Digital television transmitter/receiver and method of processing data in digital television transmitter/receiver

Abstract

A digital television (DTV) transmitter and a method of coding data in the DTV transmitter are disclosed. A data formatter generates an enhanced data packet including the enhanced data and a known data sequence. A data randomizer randomizes the enhanced data packet. A RS encoder RS-codes the randomized data packet by adding first parity data, and a data interleaver interleaves the RS-coded data packet. A trellis encoding unit trellis-encodes the interleaved data packet. Herein the trellis encoding unit includes a TCM encoder for generating a first output bit by trellis-encoding a first input bit and generating a second output bit by bypassing the first input bit, and a pre-coder for generating a third output bit by pre-coding a second input bit, wherein memories included in the TCM encoder and the pre-coder are initialized when the known data sequence is inputted to the trellis encoding unit.

What is claimed is: 
     
       1. A transmitter of transmitter for transmitting a digital broadcast signal, the transmitter comprising:
 an encoder configured to encode enhanced data; 
 a packet formatter configured to generate enhanced data packets including the encoded enhanced data and known data sequences; 
 a first multiplexer configured to multiplex the enhanced data packets and main data packets having main data; 
 a data randomizer configured to randomize the main data in the multiplexed data packets; 
 a data interleaver configured to interleave data of the enhanced data packets in the multiplexed data packets and the randomized main data; 
 a trellis encoder configured to trellis-encode encoding unit that includes a second multiplexer and a trellis encoder having memories, 
 wherein the second multiplexer selects the interleaved data or initialization data obtained based on values of the memories, 
 wherein the trellis encoder trellis-encodes the selected data, and 
 and to initializewherein the memories included in the trellis encoderare initialized by using the initialization data at a start of at least one of the known data sequences; 
 a backward-compatibility processor configured to generate parity data based on the initialization data and provide the generated parity data to the trellis encoder encoding unit; and 
 a transmission unit configured to transmit a transmission frame including the trellis encoded data, 
 wherein the transmission frame has a plurality of segments, and 
 wherein the known data sequences are located in specific segments of the transmission frame. 
 
     
     
       2. The transmitter of  claim 1 , wherein the transmitter further comprises:
 an RS (Reed-Solomon) frame encoder configured to encode mobile data in the multiplexed data packets. 
 
     
     
       3. A method of transmitting a digital broadcast signal, the method comprising:
 encoding enhanced data; 
 generating enhanced data packets including the encoded enhanced data and known data sequences; 
 multiplexing the enhanced data packets and main data packets having main data; 
 randomizing the main data in the multiplexed data packets; 
 interleaving data of the enhanced data packets in the multiplexed data packets and the randomized main data; 
 selecting, by a trellis encoding unit having memories, the interleaved data or initialization data obtained based on values of the memories;  
 trellis-encoding the interleaved selected data; 
 initializing the memories included in a trellis encoder by using the initialization data at a start of at least one of the known data sequences; 
 generating parity data based on the initialization data; 
 providing the generated parity data to the trellis encoder encoding unit; and 
 transmitting a transmission frame including the trellis encoded data, 
 wherein the transmission frame has a plurality of segments, and 
 wherein the known data sequences are located in specific segments of the transmission frame. 
 
     
     
       4. The method of  claim 3 , further comprising RS (Reed-Solomon) encoding mobile data in the multiplexed data packets.