Multipath fading effects on digital microwave links and countermeasures.

Abstract

Digital Microwave Systems suffer mainly from multipath fading, which is due to abnormal atmospheric conditions. There are two types of Multipath Fading, the Flat-Fading which degrades the system performance more than the usually considered Guassian Noise, and the Frequency-Selective Fading which deteriorates drastically the signal through Intersymbol Interference generation. The effective tool to combat MPF lies in the implementation of Equalizer systems at the receiving end, however, as the existing MPF channel modelling functions are numerous, the treatment of the Equalizers in these channel models exhibits different performances. The problem of multipath fading has been studies for different digital modulation schemes. The results were used to study the effects of digital equalization methods on the system performance in the presence of multipath phenomena.