Title:
MOBILE RADIO EQUIPMENT
Document Type and Number:
Japanese Patent JP3153671
Kind Code:
B2
Abstract:
PURPOSE: To stably perform transmission and reception even in the case that the oscillation frequency error is not small and to extend the error correction range of a reference oscillator by adding an offset to the frequency of the phase reference signal of a demodulator.
CONSTITUTION: A demodulated data monitor circuit 11 which monitors the reliability of demodulated data outputted from a demodulator 3 and a reference signal control circuit 12 which adds the offset to the frequency to the phase reference signal in the demodulator 3 at the time of detecting th degradation of the reliability by the demodulated data monitor circuit 11 are provided. That is, the offset is added to change the frequency error detection range. Consequently, the quantity of offset is switched in time series based on the reliability of demodulated data, and the frequency of the reproduced carrier wave signal outputted from the demodulator 3 is measured by a frequency counter 4 at the time of adding the proper frequency offset, and the oscillation frequency error of a reference oscillator 7 is detected by a detecting circuit 5, and the oscillation frequency is so controlled by a control circuit 6 so that this oscillation frequency error is reduced. Thus, the frequency error detection range is extended, and the frequency stability is obtained.
Inventors:
Futakata, Toshiyuki
Takami, Tadao
Chiba, Koji
Takami, Tadao
Chiba, Koji
Application Number:
JP10697193A
Publication Date:
April 09, 2001
Filing Date:
May 07, 1993
Export Citation:
Assignee:
N T T IDOU TSUUSHINMOU KK
International Classes:
H04B1/10; H04L27/22; (IPC1-7): H04L27/22; H04B1/10
Attorney, Agent or Firm:
井出 直孝 （外１名）
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