| 摘要 |
PROBLEM TO BE SOLVED: To transmit audio data without losing the real time performance at all times, even on a transmission line where a transmission frequency band fluctuates at all times. SOLUTION: Audio data are subject to time - frequency orthogonal transformation by an orthogonal transformation section 1, and the result is fed to a high-frequency component limit section 2. The high-frequency component limit section 2 limits a high-frequency component of frequency spectrum data, based on state information from a state selection section 3. A limit information addition section 4 adds a data size or a limit state or the like fed from the state selection section 3 to data whose high-frequency component is limited from the high-frequency component limit section 2 as the limit information. The data with the limit information added to them are sent to a transmission line via a transmission section 5. A transmission band monitor section 6 monitors a transmission frequency band of the transmission line. Then the state selection section 3 selects a limit state of the transmission of succeeding data based on the monitor result. A reception section compensates the information of the limited high-frequency component through an interpolation processing. |
