Title:
OFDM SIGNAL SYNCHRONIZATION DEVICE
Document Type and Number:
Japanese Patent JP2963431
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce frequency estimation errors by detecting the phase change amount of orthogonal frequency multiplex signals during a repetition time based on the orthogonal frequency multiplex signals and delay signals for which they are delayed for the repetition time, obtaining a weighted moving average based on the phase change amount and estimating the frequency error of the orthogonal frequency multiplex signals based on the weighted moving average.
SOLUTION: A delay circuit 10 outputs digital signals SG2 delayed for prescribed time to the digital signals SG1 and a phase rotation angle detection circuit 20 outputs the change amount of a phase between the digital signals SG1 and SG2 as the digital signals SG3. A weighted moving average circuit 40 calculates the weighted moving average of the digital signals SG3 and outputs it as the digital signals SG4. By using weighting, the digital signals SG4 are hardly affected by delay waves and are highly reliable. A frequency error estimation circuit 50 generates the digital signals SG5 for indicating the frequency error based on the digital signals SG4.
Inventors:
Matsumoto, Yoichi
Mochizuki, Nobuaki
Umehira, Masahiro
Mochizuki, Nobuaki
Umehira, Masahiro
Application Number:
JP1998000112272
Publication Date:
August 06, 1999
Filing Date:
April 22, 1998
Export Citation:
Assignee:
NIPPON TELEGR & TELEPH CORP <NTT>
International Classes:
H04L27/00; H04J11/00; H04L27/26; (IPC1-7): H04J11/00