Single carrier VSB digital television transmission, single-frequency networks, and repeater systems

Operation of single-carrier and multiple carrier systems under conditions of deliberately introduced echoes is examined. Problems in addition to intersymbol interference, which is specifically alleviated in multiple carrier (OFDM) systems with guard intervals, are examined. It is shown that the only advantage of coded orthogonal frequency division multiplexing (COFDM) is in the case of simple binary modulation of its individual carriers, which is not adequate to carry the data required for digital television.