Gap filler apparatus and method for providing cyclic delay diversity in a digital multimedia broadcasting system, and broadcasting relay network using the same

A method for providing cyclic delay diversity in a gap filler including a receiver and a symbol synchronization unit for a digital multimedia broadcasting (DMB) system, the method comprising:

• receiving, by the receiver, an orthogonal frequency division multiplexing (OFDM) signal transmitted as a broadcasting signal;
• acquiring symbol synchronization of the received OFDM signal by the symbol synchronization unit using a predetermined number of stored initial symbols of the OFDM signal;
• detecting a guard interval of an OFDM symbol using the acquired symbol synchronization;
• determining a sample length by which the OFDM symbol is cyclic-delayed within the guard interval;
• storing a sample of the determined length from a symbol synchronization time;
• cyclic-delaying the OFDM signal by the determined sample length without the sample of the determined length;
• and
• adding the sample of the determined length to a last part of the cyclic-delayed OFDM symbol.

A broadcasting relay network for transmitting a broadcasting signal to a terminal in a digital multimedia broadcasting (DMB) system, comprising a plurality of gap fillers,

• wherein each of the gap fillers comprises:
• a receiver for receiving an orthogonal frequency division multiplexing (OFDM) signal transmitted as the broadcasting signal;
• a symbol synchronization unit for acquiring symbol synchronization of the OFDM signal using a predetermined number of stored initial symbols of the OFDM signal, detecting a guard interval of an OFDM symbol using the symbol synchronization, determining a sample length by which the OFDM symbol is cyclic-delayed within the guard interval, storing a sample of the determined length from a symbol synchronization time, cyclic-delaying the OFDM signal by the determined sample length without the sample of the determined length, and adding the sample of the determined length to a last part of the cyclic-delayed OFDM symbol;
• an amplifier for amplifying the cyclic-delayed OFDM signal;
• and
• a transmitter for transmitting the amplified OFDM signal to a wireless network.