Fading severity effects on collaborative sensing for opportunistic spectrum access

This paper investigates the performance of collaborative sensing of opportunistic spectrum access in a Nakagami fading channel with non-integer fading parameters. This technique provides an opportunity for secondary users to utilize the unused spectrum bands by primary users (licensees). In particular, we looked at the scenario when the channel between primary and secondary users is a generalized Nakagami-m fading channel. Numerical evaluation of the probability of misdetection in Nakagami fading channel with real value fading parameters is presented. Soft decision combining techniques were considered, namely square law and maximum selection combining. The performance analysis was extended to hard decision combining techniques. The obtained results showed how the spectrum utilization improved significantly when combining techniques are applied. In addition, the results revealed how soft decision combining techniques outperformed hard ones.