Bit Error Rate
Ideally, the Bit Error Rate of a non-coherent BFSK demodulator is related to the Signal-to-Noise Ratio by an exponential function. However, when the receiver employs a limiter or there is a carrier offset, the BER is increased. This can be modeled by adding a multiplier and an offset to the SNR.
A 1200bps demodulator was build and measured in two configurations: with a linear signal path, and with a limiter. Both were tested with and without a carrier offset of 3 kHz.