Title:
DIGITAL DEMODULATION METHOD AND ITS DEVICE
Document Type and Number:
Japanese Patent JP3180674
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain a demodulation system reducing an error of a transmission line by converting a received signal to a signal in a specific band and A/D- converting its fixed section so as to obtain a mapping and a bit of a shortest distance between with a decoding signal generated by Viterbi decoding.
SOLUTION: A base band received signal after carrier adjustment is added to an input terminal 100 to be converted to the digital signal of the number of bits previously fixed by an A/D converter after limiting a band 120. A section estimating part 220 designates a sampling section and houses a sampling signal in a buffer memory 130. A distance calculating part 140 constitutes a judging and reproducing part by a Viterbi decoding and reproducing part 150, an adder 160, a shortest distance calculation part 170, a state storing part 180 and a decoding and judging part 190. The demodulation system improving the speed of the transmission line and reducing the errors of the transmission line is obtained by obtaining a mapping relation n(t) by Eq. (1) and allowing the part 190 to obtain a decoding information bit from a Viterbi decoding processing to output.
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Inventors:
Shigeru Ono
Application Number:
JP18753796A
Publication Date:
June 25, 2001
Filing Date:
July 17, 1996
Export Citation:
Assignee:
NEC
International Classes:
H04L27/22; H04L1/00; H04L7/00; H04L7/02; (IPC1-7): H04L27/22; H04L7/00
Domestic Patent References:
| JP52842A |
Attorney, Agent or Firm:
Nobuyuki Kaneda (2 others)