Joint channel assignment and power distribution in cooperative cognitive radio networks

This paper considers a cooperative cognitive radio network composed of a single primary user with heterogeneous sub-channels and multiple secondary users, where the primary user can easily achieve its traffic requirement and thus is more willing to lease its power and sub-channels to obtain additional revenue rather than enhance the performance. With the purpose of maximizing the revenue of primary user and achieving relatively high sum-rate of secondary users, a two-layer resource allocation algorithm is presented to obtain the optimal power distribution and sub-channel assignment. In the inner layer, with a power distribution which is given by the outer layer, a sub-channel assignment is implemented by using a distributed auction that results in a maximum sum-rate of secondary users. In the outer layer, the power distribution is adjusted while the total power is fixed and a local search algorithm is used to obtain an approximate optimal solution in the case of the closed-form expression of the primary user´s utility respect to the power distribution is absented. Furthermore, simulation results demonstrate that our algorithm effectively improves the primary user´s utility.