Generally, many techniques for signal compression and recovery have been introduced so far. And, applicable targets of the corresponding techniques are various data including audio data, video data and the like. Moreover, the signal compression or recovery techniques evolve in a direction to enhancing audio or video quality with high compression rates. Besides, many efforts have been made to raise transmission efficiency for adaptation to various communication environments.
However, it is still believed that there exists a margin for the enhancement of the transmission efficiency. So, many efforts need to be made to maximize transmission efficiency of signals in the very complicated communication environments through the development of new processing schemes for signals.