Patent ID: 6140869
Filing Date: 2000-10-31
Classification: H04L

Abstract:
A demodulation device for demodulating a binary phase-shift keyed signal having a carrier frequency, said demodulation device including a phase-locked loop comprising:a phase comparator having one input that receives the binary phase-shift keyed signal;a voltage-controlled oscillator coupled to the phase comparator, the voltage-controlled oscillator outputting a synchronous binary signal having a frequency that is N times the carrier frequency;a divider for dividing by N the synchronous binary signal to generate a divided binary signal having a frequency equal to the carrier frequency, the divided binary signal being supplied to another input of the phase comparator; andat least one counter that uses the synchronous binary signal to measure periods of levels of the binary phase-shift keyed signal,wherein said at least one counter comprises:a first counter that uses the synchronous binary signal to measure periods of high levels of the binary phase-shift keyed signal; anda second counter that uses the synchronous binary signal to measure periods of low levels of the binary phase-shift keyed signal.