CARRIER RECOVERY CIRCUIT AND CARRIER RECOVERY METHOD

摘要

PROBLEM TO BE SOLVED: To provide a carrier recovery circuit that recovers carriers excellently even under the circumferences that a reception state of an inputted digital modulation wave is bad. ;SOLUTION: In a carrier recovery circuit where after a complex multiplier 8 frequency-converts an input digital modulation wave into a 1st frequency conversion signal by using a 1st recovery carrier signal, a complex multiplier 11 frequency-converts the 1st frequency conversion signal into a 2nd frequency conversion signal by using a 2nd recovery carrier signal, an AFC loop controls the frequency of the 1st recovery carrier signal and a PLL loop phase-locks the 2nd recovery carrier signal to the input digital modulation wave, a phase detector 18 detects a phase error of the frequency conversion signal after a low frequency component is suppressed by low pass suppressing filters 16, 17 and a frequency detector 19 detects a frequency error of the 2nd frequency conversion signal from the phase error.;COPYRIGHT: (C)1999,JPO