Patent US4881222A successfully refreshed from Google Patents.
US4881222A
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Multicarrier demodulator
Assignee: Bosch Telecom GmbH
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Filing: 1988-03-04
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Granted: 1989-11-14
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Expires: 2008-03-04
Abstract
Abstract The present invention relates to a multicarrier demodulator for separating and demodulating a digitalized frequency multiplexed signal into a plurality (L) of individual channel signals, with the separation being performed using a frequency division demultiplexer (FDM). The separated channel signals are each filtered using bandwidth limitation filters and thereafter demodulated using a synchronous demodulator. Following demodulation, the signals are filtered by interpolation filters, data (Nyquist) filters, and subsequently decided upon in a decider. The invention is characterized by the fact that the demodulator operates upon a pair of phase displaced complex channel signals.
Inventors
- 👤 Heinz Goeckler
- 👤 Thomas Alberty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:40
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04L5/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
94 words
In a multicarrier demodulator for the separation and demodulation of a digitalized frequency multiplex signal into a plurality of individual channel signals comprising a frequency division demultiplexer for receiving and separating said digitalized frequency multiplex signal, a plurality of bandwidth limitation filters for filtering said individual separated channel signals, a synchronous demodulator for synchronously demodulating said individual separated and band-limited channel signals, a plurality of interpolation and Nyquist filters, and a decider circuit, wherein each of said individual separated and bandlimited channel signals is a complex signal and is fed to said synchronous demodulator.
Claim 2
Dependent Claim
94 words
In a multicarrier demodulator for the separation and demodulation of a digitalized frequency multiplex signal into a plurality of individual channel signals comprising a frequency division demultiplexer for receiving and separating said digitalized frequency multiplex signal, a plurality of bandwidth limitation filters for filtering said individual separated channel signals, a synchronous demodulator for synchronously demodulating said individual separated and band-limited channel signals, a plurality of interpolation and Nyquist filters, and a decider circuit, wherein each of said individual separated and bandlimited channel signals is a complex signal and is fed to said synchronous demodulator.
Claim 3
Dependent Claim
16 words
A multicarrier demodulator as defined in claim 1 wherein said bandwidth limitation filters have complex coefficients.
Claim 4
Dependent Claim
123 words
A multicarrier demodulator for the separation and demodulation of a digitalized frequency multiplex signal into a plurality of individual channel signals comprising a frequency division demultiplexer for receiving and separating said digitalized frequency mutliplex signal; a plurality of bandwidth limitation filters for filtering said individual channel signals, the output of said bandwidth limitation filters being a complex channel signal; a synchronous demodulator for synchronously demodulating said complex channel signal; a plurality of interpolation filters for filtering the output of said synchronous demodulator; a plurality of Nyquist filters for filtering the output of said interpolation filters; and a decider circuit coupled to the output of said Nyquist filters, said decider circuit having feedback circuits connected to said synchronous demodulator and to said interpolation filters.
Claim 5
Dependent Claim
123 words
A multicarrier demodulator for the separation and demodulation of a digitalized frequency multiplex signal into a plurality of individual channel signals comprising a frequency division demultiplexer for receiving and separating said digitalized frequency mutliplex signal; a plurality of bandwidth limitation filters for filtering said individual channel signals, the output of said bandwidth limitation filters being a complex channel signal; a synchronous demodulator for synchronously demodulating said complex channel signal; a plurality of interpolation filters for filtering the output of said synchronous demodulator; a plurality of Nyquist filters for filtering the output of said interpolation filters; and a decider circuit coupled to the output of said Nyquist filters, said decider circuit having feedback circuits connected to said synchronous demodulator and to said interpolation filters.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-13 | 1993-05-15 | 1993-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-13 | 1997-05-15 | 1997-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-13 | 2001-05-15 | 2001-11-14 | $7700.00 | Window Closed / Lapsed |