Title:
METHOD AND APPARATUS FOR DATA MODULATION IN CDMA SYSTEM AS WELL AS MEASURING METHOD FOR DISTANCE BETWEEN COMMUNICATION INSTALLATIONS BY USING THEM
Document Type and Number:
Japanese Patent JP3476789
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a method and an apparatus for a data modulation in a CDMA system which is of high performance and which can make a communication installation compact, and to provide a method in which the distance between communication installations is measured by using them.
SOLUTION: The data modulation method comprises a step wherein, from among predetermined mask patterns, the mask pattern in which the peak value of a signal is minimum is selected and input CDMA signal data in plurality of channels are multiplied by the mask pattern, a step wherein the level of the CDMA signal data multiplied by the mask pattern is discarded and the number of levels is reduced, a step wherein the level in each chip of the reduced signal data is converted into a pulse width and the level of a modulation signal is made always constant, and a step wherein the pulses in each chip of the modulation signal converted into the pulse width are alternately set at a high level and a low level to start.
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Inventors:
Sun Moon, Ryu
Application Number:
JP2001150076A
Publication Date:
December 10, 2003
Filing Date:
May 18, 2001
Export Citation:
Assignee:
Casa Corporation
International Classes:
H04J13/00; H04B1/707; H04B14/02; H04L25/49; H04W16/02; H04W64/00; (IPC1-7): H04J13/00; H04Q7/34
Attorney, Agent or Firm:
Kenzo Hara (3 outside)