Power control for two-way relay networks under per-node power constraint

For bidirectional multi-relay networks, where each node is assumed to have its own power constraint, the optimal relay and user power control is considered via maximizing the smaller signal-to-noise ratio (SNR) of the two end users in the network. A numerical algorithm is proposed to find the optimal solution. Then, a suboptimal algorithm with low complexity is proposed. The performance of this algorithm is shown numerically to be close to the optimal. It is also shown via simulation that proper user and relay power control significantly improves the network performance, especially when the power constraints of the two end-users in the networks are unbalanced.