A QoS-Aware Uplink Spectrum and Power Allocation With Link Adaptation for Vehicular Communications in 5G Networks

In this work, we have proposed link adaptation-based spectrum and power allocation algorithms for the uplink communication in 5G Cellular Vehicle-to-Everything (C-V2X) systems. In C-V2X, vehicle-to-vehicle (V2V) users share radio resources with vehicle-to-infrastructure (V2I) users. Existing works primarily focus on the optimal pairing of V2V and V2I users, assuming that each V2I user needs a single resource block (RB) while minimizing interference through power allocation. In contrast, in this work, we have considered that the number of RBs needed by the users is a function of their channel condition and Quality of Service (QoS) - a method called link adaptation. It effectively compensates for the frequent channel quality fluctuations at the high frequencies of 5G communication. 5G uses a multi-numerology frame structure to support diverse QoS requirements, which has also been considered in this work. The first algorithm proposed in this article greedily allocates RBs to V2I users using link adaptation. It then uses the Hungarian algorithm to pair V2V with V2I users while minimizing interference through power allocation. The second proposed method groups RBs into resource chunks (RCs) and uses the Hungarian algorithm twice - first to allocate RCs to V2I users and then to pair V2I users with V2V users. Extensive simulations reveal that link adaptation increases the number of satisfied V2I users and their sum rate while also improving the QoS of V2I and V2V users, making it indispensable for 5G C-V2X systems.