Designing zero-forcing based MIMO relay networks with channel-controlled ARQ to achieve full diversity

Wireless MIMO relay networks have caught a lot of attention because of the potential to enhance performance by exploiting the joint cooperative and spatial diversity. In this paper, we develop high-rate and low-complexity designs for multi-antenna MIMO relay networks by adopting zero-forcing linear equalizers at both relay and destination and designing a simple power scaling at relay. Furthermore, channel-controlled ARQ techniques that rely on the physical link conditions instead of error detection codes are proposed to combine with the power scaling ZF MIMO relay network design to boost the performance. We analytically prove that the proposed scheme achieves the joint cooperative and spatial diversity. The theoretical analysis is corroborated with numerical simulations.