Aggregated V2I Communications for Improved Energy Efficiency Using Non-Orthogonal Multiplexed Modulation

Nowadays, data traffic in-car communication is increasing dramatically, due to the emerging technology of self-driving and on-board infotainment applications. The direct connections between vehicles and cellular infrastructures will introduce significant signalling overhead and excessive energy consumption, especially for congested and fast moving traffic. In order to improve energy efficiency and achieve green networking, an heterogeneous network, 5G-Vehicular Ad Hoc Network (5GVANET) is presented in this paper, which coupling the high data rates of VANET and the wide coverage area of 5G. In this integrated architecture, vehicles are clustered accordingly, and one vehicle in each cluster is selected as a gateway to support aggregated traffic. To ensure the capacity of the trunk link between the gateway and base station, a Non- orthogonal Multiplexed Modulation (NOMM) scheme is proposed in this paper to effectively aggregate the Vehicle-to-Infrastructure (V2I) traffic and further improve energy efficiency. NOMM splits data stream of each user into multi-layers and modulate them simultaneously. Sparse spreading code is also applied in partially superposing the modulated symbols on several resource blocks. Furthermore, we analyzed the energy efficiency of proposed NOMM scheme and traditional M-QAM theoretically. It was also validated by simulation results that NOMM provides less power consumption than M-QAM modulation.