DTV transmitting system and method of processing DTV signal

Abstract

A digital television (DTV) transmitting system is provided that includes an encoder, a group formatter, a packet formatter and a transmission unit. The group formatter forms data groups where the plurality of second known data sequences are spaced 16 segments apart within at least one of the data groups that includes a transmission parameter inserted between the first known data sequence and the plurality of second known data sequences and the first known data sequence has a first M-symbol sequence and a second M-symbol sequence, the first M-symbol sequence and the second M-symbol sequence have a first pattern, each of the plurality of second known data sequences has a second pattern other than the first pattern, and the second pattern is positioned from a last symbol to a previous N symbol in each of the plurality of second known data sequences.

What is claimed is: 
     
       1. An apparatus for transmitting a broadcast signal, the apparatus comprising:
 an encoder configured to encode mobile data for Forward Error Correction (FEC);   a group formatter configured to form data groups, wherein at least one the data groups includes the encoded mobile data, a first known data sequence, and a plurality of second known data sequences;   a packet formatter configured to format packets including data in the data groups; and   a transmission unit configured to transmit the broadcast signal including the packets,   wherein the plurality of second known data sequences are spaced 16 segments apart within the at least one of the data groups,   wherein the at least one of the data groups includes a transmission parameter inserted between the first known data sequence and one of the plurality of second known data sequences,   wherein the first known data sequence has a first M-symbol sequence and a second M-symbol sequence,   wherein the first M-symbol sequence and the second M-symbol sequence have a first pattern,   wherein each of the plurality of second known data sequences has a second pattern other than the first pattern, and   wherein the second pattern is positioned from a last symbol to a previous N symbol in each of the plurality of second known data sequences.   
     
     
       2. The apparatus of  claim 1 , further comprising a block processor configured to perform block processing on the encoded mobile data. 
     
     
       3. A method for transmitting a broadcast signal, the method comprising:
 encoding mobile data for Forward Error Correction (FEC);   forming data groups, wherein at least one of the data groups includes the encoded mobile data, a first known data sequence, and a plurality of second known data sequences;   formatting packets including data in the data groups; and   transmitting the broadcast signal including the packets,   wherein the plurality of second known data sequences are spaced 16 segments apart within the at least one of the data groups,   wherein the at least one of the data groups includes a transmission parameter inserted between the first known data sequence and one of the plurality of second known data sequences,   wherein the first known data sequence has a first M-symbol sequence and a second M-symbol sequence,   wherein the first M-symbol sequence and the second M-symbol sequence have a first pattern,   wherein each of the plurality of second known data sequences has a second pattern other than the first pattern, and   wherein the second pattern is positioned from a last symbol to a previous N symbol in each of the plurality of second known data sequences.   
     
     
       4. The method of  claim 3 , further comprising performing block processing on the encoded mobile data. 
     
     
       5. A method of processing broadcast data, the method comprising:
 first encoding the broadcast data to add parity data;   second encoding the first-encoded broadcast data based on different code rates;   interleaving the second-encoded broadcast data, wherein null data are used in a memory for the interleaving, wherein a number of interleaving data added by the null data are larger than a number of data to be interleaved, and wherein the null data are not read from the memory; and   transmitting a broadcast signal including known data that are previously known to a receiver and the interleaved broadcast data,   wherein the known data are used for channel estimation,   wherein the known data include at least two pre-defined patterns and are inserted in specific positions in signal frames,   wherein the signal frames include different regions for the broadcast data, the different regions having the broadcast data encoded in the different code rates and interleaved, and   wherein the signal frames further include signaling information and the signaling information includes information on the different code rates.   
     
     
       6. The method of claim 5, further comprising:
 further interleaving the interleaved broadcast data in a convolutional interleaving way.   
     
     
       7. An apparatus for processing broadcast data, the apparatus comprising:
 a first encoder that encodes the broadcast data to add parity data;   a second encoder that further encodes the encoded broadcast data based on different code rates;   an interleaver that interleaves the further encoded broadcast data, wherein null data are used in a memory for the interleaving, wherein a number of interleaving data added by the null data are larger than a number of data to be interleaved, and wherein the null data are not read from the memory; and   a transmitter that transmits a broadcast signal including known data that are previously known to a receiver and the interleaved broadcast data,   wherein the known data are used for channel estimation,   wherein the known data include at least two pre-defined patterns and are inserted in specific positions in signal frames,   wherein the signal frames include different regions for the broadcast data, the different regions having the broadcast data encoded based on the different code rates and interleaved, and   wherein the signal frames further include signaling information and the signaling information includes information on the different code rates.   
     
     
       8. The apparatus of claim 7, further comprising:
 a data interleaver that further interleaves the interleaved broadcast data in a convolutional interleaving way.