Per-Relay Power Minimization for Multi-user Multi-channel Cooperative Relay Beamforming

We investigate the optimal relay beamforming problem for multi-user peer-to-peer communication with amplify-and-forward relaying in a multi-channel system. Assuming each source–destination (S–D) pair is assigned an orthogonal channel, we formulate the problem as a min–max per-relay power minimization problem with minimum signal-to-noise (SNR) guarantees. After showing that strong Lagrange duality holds for this nonconvex problem, we transform...