US5832032A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interference reduction in telecommunications systems
Assignee: RPX Clearinghouse LLC
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Filing: 1996-10-28
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Granted: 1998-11-03
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Expires: 2016-10-28
Abstract
Abstract Interference on a differential signal received at a first input to a digital data system processor is minimised or cancelled by summing a weighted portion of a local field signal with the differential signal. The local field signal may be a common-mode signal from the same line as the differential signal received at a second input. Weight may be a complex weight which shifts the local field signal in amplitude and phase. A weight control signal is derived from a comparison processor which compares the processed outputs of signal processors. Signal processors are preferably Discrete Multi-tone processors. Several iterations of this technique may be performed to establish an accurate weighting value.
Inventors
- 👤 Francis Giles Overbury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:12
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/30; H04L; H04L27/00; H04L27/26; H04L27/2601; H04L27/2647
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
85 words
A digital data system processor having a first input to receive a differential signal and a second input to receive a local field signal, the processor being arranged to: separately process the differential and local field signals; compare characteristics of the processed differential and local field signals to derive a weight control signal; set a weight according to the weight control signal; sum a weighted portion of the local field signal with the differential signal whereby to minimise or cancel interference in the differential signal.
Claim 2
Dependent Claim
85 words
A digital data system processor having a first input to receive a differential signal and a second input to receive a local field signal, the processor being arranged to: separately process the differential and local field signals; compare characteristics of the processed differential and local field signals to derive a weight control signal; set a weight according to the weight control signal; sum a weighted portion of the local field signal with the differential signal whereby to minimise or cancel interference in the differential signal.
Claim 3
Dependent Claim
132 words
A digital data system processor comprising: a first input to receive a differential signal; a second input to receive a local field signal; a summer coupled to the first input; a first signal processor coupled to an output of the summer for processing the differential signal; a second signal processor coupled to the second input for processing the local field signal; a comparison processor coupled to outputs of the first and second signal processors arranged to compare characteristics of the processed signals and to derive a weight control signal; and a weight coupled between the second input and the summer and being responsive to the weight control signal, whereby a weighted portion of the local field signal is summed with the differential signal to minimise or cancel interference in the differential signal.
Claim 4
Dependent Claim
132 words
A digital data system processor comprising: a first input to receive a differential signal; a second input to receive a local field signal; a summer coupled to the first input; a first signal processor coupled to an output of the summer for processing the differential signal; a second signal processor coupled to the second input for processing the local field signal; a comparison processor coupled to outputs of the first and second signal processors arranged to compare characteristics of the processed signals and to derive a weight control signal; and a weight coupled between the second input and the summer and being responsive to the weight control signal, whereby a weighted portion of the local field signal is summed with the differential signal to minimise or cancel interference in the differential signal.
Claim 5
Dependent Claim
34 words
A digital data system processor according to claim 2 wherein the differential and local field signals are derived from a common transmission line, the local field signal being a common-mode signal from the line.
Claim 6
Dependent Claim
23 words
A digital data system processor according to claim 2 wherein the comparison processor compares amplitudes of the processed local field and differential signals.
Claim 7
Dependent Claim
24 words
A digital data system processor according to claim 2 wherein the comparison processor compares the phase of the processed local field and differential signals.
Claim 8
Dependent Claim
26 words
A digital data system processor according to claim 2 wherein the comparison processor is a correlator which correlates characteristics of the local field and differential signals.
Claim 9
Dependent Claim
27 words
A digital data system processor according to claim 2 wherein the signal processors comprise a cascade arrangement of an analogue-to-digital converter, and a Fast Fourier Transform decoder.
Claim 10
Dependent Claim
26 words
A digital data system processor according to claim 2 wherein the weight is a complex weight which scales the local field signal in amplitude and phase.
Claim 11
Dependent Claim
49 words
A telecommunications system including a processor according to claim 1 wherein a subscriber loop carries a wanted signal to the processor at a subscriber's premises by differential-mode, and wherein radio frequency interference (RFI) induced in the common-mode of the loop is used to minimise RFI appearing in the differential-mode.
Claim 12
Independent Claim
90 words
A method of reducing the effect of interference in a digital data processor which receives a differential signal at a first input and a local field signal at a second input, the method comprising: separately processing the differential and local field signals; comparing characteristics of the processed differential and local field signals to derive a weight control signal; setting a weight according to the weight control signal; summing a weighted portion of the local field signal with the differential signal whereby to minimise or cancel interference in the differential signal.
Claim 13
Independent Claim
90 words
A method of reducing the effect of interference in a digital data processor which receives a differential signal at a first input and a local field signal at a second input, the method comprising: separately processing the differential and local field signals; comparing characteristics of the processed differential and local field signals to derive a weight control signal; setting a weight according to the weight control signal; summing a weighted portion of the local field signal with the differential signal whereby to minimise or cancel interference in the differential signal.
Claim 14
Dependent Claim
22 words
A method according to claim 10 wherein the characteristics which are compared include amplitudes of the processed local field and differential signals.
Claim 15
Dependent Claim
18 words
A method according to claim 10 wherein phase of the demodulated local field and differential signals is compared.
Claim 16
Dependent Claim
18 words
A method according to claim 10 wherein the characteristics of the local field and differential signals are correlated.
Claim 17
Dependent Claim
25 words
A method according to claim 10 wherein the weighted portion of the local field signal is a complex weighted portion which is scaled and phase-shifted.
Claim 18
Dependent Claim
76 words
A method according to claim 10 wherein a plurality of iterations are performed, each iteration comprising the steps of comparing characteristics of the processed differential and local field signals to derive a weight control signal, setting a weight according to the weight control signal, and summing a weighted portion of the local field signal with the differential signal at the first input whereby to establish a weight which minimises or cancels interference in the differential signal.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 2001-11-02 | 2002-05-04 | 2002-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-02 | 2006-05-04 | 2006-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-02 | 2010-05-04 | 2010-11-03 | $7700.00 | Window Closed / Lapsed |