Resource Allocation in Downlink OFDM Wireless Systems with User Rate Allowed Regions
Tóm tắt
In this paper, a novel adaptive resource allocation in downlink orthogonal frequency division multiplexing wireless system is investigated. Different from the conventional algorithms, user rate allowed regions are considered. That is, not only the user minimum rate requirements are to be satisfied, but also the maximum rate limitations are introduced to make resource allocation more reasonable. Given equal power distribution, a three-round subcarrier assignment is proposed at first to achieve a preliminary performance. Then, waterfilling-based power allocation is designed to guarantee user rate allowed regions and enhance system performance further. Numerical results show that the proposed algorithm ensures users achieving data rates within their allowed regions more precisely. In the mean time, the system throughput and transmit power consumption are reasonably balanced compared to the traditional methods when channel-gain-to-noise-ratio is high.
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