US5418531A
Expired / Lapsed
US
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Structured quantizer for sources with memory
Assignee: Agere Systems LLC
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Filing: 1993-10-20
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Granted: 1995-05-23
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Expires: 2013-10-20
Abstract
Abstract An improved approximation of the desired codebook boundary is achieved, when quantizing data from a source with memory, by adding a dither sequence, the samples of which are contained within the Voronoi region of an unpartitioned lattice or the first level of lattice partitioning used to generate the trellis code. A sequence of data generated by the source with memory is quantized to a nearest sequence of a predetermined trellis code which is based on coset partitioning of a predetermined lattice into translates of a coset lattice. The trellis code sequence is then filtered with an inverse source filter. A dither sample is added to each sample of the sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on a super-lattice of the coset lattice, and (2) the dither sample is inside the Voronoi region of the super-lattice.
Inventors
- 👤 Rajiv Laroia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:28
CPC Classifications
G; G06; G06T; G06T9/00; G06T9/008; H; H03; H03M; H03M7/00; H03M7/30; H03M7/3082
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
95 words
A method comprising the steps of: quantizing a sequence of data generated by a source with memory to a nearest sequence of a predetermined trellis code, the trellis code being based on coset partitioning of a predetermined lattice; filtering the trellis code sequence with an inverse source filter; and adding a dither sample to each sample of the filtered trellis code sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on said lattice, and (2) the dither sample is inside the Voronoi region of said lattice.
Claim 2
Independent Claim
95 words
A method comprising the steps of: quantizing a sequence of data generated by a source with memory to a nearest sequence of a predetermined trellis code, the trellis code being based on coset partitioning of a predetermined lattice; filtering the trellis code sequence with an inverse source filter; and adding a dither sample to each sample of the filtered trellis code sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on said lattice, and (2) the dither sample is inside the Voronoi region of said lattice.
Claim 3
Dependent Claim
12 words
The invention of claim 1 wherein said data are sampled speech data.
Claim 4
Dependent Claim
11 words
The invention of claim 1 wherein said data are discretized data.
Claim 5
Independent Claim
105 words
A method comprising the steps of: quantizing a sequence of data generated by a source with memory to a nearest sequence of a predetermined trellis code, the trellis code being based on coset partitioning of a predetermined lattice into translates of a coset lattice; filtering the trellis code sequence with an inverse source filter; and adding a dither sample to each sample of the filtered trellis code sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on a super-lattice of said coset lattice, and (2) the dither sample is inside the Voronoi region of said super-lattice.
Claim 6
Independent Claim
105 words
A method comprising the steps of: quantizing a sequence of data generated by a source with memory to a nearest sequence of a predetermined trellis code, the trellis code being based on coset partitioning of a predetermined lattice into translates of a coset lattice; filtering the trellis code sequence with an inverse source filter; and adding a dither sample to each sample of the filtered trellis code sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on a super-lattice of said coset lattice, and (2) the dither sample is inside the Voronoi region of said super-lattice.
Claim 7
Dependent Claim
12 words
The invention of claim 4 wherein said data are sampled speech data.
Claim 8
Dependent Claim
11 words
The invention of claim 4 wherein said data are discretized data.
Claim 9
Dependent Claim
97 words
Apparatus for quantizing data from a source with memory, the apparatus comprising: transmitter means for performing a nonlinear, invertible transformation on a filtered sequence of a predetermined trellis code that is based on coset partitioning of a predetermined lattice into translates of a coset lattice, the transformation adding a dither sample to each sample of said filtered trellis code sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on a super-lattice of said coset lattice, and (2) the dither sample is inside the Voronoi region of said super-lattice.
Claim 10
Dependent Claim
97 words
Apparatus for quantizing data from a source with memory, the apparatus comprising: transmitter means for performing a nonlinear, invertible transformation on a filtered sequence of a predetermined trellis code that is based on coset partitioning of a predetermined lattice into translates of a coset lattice, the transformation adding a dither sample to each sample of said filtered trellis code sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on a super-lattice of said coset lattice, and (2) the dither sample is inside the Voronoi region of said super-lattice.
Claim 11
Dependent Claim
88 words
Apparatus for quantizing data from a source with memory, the apparatus comprising: transmitter means for performing a nonlinear, invertible transformation on a filtered sequence of a predetermined trellis code that is based on coset partitioning of a predetermined lattice, the transformation adding a dither sample to each sample of said filtered trellis code sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on said predetermined lattice and (2) the dither sample is inside the Voronoi region of said lattice.
Claim 12
Dependent Claim
88 words
Apparatus for quantizing data from a source with memory, the apparatus comprising: transmitter means for performing a nonlinear, invertible transformation on a filtered sequence of a predetermined trellis code that is based on coset partitioning of a predetermined lattice, the transformation adding a dither sample to each sample of said filtered trellis code sequence, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on said predetermined lattice and (2) the dither sample is inside the Voronoi region of said lattice.
Claim 13
Dependent Claim
124 words
Receiver apparatus for processing a received signal that was generated by adding a dither sample to each sample of a sequence obtained by filtering a sequence from a predetermined trellis code, the trellis code sequence being obtained by quantizing an output signal from a source with memory, said trellis code being based on coset partitioning of a predetermined lattice, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on a super-lattice of said coset lattice, and (2) the dither sample is inside the Voronoi region of said super-lattice, the receiver apparatus comprising: means including a decoder for recovering from said received signal a quantized output which is an approximation of the data output by said source.
Claim 14
Dependent Claim
124 words
Receiver apparatus for processing a received signal that was generated by adding a dither sample to each sample of a sequence obtained by filtering a sequence from a predetermined trellis code, the trellis code sequence being obtained by quantizing an output signal from a source with memory, said trellis code being based on coset partitioning of a predetermined lattice, such that (1) a sum of the dither sample and the filtered trellis code sequence sample lies on a super-lattice of said coset lattice, and (2) the dither sample is inside the Voronoi region of said super-lattice, the receiver apparatus comprising: means including a decoder for recovering from said received signal a quantized output which is an approximation of the data output by said source.
Claim 15
Dependent Claim
55 words
The invention of claim 9 wherein the decoder comprises: codebook decoder means for converting a sequence of binary data received from the channel into a memoryless uncoded sequence of signal-space points; and memory decoder means for transforming the memoryless uncoded sequence into a coded sequence of said trellis codes reflecting said memory of said source.
Claim 16
Dependent Claim
48 words
The invention of claim 10 wherein the memory decoder means comprises a finite-state machine which generates said trellis code, the finite-state machine having a current input which is a function of a current sample of the output trellis coded sequence representing a quantized output signal from said source.
Claim 17
Dependent Claim
40 words
The invention of claim 10 wherein the memory decoder means comprises means for subtracting a dither sample from each sample of said memoryless uncoded sequence of signal-space points, wherein the dither sample lies in the Voronoi region of said super-lattice.
Claim 18
Dependent Claim
27 words
The invention of claim 12 wherein the memory decoder means further comprises a source filter which receives a sequence of signal-space points from said means for subtracting.
Claim 19
Dependent Claim
55 words
The invention of claim 10 wherein the memory decoder means comprises: means for selectively rotating the samples of the memoryless uncoded sequence to generate a second sequence of samples; and means for subtracting a dither sample from each sample of the second sequence, wherein the dither sample lies in the Voronoi region of said lattice.
References Cited (Backward Citations)
US5214672A
Cited
US5297170A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-05-22 | 1998-11-21 | 1999-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-22 | 2002-11-21 | 2003-05-23 | $3760.00 | Window Closed / Lapsed |
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