The in-band adjacent-channel
digital audio broadcasting system includes a scrambling unit for scrambling a
signal to be broadcasted, thereby generating a scrambled
signal; an outer coding unit for performing a first encoding of the scrambled
signal, thereby generating an outer encoded signal; an outer
interleaving unit for performing a first
interleaving of the outer encoded signal a
byte by
byte basis, thereby generating an outer interleaved signal; an inner coding unit for performing a second encoding the outer interleaved signal, thereby generating an inner encoded signal; an inner
interleaving unit for performing a second interleaving of the inner encoded signal, thereby generating an inner interleaved signal; a modulating unit for modulating the inner interleaved signal, thereby generating an
orthogonal frequency division multiplexing (OFDM) symbols; a
guard interval inserting unit for inserting a
guard interval between the OFDM symbols in order to eliminate an inter-symbol interference, thereby generating an OFDM frame; and an RF
processing unit for performing a conversion of the OFDM frame into an analog
radio frequency signal so that the OFDM signal can be transmitted in a specific frequency channel of an FM
frequency band, and for amplifying and outputting the analog
radio frequency signal.