Title:
PHASE MODULATION WAVE CARRIER RECOVERY CIRCUIT
Document Type and Number:
Japanese Patent JP3410841
Kind Code:
B2
Abstract:
PURPOSE: To obtain a phase modulation wave carrier recovery circuit in which a lock time for carrier recovery is short and a stable operation is attained.
CONSTITUTION: The circuit is made up of an FFT arithmetic circuit 21 applying FFT operation to phase error detection data to analyze a frequency component, a discrimination control circuit 22 discriminating a frequency deviation based on the analysis result and sending corresponding control data, and a D/A converter circuit 23 applying D/A conversion to the control data and giving the result to a VCO 9 for carrier recovery. Then considering that the phase error detection data include a frequency component corresponding to a frequency difference between a recovery carrier frequency and a frequency of a received phase shift wave as a frequency spectrum component, the frequency is analyzed by applying FFT to the phase error detection data to discriminate a frequency deviation. Thus, the carrier recovery signal matches the vicinity of an object frequency instantaneously by controlling the oscillated frequency of the VCO 9 to eliminate the frequency deviation.
Inventors:
Shigeru Uchida
Application Number:
JP31810094A
Publication Date:
May 26, 2003
Filing Date:
December 21, 1994
Export Citation:
Assignee:
Toshiba Corporation
International Classes:
H04L27/227; (IPC1-7): H04L27/227
Domestic Patent References:
| JP63178642A | ||||
| JP3171954A | ||||
| JP7221805A |
Attorney, Agent or Firm:
Takehiko Suzue