过采样OFDM信号的峰值平均功率比

在过采样条件下，分析了正交频分复用系统在不同采样率时，信号峰值平均功率比的统计特性。按Nyquist采样率均匀抽取出的采样点之间相互独立同分布，推广到过采样系数为2时，得到此时由各采样点之间相关系数构成的协方差矩阵，利用数值计算对其进行分析。结果表明：所有的采样点之间能近似满足相互独立同分布的关系，则可以得到此时信号峰值平均功率比概率分布的理论计算公式，并对此公式进行了仿真验证，其理论计算结果和实际仿真结果吻合。
关 键 词 正交频分复用; 峰值平均功率比; 过采样; 互补累积分布函数

Abstract Peak-to-average power ratio of orthogonal frequency division multiplexing signals is analyzed when the sampling rate is different. The samples according to Nyquist sample rate in one period of OFDM symbol are independent identically distributed random variables. When oversampling factor is 2, the covariance matrix composed of the coefficients of correlation between those samples can be calculated by numerical method. As a result, all samples in one symbol are approximately independent when oversampling factor is 2. So the probability distribution function of peak-to-average power ratio can be achieved. The results are proved by simulation.
Key words orthogonal frequency division multiplexing; peak-to-average power ratio; oversampling; complementary cumulative distribution function