A receiving system includes a tuner receiving a broadcast signal including data groups, each data group including enhanced data and known data sequences; a demodulator demodulating the received broadcast signal; a channel equalizer compensating channel distortions of the demodulated broadcast signal based on channel impulse responses (CIRs) estimated using at least two of the known data sequences; a block decoder decoding the enhanced data in the channel distortion compensated broadcast signal; a Reed-Solomon (RS) frame decoder correcting errors in the enhanced data based on a number of errors estimated by performing Cyclic Redundancy Check (CRC) decoding on an RS frame and a reliability map representing reliability information of the enhanced data; and a derandomizer derandomizing the error-corrected enhanced data.