Title:
VARIABLE BAND WIDTH FREQUENCY DIVISION MULTIPLEX COMMUNICATION SYSTEM
Document Type and Number:
Japanese Patent JP2738385
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a communication equipment with a small scale whose band width is variable in the frequency division multiplex communication.
SOLUTION: 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:
ICHOSHI OSAMU
Application Number:
JP9283496A
Publication Date:
April 08, 1998
Filing Date:
April 15, 1996
Export Citation:
Assignee:
NIPPON DENKI KK
International Classes:
H04J1/05; H04J3/00; H04J4/00; H04L27/34; (IPC1-7): H04J1/05; H04J3/00; H04L27/34
Domestic Patent References:
| JP63200635A | ||||
| JP4117739A | ||||
| JP1183640A |
Attorney, Agent or Firm:
Wakabayashi Tadashi
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