CDMA digital cellular overview and field trials results

Since the late 1980s, QUALCOMM Incorporated, based in San Diego, California, firmly believed that code division multiple access (CDMA), a modulation and multiple access scheme based on spread spectrum communications, could form the basis for a spectrum-efficient, economical, and quality digital cellular radio network. QUALCOMM recognized that, as a well established technology, CDMA had significant advantages over other wireless modulation techniques. These advantages included the isolation provided by an antenna system, geometric spacing, power gating of transmissions by voice activity, power control, and very efficient modem and signal designs which use error-correction coding. To verify these advantages, QUALCOMM, with the support of key cellular industry organizations, designed, developed, and tested a unique system implementation of a CDMA radio network. This system has been deployed worldwide in various configurations and wireless applications such a cellular, PCS, and wireless local loops. To date, QUALCOMM has successfully manufactured, deployed, operated, and maintained over thirty (30) field systems throughout the United States, Europe, Asia, South America, and Australia. This extensive field experience demonstrates without a doubt the viability of and support for CDMA for digital wireless applications throughout the world.