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Title:
VARIABLE BAND WIDTH FREQUENCY DIVISION MULTIPLEX COMMUNICATION SYSTEM
Document Type and Number:
Japanese Patent JPH09284242
Kind Code:
A
Abstract:

To provide a communication equipment with a small scale whose band width is variable in the frequency division multiplex communication.

In a multiplexer at a transmitter side, an A/D converter 3 converts each channel signal into a digital signal, a complex multiplier 5 converts the signal into a complex signal with different frequency for each channel interval Δf and the signal is fed to an IFFT circuit 8 conducting inverse Fourier transformation via a switch circuit 6 having plural switch elements 7. Nyquist characteristic digital sub filters 10-1 to 10-N whose Nyquist frequency of Δf/2 are arranged to the output of the IFFT circuit 8 and outputs of the digital sub filters 10-1 to 10-N are added by an adder circuit 12 via delay devices 11-1 to 11-N. A demultiplexer at a receiver side is configured similarly to the multiplexer. The band width is changed by changing the state of each switch element 7.


Inventors:
ICHIYOSHI OSAMU
Application Number:
JP1996000092834
Publication Date:
October 31, 1997
Filing Date:
April 15, 1996
Export Citation:
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Assignee:
NEC CORP
International Classes:
H04L27/34; H04J1/05; H04J3/00; H04J4/00; (IPC1-7): H04J1/05; H04J3/00; H04L27/34
Attorney, Agent or Firm:
若林 忠