed form expression of correlation function between any two given time instant is derived. When the sampling rate increases, the correlation increases quickly and the peak-to-average power ratio of oversampling OFDM signal changes neglectably. Especially, when oversampling factor is 2, the covariance matrix is analyzed. The results of analysis and simulation denote that all samples in one symbol are approximately independent. According to the result, the probability distribution function of peak-to-average power ratio is obtained.