Adaptive equalization employing pattern recognition

Apparatus for application of equalization to a signal, the apparatus comprising:

• an equalizer configured to apply equalization to an input signal;
• a detector configured to detect data values from the equalized input signal to provide a detected data sequence;
• and
• a pattern detector configured to detect the presence or absence of a predetermined signal pattern in the detected data sequence, wherein the pattern detector detects the predetermined signal pattern in the detected data sequence either before or after applying the detected data sequence to a decoder configured to decode the detected data sequence,
• wherein the equalizer is further adapted to modify the equalization applied to the input signal based upon the detected presence or absence of the predetermined signal pattern.

Apparatus for application of equalization to a signal, the apparatus comprising:

• an equalizer configured to apply equalization to an input signal;
• a detector configured to detect data values from the equalized input signal to provide a detected data sequence;
• and
• a pattern detector configured to detect the presence or absence of a predetermined signal pattern in the detected data sequence,
• wherein the equalizer is further adapted to modify the equalization applied to the input signal based upon the detected presence or absence of the predetermined signal pattern, and wherein the equalizer comprises an adaptive equalizer configured to modify the equalization applied to the input signal based upon the detected presence or absence of the predetermined signal pattern by setting at least one of a vertical threshold and a horizontal threshold of a upper latch associated with an upper eye of an eye profile and setting at least one of a vertical threshold and a horizontal threshold of a lower latch associated with a lower eye of an eye profile.

Apparatus for application of equalization to a signal, the apparatus comprising:

• an equalizer configured to apply equalization to an input signal;
• a detector configured to detect data values from the equalized input signal to provide a detected data sequence;
• and
• a pattern detector configured to detect the presence or absence of a predetermined signal pattern in the detected data sequence,
• wherein the equalizer is further adapted to modify the equalization applied to the input signal based upon the detected presence or absence of the predetermined signal pattern, and wherein the apparatus is configured to delay modification of the equalization over several detected instances of the predetermined pattern in the input signal.

A method of applying equalization to a signal, the method comprising the steps of:

• a) applying, initially, equalization to an input signal;
• b) detecting data values from the equalized input signal to provide a detected data sequence;
• c) detecting the presence or absence of a predetermined signal pattern in the detected data sequence, further comprising:
• c1) comparing portions of the detected data sequence with a copy of predetermined signal pattern from the memory to detect the presence or absence of the predetermined pattern based upon the comparison;
• and
• c2) masking portions of the copy of predetermined signal pattern from memory to detect the presence or absence of the predetermined pattern and comparing the detected data with the masked predetermined pattern;
• and
• d) modifying the equalization applied to the input signal based upon the detected presence or absence of the predetermined signal pattern.

A method of applying equalization to a signal, the method comprising the steps of:

• a) applying, initially, equalization to an input signal;
• b) detecting data values from the equalized input signal to provide a detected data sequence;
• c) detecting the presence or absence of a predetermined signal pattern in the detected data sequence;
• d) modifying the equalization applied to the input signal based upon the detected presence or absence of the predetermined signal pattern;
• and
• e) delaying modification of the equalization over several detected instances of the predetermined pattern in the input signal.