A Channel Quality Aware Algorithm for IEEE 802.16 Uplink Burst Construction

摘要

Many burst construction algorithms for Orthogonal Frequency Division Multiple Access (OFDMA) were proposed. However, these algorithms do not meet the uplink burst characteristics specified in the IEEE 802.16 standard. This paper therefore proposes the Best Sub channel Oriented algorithm (BSO). BSO not only complies with uplink burst characteristics, but also obtains high throughput by considering the issues of internal fragmentation, external fragmentation, and good-sub channels exploring. BSO shrinks the burst area to avoid internal fragmentation, if the requested bandwidth has been satisfied. BSO minimizes the external fragmentation by evaluating all divided bandwidth areas and shrinking the burst area to fit into a proper available bandwidth area if no available area can accommodate it. To explore the good sub channels, BSO analyzes the channel quality of sub channels and constructs the burst on the sub channels which provide largest throughput. The simulation results under a heavy load indicate that BSO achieves 2 times the throughput achieved by Raster, a conventional algorithm.