Frequency, phase, and gain estimation technique for use in a read channel receiver of a hard disk drive

Abstract

One or more methods and systems are presented for performing gain and timing acquisition of data read from one or more data sectors of a hard disk drive. The gain and timing information may be used to synchronize a read channel receiver of the hard disk drive to the data read from the data sector(s). In a representative embodiment, the one or more methods comprises determining one or more frequency and phase offsets using one or more preambles of one or more data sectors residing in a hard disk drive. In a representative embodiment, the gain of the one or more preambles may be determined. In another representative embodiment, the one or more systems used to determine one or more phase and frequency offsets, and amplitudes, comprise hardware and/or software capable of utilizing a sequence of consecutive samples provided by one or more preambles of one or more data sectors.

1 - 37 . (canceled) 
   
   
       38 . A method of estimating gain or amplitude of a data stream that is read from a hard disk drive comprising:
 receiving a plurality of digitized samples from reading a preamble field of a sector of a hard drive;   determining a sine component for each of said plurality of digitized samples;   determining a cosine component for each of said plurality of digitized samples;   computing a sum of squares of said sine and cosine components; and   computing a square root of said sum to generate said gain or amplitude.   
   
   
       39 . The method of  claim 38  wherein said preamble field contains less than 15 bytes of data. 
   
   
       40 . The method of  claim 38  wherein said preamble field contains 6 bytes of data. 
   
   
       41 . The method of  claim 38  wherein said preamble field precedes a sync field, said sync field used to notify or indicate that a data field immediately follows said sync field. 
   
   
       42 . The method of  claim 38  wherein said plurality of digitized samples equals 8 digitized samples. 
   
   
       43 . The method of  claim 42  wherein said plurality of digitized samples represents two periods of a sinusoidal waveform. 
   
   
       44 . A system for estimating gain or amplitude of data that is read from a hard disk drive, said system comprising:
 at least one circuitry operative for, at least:
 receiving a plurality of digitized samples from reading a preamble field of a sector of a hard drive; 
 determining a sine component for each of said plurality of digitized samples; 
 determining a cosine component for each of said plurality of digitized samples; 
 computing a sum of squares of said sine and cosine components; and 
 computing a square root of said sum to generate said gain or amplitude. 
   
   
   
       45 . The system of  claim 44  wherein said preamble field contains less than 15 bytes of data. 
   
   
       46 . The system of  claim 44  wherein said preamble field contains 6 bytes of data. 
   
   
       47 . The system of  claim 44  wherein said preamble field precedes a sync field, said sync field used to notify or indicate that a data field immediately follows said sync field. 
   
   
       48 . The system of  claim 45  wherein said plurality of digitized samples equals 8 digitized samples. 
   
   
       49 . The system of  claim 48  wherein said plurality of digitized samples represents two periods of a sinusoidal waveform. 
   
   
       50 . A system for estimating gain or amplitude of data that is read from a hard disk drive, said system comprising:
 a memory for storing a set of executable instructions;   a processor for executing said executable instructions, wherein said executing performs:
 receiving a plurality of digitized samples from reading a preamble field of a sector of a hard drive; 
 determining a sine component for each of said plurality of digitized samples; 
 determining a cosine component for each of said plurality of digitized samples; 
 computing a sum of squares of said sine and cosine components; and 
 computing a square root of said sum to generate said gain or amplitude. 
   
   
   
       51 . The system of  claim 50  wherein said preamble field contains less than 15 bytes of data. 
   
   
       52 . The system of  claim 50  wherein said preamble field contains 6 bytes of data. 
   
   
       53 . The method of  claim 50  wherein said preamble field precedes a sync field, said sync field used to notify or indicate that a data field immediately follows said sync field. 
   
   
       54 . The method of  claim 50  wherein said plurality of digitized samples equals 8 digitized samples. 
   
   
       55 . The method of  claim 54  wherein said plurality of digitized samples represents two periods of a sinusoidal waveform. 
   
   
       56 . A method for optimizing performance of a hard drive by synchronizing a read channel receiver of said hard drive to a data stream that is read, said method comprising:
 receiving a plurality of digitized samples from reading a preamble field of a sector of a hard drive;
 first determining a sine component for each of said plurality of digitized samples; 
 second determining a cosine component for each of said plurality of digitized samples; 
 dividing said cosine component with said sine component to generate a quotient; 
 computing an arctangent of said quotient to generate a preliminary phase estimate of each of said plurality of digitized samples; 
 using at least two of said plurality of digitized samples to generate at least two preliminary phase estimates based on said first determining, second determining, dividing, and computing; 
 generating a frequency offset and a phase offset by applying linear regression to said at least two preliminary phase estimates and an integer variable, said integer variable used for indexing each of said plurality of digitized samples; and 
 using said frequency offset and said phase offset to perform said synchronizing. 
   
   
   
       57 . The method of  claim 56  wherein said preamble field contains less than 15 bytes of data. 
   
   
       58 . The method of  claim 56  wherein said preamble field contains 6 bytes of data. 
   
   
       59 . The method of  claim 56  wherein said preamble field precedes a sync field, said sync field used to notify or indicate that a data field immediately follows said sync field. 
   
   
       60 . The method of  claim 56  wherein said plurality of digitized samples equals 8 digitized samples. 
   
   
       61 . The method of  claim 60  wherein said plurality of digitized samples represents two periods of a sinusoidal waveform. 
   
   
       62 . A system for optimizing performance of a hard drive by synchronizing a read channel receiver of said hard drive to a data stream that is read, said system comprising:
 at least one circuitry operative for, at least:
 receiving a plurality of digitized samples from reading a preamble field of a sector of a hard drive; 
 first determining a sine component for each of said plurality of digitized samples; 
 second determining a cosine component for each of said plurality of digitized samples; 
 dividing said cosine component with said sine component to generate a quotient; 
 computing an arctangent of said quotient to generate a preliminary phase estimate of each of said plurality of digitized samples; 
 using at least two of said plurality of digitized samples to generate at least two preliminary phase estimates based on said first determining, second determining, dividing, and computing; 
 generating a frequency offset and a phase offset by applying linear regression to said at least two preliminary phase estimates and an integer variable, said integer variable used for indexing each of said plurality of digitized samples; and 
 using said frequency offset and said phase offset to perform said synchronizing. 
   
   
   
       63 . The system of  claim 62  wherein said preamble field contains less than 15 bytes of data. 
   
   
       64 . The system of  claim 62  wherein said preamble field contains 6 bytes of data. 
   
   
       65 . The system of  claim 62  wherein said preamble field precedes a sync field, said sync field used to notify or indicate that a data field immediately follows said sync field. 
   
   
       66 . The system of  claim 62  wherein said plurality of digitized samples equals 8 digitized samples. 
   
   
       67 . The system of  claim 66  wherein said plurality of digitized samples represents two periods of a sinusoidal waveform.