The Asymptotic Limits of Interference in Multicell Networks with Channel Aware Scheduling

TL;DR

This paper investigates the asymptotic behavior of interference in multicell wireless networks with channel-aware scheduling, revealing conditions under which interference can be eliminated or persists, thus informing network design strategies.

Contribution

It provides a theoretical analysis of interference limits in multicell networks with scheduling under Rayleigh fading, distinguishing between equal and unequal path loss scenarios.

Findings

Scheduling can eliminate interference with equal path loss as user count grows.

Interference converges to a nonzero constant with unequal path loss.

Simulations confirm the theoretical predictions.

Abstract

Interference is emerging as a fundamental bottleneck in many important wireless communication scenarios, including dense cellular networks and cognitive networks with spectrum sharing by multiple service providers. Although multipleantenna (MIMO) signal processing is known to offer useful degrees of freedom to cancel interference, extreme-value theoretic analysis recently showed that, even in the absence of MIMO processing, the scaling law of the capacity in the number of users for a multi-cell network with and without inter-cell interference was asymptotically identical provided a simple signal to noise and interference ratio (SINR) maximizing scheduler is exploited. This suggests that scheduling can help reduce inter-cell interference substantially, thus possibly limiting the need for multiple-antenna processing. However, the convergence limits of interference after scheduling in a multi-cell setting are not yet identified. In this paper1 we analyze such limits theoretically. We consider channel statistics under Rayleigh fading with equal path loss for all users or with unequal path loss. We uncover two surprisingly different behaviors for such systems. For the equal path loss case, we show that scheduling alone can cause the residual interference to converge to zero for large number of users. With unequal path loss however, the interference are shown to converge in average to a nonzero constant. Simulations back our findings.