DTV receiving system and method of processing DTV signal
A digital television (DTV) receiving system includes a tuner, a demodulator, a known data detector, an equalizer, a transmission detector, and a block decoder. The tuner receives a DTV signal having a data frame in which main and mobile service data are multiplexed. The demodulator demodulates the DTV signal, and the known data detector detects known data included in the mobile service data. The equalizer equalizes the demodulated DTV signal using the detected known data, and the transmission parameter detector detects an error correction mode from the equalized DTV signal. Finally, the block decoder decodes the equalized DTV signal for error correction using the detected error correction mode.
1. A method of processing broadcast data in a broadcast transmitter, the method comprising:
performing, by a Reed Solomon (RS) encoder, RS encoding and Cyclic Redundancy Check (CRC) encoding on mobile service data, thereby packaging the mobile service data into an RS frame;
mapping, by a group formatter, the RS frame into a plurality of groups, wherein each of the plurality of groups includes a portion of the mobile service data in the RS frame, a first known data sequence, a plurality of second known data sequences, and a transmission parameter, wherein the first known data sequence has a first pattern and the plurality of second known data sequences have a second pattern other than the first pattern, wherein the transmission parameter is positioned between the first known data sequence and one of the plurality of second known data sequences, and wherein the first known data sequence and the one of the plurality of second known data sequences differ from each other in length; and
modulating, by a modulator, a broadcast signal including the plurality of groups.
2. The method of claim 1 , wherein the first pattern of the first known data sequence is configured in a same pattern repeated at least twice.
3. The method of claim 1 , wherein at least two of the plurality of second known data sequences have different lengths, and wherein the second pattern is positioned at last N symbols in each of the plurality of second known data sequences.
4. The method of claim 1 , wherein the RS frame comprises a payload of (N column*K row)-byte, RS parity data generated to each column direction based on the payload and CRC checksum data generated to each row direction based on the payload and the RS parity data, the payload including the mobile service data.
5. A broadcast transmitter comprising:
a Reed Solomon (RS) encoder for performing RS encoding and Cyclic Redundancy Check (CRC) encoding on mobile service data, thereby packaging the mobile service data into an RS frame;
a group formatter for mapping the RS frame into a plurality of groups, wherein each of the plurality of groups includes a portion of the mobile service data in the RS frame, a first known data sequence, a plurality of second known data sequences, and a transmission parameter, wherein the first known data sequence has a first pattern and the plurality of second known data sequences have a second pattern other than the first pattern, wherein the transmission parameter is positioned between the first known data sequence and one of the plurality of second known data sequences, and wherein the first known data sequence and the one of the plurality of second known data sequences differ from each other in length; and
a modulator for modulating a broadcast signal including the plurality of groups.
6. The broadcast transmitter of claim 5 , wherein the first pattern of the first known data sequence is configured in a same pattern repeated at least twice.
7. The broadcast transmitter of claim 5 , wherein at least two of the plurality of second known data sequences have different lengths, and wherein the second pattern is positioned at last N symbols in each of the plurality of second known data sequences.
8. The broadcast transmitter of claim 5 , wherein the RS frame comprises a payload of (N column*K row)-byte, RS parity data generated to each column direction based on the payload and CRC checksum data generated to each row direction based on the payload and the RS parity data, the payload including the mobile service data.