Identification of diphase and baseband waveform at 16 kbps

The identification of modulation type is a new addition to the traditional tasks of signal detection and demodulation. This paper addresses the problem of determining whether the received signal is diphase or baseband. It assumes a receiver that must handle a mixture of diphase and baseband messages without any information of the message information type. Two algorithms are described that can effectively distinguish between these two waveforms. Both algorithms were simulated and tested at signal-to-noise ratios (SNR) above 0 dB and signal bandwidths of 20 kHz, 32 kHz and 50 kHz. Algorithm 1 is slightly better in performance and complexity than algorithm 2. It was further shown that a practical design can reduce the error in type determination to a negligible level for all possible combinations of SNR and bandwidth described.