Performance of narrow-band Manchester coded FSK with discriminator detection

Due to the large discrepancies in the published results, the bit error rate (BER) performance of narrow-band Manchester-coded frequency-shift-keyed systems (MCFSK) with discriminator detection is reviewed and new results are presented which agree closely with measurements. It is found that a minimum BER is obtained for a peak-to-peak frequency deviation of about 1.35 times the bit rate and a receiver bandwidth of about 1.8 times the bit rate. The published results are shown to be rather optimistic. A coherent MCFSK demodulator is then shown to perform 3 dB better than discriminator detection.