Title:
多値変調・復調方法、多値変調・復調装置
Document Type and Number:
Japanese Patent JP4900961
Kind Code:
B2
Abstract:
Multi-level modulation that is hardly affected by non-linear characteristics of a power amplifier and is equal to or above 64-valued quadrature amplitude modulation (64-QAM) is provided. N (integer equal to or above 3) quadri-phase shift keying (QPSK) outputs having different amplitude levels, i.e., r2=r1·2 -(i-1) , i=2 ... N with respect to a maximum amplitude level r1 are superposed after power amplification to form M(=2 2N )-valued/quadrature amplitude modulation (QAM), and N-1 outputs si except the quadri-phase shift keying QPSK-1 having the maximum amplitude r1 are subjected to power amplification in this formation, then the outputs are combined by a directional coupler to obtain a combined signal, and an output of the quadri-phase shift keying QPSK-1 and the combined signal are transmitted from two systems of antennas to be vectorially superposed and combined in a space. A series/parallel converter is provided before each QPSK unit to divide and input input data of 2N bits, and a variable gain unit and a variable phase shifter adjust a gain and a phase.
Inventors:
Tanaka Masayoshi
Takuya Eguchi
Takuya Eguchi
Application Number:
JP2007534442A
Publication Date:
March 21, 2012
Filing Date:
September 06, 2006
Export Citation:
Assignee:
NIHON UNIVERSITY
International Classes:
H04L27/34; H04B7/06; H04B7/10
Domestic Patent References:
| JPH09200278A | 1997-07-31 | |||
| JP2004064154A | 2004-02-26 | |||
| JPH10270929A | 1998-10-09 | |||
| JP2004104503A | 2004-04-02 |
Foreign References:
| WO1997048219A2 | 1997-12-18 |
Attorney, Agent or Firm:
Katsushige Yamada
Katsumi Yamada
Hiroshige Yamada
Tomoshige Yamada
Katsumi Yamada
Hiroshige Yamada
Tomoshige Yamada