Patent US5577068A successfully refreshed from Google Patents.
US5577068A
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Generalized direct update viterbi equalizer
Assignee: Unwired Planet LLC
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Filing: 1994-07-18
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Granted: 1996-11-19
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Expires: 2014-07-18
Abstract
Abstract A radio receiver for demodulating and equalizing digital information is disclosed. The receiver receives radio signals and processes the signals to produce data samples which are then stored. Reference values that model what the receiver should receive for various transmitted symbol sequence hypotheses are also stored. The receiver equalizes the received data using the stored reference values to produce symbol detection information, and updates the reference values based on the symbol detection information.
Inventors
- 👤 Gregory E. Bottomley
- 👤 Sandeep Chennakeshu
- 👤 Paul W. Dent
- 👤 R. David Koilpillai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:22
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/005; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03178; H04L25/03184; H04L25/03248; H04L25/03292
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
67 words
A radio receiver for demodulating digital information comprising: means for receiving radio signals and processing them to produce data samples; means for storing reference values that model what the receiver should receive for various transmitted symbol sequence hypotheses; means for equalizing said data samples using said stored reference values to produce symbol detection information; and means for updating said reference values based on said symbol detection information.
Claim 2
Dependent Claim
67 words
A radio receiver for demodulating digital information comprising: means for receiving radio signals and processing them to produce data samples; means for storing reference values that model what the receiver should receive for various transmitted symbol sequence hypotheses; means for equalizing said data samples using said stored reference values to produce symbol detection information; and means for updating said reference values based on said symbol detection information.
Claim 3
Dependent Claim
36 words
A radio receiver according to claim 1, wherein said means for receiving radio signals includes a plurality of antennas, and said means for equalizing the received data combines branch metrics associated with said plurality of antennas.
Claim 4
Dependent Claim
16 words
A radio receiver according to claim 1, wherein said means of equalization is a fractionally-spaced equalizer.
Claim 5
Dependent Claim
16 words
A radio receiver according to claim 2, wherein said means of equalization is a fractionally-spaced equalizer.
Claim 6
Dependent Claim
19 words
A radio receiver according to claim 1, wherein said reference values are maintained for each state within the equalizer.
Claim 7
Dependent Claim
36 words
A radio receiver according to claim 1, wherein said means for receiving radio signals includes a plurality of polarizations, and said means for equalizing the received data combines branch metrics associated with said plurality of polarizations.
Claim 8
Dependent Claim
15 words
A radio receiver according to claim 1, wherein said symbol detection information includes soft information.
Claim 9
Dependent Claim
20 words
A radio receiver according to claim 1, wherein said equalization includes scaling metrics by an estimate of the noise power.
Claim 10
Dependent Claim
18 words
A radio receiver according to claim 1, wherein said equalization includes weighting said reference values by weighting values.
Claim 11
Dependent Claim
15 words
A radio receiver according to claim 1, wherein said equalization is performed using bidirectional equalization.
Claim 12
Dependent Claim
15 words
A radio receiver according to claim 1, wherein said equalization is performed using blind equalization.
Claim 13
Independent Claim
111 words
A method for equalizing a received sample, comprising the steps of: storing a plurality of reference values that correspond to unequalized expected receive sample values for different transmitted symbol sequence hypotheses; predicting a plurality of reference values using said reference values to produce a plurality of predicted reference values; forming branch metrics that correspond to magnitude squared differences between said received samples and said predicted reference values; forming accumulated metrics using said branch metrics; producing detected symbol values using said accumulated metrics; using said detected symbol values to select one of said reference values; and using said selected reference value to update one or more of said plurality of reference values.
Claim 14
Independent Claim
111 words
A method for equalizing a received sample, comprising the steps of: storing a plurality of reference values that correspond to unequalized expected receive sample values for different transmitted symbol sequence hypotheses; predicting a plurality of reference values using said reference values to produce a plurality of predicted reference values; forming branch metrics that correspond to magnitude squared differences between said received samples and said predicted reference values; forming accumulated metrics using said branch metrics; producing detected symbol values using said accumulated metrics; using said detected symbol values to select one of said reference values; and using said selected reference value to update one or more of said plurality of reference values.
Claim 15
Dependent Claim
13 words
A method according to claim 12, wherein said predicted reference values are weighted.
Claim 16
Independent Claim
59 words
A method for demodulating digital information comprising the steps of: receiving radio signals and processing them to produce data samples; storing reference values that estimate the received values for various transmitted symbol sequence hypotheses: equalizing the received dam using said stored reference values to produce symbol detection information; and updating said reference values based on said symbol detection information.
Claim 17
Independent Claim
59 words
A method for demodulating digital information comprising the steps of: receiving radio signals and processing them to produce data samples; storing reference values that estimate the received values for various transmitted symbol sequence hypotheses: equalizing the received dam using said stored reference values to produce symbol detection information; and updating said reference values based on said symbol detection information.
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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) | 1999-11-19 | 2000-05-20 | 2000-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-19 | 2004-05-20 | 2004-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-19 | 2008-05-20 | 2008-11-19 | $7700.00 | Window Closed / Lapsed |