An automatic VHF signal classifier

A quick and reliable signal classifier based on a simple feature extraction and processing algorithm is proposed for automatic real-time recognition of the basic modulation types in the VHF band. This classifier is designed for mobile and semifixed VHF radio signal acquisition systems. The classifier allows automatic recognition of the following types of received signal: analog FM, digital FM, amplitude modulation, single sideband voice modulation, binary amplitude shift keying, and unmodulated carrier and noise. This low cost and small size signal classifier can be easily implemented with standard linear and digital integrated circuits and microprocessor components. The results of preliminary tests with real signals show that the classification method provides successful recognition of the signal modulation type at the low RF input signal levels of interest