Four-dimensional signalling schemes - Application to satellite communications

TL;DR

This paper explores four-dimensional signalling schemes using dual-polarization in satellite communications, demonstrating increased power efficiency and improved timing recovery through analytical, simulation, and experimental methods.

Contribution

It introduces new four-dimensional signal constellations for satellite links and evaluates their benefits and limitations through comprehensive analysis and practical implementation.

Findings

Enhanced power efficiency of 4D constellations over traditional methods

Doubling of timing and carrier recovery precision with 4D signals

Experimental satellite transmission confirms simulation predictions

Abstract

In satellite communications both polarizations of an electromagnetic wave are used to transmit two separate signals. These two independent signals can be merged to form one dual-polarization, four-dimensional signal. The present article pursues this idea and proposes different signal constellations to be used for four-dimensional signalling in satellite links. Analytical methods and simulations predict an increased power efficiency of these constellations with respect to currently used transmission methods. The cost of this advantage is evaluated considering the limited applicability in non-linear channels. Four-dimensional signalling also implies simultaneous reception on both polarizations. Such a combined reception allows the precision of timing and carrier recovery loops to be doubled. This claim is derived analytically and illustrated by simulating an example case. An experimental transmitter/receiver pair was implemented and used to demonstrate a satellite transmission using a four-dimensional, bi-orthogonal signal in the dual-polarization channel. The experimental verification confirms the presented simulation results.