Patent ID: 6826245
Filing Date: 2004-11-30
Classification: G11B,H04L

Abstract:
A method for determining a location for a sync pattern in a digital signal stream, the method comprising:providing a digital signal bit stream that is believed to include a selected sync pattern p(k) (k=1, 2, . . . , S) with a width of S bits, where S is a selected positive integer with S&gE;2; providing a sync window with a width H bits, where H is a selected positive integer; providing a first sync pattern reference location in the digital stream; forming a selected function value F(n) depending upon at least two of S consecutive bits of the sync pattern p(k) and at least two of S consecutive bits of the digital stream s(kâˆ’n), beginning at a distance of n bits from the reference location of the first sync pattern, where n is an integer lying in a selected range Bâˆ’H/2&lE;n&lE;B+S+H/2, where B is a selected positive integer; selecting an integer n=n0 in the selected range for which the function value F(n=n0) is at least as large as the function value F(n) for any other integer in the selected range as a central integer; and when the function value F(n=n0) satisfies F(n=n0) &gE;Fmin, where Fmin is a selected threshold value, interpreting this condition as indicating that a second sync pattern in the digital stream is located n0 bits from the reference location of the first sync pattern.