Graph-Coloring Based Spectrum Sharing for V2V communication

V2V communication is always combined with cellular network and device-to-device (D2D) communication. The vehicles transmitting with a cellular base station (BS) can realize the vehicle-to-infrastructure (V2I) based on the uplink channels and infrastructure-to-vehicle (I2V) communication based on the downlink channels. The clustering methods are widely applicated on V2V communication to improve spectrum utilization. Meanwhile, the information transmission of vehicles needs enough capacity. And V2V links are vulnerable to the outage case caused by the high mobility of vehicles. To guarantee the capacity of all links and V2V stability for transmission requirements, we propose a heuristic Graph-Coloring Based Spectrum Sharing (GCSS) scheme based on both traceable slow-varying large scale fading information. The GCSS algorithm is divided into two sub-problems, including the power control considering the V2V outage probability and the graph-coloring clustering algorithm. Importantly, the allocated optimal power is calculated by V2I and I2V spectrum reusing formulation. The graph-coloring clustering method includes the available color channel building of each V2V link, the interference graph of the V2V links and the improved heuristic clustering algorithm. The simulation results show that the GCSS scheme improves the system capacity, the cellular capacity, and the V2V clusters capacity compared with the heuristic clustering algorithm.