Method of generating residual signal, and encoder and decoder performing the method

A method of generating a residual signal performed by a decoder, the method comprising:

• unpacking a bitstream received from an encoder;
• dequantizing a third residual signal extracted from the unpacked bitstream;
• determining a second residual signal transformed into a frequency domain from the dequantized third residual signal, using frequency-domain prediction (FDP) decoding, wherein an information amount of the second residual signal is greater than that of the dequantized third residual signal;
• transforming the second residual signal transformed into the frequency domain into a time domain;
• and
• generating a first residual signal having a greater information amount than the second residual signal, by inversely transforming a second residual signal transformed into the time domain,
• wherein the determining of the second residual signal comprises:
• extracting peak information of the second residual signal from the unpacked bitstream;
• and
• generating the second residual signal transformed into the frequency domain from the dequantized third residual signal and the peak information.