MAC v. PHY: How to Relay in Cellular Networks

Two cooperative relaying protocols are presented and analyzed. The first emphasizes PHY cooperation via synchronized transmissions and distributed space-time coding from the Base Station (BS) and Relay Station (RS) to the User Equipment (UE) during the protocol's cooperative phase. The second protocol emphasizes MAC cooperation using different MAC flows from the BS and RS to the UE during the cooperative phase and utilizing successive interference cancellation (SIC) at the UE. This paper discusses and compares the two protocols' flexibility and performance aspects via analytical and simulation results.