AN OPTIMAL DIVERSITY COMBINER FOR TROPOSCATTER COMMUNICATION RECEIVER

摘要

Abstract The present invention mainly relates to an optimal diversity combiner for a troposcatter communication receiver which enhances the signal reception at the receiver by exploiting multipath faded signals. The novel method of diversity combining is applicable for space diversity or frequency diversity or combination of these diversity input channels. Signals received by diversity branches of the receiver are uncorrelated most of the time due to the uncorrelated fading experienced at the different diversity channels and this property is used by the optimal diversity combiner with an appropriate algorithm to recover the original transmitted signal nullifying the effects of channel fading and eventually improving SNR. The algorithm for optimal diversity combining involves frequency offset correction and equalization performed jointly with the combiner. This method makes successive corrections to the weight vector of the equalizer of all the diversity branches simultaneously based on the combiner output rather than individual equalizer outputs. Optimal diversity combiner gives better performance at low SNR for heavily Rayleigh faded multipath channels. It achieves an enhanced data recovery performance at the digital troposcatter modem receiver by mitigating the effects of multipath fading, ISI and noise. Figure 2 (for publication)