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Title:
DELAY TIME CORRECTING DEVICE FOR DISCRETE FOURIER TRANSFORMATION VALUE
Document Type and Number:
Japanese Patent JPH06180711
Kind Code:
A
Abstract:

PURPOSE: To correct the Fourier transformation value of a delay less than one sampling period by multiplexing the Fourier transformed result of a signal to be correlated by phase correcting data shown by a specific formula to execute phase correction in a frequency area.

CONSTITUTION: A Fourier transformation part 1 executes the descrete Fourier transformation of N sample values g(-Δt), g(τ-Δt) to g((N-1)τ-Δt) in total which are defined by setting up the sampling period of analog signals to 7 and sampling point (t) as t=-Δt, τ-Δt to ((N-1)τ-Δt) to obtain a frequency component G' (f)=G(f).exp (-i2πfΔt). A phase correction calculating part 2 calculates phase correction data γ=exp (j2πfΔt) and a phase correction multiplying part 3 multiplies the G' (f) by the data γ. Consequently a delay time can be accurately corrected even in the case of the correction of a delay time less than the sampling period τ.


Inventors:
MORITA NOBORU
OKUYA SHIGEAKI
NAKAZURU TOSHIAKI
KUBO SHINICHI
Application Number:
JP1993000080991
Publication Date:
June 28, 1994
Filing Date:
April 08, 1993
Export Citation:
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Assignee:
FUJITSU LTD
International Classes:
G06F17/14; G01R23/16; G01S3/14; (IPC1-7): G06F15/332
Domestic Patent References:
JPH0563509U1993-08-24
JPH04105081A1992-04-07
JPS62233781A1987-10-14
Attorney, Agent or Firm:
Teiichi