Autocorrelation-Based Spectrum Sensing for OFDM Signals over Multipath Fading Channel in Cognitive Radio Systems

摘要

In this paper, a spectrum-sensing method is proposed which exploits the combination of a comb filter and autocorrelation function. The proposed method improves the detection performance in severe noise environments, where a cyclic prefix (CP)-based orthogonal frequency division multiplexing (OFDM)-transmitted signal is considered. In our proposed method, the primary user information is not required for spectrum sensing. The detection performance is measured over additive white Gaussian noise (AWGN) and multipath Rayleigh fading channels for different digital modulations. A comprehensive evaluation by simulation shows that the proposed method significantly outperforms the conventional schemes at a low signal-to-noise ratio (SNR).