An apparatus for transmitting or receiving a preamble in a Digital Video Broadcasting (DVB) system are provided. The apparatus includes a first processor for generating a Modulation Signaling Sequence (MSS) using a plurality of received sequences, and for outputting a modulated sequence by differentially modulating the MSS. The apparatus also includes a scrambler for scrambling the modulated sequence by multiplying the modulated sequence by a scrambling sequence. A second processor receives the scrambled sequence through each allocated subcarrier, converts the received sequence into a timedomain signal, and generates and transmits the preamble.