公开(公告)号：US06219192B1

公开(公告)日：2001-04-17

申请号：US09179148

申请日：1998-10-26

Applicant: Srinivasan Gopalaswamy ,  Bin Liu ,  Yuan Xing Lee

Inventor： Srinivasan Gopalaswamy ,  Bin Liu ,  Yuan Xing Lee

IPC: G11B502

CPC classification number: G11B20/10055 ,  G11B5/012 ,  G11B5/09 ,  G11B20/10009 ,  G11B20/10037 ,  G11B2005/0016

Abstract: The method and apparatus have application to the compensation of transient signals produced on reading a data storage device with a magneto-resistive head due to thermal contact with asperities on the data storage medium. Preferably, the data channel employs partial-response maximum-likelihood detection. The method compensates for an additive signal in a data signal and comprises the steps of: detecting the contribution to said data signal by said additive signal; initially compensating the data signal by maintaining a DC offset in said data signal, the initial level of said DC offset being set in dependence on the detected contribution; and while compensating the data signal, detecting when the compensated data signal exceeds a predetermined threshold and varying the set level of said DC offset in dependence upon said detection.

Abstract translation: 该方法和装置可应用于由于与数据存储介质上的粗糙度的热接触而使用磁阻头读取数据存储装置时产生的瞬态信号的补偿。 优选地，数据信道采用部分响应最大似然检测。该方法补偿数据信号中的加法信号，并且包括以下步骤：通过所述加法信号检测对所述数据信号的贡献; 通过维持所述数据信号中的DC偏移来初始地补偿数据信号，根据检测到的贡献来设置所述DC偏移的初始电平; 并且在补偿数据信号的同时，检测补偿数据信号何时超过预定阈值，并根据所述检测改变所述DC偏移的设定电平。

公开(公告)号：US06996597B2

公开(公告)日：2006-02-07

申请号：US10092927

申请日：2002-03-06

Applicant: Ashish Mathur ,  Srinivasan Gopalaswamy ,  Pradeep Jain

Inventor： Ashish Mathur ,  Srinivasan Gopalaswamy ,  Pradeep Jain

IPC: G06F7/38

CPC classification number: H04L27/2628

Abstract: Precision of multi-stage digital signal processing is increased by preserving least significant bits of one or more output samples of a particular processing stage, having finite word widths, while avoiding the loss of most significant bits. The technique is applicable to one or more stages of multi-stage digital signal processing, thereby increasing precision therein and the signal-to-noise ratio. A plurality of output samples are calculated using a plurality of input samples, and the dynamic range of one or more of the output samples is decreased if the output sample can be represented in a smaller dynamic range without losing a significant bit. The input samples of a particular stage, obtained from the output samples of a previous stage, may further be normalized so that the input samples are represented in the same dynamic range before being processed.