earticle

영어

The paper investigates the problem of a distributed robust relay beamforming in cognitive one-way relay networks with imperfect channel state information. We aim to the minimum the transmit power of relays, satisfying the SNR (signal-to-noise ratio) of the secondary users high a threshold and keeping the interference at primary users below an acceptable threshold. Because of the robust identity the optimal problem is a non-convex problem which is hard to be solved. In this paper we transform the non-convex problem into a convex one which can be solved efficiently by exploiting S-procedure and Schur complement theorem and relaxing the rank-one constrain. Then the robust beamforming vector can be obtained. Simulation results show that the proposed algorithm can solve the minimum problem with robust features efficiently and obtain satisfactory results.