An algorithm of adaptively cooperative spectrum sensing based on optimal relay was proposed

which can overcome the problems about fading of sensing channel and huge consumption of relaying.This algorithm was based on the consideration of sensing performance and energy consumption and obtained optimal tradeoff between performance and consumption by opportunistic relaying

benefit function based selection of optimal relay and mechanism of system parameters adjustment.Meanwhile

detailed theoretical formulas and performance analysis of the algorithm were given.And the comparative simulation of sensing performance of non-relay cooperative sensing algorithm

optimal relay fixed cooperative sensing algorithm and this algorithm under different system parameters were done as well.The results show that the proposed algorithm has certain advantages.