Analysis of optimal sensing duration with power control and partial primary user´s information

In this paper, based on a novel two-user cognitive radio channel model, under the assumption that secondary user can obtain partial primary user´s information and transmit power of secondary user is controlled properly according to the scenario whether primary user exists or not, then the relationship between channel capacity and sensing duration is respectively analyzed in the two cases that whether ignoring the false judgements of secondary user or not. Subsequently, an expression of the optimal sensing duration is obtained to maximize the channel capacity. Finally, numerical simulation results show that there exists an optimal sensing duration to maximize the channel capacity; in the cooperative sensing environment, the longer sensing duration, the fewer cooperative cognitive users when channel capacity reaches maximum.