Clock phase detection method - has monolithic integrated circuit recovering QAM clock signal by comparison with various reference positions

摘要

The method recovers the clock rate/signal in a Quad-amplitude modulated (QAM) transmission system with m power 2 modulation levels. The input signal (6) is processed by comparators (7,27) and logic circuits (10,11) in conjunction with saw tooth waveform generated by clock (36) and monostable (2), to produce outputs (14,15). The position edge of the clock pulse (1) is applied to a monostable (2) to generate a single square wave impulse (5) with a duration less than teh half clock period. USE/ADVANTAGE - QAM demodulators. Reduced number of communication errors.