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Patent Searching and Data


Title:
SYSTEM AND DEVICE FOR MODULATING/DEMODULATING PLURAL CARRIERS
Document Type and Number:
Japanese Patent JPH06232836
Kind Code:
A
Abstract:

PURPOSE: To simplify the configuration of a hardware and further to suppress carrier frequencies to one frequency by constituting the plural filter groups of a MODEM with transform multiplexer(TMUX) or transform demultiplexer(TDMUX).

CONSTITUTION: A modulator input signal is divided into plural channels and converted to a time division multiplex(TDM) signal by a demultiplexer(DMUX) 52. On the other hand, this signal is further converted to a frequency division multiplex(FDM) signal by a transform multiplexer(TMUX) 53, and a carrier signal is modulated with the FDM signal by a modulator 54. Thus, a plural carrier modulator 50 is constituted. Therefore, the modulator and a carrier signal generator, etc., are reduced in comparison with the conventional configuration, and the amount of the hardware can be reduced. Concerning even a plural carriers modulator 51, it can be similarly composed of a demodulator 55, TDMUX 56 and MUX 57.


Inventors:
ONISHI MAKOTO
OTA MASAAKI
TSUKAGOSHI KAZUAKI
ADACHI MASARU
Application Number:
JP1993000115926
Publication Date:
August 19, 1994
Filing Date:
May 18, 1993
Export Citation:
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Assignee:
HITACHI LTD
HITACHI ELECTRONICS
International Classes:
H04B7/26; H04J1/00; H04J3/00; H04J4/00; (IPC1-7): H04J4/00; H04B7/26; H04J1/00; H04J3/00
Attorney, Agent or Firm:
小川 勝男