Joint subchannel matching and power allocation for the MIMO broadcast relay channel

We propose a joint matching and relay power allocation scheme based on an interference-free architecture for the multiuser multiple-input multiple-output (MIMO) broadcast relay channel. Instead of using brute-force search, we propose a matching scheme that assigns the better subchannels at the first hop to the destinations with lower power costs. It is shown that the proposed matching scheme is optimal for certain power allocation schemes. Simulation results show that proposed matching scheme combined with water-filling power allocation is nearly optimal for the joint optimization problem of matching and power allocation.