Optimal Mobile Relays Positions and Resource Allocation for Multi-Relay Multi-Destination Wireless Networks

Deploying relays is a major means to improve the performance of wireless networks. In this paper, multiple mobile relays carried by smart drones are sent by a source to assist the communication to multiple destinations for the Public Safety Wireless Broadband Network, where the sole source is not sufficient to satisfy the quality of service (QoS) requirement of all destinations. With Rician fading between source and relays, and relays and destinations, we study two related questions: The first is where to deploy the relays for minimizing the maximum outage probability of all destinations; the second is where to deploy the relays and how to allocate the resource for maximizing the minimum throughput of all destinations. Efficient algorithms are proposed to compute the optimal solutions, which are shown to be highly effective via simulations. The maximum outage probability decreases and the minimum throughput increases as the number of relays increases. But beyond a certain number, more relays do not provide further improvement in the minimum throughput. Meanwhile, large Rician factor could decrease the maximum outage probability and increase the minimum throughput, except for the cases with very low transmit power.