Cooperative vs multihop relaying in cellular systems

Relaying has become a very active area of wireless research due to its ability to overcome wireless channel impairments. Wireless relaying, adopted in emerging standards such as 802.16j, can increase the data throughput, improve system coverage, and lower outage probability in wireless systems by reducing path loss, mitigating shadowing, and enabling spatial reuse. In cooperative relaying, numerous stations (either user stations or dedicated relay stations) create diverse paths in order to mitigate the effects of fading during the transmission of data from the source to destination. On the other hand, multihop relaying (non-cooperative) employs intermediate stations in order to relay around obstacles, mitigating the effects of shadowing and fading due to multipath scattering. In this paper, we look at the relative performance of these techniques in a Ricean channel, in which the path loss and Rice factor are modeled as functions of distance. In order to obtain results that are relevant to potential actual deployments, we use realistic system parameters and a system model appropriate on dual Rayleigh/Ricean (NLOS/LOS) channels.