Wavelets and Filter Banks in Spread Spectrum Communication Systems

Abstract

In recent years, interest in spread spectrum communication techniques has expanded from the military into the commercial domain. The term “spread spectrum” refers to a class of digital modulation techniques that produces a transmitted frequency spectrum much larger than the bandwidth of the information being transmitted. For example, a data sequence having a rate of several kilobits per second (kbps) may be transmitted using a signal having a bandwidth of several MHz. While this may seem wasteful of bandwidth, the process of “spreading” and “despreading” the spectrum produces some important, desirable properties. It is interesting to note that when used in a multiuser environment, spread spectrum techniques can actually be more bandwidth efficient than narrow-band techniques.