说明：  针对无线电监测和认知无线电系统中正交频分复用(OFDM) 信号参数估计这一重要问题,提出了用频域累积法算OFDM 信号的循环自相关函数的数值计算方法.
(For radio monitoring and cognitive radio systems, orthogonal frequency division multiplexing (OFDM) signal parameter estimation of this important issue, the accumulation method to count cycle of the OFDM signal in frequency domain autocorrelation function of the numerical method.)