DE-NOISING DIGITAL MICROWAVE SYSTEMS USING WAVELETS

Abstract

Digital microwave systems are radio communication systems using digital techniques and operated frequency ranges in the microwave region. An advantage of microwave is that transmission path is not completely interrupted by disasters or accidents (such as earthquakes, landslide, etc. Moreover, digital microwaves are robust in noise or interference on the transmission path and the signals can be easily processed using the memory, small and low-cost terminals. Beside these advantages, digital microwave systems have backwards addressed to fading, rain, radio interference, and systems required the synchronization as well. Wavelets is a method of analyzing signals into different frequency domains and studies each domain with a different discrimination. Although this method started in the early years of the century, it has only attracted our interest in recent years due to its advantages over other methods. Therefore, it has so many applications in image and audio signal processing, noise suppression, etc. This research will mention the approach of de-noising to improve the performance of digital microwave systems. The simulation programmed in Matlab 5.3 performs the QPSK, BPSK modulation and demodulation in the noise environment AWGN, Rayleigh fading channels, adjacent channels. The results are presented visually the BER cures corresponding to various mother Wavelets used for the processing.