Using threshold-based PUSC for throughput enhancement in WiMAX OFDMA

This paper presents the analysis of the throughput enhancements using threshold-based PUSC in WiMAX OFDMA system. We consider a point-to-multipoint (PMP) WiMAX network where base station (BS) schedules downlink packets for simultaneous transmissions to multiple users. Using the OFDMA option in the WiMAX standard, users are assigned different subchannels for reception of their data using the same OFDM symbol. In the proposed threshold-based scheduling scheme, the BS scheduler selects at any time instant users whose channel gains in the available subchannels equal or exceed a predetermined energy threshold. Thus, only users who can maximize BS throughput on the available subchannels are assigned data transmission opportunities. We quantify the throughput enhancement of the system, and illustrate its benefits by numerical simulations.