Transmitting data words

• US 6,574,731 B1
• Filed: 03/05/1999
• Issued: 06/03/2003
• Est. Priority Date: 03/05/1999
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Deliot, Eric Henri Ulysse, Coles, Alistair Neil
• Primary Examiner(s): Peeso, Thomas R.
• Application Number:
  US09/263,633
• Time in Patent Office: 1,551 Days
• Field of Search: 713/168, 713/179, 713/200, 713/201
• US Class Current: 713/168
• CPC Class Codes: G11B 20/1426 conversion to or from block codes or representations thereof
• CPC Class Codes: H03M 5/145 Conversion to or from block codes or representations thereof
• CPC Class Codes: H03M 7/14 Conversion to or from non-weighted codes
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 25/03866 using scrambling

Abstract

Codeword synchronization and scrambler synchronization in a block-coded serial communications link are accomplished by (i) substituting a specific comma control codeword for a selected codeword value occurring in the output of a scrambler receiving an input data stream, and (ii) using selected polarity-independent bits of the block-coded scrambled bit stream to convey samples of the scrambler state. Inversion of received control codewords indicates polarity inversion somewhere along the link, enabling automatic polarity correction to be applied.

Claims

1. A method of encoding data words for transmission, comprising the steps of:

receiving data words from a source;

scrambling the data words using a scrambling procedure which generates at least one predetermined output pattern with a predetermined probability; and

encoding the scrambled data words with a block encoding procedure to produce corresponding code words, different occurrences of the scrambled data word having said predetermined output pattern being selectively encoded with different ones of a plurality of code words associated with that scrambled data word pattern,

wherein each of said plurality of code words associated with the scrambled data pattern, and the complement of that code word, are unique with respect to code words associated with output patterns generated by the scrambling procedure other than said predetermined output pattern and with respect to complements of those code words.

2. A method of encoding data words for transmission, comprising the steps of:

receiving data words from a source;

scrambling the data words using a scrambling procedure which generates at least one predetermined output pattern with a predetermined probability; and

encoding the scrambled data words with a block encoding procedure to produce corresponding code words, different occurrences of the scrambled data word having said predetermined output pattern being selectively encoded with different ones of a plurality of code words associated with that scrambled data word, pattern,

wherein one of said plurality of code words associated with the scrambled data word pattern comprises a pattern of symbols which occurs at only one position relative to a boundary between codewords within a stream of codewords.

3. A method of encoding data words for transmission, comprising the steps of:

receiving data words from a source;

scrambling the data words using a scrambling procedure which generates at least one predetermined output pattern with a predetermined probability; and

encoding the scrambled data words with a block encoding procedure to produce corresponding code words, different occurrences of the scrambled data word having said predetermined output pattern being selectively encoded with different ones of a plurality of code words associated with that scrambled data word pattern,

wherein occurrence of a predetermined one of said plurality of code words indicates that synchronisation information relating to the scrambling procedure is present in the encoded data.

4. A method of transmitting first and second data, comprising the steps of:

encoding the first data using a block code for which correct decoding of at least some code words considered as a whole is dependent upon polarity of the code word;

encoding the second data using at least one selected input symbol position in the block code, said symbol position being selected for correct decoding of a symbol at that position to be independent of polarity of the code word;

transmitting said block code words;

decoding said first data in accordance with the values of the block code words considered as a whole; and

decoding said second data in accordance with said at least one selected symbol only.

5. The method of claim 4, wherein one of said first and second data are sent at a time.

6. The method of claim 4, wherein said first and second data are sent simultaneously.

7. The method of claim 6, wherein said first and second data are associated with different respective portions of a code word.

8. The method of claim 7, wherein the second data contain training information associated with a scrambling procedure applied to said first and second data.

9. The method of claim 8, wherein presence or absence of training information is indicated by selection of one of two alternative code words in relation to said first data.

10. The method of claim 8, including the steps of:

completing training of the scrambling procedure in accordance with said training information;

determining whether a polarity-dependent error in decoding of said first data is present; and

controlling inversion of polarity of received code words in accordance with presence of said polarity-dependent error.