Decision feedback equalization with trellis coding
First Claim
1. Apparatus for recovering information from a received signal corrupted by noise which is dominantly colored, said information being encoded using a code which provides optimum immunity to noise which is white, said apparatus comprisingmeans for filtering said received signal corrupted by noise which is dominantly colored to provide a filtered signal corrupted by noise which is dominantly white, andmeans for decoding the filtered signal corrupted by noise which is dominantly white to recover said information.
4 Assignments
0 Petitions
Accused Products
Abstract
In a telephone local loop transmission arrangement, data is communicated from the customer premises to the central office utilizing a multidimensional, passband signal illustratively at 480 kb/s. Specifically, the transmitted signal is encoded in a trellis code and the received signal is processed by a circuitry that implements decision feedback equalization in combination with trellis decoding.
109 Citations
32 Claims
-
1. Apparatus for recovering information from a received signal corrupted by noise which is dominantly colored, said information being encoded using a code which provides optimum immunity to noise which is white, said apparatus comprising
means for filtering said received signal corrupted by noise which is dominantly colored to provide a filtered signal corrupted by noise which is dominantly white, and means for decoding the filtered signal corrupted by noise which is dominantly white to recover said information.
-
6. Apparatus for processing received signals which are encoded in a trellis code, said apparatus comprising
means responsive to an individual one of said received signals for generating a feedforward signal, said feedforward signal including intersymbol interference, and means for Viterbi decoding said feedforward signal and for eliminating said intersymbol interference in response to said feedforward signal and at least one feedback signal which is generated in response to tentative decisions defined by the survival paths associated with said Viterbi decoding.
-
9. Apparatus for processing received signals corrupted by noise which is dominantly colored, said received signals being encoded using a code which provides optimum immunity to noise which is white, each of said received signals being associated with an individual one of a plurality of symbols having predetermined values, said apparatus comprising
a feedforward section for filtering an individual one of said received signals corrupted by noise which is dominantly colored to provide a filtered signal corrupted by noise which is dominantly white, and means for decoding the filtered signal corrupted by noise which is dominantly white to determine the value of the symbol associated with said individual one of said received signals corrupted by noise which is dominantly colored.
-
14. Apparatus for processing received signals which are encoded with a trellis code, each of said received signals being associated with an individual one of a plurality of symbols having predetermined values, said apparatus comprising
a feedforward section responsive to an individual one of said received signals for generating a feedforward signal, said feedforward signal including intersymbol interference, and means for forming a decision as to the value of the symbol associated with said individual one of said received signals using Viterbi decoding and for eliminating said intersymbol interference in response to said feedforward signal and at least one feedback signal which is generated in response to tentative decisions defined by the survival paths associated with said Viterbi decoding.
-
18. A method for recovering information from a received signal corrupted by noise which is dominantly colored, said information being encoded using a code which provides optimum immunity to noise which is white, said method comprising the steps of
filtering said received signal corrupted by noise which is dominantly colored to provide a flittered signal corrupted by noise which is dominantly white, and decoding the filtered signal corrupted by noise which is dominantly white to recover said information.
-
23. A method for processing received signals which are encoded in a trellis code, said method comprising the steps of
generating a feedforward signal in response to an individual one of said received signals, said feedforward signal including intersymbol interference, and Viterbi decoding said feedforward signal and eliminating said intersymbol interference in response to said feedforward signal and at least one feedback signal which is generated in response to tentative decisions defined by the survival paths associated with said Viterbi decoding.
-
26. A method for processing received signals corrupted by noise which is dominantly colored, said received signals being encoded using a code which provides optimum immunity to noise which is white, each of said received signals being associated with an individual one of a plurality of symbols having predetermined values, said method comprising the steps of
filtering an individual one of said received signals corrupted by noise which is dominantly colored to provide a filtered signal corrupted by noise which is dominantly white, and decoding the filtered signal corrupted by noise which is dominantly white to determine the value of the symbol associated with said individual one of said received signals corrupted by noise which is dominantly colored.
-
30. A method for processing received signals which are encoded with a trellis code, each of said received signals being associated with an individual one of a plurality of symbols having predetermined values, said method comprising the steps of
generating a feedforward signal in response to an individual one of said received signals, said feedforward signal including intersymbol interference, and forming a decision as to the value of the symbol associated with said individual one of said received signals using Viterbi decoding and eliminating said intersymbol interference in response to said feedforward signal and at least one feedback signal which is generated in response to tentative decisions defined by the survival paths associated with said Viterbi decoding.
Specification