Patent ID: 9225568
Filing Date: 2015-12-29
Classification: H04L

Abstract:
1. A frequency shift keying (FSK) demodulator for decoding a binary signal comprising data bits encoded in a received FSK signal, the demodulator comprising: a first comparator for processing the received FSK signal to produce a FSK pulsed waveform comprising a succession of pulses wherein one bit of data comprises ‘N’ pulses, wherein N is a positive integer greater than 1; a counter/timer, operably coupled to the first comparator, for receiving the FSK pulsed waveform and for determining measured count values of a duration of a pre-chosen number, n, where n is a positive integer and is less than N, of consecutive pulses of the FSK pulsed waveform; a second comparator, operably coupled to the counter/timer, for receiving the measured count values and for comparing the measured count values with a pre-determined threshold value and for outputting a bit value of ‘0’ or ‘1’ depending on the comparison; and a controller operably coupled to the counter/timer and to the second comparator for choosing the value ‘n’ and determining the threshold value.