Title:
BURST SIGNAL DEMODULATOR AND DEMODULATION CONTROL METHOD
Document Type and Number:
Japanese Patent JP3052518
Kind Code:
B2
Abstract:
PURPOSE: To obtain the inexpensive small sized burst signal demodulator controller coping with all frequency fluctuation including that on a satellite for a burst signal demodulator single body.
CONSTITUTION: A dummy burst signal is sent continuously from a dummy burst transmission section 2 for many times with an instruction from a control section 1 at the initial acquisition and the section 2 receives by itself via a satellite, a demodulator 7 sweeps a local oscillation frequency 13 and stops sweeping when a frequency fluctuation error is not included in a signal at a reproduction intermediate frequency band and implements demodulation. In the steady-state, while the burst signal is being received, an AFC circuit 20 is operated. Furthermore, when the burst signal is not received for a prescribed period, the dummy burst signal is sent for self-check and when the signal is not normally received, the operation is restored to the operation of the initial acquisition.
Inventors:
Hide Nawata
Application Number:
JP426092A
Publication Date:
June 12, 2000
Filing Date:
January 14, 1992
Export Citation:
Assignee:
NEC
International Classes:
H04B7/212; H04B7/155; H04J3/00; H04L27/22; (IPC1-7): H04J3/00; H04B7/155; H04L27/22
Domestic Patent References:
JP1259616A | ||||
JP63214037A | ||||
JP4339408A | ||||
JP58151132A | ||||
JP60183861A |
Attorney, Agent or Firm:
Yoshiyuki Iwasa
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