The present invention relates to a method and apparatus for processing a signal. An object of the present invention devised to solve the problem lies on a method and apparatus for processing a signal, which allows a signal having optimized signal transmission efficiency to be transmitted/received. According to an aspect of the present invention, there is provided a method for processing a signal, the method including receiving a broadcasting signal including audio data coded using a pilot reference value and a pilot difference value, demodulating the broadcasting signal in consideration of a scattered pilot which varies over time and a continual pilot which is fixed over time in a frame of the received broadcasting signal and decoding the demodulated signal to obtain a broadcasting transmission stream, demultiplexing the broadcasting transmission stream to obtain coded audio data in an Internet protocol (IP) packet and audio data coding identification information, decoding data according to a data coding scheme indicated by the audio data coding identification information, wherein the data coding scheme includes at least a pilot coding scheme, the pilot coding scheme decodes the data using the pilot reference value corresponding to a plurality of data and the pilot difference value, and the pilot difference value is generated using the data and the pilot reference value.