Least squares lattice decision feedback equalizer

An improved apparatus for equalizing signals and coupled to a data transmission channel comprising:

• a plurality of successively coupled least squares lattice stages, the first of which is coupled to receive the output from the channel and each having a selected configuration of adjustable electrical components;
• means for generating sequences of transmitted training signals for transmission therethrough;
• means for generating sequences of undistorted training signals being substantially the same as the transmitted training signals;
• error generating means coupled to each of the least squares lattice stages and to the undistorted training signal generating means for providing a succession of error terms, each being an accumulation of error quantities, representing the difference between the undistorted training signals, received by said error generating means, and the transmitted training signal after it has traveled through the data transmission channel and been received by the first one of the least squares lattice stages;
• and
• a component adjust means coupled in each least squares lattice stage and the preceding error generating means for iteratively adjusting the electrical components of its least squares lattice stage in accordance with an auto regressive moving average model of the transmission channel procedure, the interconnected preceding error generating means providing an error term which is within a prespecified limit when the electrical components are iteratively adjusted in response to the final training signal in the sequence.