Power-Domain Interference Graph Estimation for Full-Duplex Millimeter-Wave Backhauling

Traditional wisdom for network resource management allocates separate frequency-time resources for measurement and data transmission tasks. As a result, the two types of tasks have to compete for resources, and a heavy measurement task inevitably reduces available resources for data transmission. This prevents interference graph estimation (IGE), a heavy yet important measurement task, from being widely used in practice. To resolve this issue, we propose to use power as a new dimension for interference measurement in full-duplex millimeter-wave backhaul networks, such that data transmission and measurement can be done simultaneously using the same frequency-time resources. Our core insight is to consider the mmWave network as a linear system, where the received power of a node is a linear combination of the channel gains. By controlling the powers of transmitters, we can find unique solutions for the channel gains of interference links and use them to estimate the interference. To accomplish resource allocation and IGE simultaneously, we jointly optimize resource allocation and IGE with power control. Extensive simulations show that significant links in the interference graph can be accurately estimated with minimal extra power consumption, independent of the time and carrier frequency offsets between nodes.

I. Introduction

Network densification is a key mechanism to increase spectrum reuse such that the network capacity can be greatly boosted for future explosive growth of user demand. However, denser small cells will inevitably increase the deployment cost if small cells are connected with a fiber backhaul [2]. For fast and cost-effective deployment of dense small cells, millimeter-wave (mmWave) backhauling is proposed as a promising backhaul alternative. In recent years, mmWave backhauling has been adopted in the integrated access and backhaul (IAB) networks for the deployment of 5G and beyond systems [3], [4], [5], which jointly optimizes the access and backhaul networks for the overall network performance. With the self-interference cancellation (SIC) techniques [6], [7], full-duplex capability can be integrated for mmWave backhauling. Full-duplex mmWave backhauling can alleviate the network bottleneck, which greatly improves the latency and throughput of IAB networks [8].