US6094465A
Expired / Lapsed
US
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Method and apparatus for performing decoding of CRC outer concatenated codes
Assignee: Qualcomm Inc
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Filing: 1997-03-21
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Granted: 2000-07-25
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Expires: 2017-03-21
Abstract
Abstract A method and apparatus for decoding a frame of multi-rate encoded digital data which contains redundant information provided to validate the decoding operation. A frame of data is received which contains information bits and cyclic redundancy check (CRC) bits. In accordance with the invention, the received frame is decoded and a check is conducted to determine whether the CRC bits correspond correctly for the decoded information bits. If the decoded frame passes the CRC test process, the decoded fame is provided to the user. However, if the decoded frame does not pass the CRC test, then at least one additional decoding process is performed on the received frame. In the first exemplary embodiment of the present invention, on a failure of the CRC check, the data is decoded using a trellis decoder and the data that yields the next most likely path through the trellis is selected. In a second illustrative embodiment, if the CRC test fails, the trellis decoder then identifies all paths having metrics within a predetermined threshold of a metric associated with the optimal path through the trellis. The CRC test is then performed on the decoded frame with respect to the suboptimal paths (starting with the most likely path). If any of these paths pass the CRC check, the information bits are output by the decoder. If not, an error is declared.
Inventors
- 👤 Jeremy M. Stein
- 👤 Ayal Bar-David
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:26
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/004; H04L1/0056; H04L1/0067; H04L1/0068; H03; H03M; H03M13/00; H03M13/29; H03M13/37; H03M13/39; H03M13/41; H03M13/4115; H03M13/47; H03M13/65; H03M13/6502; H04L1/0045; H04L1/0054; H04L1/0071
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
134 words
A decoding system for use with a multi-rate encoded signal, said decoding system comprising: decoder means for receiving a frame of multi-rate encoded data and for trellis decoding said frame of data to provide a set of information bits and at least one check bit; check means for receiving said information bits and said at least one check bit and for determining a validity of said decoding in accordance with said information bits and said at least one check bit, said validity being determined based upon at least one Yamamoto metric, wherein said decoder means further includes means for determining a second set of information bits and second at least one check bit in accordance with a suboptimal path when said determined validity of said decoding indicates a failure to properly decode said frame.
Claim 2
Dependent Claim
134 words
A decoding system for use with a multi-rate encoded signal, said decoding system comprising: decoder means for receiving a frame of multi-rate encoded data and for trellis decoding said frame of data to provide a set of information bits and at least one check bit; check means for receiving said information bits and said at least one check bit and for determining a validity of said decoding in accordance with said information bits and said at least one check bit, said validity being determined based upon at least one Yamamoto metric, wherein said decoder means further includes means for determining a second set of information bits and second at least one check bit in accordance with a suboptimal path when said determined validity of said decoding indicates a failure to properly decode said frame.
Claim 3
Dependent Claim
86 words
A decoding system for decoding a multi-rate encoded signal, comprising: first means for decoding a multi-rate encoded information sequence representable by a trellis to provide a decoded sequence associated with an optimal path therethrough; second means for validity checking check bits associated with said information sequence; and third means responsive to said second means for identifying a suboptimal path through said trellis including means for identifying paths having Yamamoto metrics within a predetermined threshold of a Yamamoto metric associated with the optimal path through said trellis.
Claim 4
Dependent Claim
86 words
A decoding system for decoding a multi-rate encoded signal, comprising: first means for decoding a multi-rate encoded information sequence representable by a trellis to provide a decoded sequence associated with an optimal path therethrough; second means for validity checking check bits associated with said information sequence; and third means responsive to said second means for identifying a suboptimal path through said trellis including means for identifying paths having Yamamoto metrics within a predetermined threshold of a Yamamoto metric associated with the optimal path through said trellis.
Claim 5
Dependent Claim
95 words
A decoding method for use with multi-rate encoded signals, said decoding method comprising the steps of: decoding a multi-rate encoded information sequence representable by a trellis to provide a decoded sequence associated with an optimal path therethrough; validity checking check bits associated with said information sequence; and identifying a suboptimal path through said trellis including the step of identifying paths having Yamamoto metrics within a predetermined threshold of a Yamamoto metric associated with the optimal path through the trellis when the determined validity of the check bits indicates a failure to properly decode said sequence.
Claim 6
Dependent Claim
95 words
A decoding method for use with multi-rate encoded signals, said decoding method comprising the steps of: decoding a multi-rate encoded information sequence representable by a trellis to provide a decoded sequence associated with an optimal path therethrough; validity checking check bits associated with said information sequence; and identifying a suboptimal path through said trellis including the step of identifying paths having Yamamoto metrics within a predetermined threshold of a Yamamoto metric associated with the optimal path through the trellis when the determined validity of the check bits indicates a failure to properly decode said sequence.
Claim 7
Dependent Claim
25 words
The decoding method of claim 3, wherein said step of validity checking comprises cyclic redundancy checking said check bits with respect to said information sequence.
Claim 8
Dependent Claim
17 words
The decoding method of claim 4, further comprising the step of cyclic redundancy checking said suboptimal path.
Claim 9
Dependent Claim
12 words
The decoding method of claim 3, wherein said metrics are Yamamoto metrics.
Claim 10
Dependent Claim
17 words
The decoding system of claim 1, wherein said decoder means includes means for determining said suboptimal path.
Claim 11
Dependent Claim
39 words
The decoding system of claim 7, wherein said means for determining said suboptimal path includes means for identifying suboptimal paths having Yamamoto metrics within a predetermined threshold of a Yamamoto metric associated with an optimal path through a trellis.
Claim 12
Dependent Claim
25 words
The decoding system of claim 1, wherein said check means includes means for cyclic redundancy checking said check bits with respect to said information bits.
Claim 13
Dependent Claim
15 words
The decoding system of claim 2, wherein said means for decoding comprises a Viterbi decoder.
Claim 14
Dependent Claim
27 words
The decoding system of claim 2, wherein said means for validity checking includes means for cyclic redundancy checking said check bits with respect to said information sequence.
Claim 15
Dependent Claim
22 words
The decoding system of claim 2, wherein said third means includes means for selecting one of said paths as a suboptimal path.
Claim 16
Dependent Claim
16 words
The decoding system of claim 12, further including means for cyclic redundancy checking said suboptimal path.
References Cited (Backward Citations)
US4748626A
Cited
US4845714A
Cited
US5023889A
Cited
US5056117A
Cited
EP0413505A1
Cited
US5208816A
Cited
US5416787A
Cited
EP0544315A2
Cited
WO1993014588A1
Cited
US5530708A
Cited
US5509020A
Cited
US5577053A
Cited
US5689511A
Cited
US5703902A
Cited
EP0751625A2
Cited
US5784392A
Cited
US5883923A
Cited
US5751725A
Cited
US5872775A
Cited
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 |