Synchronization field pattern selection

• US 5,856,986 A
• Filed: 11/25/1996
• Issued: 01/05/1999
• Est. Priority Date: 11/25/1996
• Status: Expired due to Term

• Current Assignee: Swayze W. Daniel Jr
• Original Assignee: Texas Instruments, Inc.
• Inventors: Sobey, Charles H.
• Primary Examiner(s): Beausoliel, Jr., Robert W.
• Assistant Examiner(s): Iqbal, Nadeem
• Application Number:
  US08/756,221
• Time in Patent Office: 771 Days
• Field of Search: 371/27.7, 371/37.01, 371/37.7, 371/40.15, 371/41, 371/37.03, 371/43.7, 371/40.2, 371/40.12, 371/37.07, 371/43.6, 360/49-51, 360/77.08, 360/78.08, 395/183.18, 395/185.05
• US Class Current: 714/744
• CPC Class Codes: G11B 20/10009 Improvement or modification of read or write signals
• CPC Class Codes: G11B 20/1217 on discs
• CPC Class Codes: G11B 20/1426 conversion to or from block codes or representations thereof
• CPC Class Codes: G11B 27/3027 used signal is digitally coded
• CPC Class Codes: H04L 7/042 Detectors therefor, e.g. correlators, state machines digital correlators in general G06F17/15

Abstract

A detection device for detecting a pattern and determining valid patterns by a series of tests. These tests include rejecting patterns based on minimum Hamming distance, spectral energies that are not concentrated with a predetermined ideal spectrum, that are not valid predetermined valid codewords, patterns that are not anti-symmetric and that have closest transition spacing.

Claims

1. A device for providing byte synchronization with a data stream by detecting a sync pattern where the data stream includes a preamble section followed by a sync pattern followed by a data section, comprising:

a reading device for reading a sample pattern of bits of said data stream;

a testing device for testing said sample pattern to determine a byte synchronization condition to identify the first bit of data in said data section, wherein said testing device determines byte synchronization by finding a correlation between said sync pattern and said sample pattern based on a predetermined criteria; and

wherein said sync pattern has a minimum hamming distance over shifts of itself, a minimum hamming distance over shifts of the sync pattern and the data pattern used in the preamble section; and

an output device to provide a signal to indicate detection of said byte synchronization condition.

2. A device for providing byte synchronization as in claim 1, wherein said sync pattern is a valid codeword for data in said data section.

3. A device for providing byte synchronization as in claim 1, wherein said sync pattern has spectral energy most concentrated within the ideal spectrum of the system.

4. A device for providing byte synchronization as in claim 1, wherein said sync pattern is additionally based on a pattern that is most anti-symmetric.

5. A device for providing byte synchronization as in claim 1, wherein said sync pattern lacks close transition spacing.

7. A device for providing byte synchronization as in claim 3, wherein said sync pattern has spectral energy most concentrated within the ideal spectrum of the system.

8. A device for providing byte synchronization as in claim 3, wherein said sync pattern is additionally based on a pattern that is most anti-symmetric, meaning the valid pattern maintains a minimum hamming distance from itself as it shifts past an exact copy of itself into unknown user data in said data stream.

9. A device for providing byte synchronization as in claim 3, wherein said sync pattern lacks close transition spacing.

6. A device for providing byte synchronization with a data stream by detecting a sync pattern where the data stream includes a preamble section followed by a sync pattern followed by a data section, comprising:

a reading device for reading a sample pattern of bits of said data stream;

a testing device for testing said sample pattern to determine a byte synchronization condition to identify the first bit of data in said data section, wherein said testing device determines byte synchronization by finding a correlation between said sync pattern and said sample pattern based on a predetermined criteria; and

wherein said sync pattern has a minimum hamming distance over shifts of itself, a minimum hamming distance over shifts of the sync pattern and the data pattern used in the preamble section and wherein said sync pattern is a valid codeword for data in said data section; and

an output device to provide a signal to indicate detection of said byte synchronization condition.