PLL demodulation of binary FM in a high noise environment

In binary Frequency Modulation (FM) detection, there is little improvement in error rates using Phase-Locked Loop (PLL) demodulation. There are, however, a number of advantages to using the PLL in many applications. But substantially higher than minimum error rates can result, unless the PLL is properly designed. A comparison of the performance of a PLL demodulating binary FM in the presence of noise is conducted as a function of loop damping and phase detector type. Experimental results show that the highly damped loop requires less input signal power than an underdamped loop for the same bit error rate. This is in agreement with theory. Sequential type phase detectors require significantly more signal power than loops employing multiplier type phase detectors in a high noise environment.