SETI: The transmission rate of radio communication and the signal's detection

TL;DR

This paper calculates the potential transmission rates for radio communication with extraterrestrial intelligence over distances up to 1000 light years, analyzing modulation schemes and proposing detection methods using spectrum analysis and the Hough transform.

Contribution

It introduces a detailed calculation of ETI radio transmission rates and suggests modern spectrum analysis combined with the Hough transform for detecting drifting signals.

Findings

M-ary FSK is energy-efficient for long-distance communication.

Narrow-band, drifted signals are probable ETI signals.

Hough transform effectively detects frequency-drifted signals.

Abstract

The transmission rate of communication between radio telescopes on Earth and extraterrestrial intelligence (ETI) is here calculated up to distances of 1000 light years. Both phase-shift-keying (PSK) and frequency-shift keying (FSK) modulation schemes are considered. It is shown that M-ary FSK is advantageous in terms of energy. Narrow-band pulses scattered over the spectrum sharing a common drift rate can be the probable signals of ETI. Modern SETI spectrum analyzers are well suited to searching for these types of signals. Such signals can be detected using the Hough transform which is a dedicated tool for detecting patterns in an image. The time-frequency plane representing the power output of the spectrum analyzer during the search for ETI gives an image from which the Hough transform (HT) can detect signal patterns with frequency drift.