Patent ID: 7266163

Claim:
A method of determining an optimal slicing point for demodulating a received FSK modulated signal, said method comprising: determining continuously a current peak voltage and a current valley voltage of a voltage signal the magnitude of which is related to the frequency of the received FSK modulated signal, wherein the magnitude of the current peak and valley voltages decrease at one of at least two decay rates whenever the magnitude of the voltage signal is less than the magnitude of the current peak or valley voltage; when a packet has not been detected, selecting a fast one of the at least two decay rates whenever the difference between the current peak and current valley voltages exceeds some percentage of an expected difference, and otherwise selecting a slow one of the at least two decay rates, wherein the fast decay rate is significantly faster than the slow decay rate; determining that a packet has been acquired and an end of packet has not been reached; and selecting the slow one of the at least two decay rates based upon a received mode control signal and upon subsequently enabling selection of the fast one of the at least two decay rates once an end of packet has been detected wherein a slow decay is selected when a packet has been acquired as determined when the synch word has been received and an end of packet has not been reached and selecting a fast decay mode when the packet is not acquired or when it has been acquired and an end of packet is reached; and setting the optimal slicing point to a magnitude that is about half of the sum of the current peak and valley voltages.