Performance of Frequency Selective Scheduling and Fractional Frequency Reuse Schemes for WIMAX

WiMaX is the commercial name for the 4G OFDM based wireless broadband data transmission standard 802.16, developed by IEEE ([1] and [2]). It is currently being deployed in several countries around the world. Sub-channels (which are the basic unit of resource allocation) are formed by grouping together sub-carriers in one of two formats - PUSC or AMC. In PUSC the set of sub-carriers in a sub-channel are distributed throughout the bandwidth while in AMC the sub-carriers in a subchannel are contiguous within a portion of the bandwidth. In this paper we study two candidates that offer the potential to improve the system performance of PUSC and identify scenarios when this improvement is possible: (i) compare the performance of PUSC with two flavors of AMC; and (ii) study how the PUSC performance can be improved by a Fractional Frequency Reuse (FFR) scheme that tries to perform interference mitigation/co-ordination and improve the throughput of users at the edge of the cell.