Joint scheduling and mapping in support of downlink fairness and spectral efficiency in ieee 802.16e OFDMA system

Abstract

SUMMARYThe next generation broadband wireless networks deploy orthogonal frequency division multiple access (OFDMA) as the enabling technologies for broadband data transmission with QoS capabilities. In such broadband wireless systems, one major issue is how to utilize radio resource efficiently while maintaining fairness between sessions as well as providing adequate QoS. In this work, we propose an approach for OFDMA/time division duplex (TDD) downlink suitable for IEEE802.16e WiMAX systems that combines scheduling and burst mapping algorithms for a trade-off between session fairness, QoS, and spectral efficiency. While optimizing radio resources under QoS and fairness constraints is an NP-hard problem, we follow a heuristic approach that simplifies the complexity of the algorithm. Performance results show that while the new scheme outperforms the Proportional Fair algorithm in terms of fairness, it also improves the overall system spectral efficiency.

A MAP Overhead Aware Two-Dimensional OFDMA Burst Construction Algorithm

“…Because burst allocation is non-deterministic polynomial time (NP) problem [7], there are some algorithms proposed to maximize throughput. Positioning bursts can be viewed as a variation of a bin or strip packing problem [3,[7][8][9][10][11][12][13][14].…”

“…References [3,[12][13][14] treated the burst construction as a job assignment problem and modified the Hungarian Algorithm (HA) [11]. That is, they transform the burst construction problem, i.e., r bursts with r subchannels, to minimum the matching problem with r workers and r jobs.…”

“…Thus, burst should be placed on the 2 of 15 subchannel with the best channel quality (called best subchannels), while considering the subchannel diversity. Various burst construction methods have been proposed to solve the subchannel diversity issue [3][4][5][6][7][8][9][10][11][12][13][14].…”

“…Optimizing the burst indexing becomes an urgent need to support a massive number of and dramatically different classes of users and applications in 4G and following 5G networks. However, the methods in References [3][4][5][6][7][8][9][10][11][12][13][14] do not consider the burst index optimization problem.…”