BR9610614A - Apparatus and process for demodulating a composite signal - Google Patents

Apparatus and process for demodulating a composite signal

Info

Publication number
BR9610614A
BR9610614A BR9610614-0A BR9610614A BR9610614A BR 9610614 A BR9610614 A BR 9610614A BR 9610614 A BR9610614 A BR 9610614A BR 9610614 A BR9610614 A BR 9610614A
Authority
BR
Brazil
Prior art keywords
signals
digital
complementary
demodulating
signal
Prior art date
Application number
BR9610614-0A
Other languages
Portuguese (pt)
Inventor
Barry W Carlin
Mark J Dapper
Michael J Geile
Original Assignee
Usa Digital Radio Partners L P
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US08/604,276 external-priority patent/US5633896A/en
Application filed by Usa Digital Radio Partners L P filed Critical Usa Digital Radio Partners L P
Publication of BR9610614A publication Critical patent/BR9610614A/en

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03D—DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TO ANOTHER
    • H03D1/00—Demodulation of amplitude-modulated oscillations
    • H03D1/22—Homodyne or synchrodyne circuits
    • H03D1/2245—Homodyne or synchrodyne circuits using two quadrature channels
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2649—Demodulators
    • H04L27/26524—Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H2201/00—Aspects of broadcast communication
    • H04H2201/10—Aspects of broadcast communication characterised by the type of broadcast system
    • H04H2201/18—Aspects of broadcast communication characterised by the type of broadcast system in band on channel [IBOC]
    • H04H2201/186—AM digital or hybrid
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2649—Demodulators
    • H04L27/265—Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators
    • H04L27/26522—Fourier transform demodulators, e.g. fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators using partial FFTs

Abstract

"APARELHO E PROCESSO PARA DEMODULAR UM SINAL COMPóSITO"A invenção apresenta um processo e aparelho para demodualr uma forma de onda DAB AM composta que contem portadoras digitalmente moduladas e que emprega um misturador (180) para converter um sinal recebido (170) em dois sinais, o primeiro destes sinais representa um componente em-fase e o segundo dos sinais representa um componente em quadratura, dosi conversores analógicos/digitais (182, 184) para converter os dois sinais digitais, e dois elementos de transformação rápida de Fourier (188, 190) para extrair dados separadamente dos dois sinais digitais. Sinais de portadoras digitais complementares são recuperados da quadratura, e portadores digitais não complementares são derivados de uma soma dos lados complementares e da saída do processo FFT de componente em-fase. O escape do sinal AM através de um filtro passa-alto (186) é impedido de interferir com a demodulação do sinal de portadora complementar pelo uso de canais de demodulação separados."APPARATUS AND PROCESS FOR DEMODULATING A COMPOSITE SIGNAL" The invention features a process and apparatus for demodulating a composite DAB AM waveform containing digitally modulated carriers and employing a mixer (180) to convert a received signal (170) into two signals , the first of these signals represents an in-phase component and the second of the signals represents a quadrature component, two analog / digital converters (182, 184) to convert the two digital signals, and two fast Fourier transform elements (188, 190) to extract data separately from the two digital signals. Complementary digital carrier signals are retrieved from the square, and non-complementary digital carriers are derived from a sum of complementary sides and the in-phase component FFT process output. The escape of the AM signal through a high-pass filter (186) is prevented from interfering with the demodulation of the complementary carrier signal by the use of separate demodulation channels.

BR9610614-0A 1995-08-31 1996-08-21 Apparatus and process for demodulating a composite signal BR9610614A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US301895P 1995-08-31 1995-08-31
US08/604,276 US5633896A (en) 1996-02-21 1996-02-21 AM compatible digital waveform demodulation using a dual FFT
PCT/US1996/013526 WO1997008877A1 (en) 1995-08-31 1996-08-21 Am compatible digital waveform demodulation using a dual fft

Publications (1)

Publication Number Publication Date
BR9610614A true BR9610614A (en) 1999-12-21

Family

ID=26671176

Family Applications (1)

Application Number Title Priority Date Filing Date
BR9610614-0A BR9610614A (en) 1995-08-31 1996-08-21 Apparatus and process for demodulating a composite signal

Country Status (6)

Country Link
EP (1) EP0847642A4 (en)
JP (1) JPH11509066A (en)
AU (1) AU6853996A (en)
BR (1) BR9610614A (en)
CA (1) CA2233063A1 (en)
WO (1) WO1997008877A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6295317B1 (en) * 1998-10-02 2001-09-25 Usa Digital Radio Partners, Lp Method and apparatus for demodulating and equalizing an AM compatible digital audio broadcast signal
US6556639B1 (en) * 1999-06-24 2003-04-29 Ibiquity Digital Corporation Method and apparatus for determining transmission mode and synchronization for a digital audio broadcasting signal
GB0020624D0 (en) 2000-08-21 2000-10-11 Element 14 Inc Multi band DMT receiver
ES2181550B1 (en) * 2000-09-06 2003-12-16 Univ Valencia Politecnica CARRIER SELECTOR IN OFDM MODULATIONS (MULTIPLEXATION BY DIVISION OF ORTOGONAL FREQUENCY).

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5128964A (en) * 1990-10-10 1992-07-07 Intelligent Modem Corporation Modulation method and apparatus for multicarrier data transmission
SG44771A1 (en) * 1991-02-28 1997-12-19 Philips Electronics Nv System for broadcasting and receiving digital data receiver and transmitter for use in such system
US5278826A (en) * 1991-04-11 1994-01-11 Usa Digital Radio Method and apparatus for digital audio broadcasting and reception
DE4111855C2 (en) * 1991-04-11 1994-10-20 Inst Rundfunktechnik Gmbh Method for the radio transmission of a digitally coded data stream
FR2707064B1 (en) * 1993-06-21 1996-03-08 France Telecom

Also Published As

Publication number Publication date
EP0847642A1 (en) 1998-06-17
AU6853996A (en) 1997-03-19
EP0847642A4 (en) 2001-09-12
JPH11509066A (en) 1999-08-03
CA2233063A1 (en) 1997-03-06
WO1997008877A1 (en) 1997-03-06

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Legal Events

Date Code Title Description
FA10 Dismissal: dismissal - article 33 of industrial property law