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Title:
TDM-FDM CONVERTING DEVICE
Document Type and Number:
Japanese Patent JPS572143
Kind Code:
A
Abstract:

PURPOSE: To reduce greatly the number of arithmetic circuits, by turning the complex signal of a time-division multiplex signal into a noncyclic digital filter signal in correspondence to channels and then synthesizing the noncyclic digital output signal connected to the output side to change it into a frequency-divided multiplex signal.

CONSTITUTION: The outputs Y1r, Y1i, Y2r and Y2i of a noncyclic digital FIR filter having a 16kHz action of the time-division multiplex TDM signal are applied to input terminals 4-1∼4-4 and then added together through adders 4-5∼4-8. The outputs of this addition are led to adders 4-13 and 4-14 via FIR filters 4-9∼4-12 having a 112kHz action. The outputs of these adders are synthesized by a synthesizing circuit 4-17 via multiplying circuits 4-15 and 4-16 to be delivered in the form of a frequency-divided FDM signal. In this case, the output is calculated just with every two times through the filters 4-9∼4-12 to reduce the number of arithmetic circuits down to 1/2. In the same way, the number of arithmetic circuits can be reduced also in case the FDM signal is converted into the TDM signal.


Inventors:
AMANO FUMIO
MURANO KAZUO
SOEJIMA TETSUO
AOYAMA TOMONORI
YOSHIMURA HIROSHI
WAKABAYASHI KIYOHISA
Application Number:
JP7518680A
Publication Date:
January 07, 1982
Filing Date:
June 04, 1980
Export Citation:
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Assignee:
FUJITSU LTD
NIPPON TELEGRAPH & TELEPHONE
International Classes:
H04J1/05; H04J3/00; H04J4/00; (IPC1-7): H04J1/00; H04J3/00