| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication terminal that properly controls the level of a reception signal and a transmission signal so as to attain normal communication. SOLUTION: The communication terminal 10 includes an RF circuit 12 which is provided with 2-stages of filters (IF-BPF) able to be connected in series. A CPU 16 uses a control channel to make communication with a wireless base station in a communication standby state and compares output the levels of the two-stage filters in this case. When the output levels are coincident, the CPU 16 discriminates that no other signal (disturbing signal) exists in the vicinity of the frequency band of the received signal and decides the number of the valid stage of the filters to be 1. On the other hand, when the output levels are non-coincident, the CPU 16 discriminates that a disturbing signal exists in the vicinity of the frequency band of the receive signal and decides the number of valid stages of the filters to be 2. Since the valid stage number of the filters is properly decided through the discrimination of the presence/no presence of the disturbing signal, the communication terminal can accurately detect the received signal. |
