A digital television (DTV) transmitting system includes a first frame decoder, a second frame decoder, and a frame multiplexer. The first frame decoder forms first enhanced data frames, encodes each data frame for error correction, forms a first super frame by combining the encoded first frames, and interleaves the first super frame. The second frame decoder forms second enhanced data frames, encodes each data frame for error correction, forms a second super frame by combining the encoded second frames, and interleaves the second super frame. The frame multiplexer multiplexes the interleaved first and second enhanced data frames.