# Interference Management in UAV-assisted Integrated Access and Backhaul Cellular Networks

## TL;DR

This paper proposes an interference management algorithm for UAV-assisted integrated access and backhaul cellular networks, optimizing user association, power allocation, and UAV placement to significantly enhance network sum rate and SINR.

## Contribution

It introduces a joint optimization framework for UAV placement, user association, and power control in IAB networks, considering distributed UAVs and drone antenna arrays.

## Key findings

- Achieves up to 2.9x SINR improvement.
- Achieves up to 6.7x sum rate increase.
- UAVs boost both coverage and capacity.

## Abstract

An integrated access and backhaul (IAB) network architecture can enable flexible and fast deployment of next-generation cellular networks. However, mutual interference between access and backhaul links, small inter-site distance and spatial dynamics of user distribution pose major challenges in the practical deployment of IAB networks. To tackle these problems, we leverage the flying capabilities of unmanned aerial vehicles (UAVs) as hovering IAB-nodes and propose an interference management algorithm to maximize the overall sum rate of the IAB network. In particular, we jointly optimize the user and base station associations, the downlink power allocations for access and backhaul transmissions, and the spatial configurations of UAVs. We consider two spatial configuration modes of UAVs: distributed UAVs and drone antenna array (DAA), and show how they are intertwined with the spatial distribution of ground users. Our numerical results show that the proposed algorithm achieves an average of $2.9\times$ and $6.7\times$ gains in the received downlink signal-to-interference-plus-noise ratio (SINR) and overall network sum rate, respectively. Finally, the numerical results reveal that UAVs cannot only be used for coverage improvement but also for capacity boosting in IAB cellular networks.