Angle⁃Based Interference⁃Aware Routing Algorithm for Multicast over Wireless D2D Networks

[Abstract] Wireless device⁃to⁃device (D2D) communications sharing the spectrum of cellular networks is important for improving spectrum efficiency. Furthermore, introducing multicast and multi⁃hop communications to D2D networks can expand D2D service functions. In this paper, we propose an angle⁃based interference⁃aware routing algorithm for D2D multicast communications. This algorithm reuses the uplink cellular spectrum. Our proposed algorithm aims to reduce the outage probability and minimize the average hop count over all multicast destinations (i.e., multicast receivers), while limiting interference to cellular users to a tolerable level. In particular, our algorithm integrates two design principles for hop⁃by⁃hop route selection. First, we minimize the distance ratio of the candidate⁃to⁃destination link to the candidate⁃to⁃base⁃station link, such that the selected route advances closer to a subset of multicast receivers. Second, we design the angle⁃threshold based merging strategy to divide multicast receivers into subsets with geographically close destinations. By applying the two principles for selection of each hop and further deriving an adaptive power⁃allocation strategy, the message can be more efficiently delivered to destinations with fewer branches when constructing the multicast tree. This means fewer duplicated data transmissions. Analyses and simulations are presented to show the impact of system parameters on the routing performances. Simulation results also demonstrate the superiority of our algorithm over baseline schemes in terms of outage probability and average hop count.

[Keywords] device⁃to⁃device communications; multicast; interference⁃aware routing; cellular networks