Interference Management and Coverage Probability Enhancement in D2D Underlay Downlink Cellular Networks

Device-to-device (D2D) communication is a key technology in next-generation wireless networks to enhance spectrum resource utilization. The interference from the activated D2D links degrades the quality of service (QoS) provided to cellular users. In this work, we propose a location-based technique to tackle the interference caused by the D2D underlaying downlink cellular network. The devices operating in stationary and mobile modes are considered, with mobile devices modelled using a Gauss Markov mobility (GMM) model to simulate realistic user movement patterns. Initially, we present an interference mitigation approach that dynamically adjusts the guard zone (GZ) through power control to guarantee the required QoS for all users. A distance-based mode selection mechanism is proposed to enable the users to select their mode of communication based on different GZ regions. Furthermore, we derive the closed-form expressions of the average coverage probability for the cellular and D2D links under the proposed power control with guard zone (PC-GZ) scheme. Finally, extensive simulations confirm the efficacy of the proposed PC-GZ approach, illustrating a 15% increase in cellular coverage probability compared to the PC-ILA scheme in high D2D density scenarios.