Device-to-device assisted two-stage cooperative multicast with optimal resource utilization

Abstract

Device-to-device (D2D) communication has the potential to facilitate wireless multicast by retransmissions among users in proximity to each other. In this paper, the D2D assisted cooperative multicast (CM) is investigated in a new scenario, where a large number multicast recipients are densely distributed within a small area (called a D2D cluster). In this scenario, D2D multicast is innovatively employed in the retransmission stage, and a new relay selection scheme named nearest center protocol (NCP) is proposed. Moreover, the optimal time allocation between the two transmission stages is investigated, with the aim of minimizing the total time consumption of the two-stage CM. The time allocation problem is then formulated as an optimization problem and solved by the sequential quadratic programming (SQP) method. Simulation results show that the D2D assisted two-stage CM can achieve higher cost-efficiency than the conventional one-stage multicast, and the gain becomes larger when the D2D cluster moves farther from BS. Besides, the optimal time allocation between the two transmission stages also varies with the location of the D2D cluster, which means equal time allocation is no longer appropriate to be used in our new scenario.

D2D-Aided Multi-Antenna Multicasting

“…Both a dense model (with a finite network area) and an extended model (with a finite density) are considered. A similar two-phase multicasting scheme has been also studied by taking into account fairness between users or energy efficiency (see, e.g., [14], [15] and references therein).…”

“…The time allocation between the two phases was investigated in [17], which showed that more time should be dedicated to the second phase as the UEs move away from the BS. Finally, a similar two-phase cooperative scheme with multiple antennas at the BS was proposed in [24] in the context of broadcasting under perfect CSIT.…”

Smart Energy Efficient Device-to-Multidevice Cooperative Clustering for Multicasting Content

“…As the received signal will arrive from different sources, there may be a problem of synchronization. However, some cyclic prefix coding (CPC) schemes can be used to combine the signals arriving from different sources [19]. As long as the delay among all the cluster heads is less than one cyclic prefix, all the received signals at the cluster members can be added up to make a stronger signal.…”