| 摘要 |
PURPOSE:To obtain a spread spectrum receiver whose reception characteristic is improved providing with an arithmetic operation means calculating a spread code and a signal converted by a conversion means in which the conversion means converts a frequency of a reception signal in response to an output of the arithmetic operation means so as to receive the signal correctly. CONSTITUTION:An inputted spread signal is converted into an IF frequency signal by a down-convert mixer 21 and the signal is fed to a correlation device 1. A spread signal is fed to the other input terminal of the correlation device 1. A detector 25 is provided to an output stage of the correlation device 1 to detect a correlation output, it is A/D-converted and the resulting signal is fed to a control section 27 of a local oscillator C for down-conversion. An optimum level of the detected output is set in advance to the control section 27, which controls setting data S1 fed to a PLL 28 so as to keep its optimum level. Then an oscillated frequency of a VCO 30 is locked to a desired frequency by using the PLL IC28 and an LPF 29. Thus, the correlation output keeps a proper level. |
