Error Resilience Methods for Multi-Protocol Encapsulation Forward Error Correction Implementations

• US 20070186143A1
• Filed: 04/13/2006
• Published: 08/09/2007
• Est. Priority Date: 01/17/2006
• Status: Active Grant

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: SIRF Technology Incorporated (Qualcomm, Inc.)
• Inventors: Valmiki, Ramanujan, Gubbi, Rajugopal
• Granted Patent: US 7,644,343 B2
• Time in Patent Office: Days
• US Class Current: 714/776
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/154 Error and erasure correction, e.g. by using the error and erasure locator or Forney polynomial
• CPC Class Codes: H03M 13/2707 Simple row-column interleaver, i.e. pure block interleaving
• CPC Class Codes: H03M 13/373 with erasure correction and erasure determination, e.g. for packet loss recovery or setting of erasures for the decoding of Reed-Solomon codes
• 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
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/44004 involving video buffer management, e.g. video decoder buffer or video display buffer
• CPC Class Codes: H04N 21/4425 Monitoring of client processing errors or hardware failure
• CPC Class Codes: H04N 21/6112 involving terrestrial transmission, e.g. DVB-T
• CPC Class Codes: H04N 21/64315 DVB-H

Abstract

Transport stream (TS) packets containing sections of IP datagrams for an application level process are received and correct ones of said sections are stored into an MPE-FEC frame buffer of a receiver. Stored ones of said sections are reorganized within the frame buffer so as to leave appropriate positions, marked for erasure, within the frame buffer available for corrected data. Data bytes stored at the appropriate positions may be corrected using Reed-Solomon parity data stored in the frame buffer and then subsequently written back thereto.

Claims

1. A method, comprising storing non-erroneous data received in transport stream (TS) packets into a multi-protocol encapsulation forward error correction (MPE-FEC) frame buffer of a receiver according to locations indicated by an MPE-FEC frame buffer write pointer, said write pointer being adjusted for TS packet errors and new MPE section starts observed at the receiver, and marking for erasure, on a byte-by-byte basis, locations within the MPE-FEC frame buffer according to stored information concerning locations of said write pointer when said TS packet errors and new MPE section starts were observed.

2. The method of claim 1, further comprising correcting data bytes stored at the locations marked for erasure in the MPE-FEC frame buffer using Reed-Solomon parity data stored in the MPE-FEC frame buffer.

3. The method of claim 2, further comprising writing back to the MPE-FEC frame buffer, at the locations marked for erasure, the data bytes corrected using the Reed-Solomon parity data.

4. The method of claim 1, wherein the new MPE section starts are identified by asserted payload unit start indicator (PUSI) fields in various ones of the TS packets.

5. The method of claim 1, wherein the new MPE section starts are identified using a counter initialized using MPE field size information obtained from MPE section headers included in various ones of the TS packets.

6. A method, comprising computing positions for storing data bytes in correctly received transport stream (TS) packets succeeding one or more erasure or error packets into a multi-protocol encapsulation forward error correction (MPE-FEC) frame buffer of a receiver using a next correctly received MPE or MPE-FEC section header;

and storing the data bytes at the computed positions of the MPE-FEC frame buffer.

7. A method, comprising organizing data within an MPE-FEC frame buffer so as to leave available space for data bytes marked as erasures within said MPE-FEC frame buffer by moving previously stored data bytes in the MPE-FEC frame buffer to new locations therein as determined by previously stored information concerning locations of an MPE-FEC frame buffer write pointer at times when TS packet errors and new MPE section starts were observed.

8. The method of claim 7, wherein the data bytes marked as erasures are so indicated by one or more data bits within the MPE-FEC frame buffer.

9. The method of claim 7, wherein the data bytes marked as erasures are so indicated by data reliability information stored separately from the MPE-FEC frame buffer.

10. The method of claim 9, wherein the data reliability information includes a starting address of a block of the data within the MPE-FEC frame buffer to be marked for erasure and an erasure flag.

11. A method, comprising storing data received in TS packets into an MPE-FEC frame buffer of a receiver according to locations indicated by an MPE-FEC frame buffer write pointer, and storing reliability information regarding said data separately therefrom, said reliability information including addresses of one or more locations in said MPE-FEC frame buffer to be marked for erasure.

12. The method of claim 11, wherein the reliability information comprises a starting address of a block of the data to be marked for erasure and an erasure flag.

13. The method of claim 12, wherein only non-erroneous data from the TS packets is stored into the MPE-FEC frame buffer, and further comprising moving the non-erroneous data corresponding to an MPE section to corresponding address locations within the MPE-FEC frame buffer so as to leave appropriate positions within the MPE-FEC frame buffer available for corrected data.

14. The method of claim 13, further comprising correcting data bytes stored at locations of the MPE-FEC frame buffer marked for erasure according to the reliability information using Reed-Solomon parity data stored in the MPE-FEC frame buffer.

15. The method of claim 14, further comprising writing back to the MPE-FEC frame buffer, at the locations marked for erasure according to the reliability information, the data bytes corrected using the Reed-Solomon parity data.

16. A method, comprising receiving TS packets containing sections of IP datagrams for an application level process, storing correct ones of said sections into an MPE-FEC frame buffer of a receiver;

reorganizing stored ones of said sections within the MPE-FEC frame buffer so as to leave appropriate positions within the MPE-FEC frame buffer available for corrected data; and

marking for erasure the appropriate positions.

17. The method of claim 16, further comprising correcting data bytes stored at the appropriate positions marked for erasure in the MPE-FEC frame buffer using Reed-Solomon parity data stored in the MPE-FEC frame buffer.

18. The method of claim 17, further comprising writing back to the MPE-FEC frame buffer, at the appropriate locations marked for erasure, the data bytes corrected using the Reed-Solomon parity data.

19. The method of claim 16, wherein the sections of IP datagrams are stored into the MPE-FEC frame buffer according to locations indicated by an MPE-FEC frame buffer write pointer, said write pointer being adjusted for TS packet errors and new MPE section starts observed at the receiver, and the appropriate locations within the MPE-FEC frame buffer are marked for erasure on a byte-by-byte basis according to stored information concerning locations of said write pointer when said TS packet errors and new MPE section starts were observed.

20. The method of claim 16, wherein the appropriate locations within the MPE-FEC frame buffer are marked for erasure according to reliability information regarding said sections of IP datagrams stored separately therefrom.

21. The method of claim 20, wherein the reliability information comprises entries for only erasure blocks in the MPE-FEC frame buffer.

22. The method of claim 20, wherein the reliability information comprises entries for only non-erasure blocks in the MPE-FEC frame buffer.

23. A method of receiving a multi-protocol encapsulation forward error correction (MPE-FEC) frame, comprising storing non-erroneous data received in transport stream (TS) packets into a multi-protocol encapsulation forward error correction (MPE-FEC) frame buffer of a receiver;

and, for one or more erasure-free rows of data in the MPE-FEC frame buffer, excluding said one or more erasure-free rows of data from Reed Solomon (RS) decoding.

24. The method of claim 23, wherein excluding said one or more erasure-free rows of data from RS decoding comprises:

during reception of the MPE-FEC frame, identifying the one or more erasure-free rows of data by entries in a table; and

, during RS decoding of the data in the MPE-FEC frame buffer, checking said entries in said table to determine whether or not RS decoding of a particular row of data in the MPE-FEC frame buffer is required according to whether or not said particular row is indicated as being erasure-free or not by said entries in said table.