A digital television receiving system includes a frame encoder, a data randomizing and expanding unit, a group formatter, a block processor, a deinterleaver, and a multiplexer. The frame encoder encodes an enhanced data frame for error correction. The data randomizing and expanding unit randomizes the encoded enhanced data and expands the randomized enhanced data. The group formatter forms a group of enhanced data having head, body, and tail regions and inserts the expanded data and transmission parameters into the body region. The block processor codes the group of enhanced data, and the deinterleaver deinterleaves the coded enhanced data. The packet formatter formats the deinterleaved enhanced data into enhanced data packets.