Combined Antenna Selection and Beamforming in Cross-Layer Design for Cognitive Networks
The authors investigate the performance of an antenna selection algorithm applied with precoding to improve the throughput performance of cognitive Multiple-Input Multiple-Output (MIMO) radios. They assume cognitive MIMO radios coexist in the same frequency band with the primary users. In such event, for concurrent spectrum access, cognitive nodes use beamforming techniques to cancel the mutual information between cognitive and primary users. In that, cognitive nodes exploit the degrees of freedom offered by MIMO systems to beamform the transmitted signal in an attempt to cancel interference at primary users.