Effects of pulse shaping on the performance of Manchester coded digital FM with discriminator detection

Manchester coded digital FM with discriminator detection is known to be a fairly robust scheme for data transmission over the mobile radio channel for moderate data rates (less than 9.6 kb/s). This paper investigates the performance of such a scheme when the data rate is increased to 16 kb/s in a channel bandwidth of 25 kHz. It is shown that the introduction of pulse shaping in such a system in order to satisfy a band occupancy constraint of 99 percent signal power leads to a performance improvement of up to 3.75 dB over reduction of frequency deviation. A number of performance curves for various combinations of Gaussian or Raised Cosine shaping, modulation index and IF filters (Gaussian, second-order Butterworth or Ideal "brick wall") are presented.