Energy Detection based Cooperative Spectrum Sensing andPerformance analysis for Soft and Hard Combination Techniquesin Cognitive Radio Networks

This paper focuses on spectrum sensing in cognitive radio (CR) which is a recently introduced technology inorder to increase the efficiency of spectrum utilization. Increasing efficiency of the spectrum usage is an urgent need asan intrinsic result of the increasing demand for higher data rates, better quality of services and higher capacity. Thereare several spectrum sensing techniques proposed in literature for CR based systems like non cooperative and cooperativespectrum sensing. In this paper, energy detection based cooperative spectrum sensing approaches and its various forms,soft combination techniques such as MRC, EGC, OC, SC, SLS, SLC and hard combination methods consist of AND, ORand MAJORITY for CRs with and without multiple antenna are examined and comparative performance results areobtained in fading channels. We consider the most common multiple antenna processing methods and analyze theirdetection performance based on the achieved probability of detection for a pre-specified probability of false alarm andgiven signal-to-noise ratio. Simulations results show that the EGC and MRC achieve the highest gain and multiplecooperating users increase diversity by providing multiple measurements of the signal and thus guarantees betterperformance at low SNR.