Granted Patent B2

US 8,036,292 · App. 12/131,412 · Granted Oct 11, 2011

Abstract

Claims (42)

1. A method of segmented frame synchronization for Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) and Integrated Services Digital Broadcasting-Terrestrial Sound Broadcasting (ISDB-TSB) systems, said method comprising:

receiving a wireless digital signal comprising an Orthogonal Frequency Division Multiplexing (OFDM) frame in a receiver, wherein said OFDM frame comprises OFDM symbols, and wherein said receiver comprises a time de-interleaver, a bit de-interleaver, and a descrambler;

filling memory of said time de-interleaver and bit de-interleaver by said received wireless digital signal;

determining an OFDM segmented frame boundary when the said memory of said time de-interleaver and bit de-interleaver are full;

decoding bits from said time de-interleaver and said bit de-interleaver using a Viterbi decoder;

outputting the Viterbi decoding bits from said time de-interleaver and said bit de-interleaver when said OFDM segmented frame boundary is detected;

obtaining a segmented multiplexing frame boundary upon receipt of a first bit from said Viterbi decoder; and

synchronizing the OFDM frame based on the segmented multiplexing frame boundary.

2. The method of claim 1 , wherein said segmented multiplexing frame boundary comprises a quarter segment.

3. The method of claim 1 , wherein said segmented multiplexing frame boundary comprises a half segment, an eighth segment, or a sixteenth segment.

4. The method of claim 1 , further comprising detecting whether a symbol number corresponding to a received OFDM symbol is any of symbol 0 , symbol 204 /x, symbol 2 *( 204 /x), and symbol 3 *( 204 /x), where x is a reciprocal of a segment boundary.

5. The method of claim 4 , wherein if it is detected that said symbol number is any of symbol 0 , symbol 204 /x, symbol 2 *( 204 /x), and symbol 3 *( 204 /x), where x is a reciprocal of a segment boundary, said method further comprising determining that said OFDM segmented frame boundary is achieved.

6. The method of claim 2 , wherein said descrambler starts descrambling only at quarter frame multiplexing.

7. The method of claim 1 , wherein said segmented multiplexing frame boundary indicates a start of a transport packet.

8. The method of claim 1 , further comprising performing additional decoding on the Viterbi decoded bits upon completion of the outputting process.

9. An apparatus for segmented frame synchronization for Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) and Integrated Services Digital Broadcasting- Terrestrial Sound Broadcasting (ISDB-TSB) systems, said apparatus comprising:

a receiver that receives a wireless digital signal comprising an Orthogonal Frequency Division Multiplexing (OFDM) frame, wherein said OFDM frame comprises OFDM symbols;

a time de-interleaver comprising memory that is filled by said received wireless digital signal;

a bit de-interleaver comprising memory that is filled by said received wireless digital signal;

a detector that determines a location of an OFDM segmented frame boundary when the said memory of said time de-interleaver and bit de-interleaver are full;

a Viterbi decoder that decodes bits from said time de-interleaver and said bit de-interleaver, wherein Viterbi decoding bits are output from said time de-interleaver and said bit de-interleaver when said OFDM segmented frame boundary is detected, and wherein a segmented multiplexing frame boundary is obtained upon receipt of a first bit from said Viterbi decoder; and

a processor that synchronizes the OFDM frame based on the segmented multiplexing frame boundary.

10. The apparatus of claim 9 , wherein said segmented multiplexing frame boundary comprises a quarter segment.

11. The apparatus of claim 9 , wherein said segmented multiplexing frame boundary comprises a half segment, an eighth segment, or a sixteenth segment.

12. The apparatus of claim 9 , wherein said detector detects whether a symbol number corresponding to a received OFDM symbol is any of symbol 0 , symbol 204 /x, symbol 2 *( 204 /x), and symbol 3 *( 204 /x), where x is a reciprocal of a segment boundary.

13. The apparatus of claim 12 , wherein if said detector detects that said symbol number is any of symbol 0 , symbol 204 /x, symbol 2 *( 204 /x), and symbol 3 *( 204 /x), where x is a reciprocal of a segment boundary, said processor determines that said OFDM segmented frame boundary is achieved.

14. The apparatus of claim 10 , further comprising a descrambler that starts descrambling only at quarter frame multiplexing.

15. The apparatus of claim 9 , wherein said segmented multiplexing frame boundary indicates a start of a transport packet.

16. The apparatus of claim 9 , further comprising means for performing decoding on the Viterbi decoded bits that are output from said time de-interleaver and said bit de-interleaver.

17. A system for quarter-frame synchronization for Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) and Integrated Services Digital Broadcasting- Terrestrial Sound Broadcasting (ISDB-TSB) systems, said system comprising:

a receiver that receives a wireless digital signal comprising an Orthogonal Frequency Division Multiplexing (OFDM) frame, wherein said OFDM frame comprises OFDM symbols, and wherein said receiver comprises a time de-interleaver, a bit de-interleaver, and a descrambler;

means for filling memory of said time de-interleaver and bit de-interleaver by said received wireless digital signal;

means for determining an OFDM quarter-frame boundary when the said memory of said time de-interleaver and bit de-interleaver are full;

a Viterbi decoder that decodes bits from said time de-interleaver and said bit de-interleaver;

means for outputting the Viterbi decoding bits from said time de-interleaver and said bit de-interleaver when said OFDM quarter-frame boundary is detected;

means for obtaining a quarter-multiplexing frame boundary upon receipt of a first bit from said Viterbi decoder; and

means for synchronizing the OFDM frame based on the quarter-multiplexing frame boundary.

18. The system of claim 17 , further comprising means for detecting whether a symbol number corresponding to a received OFDM symbol is any of symbol 0 , symbol 204 /x, symbol 2 *( 204 /x), and symbol 3 *( 204 /x), where x is a reciprocal of a segment boundary.

19. The system of claim 18 , wherein if it is detected that said symbol number is any of symbol 0 , symbol 204 /x, symbol 2 *( 204 /x), and symbol 3 *( 204 /x), where x is a reciprocal of a segment boundary, said system further comprising means for determining that said OFDM segmented frame boundary is achieved.

20. The system of claim 17 , wherein said descrambler starts descrambling only at quarter frame multiplexing.

21. The system of claim 17 , wherein said segmented multiplexing frame boundary indicates a start of a transport packet.

22. The system of claim 17 , further comprising means for performing additional decoding on the Viterbi decoded bits upon completion of the outputting of the Viterbi decoding bits from said time de-interleaver and said bit de-interleaver.

Assignments (23)