Optimal Resource Allocation for Quality-of-Service in D2D Communication Underlying Imperfect CSI

Device-to-device (D2D) communication has become a forefront technology to deal with the escalating demand for wireless network traffic. It allows devices in proximity to transmit data directly without the intervention of the base station for both uplink and downlink procedures. Devices in D2D communication can communicate either in underlay or overlay modes. The overlay D2D communication has a dedicated spectrum, hence reduces the interferences and spectral efficiency. In contrast, the underlay mode improves spectral efficiency with resource reuse. It increases the data rate, power control, and energy efficiency, but can experience co-channel and cross-channel interferences. To mitigate these issues, we propose a Heuristic-based optimal resource allocation scheme for the D2D communication network under imperfect channel state information (CSI). Both cellular and D2D users use the orthogonal frequency division multiple access (OFDMA) scheme for uplink and downlink resources. The proposed scheme significantly improves the average network data rate and optimizes the energy of the cellular network.