Energy-Efficient Hybrid Spectrum Access Scheme in Cognitive Vehicular Ad hoc Networks

This letter focuses on an energy-efficient hybrid spectrum access scheme in a vehicle-to-infrastructure uplink communication scenario in cognitive vehicular ad hoc networks (cognitive VANETs). Considering path loss exponent of the channel between a vehicle and an access point, a constrained optimization problem is formulated to minimize the overall energy consumption. Meanwhile, the quality of service of the vehicular communications is maintained. The vehicle detects optimal spectrum bands for transmission, and selects different access schemes adaptively based on the energy efficiency and the location information. Numerical results show that the vehicle using the proposed scheme can achieve lower energy consumption, comparing with both direct transmission scheme and equal switching time scheme.