A method of processing a signal is disclosed. The present invention includes receiving a maximum number of band and a code value of at least one section length, calculating a bit number corresponding to the code value of the at least one section length using the maximum number of the band, and obtaining the section length information by decoding the code value of the section length based on the bit number. A method of processing a signal is disclosed. The present invention includes receiving factor information of a current frame, receiving flag information indicating whether a coding mode of the factor information is an absolute value mode or a relative value mode, and obtaining factor data of the current frame using factor data of a previous frame and the received factor information based on the flag information.