US5673288A
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System and method for adaptive maximum likelihood sequence estimation
Assignee: NEC Corp
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Filing: 1994-12-21
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Granted: 1997-09-30
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Expires: 2014-12-21
Abstract
Abstract A maximum likelihood sequence estimator implemented to cope with an intersymbol interference from a single symbol employs a necessary channel impulse response estimation vector of two components for a decision to estimate a maximum likelihood sequence. A channel impulse response estimator implemented to estimate a channel impulse response in consideration of intersymbol interferences from up to two symbols outputs a channel impulse response estimation vector of three components. The three-component vector is input to a converter, where it is converted into the two-component vector to be output to the maximum likelihood sequence estimator.
Inventors
- 👤 Kazuhiro Okanoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:48
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03178; H04L25/03248; H04L25/03292; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0837; H04B7/0842; H04B7/0848
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
140 words
A system for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising: a maximum likelihood sequence estimator means for performing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; a channel impulse response estimator means for generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal and the decision result; and a converter means for converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components.
Claim 2
Independent Claim
140 words
A system for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising: a maximum likelihood sequence estimator means for performing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; a channel impulse response estimator means for generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal and the decision result; and a converter means for converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components.
Claim 3
Dependent Claim
146 words
The system as claimed in claim 1, wherein: the converter means comprises: a power detector group of M+1 power detectors each for determining a power value representative of channel impulse response power of a corresponding component of the channel impulse response estimation vector of M+1 components; an adder group of M-N+1 adders each for determining a sum value of the power value of continuous N+1 components of the channel impulse response estimation vector of M+1 components, covering the M+1 components; a maximum value detector means for detecting a maximum one of the respective sum values determined by the M-N+1 adders; and a control means for determining corresponding N+1 components to a corresponding adder to the maximum sum value of the channel impulse response estimation vector of M+1 components and for selecting the corresponding N+1 components to generate the channel impulse response estimation vector of N+1 components.
Claim 4
Dependent Claim
58 words
The system as claimed in claim 2, wherein: each power detector of the power detector group generates a corresponding component of a channel impulse response power estimation vector of M+1 components representing the power value; and each adder of the adder group determines the sum value from corresponding N+1 components of the channel impulse response power estimation vector.
Claim 5
Dependent Claim
81 words
The system as claimed in claim 2, wherein: the control means comprises a controller for generating a control signal representative of the corresponding N+1 components to the corresponding adder to the maximum sum value of the channel impulse response estimation vector of M+1 components, and a switch means for responding the control signal to select the corresponding N+1 components of the channel impulse response estimation vector of M+1 components thereby to generate the channel impulse response estimation vector of N+1 components.
Claim 6
Independent Claim
235 words
A system for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal on a burst of a training sequence field and a data sequence field thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising: a maximum likelihood sequence estimator means for performing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; a timing control means for generating a monitoring signal while detecting the training sequence field; a training sequence pattern generating means for generating a training sequence pattern while detecting the monitoring signal; an output means for outputting the training sequence pattern while detecting the monitoring signal and for outputting the decision result while not detecting the monitoring signal; a channel impulse response estimator means for generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal on the burst and on the training sequence pattern and the decision result, as either of these is output from the output means; and a converter means for converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components, while detecting the monitoring signal.
Claim 7
Independent Claim
235 words
A system for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal on a burst of a training sequence field and a data sequence field thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising: a maximum likelihood sequence estimator means for performing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; a timing control means for generating a monitoring signal while detecting the training sequence field; a training sequence pattern generating means for generating a training sequence pattern while detecting the monitoring signal; an output means for outputting the training sequence pattern while detecting the monitoring signal and for outputting the decision result while not detecting the monitoring signal; a channel impulse response estimator means for generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal on the burst and on the training sequence pattern and the decision result, as either of these is output from the output means; and a converter means for converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components, while detecting the monitoring signal.
Claim 8
Dependent Claim
167 words
The system as claimed in claim 5, wherein: the converter means comprises: a power detector group of M+1 power detectors each for determining a power value representative of channel impulse response power of a corresponding component of the channel impulse response estimation vector of M+1 components; an adder group of M-N+1 adders each for determining a sum value of the power value of continuous N+1 components of the channel impulse response estimation vector of M+1 components, covering the M+1 components; a channel impulse response setting means for setting a channel impulse response componentwise representative value on the basis of the sum value determined by each adder, while detecting the monitoring signal, and for determining a corresponding adder to a maximum channel impulse response componentwise representative value; and a control means for determining corresponding N+1 components to the corresponding adder of the channel impulse response estimation vector of M+1 components and for selecting the corresponding N+1 components to generate the channel impulse response estimation vector of N+1 components.
Claim 9
Dependent Claim
70 words
The system as claimed in claim 6, wherein: the channel impulse response setting means comprises an integrator group of M-N+1 integrators each for integrating the sum value to obtain the channel impulse response componentwise representative value while detecting the monitoring signal, and a maximum value detector means for detecting the maximum channel impulse response componentwise representative value while not detecting the monitoring signal and for determining the corresponding adder thereto.
Claim 10
Independent Claim
125 words
A method for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising the steps of: executing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal and the decision result; and converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components.
Claim 11
Independent Claim
125 words
A method for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising the steps of: executing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal and the decision result; and converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components.
Claim 12
Independent Claim
202 words
A method for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal on a burst of a training sequence field and a data sequence field thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising the steps of: executing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; generating a monitoring signal while detecting the training sequence field; generating a training sequence pattern while detecting the monitoring signal; outputting the training sequence pattern while detecting the monitoring signal or the decision result while not detecting the monitoring signal; generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal on the burst and on the training sequence pattern and the decision result, as either of these is output at the outputting step; and converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components, while detecting the monitoring signal.
Claim 13
Independent Claim
202 words
A method for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal on a burst of a training sequence field and a data sequence field thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising the steps of: executing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; generating a monitoring signal while detecting the training sequence field; generating a training sequence pattern while detecting the monitoring signal; outputting the training sequence pattern while detecting the monitoring signal or the decision result while not detecting the monitoring signal; generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal on the burst and on the training sequence pattern and the decision result, as either of these is output at the outputting step; and converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components, while detecting the monitoring signal.
Claim 14
Independent Claim
126 words
A method for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from a predetermined number of symbols, comprising the steps of: executing the decision depending on a first estimation vector representative of an estimated channel impulse response, the first estimation vector of a larger number of components than the predetermined symbol number; generating a second estimation vector representative of the estimated channel impulse response, the second estimation vector of a yet larger number of components than the predetermined symbol number; and converting the second estimation vector to the first estimation vector by stepwise reducing the number of components of the second estimation vector.
Claim 15
Independent Claim
126 words
A method for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from a predetermined number of symbols, comprising the steps of: executing the decision depending on a first estimation vector representative of an estimated channel impulse response, the first estimation vector of a larger number of components than the predetermined symbol number; generating a second estimation vector representative of the estimated channel impulse response, the second estimation vector of a yet larger number of components than the predetermined symbol number; and converting the second estimation vector to the first estimation vector by stepwise reducing the number of components of the second estimation vector.
Claim 16
Independent Claim
134 words
A system for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising: a maximum likelihood sequence estimator performing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; a channel impulse response estimator generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal and the decision result; and a converter converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components.
Claim 17
Independent Claim
134 words
A system for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer, comprising: a maximum likelihood sequence estimator performing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; a channel impulse response estimator generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal and the decision result; and a converter converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components.
Claim 18
Independent Claim
223 words
A system for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal on a burst of a training sequence field and data sequence field thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer comprising: a maximum likelihood sequence estimator performing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; a timing controller generating a monitoring signal while detecting the training sequence field; a training sequence pattern generator generating a training sequence pattern while detecting the monitoring signal; an output device outputting the training sequence pattern while detecting the monitoring signal and outputting the decision result while not detecting the monitoring signal; a channel impulse response estimator generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal on the burst and on the training sequence pattern and the decision result, as either of these is output from the output device means; and a converter converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components, while detecting the monitoring signal.
Claim 19
Independent Claim
223 words
A system for a decision to conduct an adaptive maximum likelihood sequence estimation by equalizing a reception signal on a burst of a training sequence field and data sequence field thereby to output a decision result, the reception signal having distortions due to an intersymbol interference from among N symbols, where N is an integer comprising: a maximum likelihood sequence estimator performing the decision depending on a channel impulse response estimation vector of N+1 components representative of an estimated channel impulse response; a timing controller generating a monitoring signal while detecting the training sequence field; a training sequence pattern generator generating a training sequence pattern while detecting the monitoring signal; an output device outputting the training sequence pattern while detecting the monitoring signal and outputting the decision result while not detecting the monitoring signal; a channel impulse response estimator generating a channel impulse response estimation vector of M+1 components representative of an intersymbol interference from among M symbols, where M is such an integer that 0<N<M, depending on the reception signal on the burst and on the training sequence pattern and the decision result, as either of these is output from the output device means; and a converter converting the channel impulse response estimation vector of M+1 components into the channel impulse response estimation vector of N+1 components, while detecting the monitoring signal.
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