Automatic Modulation Classification: Principles, Algorithms and Applications

1Introduction

1.1 Background

Automatic modulation classification (AMC) was first motivated by its application in military scenarios where electronic warfare, surveillance and threat analysis requires the recognition of signal modulations in order to identify adversary transmitting units, to prepare jamming signals, and to recover the intercepted signal. The term ‘automatic’ is used as opposed to the initial implementation of manual modulation classification where signals are processed by engineers with the aid of signal observation and processing equipment. Most modulation classifiers developed in the past 20 years are implemented through electronic processors. During the 1980s and 1990s there were considerable numbers of researchers in the field of signal processing and communications who dedicated their work to the problem of automatic modulation classification. This led to the publication of the first well received book on the subject by Azzouz and Nandi (1996). The interest in AMC for military purposes is sustained to this very day.

The beginning of twenty-first century saw a large number of innovations in communications technology. Among them are few that made essential contributions to the staggering increase of transmission throughput in various communication systems. Link adaptation (LA), also known as adaptive modulation and coding (AM&C), creates an adaptive modulation scheme where a pool of multiple modulations are employed by the same system (Goldsmith and Chua, 1998). ...