System Design and Resource Allocation in 802.16j Multi-Hop Relay Systems Under the User Rate Fairness Constraint

IEEE 802.16j multi-hop relay task standard includes two mutually exclusive options: transparent relay stations (T-RS) and non-transparent relay stations (NT-RS). In this work, a system design approach is proposed to compare different relay systems in term of their capacity with rate fairness constraint among the mobile stations (MS). Single-input single-output (SISO) and multi-input multi-output (MIMO) antenna systems are considered in the links between the base station (BS) and relay stations (RS). 1 and 3 RSs per sector are considered. Our simulation results show that for any case, the highest capacity is achieved by NT-RS with 3 RSs per sector in distributed scheduling mode. In addition, the effect of the MS association rule, which determines the access station (BS or RS) for each MS, is also investigated. Two rules: highest MCS scheme with the highest modulation and coding rate, and highest (Mod) ESE scheme with the highest (modified) effective spectrum efficiency, are studied along with the optimal rule that maximizes system capacity with rate fairness constraint. It is demonstrated that highest (Mod) ESE scheme performs closely to the optimal rule in term of capacity.