Carrier recovery circuit and demodulation circuit using the carrier recovery circuit

摘要

PROBLEM TO BE SOLVED: To demodulate a receiving signal by accurately regenerating a carrier signal by the use of a simple configuration and using the regenerated carrier signal. ;SOLUTION: An input analog signal is sampled by a sampling frequency fs, 4 times of a carrier frequency fc. A demultiplexer 12 outputs received data sequentially to four systems to generate 1st to 4th signals. The 1st to 4th signals are delayed by delay circuits 13 to 16 and the delayed signals are respectively fed to adaptive filters 17 to 20. A multiplexer 23 selects sequentially output data from the adaptive filters 17 to 20 and provides an output of the selected signals. A subtractor 21 obtains a difference between the 1st signal and an output of the adaptive filter 17. A control section 22 sets a tap coefficient of the adaptive filters 17 to 20 according to the LSM algorithm based on the difference.;COPYRIGHT: (C)1997,JPO