System and method for frequency error composition

Abstract

Frequency error combination for a multi-channel data detection system with a phase locked loop for each channel, comprises receiving frequency error information with respect to each channel; combination logic configured to combine the received frequency error information and generate a combined phase error, weighting the received frequency error information from each channel; and a frequency error output configured to apply the combined frequency error to at least one channel phase locked loop.

Description

[0001] Literature incorporated by reference [0002] Commonly assigned U.S. Patent No. 5,442,315 is introduced to describe a phase locked loop used in data detection. technical field [0003] The present invention relates to multi-channel data detection, and more particularly, to multiple channels using phase-locked loops. Background technique [0004] Data storage with multiple channels typically uses removable media where data is recorded on one pass of the media and at a later time, possibly on a different pass of the media, and possibly on a different drive than the one used to record the data On the drive, read back and test the data. An example of removable media is a magnetic tape with multiple parallel recording tracks. Symbol timing recovery during readback represents one of the most critical functions in a data storage read channel. Sampling the analog readback signal at the appropriate instant is very important for good overall performance. The various challen...

AI Technical Summary

Problems solved by technology

This phenomenon often results in long bursts of bit and symbol errors, which can exceed the error correction capabilities of error-correcting codes such as Reed-Solomon codes, leading to severe performance degradation or even permanent error conditions

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