Signal space based adaptive modulation for software radio

This paper describes an automatic modulation scheme recognition technique. The technique is designed for a real-time software radio using general-purpose processors and is based on modified pattern recognition and signal space approaches. It is robust and efficient with a processing time overhead that still allows the software radio to maintain its real-time operating objectives. Both digital and analogue modulation schemes can be identified. Tests and simulations using an AWGN channel show that the SNR threshold for correct analogue modulation scheme classification is approximately 6.5 dB.