基于信道反转的C-V2X动态功率控制方案

蜂窝车用无线通信(cellular vehicle-to-everything,C-V2X)系统中,基于V2V(vehicle-to-vehicle)车载通信采用复用蜂窝用户(cellular user,CUE)的频谱资源减轻基站负载实现部分近场V2V通信,在提高系统传输速率的同时也产生了同频干扰的问题。针对该问题,提出基于信道反转的动态功率控制方案,在非截断区内对V2V用户(V2V user,VUE)进行信道反转功率控制,补偿因发射功率有限造成的截断中断,通过动态功率控制解决蜂窝用户和V2V用户间的同频干扰。在此基础上,通过拉格朗日乘子法得到目标函数的最优对偶解,利用二分法确定CUE和VUE的最优功率,满足蜂窝用户传输速率要求的同时最大化V2V用户的总传输速率。数值仿真结果表明,当VUE总中断概率为0.866时,该方案使系统性能提升了48%。

Dynamic power control scheme for C-V2X communication with channel inversion

In cellular vehicle-to-everything(C-V2X)system,V2V(vehicle-to-vehicle)-based communication utilizes the spectrum resource of cellular users(CUE)to reduce the load of base stations,and thus realize partial near-field V2V communication.Although the V2V-based communication can improve the transmission rate of system,it causes co-frequency interference.To solve the problem,a dynamic power control scheme with channel inversion was proposed.In this scheme,channel inversion power control on V2V users(VUE)was performed to compensate the truncation interruption caused by limited transmission power in the non-truncated area,where the co-frequency interference between cellular users and V2V users was solved through dynamic power control.Furthermore,the optimal dual solution of objective function was obtained by Lagrange multiplier method and the optimal power allocation was carried out for cellular users and V2V users by bisection method,which met the rate requirements of all cellular users.Finally,the total transmission rate of V2V users was maximized.Numerical simulation results were shown that when the total outage probability of V2V users was 0.866,the proposed scheme was promoted by 48%.