Robust transceiver beamforming in MIMO cognitive radio via second-order cone programming

This paper considers the spectrum sharing multiple- input multiple-output (MIMO) cognitive radio network, in which multiple primary users (PUs) coexist with multiple secondary users (SUs). Due to the limited cooperation between SBS and PUs, perfect information of primary links may not be available at SBS which could lead to severe interference to the PUs. Robust joint transceiver cognitive beamforming is developed to minimize the transmit power of the SU base station (SBS) while simultaneously targeting lower bounds on the received signal-to-interference- plus-noise ratio (SINR) for the SUs and imposing upper limits on the interference temperature to the PUs. With the perfect knowledge of all links, the optimal secondary transceiver beamformer is achieved iteratively. Simulation results are presented to validate the effectiveness of the proposed algorithms that minimizes the total transmit power and simultaneously guarantees quality-of- service (QoS) of both SUs and PUs, and the robustness against channel imperfections.