Elements of Cellular Blind Interference Alignment --- Aligned Frequency Reuse, Wireless Index Coding and Interference Diversity

TL;DR

This paper investigates the degrees of freedom in cellular networks without channel state information, introducing aligned frequency reuse, wireless index coding, and interference diversity as key concepts for interference management.

Contribution

It presents a novel framework combining three fundamental elements to characterize and improve DoF in partially connected wireless networks without CSI.

Findings

Aligned frequency reuse often achieves optimal orthogonal resource allocation.

Wireless index coding reveals the link between index coding and blind interference alignment.

Interference diversity offers new opportunities for robust interference alignment strategies.

Abstract

We explore degrees of freedom (DoF) characterizations of partially connected wireless networks, especially cellular networks, with no channel state information at the transmitters. Specifically, we introduce three fundamental elements --- aligned frequency reuse, wireless index coding and interference diversity --- through a series of examples, focusing first on infinite regular arrays, then on finite clusters with arbitrary connectivity and message sets, and finally on heterogeneous settings with asymmetric multiple antenna configurations. Aligned frequency reuse refers to the optimality of orthogonal resource allocations in many cases, but according to unconventional reuse patterns that are guided by interference alignment principles. Wireless index coding highlights both the intimate connection between the index coding problem and cellular blind interference alignment, as well as the added complexity inherent to wireless settings. Interference diversity refers to the observation that in a wireless network each receiver experiences a different set of interferers, and depending on the actions of its own set of interferers, the interference-free signal space at each receiver fluctuates differently from other receivers, creating opportunities for robust applications of blind interference alignment principles.