OFDMA Downlink Burst Allocation Mechanism for IEEE 802.16e Networks

Abstract

Abstract. Orthogonal Frequency Division Multiple Access (OFDMA) is one of the most promising, demanded and researched modulation and access methods for future mobile wireless networks. Emerging technologies, like Worldwide Interoperability for Microwave Access (WiMAX) or Long Term Evolution (LTE), are adopting OFDMA due to its high spectral efficiency, scalability for high amounts of users and mobility support. In OFDMA, before data is actually transmitted, it must be mapped into a time-frequency matrix through a resource allocation process. This step is critical for a correct network behaviour, and several factors must be taken into account like efficiency, Quality of Service (QoS) fulfillment or power consumption. In this paper, we propose a novel approach for the mapping process of IEEE 802.16e networks, and we compare its performance with several existing algorithms. The effectiveness of our proposal is evaluated in different scenarios by means of extensive simulation.

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].…”

“…However, fully utilizing the bandwidth resource does not mean higher throughput, since they all do not consider the problem of subchannel diversity. Therefore, the algorithms proposed in References [9,10] are to reduce the number of bursts by grouping bursts with the same modulation coding scheme (MCS) but for different connections, so the MAP size is minimal. The adopted MCS of each connection is given in advance.…”

“…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.…”