一种基于拥塞等级划分的LTE-V资源碰撞避免机制

为了降低车联网（Long Term Evolution-Vehicle to Everything，LTE-V）终端间的相互干扰并提升通信的可靠性，提出通过资源分配和拥塞控制来解决资源碰撞的问题。依据信道忙率（Channel Busy Ratio，CBR）划分拥塞等级，融合资源分配与拥塞控制提出相应的方案，形成资源碰撞避免机制。为了减少重选资源时发生的碰撞，提出了资源重选竞争退避机制以降低重选带来的不确定性；针对拥塞导致的碰撞，改变调制编码策略从而优化资源占用。仿真结果表明，与标准中基于感知的半持续调度（Semi-persistent Scheduling，SPS）相比，所提出的机制在传输距离为300 m时可以实现0.85以上的数据包投递率，有效减少资源碰撞，提升传输可靠性。

A resource collision avoidance mechanism of LTE-V based on congestion level division

In the Long Term Evolution-Vehicle to Everything(LTE-V) system,to reduce mutual interference between terminals and improve the reliability of communication,it is proposed to reduce resource collisions through resource allocation and congestion control.The channel occupancy is divided into different congestion levels according to the channel busy ratio(CBR).The corresponding schemes are proposed by integrating resource allocation and congestion control to form a resource collision avoidance mechanism.To reduce the collisions of reselecting resources and the uncertainty caused by reselection,a resource reselection competition back off mechanism is proposed.For collisions caused by congestion,the modulation and coding scheme is changed to optimize resource occupancy.Simulation results demonstrate that the proposed mechanism can achieve a packet delivery ratio above 0.85 when the transmission distance is 300 m.It can effectively reduce resource collisions and improve transmission reliability in comparison with the sensing-based Semi-persistent Scheduling(SPS) proposed in the specification.