| 摘要 |
PURPOSE:To minimize the level variation of a single component caused by the C/N variation of a received input spread spectrum wave by controlling the gain of the received spread spectrum wave in accordance with the peak value of an output from a matched filter. CONSTITUTION:The peak value of an output from the digital matched filter 6 is digitally detected by a peak detector 21, then the result is converted to an analog signal by a D/A converter 22, smoothed by an AGC filter 4 and thus is made a control voltage for a gain control circuit 2. Accordingly, output signals from the circuit 2 are so gain-controlled automatically that the peak values of outputs from the filter 6 are always constant. In such a way, the level variation of a signal component caused by the C/N variation of a received input spread spectrum wave can be minimized, the capturing of a code by the matched filter 6 can be facilitated, and furthermore, code tracking by a delay lock loop can be stabilized. |
