Adaptive equalizer with integrated alignment of the output level
AssigneeInfineon Technologies AG
InventorHolger Gryska
Life of this patent
Estimating the term…
Abstract
The transfer function of a filter processing unit is defined by a set of filter coefficients that are continually updated in a coefficient-updating unit. The level of the output signal is adjusted by a level-adjustment unit where, if the largest filter coefficient exceeds an upper threshold value or is below a lower threshold value, a comparator outputs control signals to coefficient-based shifters and to a data signal shifter such that these shift their applied bit sequences in opposite directions and thus multiply or divide the applied data signals by a factor≧2.
Claims13
A method for adaptive channel equalization, which comprises:
- providing a filter processing unit having a transfer function defined by a set of filter coefficients;
- comparing a largest filter coefficient with a lower threshold value and an upper threshold value;
- updating the filter coefficients in response to an error signal derived from an output signal from the equalizer and adjusting an output signal level of the filter processing unit by:
- if the largest filter coefficient exceeds the upper threshold value, shifting bit sequences of the filter coefficients one bit position downwards and simultaneously shifting a bit sequence of an output signal from the filter processing unit one bit position upwards, and
- if the largest filter coefficient is below the lower threshold value, shifting the bit sequences of the filter coefficients one bit position upwards and simultaneously shifting the bit sequence of the output signal from the filter processing unit one bit position downwards.
An adaptive equalizer, comprising:
- a filter processing unit having a transfer function defined by a set of filter coefficients, said filter processing unit having an output;
- a coefficient-updating unit having a plurality of coefficient-updating stages;
- and
- a level-adjustment unit including:
- a comparator for comparing a largest one of said filter coefficients with a lower threshold value and an upper threshold value,
- a plurality of coefficient-based shifters having control inputs connected to said comparator, and
- a data signal shifter at said output of said filter processing unit, said data signal shifter having a control input connected to said comparator.
Dependencies are inferred from the claim text.