TwoWay Transmission for LowLatency and HighReliability 5G Cellular V2X Communications As one of key technologies of future networks, vehicletoeverything (V2X) communication has recently been proposed to improve conventional vehicle systems in terms of traffic and communications. Main benefits of using V2X are efficient and safe traffic as well as lowlatency communications and reliable massive connections. Nonorthogonal multiple access (NOMA) scheme was introduced as a promising solution in the fifthgeneration (5G) mobile communications, by which qualityofservice (QoS) requirements of many 5Genabled applications are satisfied as a result of improved network throughput and lower accessing and transmission latency. In this paper, we study NOMAbased communications between vehicles equipped with multiple antennas over Nakagamim fading channels in V2X networks, in which uplink and downlink transmission between two vehicles with upper controller are supported by a road side unit (RSU) to increase the capacity rather than simply be connected to the base station. In the NOMAV2X system under study, the outage probability depends on the power allocation factor of RSU transmission and the operation of successive interference cancellation (SIC) at vehicles. Analyses and simulations verify that the outage performance of NOMAV2X system are mainly affected by fading parameters, levels of imperfect SIC, and power allocation factors.

Radio resource management for vehicular communication via cellular device to device links: review and challenges The vehicletoeverything (V2X) communications, as enabled by cellular devicetodevice (D2D) links, has recently gained greater attention owing to the remarkable capacity it displays in enhancing traffic safety, effectiveness, and comfort. It is in this context that the present paper can be set, whereby a new technology is advanced, relating to the fifth generation (5G) associated D2D based vehicular communication, as lately approved by the 3GPP standardization community. In effect, V2X communication appears to raise a number of critical issues that are closely interrelated, mainly, those attached to stringent latency and reliability requirements. In this respect, an exhaustive investigation of the state of the art is put forward D2D based vehicular communication is detailed, throughout the scope of the present work. In the first place, a thorough examination of the D2D associated works, treating such a study area from different perspectives, is displayed. In a second place, the major reason lying behind the application of the D2D communication for vehicular service purposes, involving the possibilities it provides, along with the expected prospective potentials, it could offer, are investigated. In addition, a special emphasis is laid on the particular restrictions associated with the implementation of the V2X Radio Resource Management problem formulation. In a last step, and on reviewing a number of papers dealing with the area of D2D based vehicular communication, some disciplines that do not see to have been satisfactorily and exhaustively elaborated are depicted, while highlighting potential work associated challenges, mainly concerning the D2D effective integration for vehicular communication purposes.