| 摘要 |
PROBLEM TO BE SOLVED: To execute a test for adjusting the direction of a receiving antenna even in a further slight reception electric field, and also, to allow a demodulator to grasp a state that it is in the middle of setting for the test. SOLUTION: In the transmission system, an OFDM signal including a guide interval period is transmitted with a transmitter 12. The OFDM signal is received with the receiving antenna 21. Correlation calculation in the guide interval period of the OFDM signal is executed with the demodulator 22. The direction of the receiving antenna is adjusted by generating a signal for adjusting the direction of the receiving antenna on the basis of a correlation signal obtained as a result of the correlation calculation. The transmitter 12 is equipped with amplitude converting means (61, 62) for making amplitude of a signal in the guide interval period larger than that of a signal in an effective symbol period. The demodulator 22 is equipped with a detection means 70 which detects the amplitude of the signal in the guide interval period of the received OFDM signal, and a notification means 80 for notifying an operator of the detected results. COPYRIGHT: (C)2006,JPO&NCIPI
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