A simple method for distinguishing modulation types
P. Halpern, P. Mallory · IEEE Transactions on Acoustics Speech and Signal Processing · 1982
For distinguishing between two modulation types, A and B, one can simply correlate the output of two orthogonal filters. The optimum filters' impulse responses can be expressed as the sum and difference of certain eigenfunctions of the difference of the autocorrelation functions of the two processes. A comparison of the simple method with a maximum likelihood system shows a measurable degradation in performance for a sample calculation; however, the simple method requires knowledge only of the autocorrelation function of the processes.