US6094464A
Expired / Lapsed
US
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Burst mode receiver
Assignee: Motorola Wireline Networks Inc
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Filing: 1996-10-11
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Granted: 2000-07-25
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Expires: 2016-10-11
Abstract
Abstract In a burst mode communication system bursts arrive at a receiver which must correctly acquire and track carrier and clock phases in order to recover the transmitted symbols. A burst mode receiver is used to recover the clock and carrier phase. The detection of an initiator pulse indicates the presence of a burst signal, and a cross-coupled fractionally spaced digital filter structure is used with a known preamble to perform symbol sampling phase recovery and carrier phase acquisition, and during the normal mode of operation results in a tracking of the symbol and carrier phases.
Inventors
- 👤 Lawrence Ebringer
- 👤 Scott C. Petler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:04
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/26; H04L27/28; H04L27/0014; H04L23/00; H04L23/02; H04L27/18; H04L27/22; H04L27/233; H04L27/2332; H04L27/32; H04L27/34; H04L27/38; H04L27/3845; H04L27/3854; H04L7/00; H04L7/04; H04L7/041; H04L7/042; H04L7/044; H04L2027/0024; H04L2027/0026; H04L2027/003; H04L2027/0038; H04L2027/0042; H04L2027/0083; H04L2027/0089; H04L2027/0093; H04L2027/0095
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
189 words
A method for generating recovered symbols from a received signal at a receive end of a burst mode communications system, said burst mode communications system having bursts containing a predetermined preamble and data which are coded into symbols, modulated onto a carrier and transmitted from a transmit end, said method comprising: (a) converting a received signal from a continuous time signal to a discrete time signal; (b) downconverting said discrete time signal to produce a first complex baseband signal having at least two signal samples per symbol; (c) detecting the presence of a burst in said first complex baseband signal; (d) filtering said first complex baseband signal using at least one digital filter means having adjustable tap coefficients; (e) decimating said first complex baseband signal to produce a second complex baseband signal having one signal sample per symbol; (f) thresholding said second complex baseband signal to produce a third complex baseband signal containing recovered symbols; (g) generating an error signal based upon a comparison of said recovered symbols to a set of symbols stored at said receiver end; and (h) adjusting said tap coefficients to minimize said error signal.
Claim 2
Independent Claim
189 words
A method for generating recovered symbols from a received signal at a receive end of a burst mode communications system, said burst mode communications system having bursts containing a predetermined preamble and data which are coded into symbols, modulated onto a carrier and transmitted from a transmit end, said method comprising: (a) converting a received signal from a continuous time signal to a discrete time signal; (b) downconverting said discrete time signal to produce a first complex baseband signal having at least two signal samples per symbol; (c) detecting the presence of a burst in said first complex baseband signal; (d) filtering said first complex baseband signal using at least one digital filter means having adjustable tap coefficients; (e) decimating said first complex baseband signal to produce a second complex baseband signal having one signal sample per symbol; (f) thresholding said second complex baseband signal to produce a third complex baseband signal containing recovered symbols; (g) generating an error signal based upon a comparison of said recovered symbols to a set of symbols stored at said receiver end; and (h) adjusting said tap coefficients to minimize said error signal.
Claim 3
Dependent Claim
15 words
The method described in claim 1 wherein said error signal is an initial error signal.
Claim 4
Dependent Claim
57 words
The method described in claim 2 further comprising the steps of: (a) generating a normal mode operation error signal based upon a comparison of said recovered symbols to said second complex baseband signal; and (b) adjusting tap coefficients of a digital signal filter means at said receiver end node to minimize said normal mode operation error signal.
Claim 5
Dependent Claim
27 words
The method described in claim 1 wherein adjustment of said adjustable tap coefficients to minimize said initial error signal is based on a least mean squares solution.
Claim 6
Dependent Claim
29 words
The method described in claim 3 wherein adjustment of said adjustable tap coefficients to minimize said normal mode operation error signal is based on a least mean squares solution.
Claim 7
Dependent Claim
18 words
The method described in claim 1 wherein said digital filter means is a fractionally spaced cross-coupled equalizer means.
Claim 8
Dependent Claim
19 words
The method described in claim 6 wherein said fractionally spaced cross-coupled equalizer means has 4 to 6 tap means.
Claim 9
Dependent Claim
34 words
The method described in claim 1 wherein said conversion of said received signal from a continuous time signal to a discrete time signal results in a discrete time signal with 6 bits of resolution.
Claim 10
Independent Claim
242 words
A method for generating recovered symbols from a received signal at a receive end of a burst mode communications system, said burst mode communications system having bursts containing a predetermined preamble and data which are coded into binary symbols, modulated onto orthogonal carriers and transmitted from a transmit end, said method comprising: (a) converting a received signal from a continuous time signal to a discrete time signal; (b) downconverting said discrete time signal to produce a first complex baseband signal having at least two signal samples per symbol; (c) detecting the presence of a burst in said first complex baseband signal; (d) filtering said first complex baseband signal using at least one fractionally spaced cross-coupled equalizer having adjustable tap coefficients; (e) decimating said first complex baseband signal to produce a second complex baseband signal having one signal sample per symbol; (f) thresholding said second complex baseband signal to produce a third complex baseband signal containing recovered binary symbols; (g) generating an initial error signal based upon a comparison of said recovered symbols to a set of binary symbols stored at said receiver end; and (h) adjusting said tap coefficients to minimize said initial error signal; (a) generating a normal mode operation error signal based upon a comparison of said recovered binary symbols to said second complex baseband signal; and (b) adjusting tap coefficients of a digital signal filter means at said receiver end node to minimize said normal mode operation error signal.
Claim 11
Independent Claim
242 words
A method for generating recovered symbols from a received signal at a receive end of a burst mode communications system, said burst mode communications system having bursts containing a predetermined preamble and data which are coded into binary symbols, modulated onto orthogonal carriers and transmitted from a transmit end, said method comprising: (a) converting a received signal from a continuous time signal to a discrete time signal; (b) downconverting said discrete time signal to produce a first complex baseband signal having at least two signal samples per symbol; (c) detecting the presence of a burst in said first complex baseband signal; (d) filtering said first complex baseband signal using at least one fractionally spaced cross-coupled equalizer having adjustable tap coefficients; (e) decimating said first complex baseband signal to produce a second complex baseband signal having one signal sample per symbol; (f) thresholding said second complex baseband signal to produce a third complex baseband signal containing recovered binary symbols; (g) generating an initial error signal based upon a comparison of said recovered symbols to a set of binary symbols stored at said receiver end; and (h) adjusting said tap coefficients to minimize said initial error signal; (a) generating a normal mode operation error signal based upon a comparison of said recovered binary symbols to said second complex baseband signal; and (b) adjusting tap coefficients of a digital signal filter means at said receiver end node to minimize said normal mode operation error signal.
Claim 12
Dependent Claim
27 words
The method described in claim 9 wherein adjustment of said adjustable tap coefficients to minimize said initial error signal is based on a least mean squares solution.
Claim 13
Dependent Claim
22 words
The method described in claim 9 wherein said fractionally spaced cross-coupled equalizer with adjustable tap coefficients has 4 to 6 tap means.
Claim 14
Dependent Claim
34 words
The method described in claim 9 wherein said conversion of said received signal from a continuous time signal to a discrete time signal results in a discrete time signal with 6 bits of resolution.
Claim 15
Independent Claim
205 words
An apparatus for generating recovered symbols from a received signal at a receive end of a burst mode communications system, said burst mode communications system having bursts containing a predetermined preamble and data which are coded into symbols, modulated onto a carrier and transmitted from a transmit end, said apparatus comprising: (a) means for converting a received signal from a continuous time signal to a discrete time signal; (b) means for downconverting said discrete time signal to produce a first complex baseband signal having at least two signal samples per symbol; (c) means for detecting the presence of a burst in said first complex baseband signal; (d) means for filtering said first complex baseband signal using at least one digital filter means having adjustable tap coefficients; (e) means for decimating said first complex baseband signal to produce a second complex baseband signal having one signal sample per symbol; (f) means for thresholding said second complex baseband signal to produce a third complex baseband signal containing recovered symbols; (g) means for generating an error signal based upon a comparison of said recovered symbols to a set of symbols stored at said receiver end; and (h) means for adjusting said tap coefficients to minimize said error signal.
Claim 16
Independent Claim
205 words
An apparatus for generating recovered symbols from a received signal at a receive end of a burst mode communications system, said burst mode communications system having bursts containing a predetermined preamble and data which are coded into symbols, modulated onto a carrier and transmitted from a transmit end, said apparatus comprising: (a) means for converting a received signal from a continuous time signal to a discrete time signal; (b) means for downconverting said discrete time signal to produce a first complex baseband signal having at least two signal samples per symbol; (c) means for detecting the presence of a burst in said first complex baseband signal; (d) means for filtering said first complex baseband signal using at least one digital filter means having adjustable tap coefficients; (e) means for decimating said first complex baseband signal to produce a second complex baseband signal having one signal sample per symbol; (f) means for thresholding said second complex baseband signal to produce a third complex baseband signal containing recovered symbols; (g) means for generating an error signal based upon a comparison of said recovered symbols to a set of symbols stored at said receiver end; and (h) means for adjusting said tap coefficients to minimize said error signal.
Claim 17
Dependent Claim
15 words
The apparatus described in claim 13 wherein said error signal is an initial error signal.
Claim 18
Dependent Claim
61 words
The apparatus described in claim 14 further comprising the steps of: (a) means for generating a normal mode operation error signal based upon a comparison of said recovered symbols to said second complex baseband signal; and (b) means for adjusting tap coefficients of a digital signal filter means at said receiver end node to minimize said normal mode operation error signal.
Claim 19
Dependent Claim
29 words
The apparatus described in claim 15 wherein adjustment of said adjustable tap coefficients to minimize said normal mode operation error signal is based on a least mean squares solution.
Claim 20
Dependent Claim
27 words
The apparatus described in claim 13 wherein adjustment of said adjustable tap coefficients to minimize said initial error signal is based on a least mean squares solution.
Claim 21
Dependent Claim
18 words
The apparatus described in claim 13 wherein said digital filter means is a fractionally spaced cross-coupled equalizer means.
Claim 22
Dependent Claim
19 words
The apparatus described in claim 18 wherein said fractionally spaced cross-coupled equalizer means has 4 to 6 tap means.
Claim 23
Dependent Claim
34 words
The apparatus described in claim 13 wherein said conversion of said received signal from a continuous time signal to a discrete time signal results in a discrete time signal with 6 bits of resolution.
Claim 24
Independent Claim
262 words
An apparatus for generating recovered symbols from a received signal at a receive end of a burst mode communications system, said burst mode communications system having bursts containing a predetermined preamble and data which are coded into binary symbols, modulated onto orthogonal carriers and transmitted from a transmit end, said apparatus comprising: (a) means for converting a received signal from a continuous time signal to a discrete time signal; (b) means for downconverting said discrete time signal to produce a first complex baseband signal having at least two signal samples per symbol; (c) means for detecting the presence of a burst in said first complex baseband signal; (d) means for filtering said first complex baseband signal using at least one fractionally spaced cross-coupled equalizer having adjustable tap coefficients; (e) means for decimating said first complex baseband signal to produce a second complex baseband signal having one signal sample per symbol; (f) means for thresholding said second complex baseband signal to produce a third complex baseband signal containing recovered binary symbols; (g) means for generating an initial error signal based upon a comparison of said recovered symbols to a set of binary symbols stored at said receiver end; and (h) means for adjusting said tap coefficients to minimize said initial error signal; (a) means for generating a normal mode operation error signal based upon a comparison of said recovered binary symbols to said second complex baseband signal; and (b) means for adjusting tap coefficients of a digital signal filter means at said receiver end node to minimize said normal mode operation error signal.
Claim 25
Independent Claim
262 words
An apparatus for generating recovered symbols from a received signal at a receive end of a burst mode communications system, said burst mode communications system having bursts containing a predetermined preamble and data which are coded into binary symbols, modulated onto orthogonal carriers and transmitted from a transmit end, said apparatus comprising: (a) means for converting a received signal from a continuous time signal to a discrete time signal; (b) means for downconverting said discrete time signal to produce a first complex baseband signal having at least two signal samples per symbol; (c) means for detecting the presence of a burst in said first complex baseband signal; (d) means for filtering said first complex baseband signal using at least one fractionally spaced cross-coupled equalizer having adjustable tap coefficients; (e) means for decimating said first complex baseband signal to produce a second complex baseband signal having one signal sample per symbol; (f) means for thresholding said second complex baseband signal to produce a third complex baseband signal containing recovered binary symbols; (g) means for generating an initial error signal based upon a comparison of said recovered symbols to a set of binary symbols stored at said receiver end; and (h) means for adjusting said tap coefficients to minimize said initial error signal; (a) means for generating a normal mode operation error signal based upon a comparison of said recovered binary symbols to said second complex baseband signal; and (b) means for adjusting tap coefficients of a digital signal filter means at said receiver end node to minimize said normal mode operation error signal.
Claim 26
Dependent Claim
27 words
The apparatus described in claim 21 wherein adjustment of said adjustable tap coefficients to minimize said initial error signal is based on a least mean squares solution.
Claim 27
Dependent Claim
22 words
The apparatus described in claim 21 wherein said fractionally spaced cross-coupled equalizer with adjustable tap coefficients has 4 to 6 tap means.
Claim 28
Dependent Claim
34 words
The apparatus described in claim 21 wherein said conversion of said received signal from a continuous time signal to a discrete time signal results in a discrete time signal with 6 bits of resolution.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-07-25 | 2004-01-24 | 2004-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-07-25 | 2008-01-24 | 2008-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-07-25 | 2012-01-24 | 2012-07-25 | $7700.00 | Window Closed / Lapsed |