研究了捕获效应对分布式协调功能(Distributed coordination function,DCF)饱和性能的影响.通过捕获概率的推导以及信道状态与节点状态同步变化的证明,提出了一种改进的时隙分析模型.利用这一模型,分析了IEEE 802.11 DCF在捕获效应下的饱和性能,导出了其归一化饱和吞吐量和平均接入时延的闭合表达式,并对饱和状态与平均接入时延之间的关系进行了阐释.理论分析与仿真结果表明,该时隙分析模型可有效提高IEEE802.11 DCF机制的饱和性能的理论估计精度.%The impact of capture effect on the saturation performance of distributed coordination function (DCF) is studied. On the basis of the inference of capture probability and the validation of the channel states and the node states synchronously transiting, an improved slotted analytical model is proposed. Making use of the proposed model, the saturation performance of IEEE 802.11 DCF under capture effect is analyzed, and the close-form expressions of its normalized saturation throughput and average access delay are presented. Furthermore, the relation between saturation state and average access delay is illustrated. Theoretical analysis and simulation results show that the slotted analytical model can efficiently improve the precision in theoretical estimate of saturation performance of IEEE 802.11 DCF mechanism.
展开▼
