RECEIVED SIGNAL PROCESSING APPARATUS AND METHOD

PROBLEM TO BE SOLVED: To compensate out-of-band signal components of a signal to signal components where the influence of signal deterioration, which has not been a problem in the case of system length of a transmission line shorter than about 3,000 km appears in the case of long distance transmissi...

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Bibliographic Details
Main Authors SHIMIZU MASAYA, ISHIGURO KAZUHIKO
Format Patent
LanguageEnglish
Published 16.05.2003
Edition7
Subjects
ELECTRIC COMMUNICATION TECHNIQUE
ELECTRICITY
TRANSMISSION
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Summary:PROBLEM TO BE SOLVED: To compensate out-of-band signal components of a signal to signal components where the influence of signal deterioration, which has not been a problem in the case of system length of a transmission line shorter than about 3,000 km appears in the case of long distance transmission of about 8,000 km, and a bandwidth is increased accompanying this. SOLUTION: When cable loss of an optical fiber is measured, the bandwidth of a spectrum waveform of a signal transmitted up to the far end of a transmission line is spread as compared with a signal transmitted as far as a near end, when a received signal after detection is subjected to A/D conversion. The out-of-band signal components of the spread spectrum waveform are compensated by increasing the receiving bandwidth of a bandpass filter 2. Increase of noise components caused by increasing the receiving bandwidth, in order to compensate the out-of-band signal components, is compensated by increasing the number of samples of a digital signal after A/D conversion and by taking the moving average.
Bibliography:Application Number: JP20010335106