SYSTEM FOR TRANSMITTING DIGITAL AUDIO BROADCASTING WITH IBAC TYPE

摘要

PURPOSE: A system for transmitting a digital audio broadcasting with an IBAC(In-Band Adjacent-Channel) type is provided to be unnecessary for securing a new frequency band by embodying a digital audio broadcasting service in a conventional FM frequency band. CONSTITUTION: A scrambler(20) scatters the energy of an output signal of a signal coding unit(10). An outer encoder(30) performs an RS encoding. An external interleaver(40) interleaves a packet with 204 bytes started as a synchronous code or an inverted synchronous code using a convolutional interleaver. An inner encoder(50) performs a convolution encoding. A signal mapper(70) enhances the use efficiency of a spectrum and secures a sufficient data transmission rate. A frame adaptation unit(90) composes a transmission frame using a signal inputted from a TPS(Transmission Parameter Signaling) and a pilot inserting unit(80) and an OFDM(Orthogonal Frequency Division Multiplexing) symbol. An IF(Intermediate Frequency) unit(100) converts the OFDM symbols into IF signals. A protection interval inserting unit(110) inserts a protection interval for removing an ISI(Inter-Symbol Interference). A D/A converter(120) converts a digital signal into an analog signal. A frequency upward device(130) performs frequency upward conversion for transmitting the IF signal in a specific frequency channel of an FM frequency band. A high power amplifier(140) amplifies an RF(Radio Frequency) signal.