Title:
TRANSMITTER
Document Type and Number:
Japanese Patent JP3111776
Kind Code:
B2
Abstract:
PURPOSE: To provide a transmission reception system in which much more information is sent by the same frequency band as that of a conventional system by solving a problem that a transmission information quantity cannot be increased when a frequency band is limited in the transmitter sending a digital signal.
CONSTITUTION: A modulator 4 of a transmitter 1 implementing m-ary QAM modulation allocates n-ary data of a 1st data string to a signal point group resulting from grouping signal points of n-ary 1st data string, p-ary 2nd and 3rd data strings on a signal space diagram to obtain a modified m-ary QAM modulation signal, which is sent from the transmitter 1. When a demodulator 25 of a 1st receiver 23 demodulates the n-ary 1st data string, a 2nd receiver 33 the 1st and 2nd data strings, and 3rd receiver 43 demodulates the 1st, 2nd and 3rd data strings to receive the m-ary modified multi-value modulation wave, the transmitter is obtained in which even the receiver having only n-ary demodulation capability (n<m) can demodulate the data of the n-ary 1st data string when the m-ary modified multilevel modulation wave is received.
Inventors:
Mitsuaki Ohshima
Application Number:
JP26161193A
Publication Date:
November 27, 2000
Filing Date:
September 24, 1993
Export Citation:
Assignee:
Matsushita Electric Industrial Co., Ltd
International Classes:
H03M13/25; H03M13/35; H04B1/66; H04B14/04; H04H20/00; H04H20/06; H04J11/00; H04L1/00; H04L27/00; H04L27/02; H04L27/04; H04L27/18; H04L27/22; H04L27/26; H04L27/34; H04L27/36; H04L27/38; H04N5/38; H04N5/40; H04N5/44; H04N5/455; H04N5/46; H04N7/00; H04N7/015; H04N7/08; H04N7/081; H04N7/20; H04N11/24; H04N21/2662; H04N21/647; H04N21/845; (IPC1-7): H04J11/00
Domestic Patent References:
| JP575568A | ||||
| JP53137657A | ||||
| JP779415A |
Attorney, Agent or Firm:
Aoyama Ryo (1 person outside)