Optimal Spectrum Management in Multiuser Interference Channels

TL;DR

This paper develops a convex optimization framework for optimal spectrum management in multiuser interference channels, enabling globally optimal and distributed solutions for maximizing sum-rate in complex frequency-selective environments.

Contribution

It introduces a novel convex optimization approach that transforms a non-convex spectrum management problem into a convex one, applicable to multiple users and asymmetric channels.

Findings

Derived a pairwise channel condition for FDMA to achieve Pareto optimality.

Provided an analytical solution for two-user symmetric flat channels.

Extended the solution to K-user asymmetric frequency selective channels.

Abstract

In this paper, we study the non-convex problem of continuous frequency optimal spectrum management in multiuser frequency selective interference channels. Firstly, a simple pairwise channel condition for FDMA schemes to achieve all Pareto optimal points of the rate region is derived. It enables fully distributed global optimal decision making on whether any two users should use orthogonal channels. Next, we present in detail an analytical solution to finding the global optimum of sum-rate maximization in two-user symmetric flat channels. Generalizing this solution to frequency selective channels, a convex optimization is established that solves the global optimum. Finally, we show that our method generalizes to K-user (K>=2) weighted sum-rate maximization in asymmetric frequency selective channels, and transform this classic non-convex optimization in the primal domain to an equivalent convex optimization. The complexity is shown to be separable in its dependence on the channel parameters and the power constraints.