Topological Interference Management with Alternating Connectivity: The Wyner-Type Three User Interference Channel

TL;DR

This paper investigates interference management in a three-user Wyner-type interference channel with alternating connectivity, deriving DoF bounds and demonstrating that joint encoding across states improves capacity over separate encoding.

Contribution

It introduces a joint encoding scheme for alternating connectivity states in a Wyner-type channel, achieving higher degrees of freedom than separate state encoding.

Findings

Achieves 2+1/9 DoF with joint encoding

Joint encoding outperforms separate state encoding

Provides upper and lower bounds on DoF

Abstract

Interference management in a three-user interference channel with alternating connectivity with only topological knowledge at the transmitters is considered. The network has a Wyner-type channel flavor, i.e., for each connectivity state the receivers observe at most one interference signal in addition to their desired signal. Degrees of freedom (DoF) upper bounds and lower bounds are derived. The lower bounds are obtained from a scheme based on joint encoding across the alternating states. Given a uniform distribution among the connectivity states, it is shown that the channel has 2+ 1/9 DoF. This provides an increase in the DoF as compared to encoding over each state separately, which achieves 2 DoF only.