MIMO System With Receive Combiner Bank and Power Control for Cognitive Radio Networks

The multiple-input-multiple-output (MIMO) system with a receive combiner bank (MIMO-RCB), in which a bank of receive combiners is added before the decoding (or detecting) unit of the MIMO receiver for suppressing the cochannel interference, is applied to cognitive radio (CR) networks, and the variable-signal-to-interference-plus-noise-ratio (SINR)-target-based joint weight adjustment and power control (VST-JWAPC) algorithm is proposed for MIMO-RCB-based CR networks. Theoretical results and simulation results show that MIMO-RCB can suppress the cochannel interference from both the primary user (PU) and the secondary user (SU) to provide a significant SINR gain. The receive combining strategy that aims to minimize other-user interference plus noise outperforms previously introduced receive combining strategies in the SINR gain. In addition, we found from theory and simulation that the VST-JWAPC algorithm increases the achievable (minimal) SINR among all SUs while assuring the quality of service of each PU for each iteration. The VST-JWAPC algorithm outperforms the previously proposed fixed-target-based algorithms in the achievable SINR among all SUs.