Performance of Cooperative Spectrum Sensing in Log-normal Shadowing and Fading under Fusion Rules

The performance of a cognitive radio (CR) user is sometimes limited due to severe fading or shadowing. In order to detect the primary user (PU) more accurately, we allow the CR users to cooperate by sharing their information. In this paper we investigate performance of single CR user and cooperative CR user based spectrum sensing (CSS) using energy detector (ED) in channels such as Log-normal shadowing, Rayleigh and Nakagami fading channels. Hard decision combining fusion rule (OR-logic, AND-logic and MAJORITY-logic) is performed at fusion center (FC) to make the final decision about the presence of PU. The performance of single CR user based spectrum sensing scheme has been assessed in terms of missed detection (Pm) and false detection probabilities (Pf). The performances of energy detector for different values of average SNR are characterized through complementary receiver operating characteristic (ROC) curves. Comparison among fusion rules has been investigated for a wide range of average SNR values in Rayleigh and Nakagami fading channels. A simulation model has been developed to evaluate performance of CSS in different fading environments. The performance of CSS has also been studied for various data fusion rules in Lognormal shadowing channel.