Performance analysis of D2D cooperative networks based on probabilistic relay forwarding mechanism

In cellular networks, cellular user (CU) packets often fail to transmit due to the failure to meet the minimum data transmission rate of cellular links, resulting in low network throughput. Based on the introduction of Device-to-Device (D2D) assisted communication in cellular networks, this paper proposes a probabilistic relay forwarding mechanism, which uses D2D communication devices as relay nodes to assist CU packets in completing transmission from cellular devices to base stations (BSs). By studying the behaviors of two types of users in the network, a queueing model is constructed, and the key performance indexes of CUs and D2D users are deduced by building and analyzing a 3-dimensional Markov chain (3DMC). Numerical experiments are performed to analyze the changing trends of these performance indexes, and the rationality of these changing trends are verified by simulation experiments. The results of comparative experiments show that the proposed probabilistic relay forwarding mechanism can efficiently improve the throughput and decrease the blocking rate of the network.