Design and Development of a Burst Acquisition System for Geosynchronous Satcom Channels

TL;DR

This paper presents a discrete-time burst acquisition system for geosynchronous satellite channels, featuring algorithms that achieve fast synchronization and detection for turbo-coded QPSK signals under challenging conditions.

Contribution

It introduces novel transmitter and receiver algorithms for turbo-coded offset QPSK signals that enable rapid acquisition and robust synchronization in satellite communication channels.

Findings

Effective at SNR per bit close to 1.5 dB

Acquisition time equals preamble length due to up-sampling and matched filtering

Carrier recovery algorithm avoids phase ambiguity

Abstract

The key contribution of this work is to develop transmitter and receiver algorithms in discrete-time for turbo- coded offset QPSK signals. The proposed synchronization and detection techniques perform effectively at an SNR per bit close to 1.5 dB, in the presence of a frequency offset as large as 30 % of the symbol-rate and a clock offset of 25 ppm (parts per million). Due to the use of up-sampling and matched filtering and a feedforward approach, the acquisition time for clock recovery is just equal to the length of the preamble. The carrier recovery algorithm does not exhibit any phase ambiguity, alleviating the need for differentially encoding the data at the transmitter. The proposed techniques are well suited for discrete-time implementation.