EP 0990324 A1 20000405 - IMPROVED METHOD FOR PARTIALLY MODULATING AND DEMODULATING DATA IN A MULTI-CARRIER TRANSMISSION SYSTEM
Title (en)
IMPROVED METHOD FOR PARTIALLY MODULATING AND DEMODULATING DATA IN A MULTI-CARRIER TRANSMISSION SYSTEM
Title (de)
VERBESSERTES VERFAHREN ZUM TEILWEISE MODULIEREN UND DEMODULIEREN VON DATEN IN EINEM MEHRTRÄGER-ÜBERTRAGUNGSSYSTEM
Title (fr)
PROCEDE AMELIORE DE MODULATION ET DEMODULATION PARTIELLES DE DONNEES DANS UN SYSTEME DE TRANSMISSION A PORTEUSES MULTIPLES
Publication
Application
Priority
US 9708209 W 19970517
Abstract (en)
[origin: WO9853572A1] A decoder (200) and an encoder (300) for extracting a subset of symbols from, or inserting a subset of symbols into, a communication channel (333) in which M symbols are transmitted as the amplitudes of M sinusoidal carriers. The decoder (200) recovers K symbols, Sp...Sp+K-1, from an analog signal generated by modulating M sinusoidal carriers for a frame period. Each carrier is modulated with an amplitude proportional to the value of one of M symbols, the i<th> carrier being modulated by symbol Si. The K symbols are a contiguous subset of the M symbols. The decoder (200) includes a down-converter (201, 211, 202, 212) for down-converting the modulated signal on the communication channel to generate a down-converted signal in which the carriers corresponding to Sp...Sp+K-1 occupy frequencies starting from O. An analog-digital converter (203, 313) generates K time-domain samples in each frame period from the down-converted signal. These time-domain samples are converted to K frequency-domain values representing the symbols Sp...Sp+K-1 by a time-domain to frequency-domain overlapped transform. The encoder (300) encodes K symbols, S1...SK, as the amplitudes of K sinusoidal carriers, the K sinusoidal carriers comprising a contiguous block of carriers in a signal comprising M sinusoidal carriers in which each of the carriers is modulated by a signal having an amplitude determined by the value of one of the symbols for a time equal to one frame period. The encoder (300) includes a frequency-domain to time-domain overlapped transform (302, 312) for generating K time-domain samples from the K symbols, the time-domain samples representing a modulated carrier comprising K sinusoidal carriers, each of the carriers being modulated by a signal having an amplitude determined by the value of one of the K symbols. A digital-to-analog converter (304, 314) converts the K time-domain samples to an analog signal. The analog signal is then up-converted such that the sinusoidal carrier modulated by S1 has a frequency equal to the p<th> carrier of the M sinusoidal carriers, wherein p>/=0.
IPC 1-7
IPC 8 full level
H04J 11/00 (2006.01); H04L 5/02 (2006.01); H04L 27/26 (2006.01)
CPC (source: EP US)
H04L 5/023 (2013.01 - EP US); H04L 27/2633 (2013.01 - EP US); H04L 27/26532 (2021.01 - EP US)
Citation (search report)
See references of WO 9853572A1
Designated contracting state (EPC)
DE ES FR GB
DOCDB simple family (publication)
WO 9853572 A1 19981126; AU 3067397 A 19981211; AU 743020 B2 20020117; CA 2289529 A1 19981126; EP 0990324 A1 20000405; JP 2002507337 A 20020305
DOCDB simple family (application)
US 9708209 W 19970517; AU 3067397 A 19970517; CA 2289529 A 19970517; EP 97925573 A 19970517; JP 55030698 A 19970517