System and method for adaptive maximum likelihood sequence estimation
AssigneeNEC Corporation
InventorKazuhiro Okanoue
Life of this patent
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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.
Claims12
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.
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.
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.
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.
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.
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.
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.
Dependencies are inferred from the claim text.