Abstract: Based on the protocol of IEEE 802.11 for Ad Hoc networks，the Distributed Coordination Function（DCF） of Ad Hoc networks is modified，and an Adaptive minimum contention Window Binary Exponential Backoff algorithm（AWBEB algorithm） is presented.The bidimensional discrete-time Markov chain model for AWBEB algorithm is established，the stationary distribution probabilities and the probability that a given node will transmit in an arbitrary time slot of AWBEB algorithm are educed.The throughput and the stationary throughput of AWBEB algorithm are analyzed theoretically，and then the throughputs of AWBEB algorithm are simulated and calculated.Simulations are conducted to validate the theoretical analysis.The study results show that the system throughputs of AWBEB algorithm are better than that of DCF algorithm，and the results of AWBEB throughputs simulated by program agree with the calculation results preferably.

摘要： 基于Ad Hoc网络IEEE 802.11协议原理，对Ad Hoc网络标准DCF算法进行了改进，提出了一种自动调整最小竞争窗口W0的退避算法（Adaptive minimum contention Window Binary Exponential Backoff algorithm，简称AWBEB算法），建立了AWBEB算法的二维Markov链模型，导出了该算法的稳态分布和终端数据发送概率，分析了该算法的吞吐量和稳态吞吐量，对该算法吞吐量进行了编程仿真及数学解析研究，验证了AWBEB算法。研究结果表明，与DCF算法相比，AWBEB算法具有更好的网络吞吐性能；AWBEB算法网络吞吐量的编程仿真结果与数值计算结果吻合较好。