Abstract: An outdated channel state information (CSI) modeling method based on geometry is proposed for vehi-cle-to-vehicle (V2V) channels. To address the bottleneck problems of high-speed time-varying characteristics and low resource utilization of V2V communication networks, a power allocation scheme of cognitive non-orthogonal multiple access (NOMA) V2V networks based on outdated CSI and imperfect successive inter-ference cancellation (SIC) is studied. The performance impact of outdated CSI on V2V communication networks based on a geometric three-dimensional (3D) two-cylinder channel model is studied, and the throughput region of cognitive NOMA V2V networks is analyzed. Under Quality of Service (QoS) constraints as to achievable rate and outage probability of primary user (PU) and secondary user (SU), a power allocation scheme is proposed. Simu-lation results show that the proposed scheme can effectively increase throughout of SU, improve outage perfor-mance of the system. The simulation results show that compared with the existing power allocation methods, the proposed scheme has higher throughput and better outage performance for V2V communication networks with outdated CSI.

Key words: non-orthogonal multiple access, vehicle-to-vehicle communication, cognitive radio, outdated channel state information, imperfect successive interference cancellation, power allocation