Power Control for Relay-Assisted Cognitive Radio Networks-Part II: Distributed Scenario

Optimal power control for relay-assisted cognitive radio networks in which secondary users are assisted by cognitive relays is investigated. A monomial approximation based distributed geometric programming algorithm (MaDGP) is developed to maximize the secondary system utility under the individual and total power constraints of secondary users as well as the interference temperature limits of the primary users. The presented power control algorithm is distributively formulated using geometric programming and is then solved using the Lagrangian primal-dual decomposition. Numerical results demonstrate the effectiveness of our proposed algorithm.