Optimal resource allocation for OFDM multiuser channels

TL;DR

This paper presents a unified framework for resource allocation in OFDM multiuser channels, addressing rate maximization and power minimization problems jointly, and introduces optimal decoding order strategies.

Contribution

It introduces a novel higher-dimensional framework that unifies various resource allocation problems in OFDM multiuser channels and identifies optimal decoding orders.

Findings

Optimal decoding orders correspond to Lagrangian factor orderings.

Unified approach handles multiple resource allocation problems simultaneously.

New solutions for combined rate and power constraints in OFDM systems.

Abstract

In this paper, a unifying framework for orthogonal frequency division multiplexing (OFDM) multiuser resource allocation is presented. The isolated seeming problems of maximizing a weighted sum of rates for a given power budget $\bar{P}$ and minimizing sum power for given rate requirements $\mathbf{\bar{R}}$ can be interpreted jointly in this framework. To this end we embed the problems in a higher dimensional space. Based on these results, we subsequently consider the combined problem of maximizing a weighted sum of rates under given rate requirements $\mathbf{\bar{R}}$ and a fixed power budget $\bar{P}$. This new problem is challenging, since the additional constraints do not allow to use the hitherto existing approaches. Interestingly, the optimal decoding orders turn out to be the ordering of the Lagrangian factors in all problems.