中文摘要：

车辆自组织网络（VANET）为车辆提供公平、高效的数据传输。针对密集高速移动场景，提出一种自适应门限的指数增加线性减小MAC层退避算法（A-EInLD）改善其数据冲突问题，提高系统性能。通过动态记录并更新每次成功发送时窗口的平均值并与获取的邻居节点窗口值进行比较得出竞争窗口的门限值，成功发送时基于该门限值通过连接数目对数值线性减小窗口大小从而避免冲突。最后，应用二维马尔科夫链模型分析算法并通过仿真评价性能结果。

英文摘要：

Vehicular wireless communication should be able to provide vehicles with fair and efficient data transmissions. This paper presents a modified MAC algorithm, that is, A-EInLD （Adaptive Threshold Exponential Increase Exponential Decrease） algorithm, thus to solve the collision in dense and moving scenario. BY reserving the mean contention window after a successful transmission and comparing with one-hop neighbor CW Information （CI） as a threshold contention window （CWThreshold）, and based on number of donnections linearly decreasing the CW size, the algorithm could reduce the collisions. In addition, the performance of this algorithm is analyzed with 2-Demension Markov model, and simulation indicates that this system is of feasibility and practicability.