Method of a wide-band and weak spread spectrum signal demodulation using acousto-optic correlators

A method of correlative demodulation of a wide-band and weak spread spectrum signal is proposed using an acoustooptic correlator. A mathematical model of the acousto-optic correlator and photodetector is given, then the dynamic ranges of two kinds of diffraction light detection methods are derived. The effects of the Gaussian distribution of laser amplitude, laser window's function and the acoustic attenuation of medium on correlative peak and the main-peak to side-lobe are obtained by computer simulation and experiments. The principle experiment of acousto-optic correlative demodulation of the spread spectrum signal is done. The results of experiments are basically consistent with the theoretical analysis. The capabilities of the method are demonstrated.