DTV transmitter and method of coding main and enhanced data in DTV transmitter

Abstract

A DTV transmitter includes a pre-processor pre-processing enhanced data, a data formatter generating enhanced data packets including the pre-processed enhanced data, and a multiplexer multiplexing the enhanced data packets with main data packets. The transmitter further includes an RS encoder RS-coding the multiplexed packets by adding systematic RS parity data to each main data packet and by adding non-systematic RS parity place holders to each enhanced data packet, and a data interleaver interleaving the RS-coded packets. The non-systematic RS parity place holders are placed after the enhanced data within each interleaved enhanced data packet, and a sequence of known data place holders is periodically included in the interleaved enhanced data packets.

What is claimed is: 
     
       1. A digital television (DTV) broadcast transmitter for processing broadcast data, the DTV digital broadcast transmitter comprising:
 a first randomizer for randomizing enhanced data; 
 a Reed Solomon (RS) frame encoder for performing at least one of error correction encoding and error detection encoding on the randomized enhanced data; RS encoding on an RS frame payload including 187*N bytes of the randomized enhanced data to add P bytes of RS parity data at each column of the RS frame payload and then Cyclic Redundancy Check (CRC) encoding on the RS frame payload having the RS parity data to add two bytes of CRC data at each row of the RS frame payload having the RS parity data, thereby generating an RS frame having a size of (187+P)*(N+2) bytes, wherein N is a number of columns in the RS frame payload, 187 is a number of rows in the RS frame payload and P is a number of bytes of the RS parity data; 
 a block processor for encoding the encoded enhanced data at a coding rate of 1/L, wherein L is greater than 1; 
 a group formatting unit for mapping the enhanced data encoded at the coding rate of 1/L to at least one region of a data group including a plurality of regions, the data group further including a plurality of known data sequences, RS parity data place holders and MPEG header data place holders; 
 a data deinterleaver for deinterleaving the data group; 
 a packet formatter for adding data of the deinterleaved data group to MPEG header data, thereby outputting enhanced data packets; 
 a packet formatter for removing the RS parity data place holders in the deinterleaved data group, replacing the MPEG header data place holders in the deinterleaved data group with MPEG header data, and outputting enhanced data packets; 
 a second randomizer for randomizing the MPEG header data in the enhanced data packets; 
 an RS encoder for RS encoding the enhanced data packets having the randomized MPEG header data in order to insert non-systematic RS parity data in predetermined positions within the enhanced data packets, wherein the non-systematic RS parity data are inserted in predetermined positions within the enhanced data packets; 
 a data interleaver for interleaving the RS encoded enhanced data packets; and 
 a trellis encoder for trellis-encoding data of the interleaved enhanced data packets, wherein and initializing memories of the trellis encoder are initialized by initialization data at a start of at least one known data sequence, wherein the initialization data by initialization data that are determined according to values of the memories. 
 
     
     
       2. The DTV transmitter of  claim 1 , wherein the RS frame encoder performs at least one of RS encoding and Cyclic Redundancy Check (CRC) encoding on the randomized enhanced data. 
     
     
       3. The DTV transmitter of  claim 2 , wherein the RS frame encoder generates an RS frame by adding RS parity data to columns of an RS frame payload and adding CRC data to right ends of rows of the RS frame payload including the RS parity data, the RS frame payload further including the randomized enhanced data. 
     
     
       4. The DTV digital broadcast transmitter of  claim 1 , wherein the data interleaver outputs interleaved enhanced data packets further include at least two known data sequences which are spaced N segments apart. 
     
     
       5. A method of processing broadcast data in a digital television (DTV) broadcast transmitter, the method comprising:
 randomizing, by a first randomizer, enhanced data; 
 performing, by a Reed Solomon (RS) frame encoder, at least one of error correction encoding and error detection encoding on the randomized enhanced data;performing, by a Reed Solomon (RS) frame encoder, RS encoding on an RS frame payload including 187*N bytes of the randomized enhanced data to add P bytes of RS parity data at each column of the RS frame payload and then Cyclic Redundancy Check (CRC) encoding on the RS frame payload having the RS parity data to add two bytes of CRC data at each row of the RS frame payload having the RS parity data, thereby generating an RS frame having a size of (187+P)*(N+2) bytes, wherein N is a number of columns in the RS frame payload, 187 is a number of rows in the RS frame payload and P is a number of bytes of the RS parity data; 
 encoding, by a block processor, the encoded enhanced data at a coding rate of 1/L, wherein L is greater than 1; 
 mapping, by a group formatting unit, the enhanced data encoded at the coding rate of 1/L to at least one region of a data group including a plurality of regions, the data group further including a plurality of known data sequences, RS parity data place holders and MPEG header data place holders; 
 deinterleaving, by a data deinterleaver, the data group; 
 adding, by a packet formatter, data of the deinterleaved data group to MPEG header data, thereby outputting enhanced data packets; 
 removing, by a packet formatter, the RS parity data place holders in the deinterleaved data group, replacing the MPEG header data place holders in the deinterleaved data group with MPEG header data, and outputting enhanced data packets; 
 randomizing, by a second randomizer, the MPEG header data in the enhanced data packets; 
 RS encoding, by an RS encoder, the enhanced data packets having the randomized MPEG header data in order to insert non-systematic RS parity data in predetermined positions within the enhanced data packets, wherein the non-systematic RS parity data are inserted in predetermined positions within the enhanced data packets; 
 interleaving, by a data interleaver, the RS encoded enhanced data packets; and 
 trellis-encoding, by a trellis encoder, data of the interleaved enhanced data packets, wherein and initializing memories of the trellis encoder are initialized by initialization data at a start of at least one known data sequence, wherein the initialization data by initialization data that are determined according to values of the memories. 
 
     
     
       6. The method of  claim 5 , wherein performing at least one of error correction encoding and error detection encoding comprises:
 performing at least one of RS encoding and Cyclic Redundancy Check (CRC) encoding on the randomized enhanced data; and   outputting an RS frame.   
     
     
       7. The method of  claim 6 , wherein the RS frame comprises an RS frame payload including the randomized enhanced data, RS parity data added at bottom ends of columns of the RS frame payload and CRC data added at right ends of rows of the RS frame payload further including the RS parity data. 
     
     
       8. The method of  claim 5 , wherein interleaving the RS encoded enhanced data packets comprises outputting the interleaved enhanced data packets further include at least two known data sequences which are spaced N segments apart.