认知无线电中OFDM信号的频谱感知方法

he problem of detecting OFDM signals in Cognitive Radios is of great significance due to the extensive use of OFDM in wireless communication systems. This paper introduces a simple and computationally efficient Generalized Likelihood Ratio Test（GLRT）sensing scheme for OFMD signal based on its non-stationary correlation structure. This scheme dose not require any knowledge of the signal power or noise power, which should be perfectly known in energy detection. Performance of GLRT sensing scheme is compared with energy detector and is shown to have a better performance when the noise variance is unknown.