| 摘要 |
PROBLEM TO BE SOLVED: To enable high quality communication at a low cost and with low power consumption when communication using weak radio waves that do not need a license based on a radio law. SOLUTION: This device has a signal transmitting and receiving part 2 which transmits and receives a signal through an antenna 1 and also can output signal strength under a communication environment, a spread spectrum processing part 3 which performs spread spectrum processing of a signal to be transmitted when the signal is transmitted and applies inverse spread processing to a received signal when the signal is received and a controlling part 4 which calculates a noise level on the basis of signal strength obtained from the part 2 and sets a spread coefficient according to the noise level. When a user is on a receiving side, the spread coefficient set by the part 4 is notified to a transmitting side, and when the user is on a transmitting side, spread processing by the part 3 is performed according to the spread coefficient notified from the receiving side and data to be transmitted is sent to the receiving side. The part 4 also applies band control to a prescribed filter existing in the part 2 in accordance with the spread coefficient. |
