中文摘要：

提出利用OFDM信号导频的周期性来估计噪声功率,从而使得能量检测法对噪声不确定性稳健。该方法具有不需要时间和频率同步等优点。通过由GNU Radio和USRP搭建的OFDM通信系统验证了所提方法的有效性。实验结果表明,不管OFDM信号是否存在,所提方法都能有效估计噪声功率,从而使得能量检测法对噪声不确定性稳健。

英文摘要：

This paper proposes to estimate noise power by employing the pilot periodicity of OFDM（Orthogonal Frequency Division Multiplexing） signals.Using the estimated noise power,energy detection（ED） is robust against noise uncertainty.The noise power estimator has the advantage in not requiring time and frequency synchronizations.The effectiveness of the presented method is verified through an OFDM experimental system based on GNU Radio and USRP（Universal Software Radio Peripheral）.Finally,experimental results demonstrate that the presented method effectively estimates the noise power no matter whether the OFDM signals exist.This makes the energy detection works well under noise uncertainty.