A DTV transmitting system includes a frame encoder, a randomizer, a block processor, a group formatter, a deinterleaver, and a packet formatter. The frame encoder builds an enhanced data frame and adds parity data into the data frame. The frame encoder further divides the data frame into first and second sub-frames including first and second portions of the parity data, respectively, and permutes a plurality of the first sub-frames and a plurality of the second sub-frames, respectively. The randomizer randomizes enhanced data in the permuted sub-frames, and the block processor codes the randomized data at a rate of 1/N1. The group formatter forms a group of enhanced data having one or more data regions and inserts the 1/N1 coded data into at least one of the data regions. The deinterleaver deinterleaves the group of enhanced data, and the packet formatter formats the deinterleaved data into enhanced data packets.