Modulated signal generation apparatus for a digital communication system incorporating fading simulator

摘要

A modulated signal generation apparatus incorporates a fading simulator for fading a signal to be transmitted to a device to be tested. A baseband signal generation unit (21) generates a digital baseband signal at a predetermined clock rate, and sequentially outputs time information corresponding to the predetermined clock rate. A fading parameter generation unit (32, 31) receives the time information together with the digital baseband signal, and outputs a desired fading parameter in correspondence with the time information. A fading addition operation unit (22) executes a fading addition operation for the digital baseband signal by using the desired fading parameter, and outputs a signal indicating the result. A digital/analog conversion unit (26a, 26b) D/A-converts the signal output from the fading addition operation unit (22). A quadrature modulation unit (27) quadrature-modulates the converted signal and outputs the quadrature-modulated signal as a modulated signal.