An analysis of error rates for nyquist- and partial response- baseband-filtered digital FM with discriminator detection

It has been known that error rates as well as spectrum performances can be improved by adoption of transit- and receive-baseband filters for digital FM/discriminator detection schemes. the present paper studies these modulation/demodulation schemes with baseband filters for Nyquist (NYQ) and class I, II partial-response (PR) transmission. Error rates are analyzed theoretically with and without consideration of the intersymbol interference due to a bandpass filter. Two methods are obtained: in the former case, a generally applicable calculation method which requires the assumption of a symbol sequence, and in the latter case, a simpler calculation method than that before. The calculated results agreed well with the computer simulated results. In comparison with 2, 4 and 8 level NYQ, 3 and 7 level class I PR and 5 level class II PR, higher performance is given by the method in the order of 7 level class I PR, 8 and 4 level NYQ for narrow band transmission.