| 摘要 |
<p>AT THE TRANSMITTER (5) SIDE, CARRIER WAVES ARE MODULATED ACCORDING TO AN INPUT SIGNAL FOR PRODUCING RELEVANT SIGNAL POINTS IN A SIGNAL SPACE DIAGRAM. THE INPUT SIGNAL IS DIVIDED INTO, TWO, FIRST AND SECOND, DATA STREAMS. THE SIGNAL POINTS ARE DIVIDED INTO SIGNAL POINT GROUPS TO WHICH DATA OF THE FIRST DATA STREAM ARE ASSIGNED. ALSO, DATA OF THE SECOND DATA STREAM ARE ASSIGNED TO THE SIGNAL POINTS OF EACH SIGNAL POINT GROUP. A DIFFERENCE IN THE TRANSMISSION ERROR RATE BETWEEN FIRST AND SECOND DATA STREAMS IS DEVELOPED BY SHIFTING THE SIGNAL POINTS TO OTHER POSITIONS IN THE SPACE DIAGRAM EXPRESSED AT LEAST IN THE POLAR COORDINATE SYSTEM. AT THE RECEIVER (33, 43) SIDE, THE FIRST AND/OR SECOND DATA STREAMS CAN BE RECONSTRUCTED FROM A RECEIVED SIGNAL. IN TV BROADCAST SERVICE, A TV SIGNAL IS DIVIDED BY A TRANSMITTER (5) INTO, LOW AND HIGH, FREQUENCY BAND COMPONENTS WHICH ARE DESIGNATED AS A FIRST AND A SECOND DATA STREAMS RESPECTIVELY. UPON RECEIVING THE TV SIGNAL, A RECEIVER (33, 43) CAN REPRODUCE ONLY THE LOW FREQUENCY BAND COMPONENT OR BOTH THE LOW AND HIGH FREQUENCY BAND COMPONENTS, DEPENDING ON ITS CAP ABILITY. FURTHERMORE, A COMMUNICATION SYSTEM BASED ON AN OFDM SYSTEM IS UTILIZED FOR DATA TRANSMISSION OF A PLURALITY OF SUB CHANNELS, WHEREIN THE SUBCHANNELS ARE DIFFERENTIATED BY CHANGING THE LENGTH OF A GUARD TIME SLOT (797) OR A CARRIER WAVE INTERVAL OF A SYMBOL TRANSMISSION TIME SLOT (796), OR CHANGING THE TRANSMISSION ELECTRIC POWER OF THE CARRIER. (FIGURE 1)</p> |
