Although there are many types of spread spectrum communications systems, this presentation
gives an overview of the proposed CDMA cellular system defined by the TIA 45.5 sub-committee.
Largely based on the CDMA system developed by Qualcomm, the TIA system uses direct
sequence modulation with digital codes to spread its spectrum. Other types of spread spectrum
systems use frequency hopping techniques or a combination of frequency hopping and
modulation with digital codes (direct sequence). The intent of this paper is to provide insight into
the technology of CDMA and to describe some of the operating features of the now standardized
TIA CDMA system. The TIA standard documents that define this system are EIA/TIA-95-B (the
common air interface), EIA/TIA-98-B (mobile minimum performance standard), and EIA/TIA-97-B
(base station minimum performance standard). For PCS system