Zero Forcing in General Two-Hop Relay Networks

In this paper, we investigate four different two-hop amplify and forward relay networks, which differ on the processing capabilities at the source, relay, and destination nodes. We derive new exact outage probability expressions where zero-forcing processing is performed at the following four areas: (1) source and relay; (2) relay; (3) relay and destination; and (4) destination nodes only. We show that, depending on the particular scheme, adding source, relay, and/or destination nodes can be either beneficial or detrimental to the outage probability. We confirm our results through comparison with Monte Carlo simulations.