Unmanned Aerial Vehicle Assisted Cellular Communication

Abstract

In this paper, we consider unmanned aerial vehicle (UAV) assisted cellular communications where UAVs are used as amplify-and-forward (AF) relays. The effective channel with UAV-assisted communication is modeled as a Rayleigh product channel, for which we derive a tight lower-bound of the ergodic capacity in closed-form. With the obtained lower-bound, tradeoffs between the transmit power and the equipped number of antennas of the UAVs can be analyzed. Alternatively, for a given setting of users and the base-transceiver station (BTS), the needed transmit power and number of antennas for the UAVs can be derived in order to have a higher ergodic capacity with the UAVassisted communication than that without it.

UAV-Assisted Underwater Sensor Networks using RF and Optical Wireless Links

“…The end-to-end SNR for the kth SN in the downlink, i.e., j = 1, and uplink, i.e., j = 2, is defined as γ j,k = min γ k , γj,k , γk . Herein, γ k , γj,k , and γk are the SNRs of the UWOC, FSO, and RF links, which are previously presented in ( 7), ( 16) or (23), and (30). Therefore, the CDF of γ j,k is computed as [43]…”

“…Low-cost and highly mobile unmanned aerial vehicles (UAVs) have been used for many diverse applications, e.g., disaster management, environmental monitoring, and cellular (or satellite) networks [28]- [30]. Thanks to their structures, UAVs enable fast deployment, flexible reconfiguration, and LOS connections without complex infrastructure requirements [31] and [32].…”

On Ergodic Capacity and Optimal Number of Tiers in UAV-Assisted Communication Systems

“…Unmanned aerial vehicles (UAVs) have gained much attention in advanced communication systems [1]- [5], [52]- [56]. Due to the advantages such as mobility, flexibility, efficiency, and low-cost in deployment, cellular-connected UAVs have potentials in 5G beyond and IoT [7]- [9], [55] systems.…”

“…In [1], we have derived a tight lower-bound of R for the product of two Rayleigh MIMO channels, i.e., a single UAVtier assisted communication system. We analyze trade-offs between the number of antennas and the transmit power of the UAV-tire in order to have higher ergodic capacity than a direct connection between the uses and the BTS.…”

“…We analyze trade-offs between the number of antennas and the transmit power of the UAV-tire in order to have higher ergodic capacity than a direct connection between the uses and the BTS. Following [1], we consider tight approximation of the ergodic capacity for multi-tier UAV assisted communication systems, and the optimization of number of tiers that maximizes R for a given M UAVs. We point out that we only consider the cases that the distance between adjacent UAV-tiers are relatively far and the channel can be model as Rayleigh fading such as in [12]- [14], [25]- [29].…”