Resource Allocation for Cellular V2X Networks Mode-3 With Underlay Approach in LTE-V Standard.

In this paper, we propose a system model for cellular vehicle-to-everything (C-V2X) networks mode-3, with two user groups: cellular users and vehicular users. Cellular users communicate with each other through the base station (BS). Vehicular users communicate through direct vehicular links while sharing the spectrum of an orthogonal frequency division multiplexing (OFDM) system with cellular users. In particular, we focus on the underlay approach, in which vehicular users can transmit at the same time in a sub-carrier that is being used by a cellular user. Assuming a limited number of sub-carriers, the number of allowed vehicular links is limited by the quality of service (QoS) requirement for cellular users because of the interference from vehicular links. Our goal is to maximize the number of vehicular links while satisfying the QoS for cellular users. To achieve this goal, we state the optimization problem of resource allocation in C-V2X networks mode-3, assuming high mobility of vehicular users, which results in Doppler effect for them. We also assume that the global channel state information (CSI) of mobile links is not available for the BS. We propose a novel scheme for the BS to jointly allocate resources, such as power and sub-carriers, to cellular and vehicular users, while minimizing the number of non-allowed vehicular links, considering high data rate requirements for cellular users and high reliability requirements for vehicular users. Using numerical results, we obtain the maximum number of vehicular links that can be established for a given available bandwidth and cellular user distribution. [ABSTRACT FROM AUTHOR]