On a Multiple-Access in a Vector Disjunctive Channel

TL;DR

This paper proposes an improved signal-code construction for multiple-access vector disjunctive channels, enhancing sum rate for small user numbers and providing bounds close to optimal with both exhaustive and reduced-complexity decoding methods.

Contribution

It introduces a new resource allocation strategy for small user groups and derives a near-optimal lower bound on the sum rate, including reduced-complexity decoding techniques.

Findings

Lower bound on sum rate close to maximum in prior work

Enhanced resource allocation for small user groups

Reduced-complexity decoding achieves comparable user capacity

Abstract

We address the problem of increasing the sum rate in a multiple-access system from [1] for small number of users. We suggest an improved signal-code construction in which in case of a small number of users we give more resources to them. For the resulting multiple-access system a lower bound on the relative sum rate is derived. It is shown to be very close to the maximal value of relative sum rate in [1] even for small number of users. The bound is obtained for the case of decoding by exhaustive search. We also suggest reduced-complexity decoding and compare the maximal number of users in this case and in case of decoding by exhaustive search.