Joint Optimization of Communication and Traffic Efficiency in Vehicular Networks

Consider single-cell downlink vehicular networks, where a base station (BS) employing massive multiple-input multiple-output simultaneously transmits information to multiple vehicles on its covered road. Taking into account both the traffic and communication performance, the Flow rate of vehicles to the Power consumption of the BS Ratio (FPR) is defined as a comprehensive metric to represent the number of vehicles supported under limited transmit power. The objective of this paper is to maximize the FPR while guaranteeing the information rate requirements of the vehicles. We first derive the average power consumption of the BS with respect to vehicle density, based on which the FPR is established by using a flow rate function that quantifies the number of passed vehicles per time unit in terms of traffic density. Then, the optimal vehicle density is given in order to maximize the FPR. Simulation results indicate that the proposed scheme can significantly improve the power efficiency of the vehicular networks.