Patent ID: 7801243

Claim:
A digital television (DTV) receiver for processing digital broadcast data, the DTV receiver comprising: a tuner for receiving a broadcast signal comprising a data group, the data group having first and second data regions, the first data region including main data and enhanced data, the second data region having enhanced data, regularly spaced known data sequences, and signaling information, wherein the broadcast signal results from: generating an RS frame by adding RS parity data and CRC data to enhanced data, encoding the enhanced data in the RS frame with an encoding rate of 1/H, wherein H≧2, interleaving symbols corresponding to the encoded enhanced data in a symbol interleaver, wherein the symbol interleaver interleaves the symbols using the following steps: calculating L, where L=2 m , where m is an integer, listing all permuted positions P′(i) in ascending order of i according to the following equation: P ′( i )={89 *i *( i +1)/2} mod L, where i is a natural number within 0 to L−1, discarding all P′(i) that are P′(i)≧B, B being a block length of symbols being input to the symbol interleaver, and condensing the list by, starting with a lowest i, shifting P(i) entries to the left to fill empty locations created by the discarding step, mapping enhanced data corresponding to the interleaved symbols into a data group and adding regularly spaced known data sequences and signaling information into the data group, trellis encoding the data group, and modulating the trellis-encoded data group; a demodulator for demodulating the broadcast signal; an equalizer for compensating channel distortion of the demodulated signal by using the known data sequences; an inner decoder for inner decoding the equalized signal; and an outer decoder for outer decoding the inner-decoded signal.