Abstract

Digital radio transmission systems use complex modulation schemes that require powerful signal-processing techniques to correct channel distortions and to minimize bit error rates. Acousto-optic processors are used, in conjunction with adaptive digital equalizers, to reduce the bit error rate of the digital radio receiver. The acousto-optic processor implements an inverse channel filter that is rapidly adaptable to time-varying distortions. A specific architecture is identified and a laboratory system is tested to verify the ability of the processor to track and correct time-varying channels. Computer simulations are used to show that the hybrid acousto-optic and digital equalizer permits a fourfold increase in the modulation capacity of radio, relative to all digital equalization, while improving the bit error rate performance.

© 1993 Optical Society of America

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