| Summary: | 碩士 === 淡江大學 === 資訊工程學系碩士班 === 97 === This paper proposes a channel-aware downlink resource management scheme in IEEE 802.16 OFDMA system. The scheme is composed of two mechanisms: subchannel renumbering mechanism and burst allocation mechanism, for throughput gains and control message overhead reduction, respectively. Due to the variation of channel conditions, each MS in each subchannel has different receiving condition. BS is expected to transmit data to each MS in good subchannels. Thus, more bursts result in a large burst overhead in the form of DL-MAP. By subchannel renumbering mechanism, the subchannels with highest modualtion can be adjacent as well as the decrease of DL-MAP overhead.Since bursts in downlink subframe are rectangular mapping, how to allocate and schedule each burst for each MS without slots wastage will affect downlink bandwidth usage. Therefore, burst allocation mechanism is used to decide the size, shape and position of each burst in order to alleviate the slots wastage as well as increase the network throughput. The simulation results show that the mechanism can provide higher throughput, higher spectral efficiency, lower fragmentation ratio and lower DL-MAP overhead.
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