In this paper, the Narrowband Binary FM Data-Transmission System---the Phase-Continuous Frequency-shift-keying System--is treated.
The effects of the deviation ratio h on the band occupancy and the probability of error are considered, when the phase-locked loop is used as a detector of this system.
With the pseudo-random digital data, measured error rates vs. signal-to-noise ratio for the additive white Gaussian noise are presented. It is shown that when the signal bandwidth is within the tracking range of PLL, the measured probability of error is in good agreement with the calculated probability of error.