| 摘要 |
PROBLEM TO BE SOLVED: To keep speech quality constant by using a band elimination filter with a simple configuration so as to eliminate an interference wave at a narrow band intruded in an optional frequency location in a broad band spread signal. SOLUTION: Part of a reception signal S1 is multiplied with a detection local signal S16 that is changing sequentially at a detection frequency converter 14 and converted into a detection intermediate frequency signal 17, and an electric field detector 19 measures an electric field level corresponding to the band characteristic. An arithmetic section 23 controls an oscillating frequency of 1st and 2nd local oscillators 5, 10 corresponding to the frequency at the maximum level, a frequency at a maximum level of the reception signal converted into a 1st intermediate frequency signal S7 is eliminated with respect to a center frequency of a band elimination filter BEF 8, the reception signal whose disturbing wavy component is eliminated is converted into a 2nd intermediate frequency signal S12 at a prescribed band and inversely spread and demodulated at a demodulator 29. |
