Resource Allocation Complexity Analysis for Relay-based Multihop V2V Communication

Over last 4-5 years, there has been tremendous development globally towards autonomous driving. However, in order to understand the neighborhood road environment, solutions using Camera, RADAR and LIDAR have significant disadvantages. The primary drawback being that the vehicles should be in visible/direct line-of- sight of each other. In this regard, vehicle-to-vehicle communication (V2V) has a great advantage that it enables transmission of information from one vehicle to another even if they are not in the line-of-sight range. The expected data rate in next generation connected vehicles for autonomous driving is expected to be in the range of 100 Mbps or higher. In this regard, a relay-based multi-hop V2V mechanism has been explored for communication between far-located source and destination vehicle. However, the number of multiple hops in V2V would affect the resource allocation in 5G/next generation network. This paper investigates the number of multiple hops required as the maximum transmission range is varied. Importantly, the paper investigates the complexity in the resource allocation as the number of multiple hops among source and destination vehicle is increased. The number of multiple hops required increases exponentially, when the communication range is around 0.3 times the maximum transmission range. Further, there is a humongous increase in the complexity of resource allocation when the number of multiple hops increase. Especially with spatial reuse in multi-hop mode, the complexity of resource allocation increases to 10(80) for a 50-node vehicular network. This is an important aspect to be considered while designing next generation connected vehicle environment.