On the achievable diversity-multiplexing tradeoff in interference channels

TL;DR

This paper investigates the limits of diversity and multiplexing tradeoffs in two-user interference channels, demonstrating optimal coding strategies for different interference regimes with perfect receive CSI.

Contribution

It proves that a stripping decoding method achieves the DMT outer bound in very strong interference scenarios and characterizes the DMT of superposition coding schemes for general interference levels.

Findings

Stripping decoding achieves the DMT outer bound in very strong interference.

Superposition coding scheme is DMT-optimal at certain multiplexing rates.

Provides code design criteria for DMT optimality.

Abstract

We analyze two-user single-antenna fading interference channels with perfect receive channel state information (CSI) and no transmit CSI. For the case of very strong interference, we prove that decoding interference while treating the intended signal as noise, subtracting the result out, and then decoding the desired signal, a process known as "stripping", achieves the diversity-multiplexing tradeoff (DMT) outer bound derived in Akuiyibo and Leveque, Int. Zurich Seminar on Commun., 2008. The proof is constructive in the sense that it provides corresponding code design criteria for DMT optimality. For general interference levels, we compute the DMT of a fixed-power-split Han and Kobayashi type superposition coding scheme, provide design criteria for the corresponding superposition codes, and find that this scheme is DMT-optimal for certain multiplexing rates.