Performance analysis of device-to-device underlay communication in Rician fading channels

Device-to-device (D2D) communication has been developed as a promising technology to meet the unrelenting demand for high data rate services by providing a direct link between users. In this paper, we investigate the performance of D2D communications underlaying cellular networks using stochastic geometry, where Rician fading is modeled to characterize the line-of-sight (LoS) component in the D2D direct link. In order to avoid causing harmful interference to the cellular network, we divide the whole bandwidth into two parts, namely shared subchannels, which are jointly used by the cellular network and D2D connections, and dedicated subchannels, which are exclusively used by the cellular network. The cellular and D2D performances are evaluated in terms of both success probability and average achievable throughput. Furthermore, we provide insights into the optimal subchannel allocation ratio under the quality-of-service (QoS) guarantee of the cellular network. Numerical results demonstrate the impact of Rician K-factor on the D2D performance as well as the benefit provided by the subchannel allocation scheme.