Channel estimation enhanced LMS equalizer

A method for performing equalization on received signals, the method comprising:

• generating samples of received signals;
• generating a channel estimate based on the samples;
• storing the samples in a delay buffer to delay the samples for a predetermined period of time before forwarding the samples to an equalizer filter;
• processing the samples with the equalizer filter to generate filtered samples;
• and
• generating new filter tap coefficients of the equalizer filter using the channel estimate.

An integrated circuit (IC) for equalization, the IC comprising:

• a channel estimator for generating a channel estimate;
• an equalizer filter for processing samples with filter tap coefficients to generate filtered samples;
• a delay buffer to delay the samples for a predetermined period of time before the samples are forwarded to the equalizer filter;
• and
• a filter tap coefficients generator for updating the filter tap coefficients using the channel estimate.

A filter tap coefficient generator for generating filter tap coefficients for an adaptive filter, the filter tap coefficient generator comprising:

• a first conjugate unit for generating a conjugate of channel estimate;
• a second conjugate unit for generating a conjugate of a state vector of samples shifted into a tapped delay line of an adaptive filter;
• a first multiplier for multiplying descrambled filtered samples to the conjugate of the state vector;
• an adder for subtracting output of the first multiplier from the conjugate of the channel estimate to generate an unscaled correction term;
• a vector norm square generator for computing a vector norm square of the state vector;
• a divider for dividing a step size parameter by the vector norm square to generate a scaling factor;
• a second multiplier for multiplying the scaling factor to the unscaled correction term to generate a scaled correction term;
• and
• a loop filter for storing filter tap coefficients of a previous iteration and outputting updated filter tap coefficients by adding the scaled correction term to the filter tape coefficients of the previous iteration.

A method for generating filter tap coefficient for an adaptive filter, the method comprising:

• generating conjugate of channel estimates;
• multiplying conjugate of a state vector of samples shifted in a tapped delay line of an adaptive filter to descrambled filtered samples;
• subtracting multiplication result from the conjugate of the channel estimate to generate an unscaled correction term;
• generating a scale factor by dividing a step size by a vector norm square of the state vector of samples shifted in the tapped delay line;
• multiplying the scale factor to the unscaled correction term to generate a scaled correction term;
• and
• adding the scaled correction term to filter tap coefficients of a previous iteration to generate an updated filter tap coefficients.