Physical-Layer Network Coding Based Multi-User Cooperative Relay Transmission With Multi-Antennas in Cognitive Wireless Networks

A promising way to improve the performance and guarantee the quality of service (QoS) of cognitive wireless cooperative relay networks is to jointly employ physical-layer network coding (PNC) and multi-antenna space-time block coding. This paper proposes a new multi-user transmission coding scheme, cooperative quadrature PNC (CQPNC), for cognitive wireless networks. In CQPNC scheme, two source nodes (users) first use quadrature carriers to transmit signals simultaneously, which are received and processed by a cooperative relay node using the PNC method. The processed signal is then transmitted to the destination node, which makes a combination of the signals from the direct path and relay path to obtain the information transmitted by the source node. Simulation results in difference cases of cognitive wireless networks show that the CQPNC scheme outperforms the traditional cooperation and cooperative network coding transmission schemes on the performance of anti-noise and throughput.