DESCRIPTION
This lecture describes common filtering techniques for reducing the occupied bandwidth of a communications channel. The more compact the spectrum, the more users that can be accommodated. This is a crucial issue for providers of wireless systems. The specific filters are uniform time filter, the optimum Nyquist filter, the raised cosine filter, and the root raised cosine filter. We describe not only the nature of these filters, but their intersymbol interference (ISI) performance when used as a matched filter for optimum detection.

PREREQUISITES
A basic background in communication theory, and an understanding of the relation of the time and frequency domain representation of signals via the Fourier transform