DIGITAL TELEVISION TRANSMITTER AND METHOD OF CODING DATA IN DIGITAL TELEVISION TRANSMITTER

• US 20070076829A1
• Filed: 06/30/2006
• Published: 04/05/2007
• Est. Priority Date: 10/05/2005
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Choi, In Hwan, Kang, Kyung, Kwak, Kook, Hong, Sung, Hong, Young
• Granted Patent: US 7,764,323 B2
• Time in Patent Office: Days
• US Class Current: 375/346
• CPC Class Codes: H03M 13/27 using interleaving techniques
• CPC Class Codes: H03M 13/2936 comprising an outer Reed-Solomon code and an inner convolutional code
• CPC Class Codes: H03M 13/356 Unequal error protection [UEP]
• CPC Class Codes: H03M 13/41 using the Viterbi algorithm or Viterbi processors
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0054 Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/007 Unequal error protection for format H04L1/0078; for codes per se H03M13/35
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence

Abstract

A pre-processor pre-processes enhanced data packets by coding the enhanced data packets for forward error correction (FEC) and expanding the FEC-coded data packets. A data formatter adds first null data into first place holders within each pre-processed enhanced data packet. A first multiplexer multiplexes the main data packets with the enhanced data packets having the first null data. A holder inserter inserts second null data into second place holders within an enhanced data packet outputted from the first multiplexer. A data interleaver replaces the second null data with parity data. A data generator generates at least one known data sequence. A symbol processor replaces the first null data included in an output of the data interleaver with the known data sequence(s). A non-systematic RS encoder generates the parity data by performing non-systematic RS-coding on an output of the symbol processor, and provides the parity data to the data interleaver.

Claims

1. A digital television (DTV) transmitter for coding main and enhanced data packets for transmission, the DTV transmitter comprising:

a pre-processor for pre-processing the enhanced data packets by coding the enhanced data packets for forward error correction (FEC) and expanding the FEC-coded data packets;

a data formatter for adding first null data into first place holders within each pre-processed enhanced data packet;

a first multiplexer for multiplexing the main data packets with the enhanced data packets having the first null data;

a holder inserter for inserting second null data into second place holders within an enhanced data packet outputted from the first multiplexer;

a data interleaver for replacing the second null data with parity data;

a data generator for generating at least one known data sequence;

a symbol processor for replacing the first null data included in an output of the data interleaver with the at least one known data sequence; and

a non-systematic Reed-Solomon (RS) encoder for generating the parity data by performing non-systematic RS-coding on an output of the symbol processor, and for providing the parity data to the data interleaver.

2. The DTV transmitter of claim 1, wherein the data formatter further adds an MPEG header to each enhanced data packet having the first null data.

3. The DTV transmitter of claim 2, wherein an output of the data formatter is a 188-byte enhanced data packet, and a size of the MPEG header is 4 bytes.

4. The DTV transmitter of claim 1, further comprising a byte-symbol converter for converting an output of the data interleaver into symbols and providing the symbols to the symbol processor.

5. The DTV transmitter of claim 1, further comprising a symbol-byte converter for converting an output of the symbol processor into data bytes and providing the data bytes to the non-systematic RS encoder.

6. The DTV transmitter of claim 1, wherein the second place holders are determined according to the following equation:

b=(52×

p)+(s mod

     52)mod 207, p=187, 188, . . . , 206,

wherein s represents a segment number after a field synchronization signal, b represents a location of a parity byte within a segment identified by s, and mod represents a remainder operator.

7. The DTV transmitter of claim 6, wherein s is any one of 0 to 311, and b is any one of 0 to 206.

8. The DTV transmitter of claim 1, wherein the second place holders are determined such that the data interleaver outputs the replaced parity data after it outputs non-parity data.

9. The DTV transmitter of claim 1, wherein the second place holders are determined such that the data interleaver outputs the replaced parity data after it outputs non-parity data other than a header.

10. The DTV transmitter of claim 1, further comprising a trellis encoder for trellis-encoding an output of the symbol processor, the trellis encoder being initialized each time a known data sequence is inputted to the trellis encoder.

11. A digital television (DTV) transmitter for coding main and enhanced data packets for transmission, the DTV transmitter comprising:

a pre-processor for pre-processing the enhanced data packets by coding the enhanced data packets for forward error correction (FEC) and expanding the FEC-coded data packets;

a data formatter for adding known data sequences into the pre-processed enhanced data packets;

a first multiplexer for multiplexing the main data packets with the enhanced data packets having the known data sequence;

a holder inserter for inserting null data into place holders within an enhanced data packet outputted from the first multiplexer;

a data interleaver for replacing the null data with parity data;

a symbol processor for coding enhanced data outputted from the data interleaver; and

a non-systematic Reed-Solomon (RS) encoder for generating the parity data by performing non-systematic RS-coding on an output of the symbol processor, and for providing the parity data to the data interleaver.

12. A method of coding main and enhanced data packets in a digital television (DTV) transmitter, the method comprising:

pre-processing the enhanced data packets by coding the enhanced data packets for forward error correction (FEC) and expanding the FEC-coded data packets;

adding first null data into first place holders within each pre-processed enhanced data packet;

multiplexing the main data packets with the enhanced data packets having the first null data;

inserting second null data into second place holders within each enhanced data packet having the first null data;

replacing the second null data placed in the second place holders with parity data using a data interleaver;

generating at least one known data sequence;

replacing the first null data included in an output of the data interleaver with the at least one known data sequence; and

generating the parity data by performing non-systematic Reed-Solomon (RS)-coding on the enhanced data packet having the at least one known data sequence, and providing the parity data to the data interleaver.

13. The method of claim 12, further comprising adding an MPEG header to each enhanced data packet having the first null data.

14. The method of claim 13, wherein a size of each enhanced data packet having the first null data is 188 bytes, and a size of the MPEG header is 4 bytes.

15. The method of claim 12, further comprising converting an output of the data interleaver into symbols.

16. The method of claim 12, further comprising converting the enhanced data packet having the at least one known data sequence into data bytes.

17. The method of claim 12, wherein the second place holders are determined according to the following equation:

b=((52×

p)+(s mod

     52)mod 207, p=187, 188, . . . , 206,

wherein s represents a segment number after a field synchronization signal, b represents a location of a parity byte within a segment identified by s, and mod represents a remainder operator.

18. The method of claim 17, wherein s is any one of 0 to 311, and b is any one of 0 to 206.

19. The method of claim 12, wherein the second place holders are determined such that the data interleaver outputs the replaced parity data after it outputs non-parity data.

20. The method of claim 12, wherein the second place holders are determined such that the data interleaver outputs the replaced parity data after it outputs non-parity data other than a header.

21. The method of claim 12, further comprising:

trellis-encoding the enhanced data packet having the at least one known data sequence in a trellis encoder; and

initializing the trellis encoder each time a known data sequence is inputted to the trellis encoder.

22. A digital television (DTV) receiver, comprising:

a tuner for receiving a DTV signal having main data and enhanced data from a DTV transmitter, the enhanced data being coded for forward error correction (FEC) and expanded by the DTV transmitter;

a demodulator for demodulating the DTV signal by performing carrier and timing recovery;

an equalizer for compensating channel distortion included in the demodulated DTV signal;

a data detector for detecting one or more known data sequences from the enhanced data included in the demodulated DTV signal, wherein the demodulator and the equalizer use the detected known data sequences when performing the carrier and timing recovery and the channel distortion compensation, respectively;

a Viterbi decoder for Viterbi-decoding main and enhanced data symbols outputted from the equalizer;

a data deinterleaver for deinterleaving the Viterbi-decoded data; and

a non-systematic Reed-Solomon (RS) parity remover for removing non-systematic RS parity bytes from an enhanced data packet outputted from the data deinterleaver.

23. A method of decoding a signal in a digital television (DTV) receiver, the method comprising:

receiving a DTV signal having main data and enhanced data from a DTV transmitter, the enhanced data being coded for forward error correction (FEC) and expanded by the DTV transmitter;

modulating the DTV signal by performing carrier and timing recovery;

compensating channel distortion included in the demodulated DTV signal;

detecting one or more known data sequences from the enhanced data included in the demodulated DTV signal, wherein the modulation and the channel distortion compensation of the DTV signal are performed using the detected known data sequences;

Viterbi-decoding main and enhanced data symbols included in the channel-distortion-compensated DTV signal;

deinterleaving the Viterbi-decoded data in a deinterleaver; and

a non-systematic Reed-Solomon (RS) parity remover for removing non-systematic RS parity bytes from an enhanced data packet outputted from the deinterleaver.