Exploiting Orthogonally Dual-Polarized Antennas in Cooperative Cognitive Radio Networking

This work is concerned with enhancement of spectrum utilization by using polarization enabled two-phase cooperation between primary users (PUs) and secondary users (SUs) in cooperative cognitive radio networking (CCRN). The use of orthogonally dual-polarized antennas (ODPAs) enables concurrent transmissions of multiple independent signals of PUs and SUs, and interference suppression via polarization zero-forcing and polarization filtering to obtain significant performance improvement. To maximize a weighted sum throughput of PUs and SUs under energy/power constraints, the problem is formulated and solved based on a multi-timescale Markov decision process, and two modified backward iteration algorithms are devised to attain the optimal policies. Numerical results validate the effectiveness of the proposed CCRN framework, showing that the obtained policy outperforms both greedy and random ones.