US5809074A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Technique for improving the blind convergence of an adaptive equalizer using a transition algorithm
Assignee: Avago Technologies International Sales Pte Ltd
•
Filing: 1996-11-08
•
Granted: 1998-09-15
•
Expires: 2016-11-08
Abstract
Abstract A blind equalization technique uses both the "constant modulus algorithm" (CMA) and the "multimodulus algorithm" (MMA) during blind start-up. This approach provides the basis for a "transition algorithm." One example of a transition algorithm is the CMA-MMA transition algorithm in which an adaptive filter simply switches from CMA to MMA. Other examples are variations of the CMA-MMA transition algorithm and are illustrated by the "Constant Rotation CMA-MMA" transition algorithm and the "Dynamic Rotation CMA-MMA" transition algorithm.
Inventors
- 👤 Jean-Jacques Werner
- 👤 Jian Yang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:47
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03019; H04L25/03038; H04L25/0305; H04L25/38; H04L25/40; H04L25/49; H04L25/4917; H04L25/4919; H04L25/4921; H04N; H04N5/00; H04N5/14; H04N5/21; H04N5/211
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
22 words
An improved method for performing blind equalization in a receiver, the improvement comprising: using a transition algorithm to perform the blind equalization.
Claim 2
Dependent Claim
22 words
An improved method for performing blind equalization in a receiver, the improvement comprising: using a transition algorithm to perform the blind equalization.
Claim 3
Dependent Claim
49 words
The method of claim 1 wherein the using step includes the steps of: using a constant modulus algorithm (CMA) to initially adapt a set of coefficient values of an adaptive filter; and using a multimodulus algorithm (MMA) to finally adapt the set of coefficient values of the adaptive filter.
Claim 4
Dependent Claim
57 words
The method of claim 2 wherein the CMA algorithm initially adapts the set of coefficients of the adaptive filter until a calculated error rate of a received signal is less than or equal to a predetermined value, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the adaptive filter.
Claim 5
Dependent Claim
47 words
The method of claim 2 wherein the CMA algorithm initially adapts the set of coefficients of the adaptive filter until a predetermined number of iterations is reached, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the adaptive filter.
Claim 6
Dependent Claim
33 words
The method of claim 1 wherein the using step includes the step of: sequentially using each one of a plurality of different convergence algorithms to blindly converge an adaptive filter of the receiver.
Claim 7
Dependent Claim
21 words
The method of claim 5 wherein the plurality of different convergence algorithms include a constant modulus algorithm and a multimodulus algorithm.
Claim 8
Dependent Claim
70 words
The method of claim 1 wherein the using step includes the steps of: using a constant modulus algorithm (CMA) to initially adapt a set of coefficient values of an adaptive filter; changing to a Constant Rotation CMA-MMA algorithm to continue to adapt the set of coefficient values of the adaptive filter; and changing to a multimodulus algorithm (MMA) to finally adapt the set of coefficient values of the adaptive filter.
Claim 9
Dependent Claim
24 words
The method of claim 7 wherein the transition from the CMA algorithm occurs when a number of iterations is greater than a predetermined number.
Claim 10
Dependent Claim
70 words
The method of claim 1 wherein the using step includes the steps of: using a constant modulus algorithm (CMA) to initially adapt a set of coefficient values of an adaptive filter; changing to a Dynamic Rotation CMA-MMA algorithm to continue to adapt the set of coefficient values of the adaptive filter; and changing to a multimodulus algorithm (MMA) to finally adapt the set of coefficient values of the adaptive filter.
Claim 11
Dependent Claim
23 words
The method of claim 9 wherein the transition from the CMA-MMA algorithm occurs when a calculated mean-squared-error is less than a predetermined value.
Claim 12
Dependent Claim
41 words
The method of claim 1 further comprising the step of switching to a decision directed adaptation algorithm, after the blind equalization converges, for adjusting the set of tap coefficient values when a calculated error rate is less than a predetermined value.
Claim 13
Dependent Claim
19 words
The method of claim 11 wherein the decision directed adaptation algorithm uses a least means squared tap updating algorithm.
Claim 14
Independent Claim
53 words
A method for use in a communications receiver, the method comprising the steps of: using an adaptive filter structure for processing a received signal, the adaptive filter structure including a corresponding set of tap coefficient values; and using at least two different convergence algorithms for blindly converging the set of tap coefficient values.
Claim 15
Independent Claim
53 words
A method for use in a communications receiver, the method comprising the steps of: using an adaptive filter structure for processing a received signal, the adaptive filter structure including a corresponding set of tap coefficient values; and using at least two different convergence algorithms for blindly converging the set of tap coefficient values.
Claim 16
Dependent Claim
55 words
The method of claim 13 wherein the using at least two different convergence algorithms step includes the steps of: using a constant modulus algorithm (CMA) to initially adapt the set of coefficient values of the adaptive filter; and using a multimodulus algorithm (MMA) to finally adapt the set of coefficient values of the adaptive filter.
Claim 17
Dependent Claim
57 words
The method of claim 14 wherein the CMA algorithm initially adapts the set of coefficients of the adaptive filter until a calculated error rate of the received signal is less than or equal to a predetermined value, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the adaptive filter.
Claim 18
Dependent Claim
47 words
The method of claim 14 wherein the CMA algorithm initially adapts the set of coefficients of the adaptive filter until a predetermined number of iterations is reached, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the adaptive filter.
Claim 19
Dependent Claim
70 words
The method of claim 13 wherein the using step includes the steps of: using a constant modulus algorithm (CMA) to initially adapt the set of coefficient values of the adaptive filter; changing to a Constant Rotation CMA-MMA algorithm to continue to adapt the set of coefficient values of the adaptive filter; and changing to a multimodulus algorithm (MMA) to finally adapt the set of coefficient values of the adaptive filter.
Claim 20
Dependent Claim
24 words
The method of claim 17 wherein the transition from the CMA algorithm occurs when a number of iterations is greater than a predetermined number.
Claim 21
Dependent Claim
70 words
The method of claim 13 wherein the using step includes the steps of: using a constant modulus algorithm (CMA) to initially adapt the set of coefficient values of the adaptive filter; changing to a Dynamic Rotation CMA-MMA algorithm to continue to adapt the set of coefficient values of the adaptive filter; and changing to a multimodulus algorithm (MMA) to finally adapt the set of coefficient values of the adaptive filter.
Claim 22
Dependent Claim
23 words
The method of claim 19 wherein the transition from the CMA-MMA algorithm occurs when a calculated mean-squared-error is less than a predetermined value.
Claim 23
Dependent Claim
41 words
The method of claim 13 further comprising the step of switching to a decision directed adaptation algorithm, after the blind equalization converges, for adjusting the set of tap coefficient values when a calculated error rate is less than a predetermined value.
Claim 24
Dependent Claim
19 words
The method of claim 21 wherein the decision directed adaptation algorithm uses a least means squared tap updating algorithm.
Claim 25
Dependent Claim
32 words
An improved equalizer for use in a receiver for performing blind equalization; the improvement comprising: a processor that adapts coefficients of the equalizer by using at least two different blind equalization algorithms.
Claim 26
Dependent Claim
32 words
An improved equalizer for use in a receiver for performing blind equalization; the improvement comprising: a processor that adapts coefficients of the equalizer by using at least two different blind equalization algorithms.
Claim 27
Dependent Claim
13 words
The apparatus of claim 23 wherein the processor is a digital signal processor.
Claim 28
Dependent Claim
25 words
The apparatus of claim 23 wherein the at least two different blind equalization algorithms are a constant modulus algorithm (CMA) and a multimodulus algorithm (MMA).
Claim 29
Dependent Claim
58 words
The apparatus of claim 25 wherein the CMA algorithm is used to initially adapt the set of coefficients of the equalizer until a calculated error rate of the received signal is less than or equal to a predetermined value, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the equalizer.
Claim 30
Dependent Claim
48 words
The apparatus of claim 25 wherein the CMA algorithm is used to initially adapt the set of coefficients of the equalizer until a predetermined number of iterations is reached, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the equalizer.
Claim 31
Dependent Claim
46 words
An improved equalizer for use in a receiver for performing blind equalization; the improvement comprising: a processor a) for providing an equalizer finction for equalizing a received signal, and b) for adapting coefficients of the equalizer function by using at least two different blind equalization algorithms.
Claim 32
Dependent Claim
46 words
An improved equalizer for use in a receiver for performing blind equalization; the improvement comprising: a processor a) for providing an equalizer finction for equalizing a received signal, and b) for adapting coefficients of the equalizer function by using at least two different blind equalization algorithms.
Claim 33
Dependent Claim
13 words
The apparatus of claim 28 wherein the processor is a digital signal processor.
Claim 34
Dependent Claim
25 words
The apparatus of claim 28 wherein the at least two different blind equalization algorithms are a constant modulus algorithm (CMA) and a multimodulus algorithm (MMA).
Claim 35
Dependent Claim
58 words
The apparatus of claim 30 wherein the CMA algorithm is used to initially adapt the set of coefficients of the equalizer until a calculated error rate of the received signal is less than or equal to a predetermined value, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the equalizer.
Claim 36
Dependent Claim
48 words
The apparatus of claim 30 wherein the CMA algorithm is used to initially adapt the set of coefficients of the equalizer until a predetermined number of iterations is reached, at which point the MMA algorithm is used to fmally adapt the set of coefficient values of the equalizer.
Claim 37
Dependent Claim
75 words
Apparatus for use in performing blind equalization in a receiver, the apparatus comprising: a memory for storing a transition algorithm for performing blind equalization and for storing a set of tap coefficient values; and a processor a) for filtering an input signal as a function of the set of stored tap coefficient values to provide an output signal, and b) for executing the transition algorithm to blindly adapt the set of stored tap coefficient values.
Claim 38
Dependent Claim
75 words
Apparatus for use in performing blind equalization in a receiver, the apparatus comprising: a memory for storing a transition algorithm for performing blind equalization and for storing a set of tap coefficient values; and a processor a) for filtering an input signal as a function of the set of stored tap coefficient values to provide an output signal, and b) for executing the transition algorithm to blindly adapt the set of stored tap coefficient values.
Claim 39
Dependent Claim
17 words
The apparatus of claim 33 wherein the transition algorithm comprises at least two different blind equalization algorithms.
Claim 40
Dependent Claim
25 words
The apparatus of claim 34 wherein the at least two different blind equalization algorithms are a constant modulus algorithm (CMA) and a multimodulus algorithm (MMA).
Claim 41
Dependent Claim
58 words
The apparatus of claim 35 wherein the CMA algorithm is used to initially adapt the set of coefficients of the equalizer until a calculated error rate of the received signal is less than or equal to a predetermined value, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the equalizer.
Claim 42
Dependent Claim
38 words
The apparatus of claim 35 wherein the CMA algorithm is used to initially adapt the set of coefficients of the equalizer and the MMA algorithm is used to finally adapt the set of coefficient values of the equalizer.
Claim 43
Dependent Claim
47 words
Apparatus for use in a receiver, the apparatus comprising: an equalizer having a set of tap coefficient values and for providing an equalized version of an applied input signal; and a processor for blindly adapting the set of tap coefficients as a function of a transition algorithm.
Claim 44
Dependent Claim
47 words
Apparatus for use in a receiver, the apparatus comprising: an equalizer having a set of tap coefficient values and for providing an equalized version of an applied input signal; and a processor for blindly adapting the set of tap coefficients as a function of a transition algorithm.
Claim 45
Dependent Claim
17 words
The apparatus of claim 38 wherein the transition algorithm comprises at least two different blind equalization algorithms.
Claim 46
Dependent Claim
25 words
The apparatus of claim 39 wherein the at least two different blind equalization algorithms are a constant modulus algorithm (CMA) and a multimodulus algorithm (MMA).
Claim 47
Dependent Claim
58 words
The apparatus of claim 40 wherein the CMA algorithm is used to initially adapt the set of coefficients of the equalizer until a calculated error rate of the received signal is less than or equal to a predetermined value, at which point the MMA algorithm is used to finally adapt the set of coefficient values of the equalizer.
Claim 48
Dependent Claim
38 words
The apparatus of claim 40 wherein the CMA algorithm is used to initially adapt the set of coefficients of the equalizer and the MMA algorithm is used to finally adapt the set of coefficient values of the equalizer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-14 | 2002-03-16 | 2002-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-14 | 2006-03-16 | 2006-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-14 | 2010-03-16 | 2010-09-15 | $7700.00 | Window Closed / Lapsed |