Optical line terminal and optical network terminal

• US 7,978,972 B2
• Filed: 07/06/2007
• Issued: 07/12/2011
• Est. Priority Date: 12/13/2006
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tonoduka, Taro, Ohira, Masaki
• Primary Examiner(s): Vanderpuye; Ken N
• Assistant Examiner(s): Jacob; Oommen
• Application Number:
  US11/822,543
• Publication Number:
  US 20080145064A1
• Time in Patent Office: 1,467 Days
• Field of Search: 708/492
• US Class Current: 398/25
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/152 Bose-Chaudhuri-Hocquenghem [BCH] codes
• CPC Class Codes: H03M 13/1535 using the Euclid algorithm
• CPC Class Codes: H03M 13/1545 Determination of error locations, e.g. Chien search or other methods or arrangements for the determination of the roots of the error locator polynomial
• CPC Class Codes: H03M 13/155 Shortening or extension of codes
• CPC Class Codes: H03M 13/6561 Parallelized implementations
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence

Abstract

The optical line terminal has a PON transceiver including an error correction code decoder. The error correction decoder includes: a shortening compensation parameter table; and a syndrome calculator for calculating a syndrome by referring to the shortening compensation parameter table, or an error search part for calculating an error position or an error value by referring to the shortening compensation parameter table. Also the optical network terminal has a PON transceiver including an error correction code decoder. The error code decoder includes: a shortening compensation parameter table; and a syndrome calculator for calculating a syndrome by referring to the shortening compensation parameter table, or an error search part for calculating an error position or an error value by referring to the shortening compensation parameter table.

Claims

1. An optical line terminal comprising:

a photoelectric converter;

a PON transceiver; and

a physical layer,

wherein said PON transceiver includes an error correction code decoder including;

a shortening compensation parameter table;

a syndrome calculator for calculating a syndrome by referring to said shortening compensation parameter table, and

an error search part for calculating an error position or an error value by referring to the shortening compensation parameter table, wherein;

said syndrome calculator includes a first parameter variable multiplier, and said first parameter variable multiplier varies multiplex coefficients by changing internal matrix parameters depending on the shortening compensation parameter table and said error search part includes a second parameter variable multiplier, and said second parameter variable multiplier varies multiplex coefficients by changing internal matrix parameters depending on the shortening compensation parameter table.

2. The optical line terminal according to claim 1, further comprising an inverse parameter table,

wherein said error search part calculates the error value by referring to said inverse parameter table.

3. The optical line terminal according to claim 1, further comprising a polynomial coefficient calculator for calculating an error position polynomial or an error evaluation polynomial.

4. The optical line terminal according to claim 2, further comprising a polynomial coefficient calculator for calculating an error position polynomial or an error evaluation polynomial.

9. The optical line terminal according to claim 1, wherein said syndrome calculator further includes a syndrome controller for generating hook compensation information, and performs 16-bit parallel syndrome calculation depending on the hook compensation information.

5. An optical network terminal comprising:

a photoelectric converter;

a PON transceiver; and

a physical layer,

wherein said PON transceiver includes an error correction code decoder including;

a shortening compensation parameter table;

a syndrome calculator for calculating a syndrome by referring to said shortening compensation parameter table; and

an error search part for calculating an error position or an error value by referring to the shortening compensation parameter table, wherein;

said syndrome calculator includes a first parameter variable multiplier, and said first parameter variable multiplier varies multiplex coefficients by changing internal matrix parameters depending on the shortening compensation parameter table, and

said error search part includes a second parameter variable multiplier, and said second parameter variable multiplier varies multiplex coefficients by changing internal matrix parameters depending on the shortening compensation parameter table.

6. The optical network terminal according to claim 5, further comprising an inverse parameter table,

wherein said error search part calculates the error value by referring to said inverse parameter table.

7. The optical network terminal according to claim 5, further comprising a polynomial coefficient calculator for calculating an error position polynomial or an error evaluation polynomial.

8. The optical network terminal according to claim 6, further comprising a polynomial coefficient calculator for calculating an error position polynomial or an error evaluation polynomial.

10. The optical network terminal according to claim 5, wherein said syndrome calculator further includes a syndrome controller for generating hook compensation information, and performs 16-bit parallel syndrome calculation depending on the hook compensation information.