Dynamic In-band Self-backhauling for 5G Systems with Inter-cell Resource Coordination

Abstract

5G systems are expected to utilize frequency bands above 6 GHz in the so-called millimeter-wave (mmWave) spectrum because of large bandwidths. It is well know that higher carrier frequency bands suffer from higher path loss attenuation. It addition, dynamic blockages can be a challenge for achieving good coverage. Therefore, millimeter-wave deployments require cell densification to achieve high data rates. However, densification further leads to challenges in the system design because of the need for low cost backhaul. The concept of wireless self-backhauling (sBH) aims to provide a provide a backhaul solution at reduced cost. Self-backhaul solution makes use of integrated access and backhaul (IAB) at each base station to realize on-demand flexible backhaul and access. In this paper, we investigate the performance of in-band self-backhauling with integrated access and backhaul in a real-life street canyon scenario. We consider centralized scheduling which can effectively allocate radio resources for backhaul and access on a time slot basis with half duplex constraint. The centralized scheduler further mitigates cross-interference between backhaul and access using a beam coordination and interference cancellation. Our results show that the proposed relaying concept offers good user throughput gains for cell edge users and is also robust to offloading of users to relay cells. Results also show that interference cancellation receivers can improve the uplink and backhaul spectral efficiency in IAB deployment by around 10%.