基于信噪比门限的车载协作通信功率分配优化方案  

Optimal power allocation scheme for multi-vehicle cooperative communication based on SNR threshold

作　　者：吴琪 邱斌[1,2] 蒋为[1] 李婉莹 WU Qi;QIU Bin;JIANG Wei;LI Wanying(School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,China;College of Information Science and Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学信息与通信学院,广西桂林541004 [2]桂林理工大学信息科学与工程学院,广西桂林541004

出　　处：《现代电子技术》2020年第7期10-13,共4页Modern Electronics Technique

基　　金：国家自然科学基金(61261018);国家自然科学基金(61472094);广西自然科学基金杰出青年基金(2014GXNSFA118007);广西青年科学基金项目(2018GXNSFBA281057)。

摘　　要：在车联网中,车流量的实时改变以及安全信息的广播通信模式会对信道负载产生影响。当车辆密度较高时,信道的拥塞会导致安全信息的广播作用失效;当车辆密度较小时,采用大功率发送安全信息会导致能量的利用率较低。针对该问题,提出基于信噪比门限的车载协作通信功率优化分配方案。首先,建立通用的交通流信道模型;然后,根据信噪比捕获效应模型来确定合适的协作节点;最后,通过系统的中断概率推导出源节点功率和协作节点功率分配表达式。数值分析表明,该方案在车辆密度较小时与等功率分配方案相比,总功率降低11.5 dBm,在车流密度较大时与等功率分配方案相比,平均信道容量提高57 bit·s-1·Hz-1。In VANET,the real-time traffic change and the broadcast communication mode of security information have influence on the channel load.The high vehicle density leads to channel congestion that results in the failure of the broadcast of safety information.The low vehicle density brings about low energy utilization due to high-power safety information sending.To solve this problem,an optimal power allocation scheme is presented for multi-vehicle node cooperative communication based on SNR threshold.In the scheme,a commonly-used model is established first to describe accurately the traffic road,and then,the appropriate cooperative node is determined according to the capture effect of the SNR model,and the distribution expression of source node power and cooperative node power is derived on the basis of the outage probability of the cooperative communication system.Numerical simulation results show that,when the vehicle density is low,the total power is reduced by 11.5 dBm,and when the vehicle density is high,the average channel capacity is increased by 57 bit·s-1·Hz-1 in comparison with equal power allocation scheme.

关 键 词：车联网 协作通信 时变信道 拥塞控制 信噪比门限 功率优化 

分 类 号：TN949.6-34[电子电信—信号与信息处理]