Figure 2
From: Probabilistic constrained multicast beamforming in cognitive relay systems
Optimal structure of the forwarding matrix at the relay node. The optimal forwarding matrix in CRM is the combination of the match-filter receiver and the adaptive beamformer. In other words, the cognitive relay first maximizes the received signal quality with maximal ratio combining and then precodes the received signal with a beamforming vector w to balance the received power at different cognitive destinations and reduce the received interference at primary users.