Digital Filters

Abstract

One of the most important applications for digital signal processing in communications equipment is filtering. Filtering allows the selection of the desired signal and the rejection of unwanted signals and noise. The demands of modern communications equipment are often quite severe in this respect and, consequently, many of the filters used in modern equipment are difficult to build using analog techniques. There is also a considerable amount of variation from unit to unit in analog filters, which forces the manufacturer to perform extensive testing on each unit. It is not surprising that digital filters are playing an increasingly important role in the design of high-performance communications equipment.