Information and multiaccess interference in a complexity-constrained vector channel

TL;DR

This paper introduces a complexity-constrained noisy vector channel model and analyzes its capacity, revealing that interference-based multiuser cooperation at the transmitter enhances performance, especially when transmitters use uniform amplitude.

Contribution

It presents a novel complexity-constrained channel model and provides an asymptotic analysis showing non-trivial capacity and the importance of transmitter cooperation.

Findings

Channel exhibits non-trivial Shannon capacity under constraints

Performance improves with interference-based multiuser cooperation

Optimal cooperation occurs when transmitters use the same amplitude

Abstract

Rodrigo de Miguel et al 2007 J. Phys. A: Math. Theor. 40 5241-5260: A noisy vector channel operating under a strict complexity constraint at the receiver is introduced. According to this constraint, detected bits, obtained by performing hard decisions directly on the channel's matched filter output, must be the same as the transmitted binary inputs. An asymptotic analysis is carried out using mathematical tools imported from the study of neural networks, and it is shown that, under a bounded noise assumption, such complexity-constrained channel exhibits a non-trivial Shannon-theoretic capacity. It is found that performance relies on rigorous interference-based multiuser cooperation at the transmitter and that this cooperation is best served when all transmitters use the same amplitude.