A Two-Dimensional Signal Space for Intensity-Modulated Channels

TL;DR

This paper introduces a new two-dimensional signal space for intensity-modulated channels, designing modulation formats that optimize power and spectral efficiency under specific constraints, and compares their performance to existing formats.

Contribution

It presents a novel two-dimensional signal space and modulation formats that outperform existing subcarrier formats under certain bandwidth measurements.

Findings

New formats are simpler than existing ones.

Superior in 90% in-band power bandwidth measurement.

Existing formats are better at 99% in-band power measurement.

Abstract

A two-dimensional signal space for intensity- modulated channels is presented. Modulation formats using this signal space are designed to maximize the minimum distance between signal points while satisfying average and peak power constraints. The uncoded, high-signal-to-noise ratio, power and spectral efficiencies are compared to those of the best known formats. The new formats are simpler than existing subcarrier formats, and are superior if the bandwidth is measured as 90% in-band power. Existing subcarrier formats are better if the bandwidth is measured as 99% in-band power.