The cdma2000 System for Mobile Communications: 3G Wireless Evolution

Chapter 1 Introduction to CDMA

Spread spectrum transmission techniques, in most general terms, employ larger bandwidth than absolutely necessary to transmit a given amount of information. This is in contrast to the traditional approach in communications where a system designer attempts to maximize the amount of transmitted information per unit bandwidth, which is important for most communication channels and in particular when the bandwidth is scarce. The spectral redundancy introduced by means of spread spectrum transmission is exploited in a variety of communications systems. For example, spread spectrum is used to combat jamming or to facilitate low probability of intercept in military communications, and is used for accurate ranging and ...