Spectrum sensing for OFDM cognitive radio using matched filter detection

Abstract

The exponentially increasing high data rate applications demand more spectrum. Conventional spectrum allocation schemes failed in providing spectrum to meet the requirement. Cognitive radio introduces dynamic spectrum allocation. Spectrum sensing plays a very important role in cognitive radio. In this paper, OFDM with sensing algorithm based on matched filter detection is presented. An Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix is used to reduce Inter Block Interference between successive symbols. The Receiver Operating Characteristics (RoC), detection probability with respect to Signal to Noise Ratio (SNR) for a given False Alarm Probability (PFA) obtained and analyzed. Simulation results shows that, this algorithm achieves probability of detection values 0.38 and 0.9 for SNR values of-20dB and-15 dB respectively at PFA=10-2. Chen, Hou-Shin, considered Time Domain Symbol Cross-correlation between two OFDM symbols. This paper mainly focusses on improving the detection probability at low SNR values without considering cross-correlation, which requires more computations.