外文原文
CDMA AND COMMUNICATION NETWORKS
The great attraction of CDMA (Code Division Multiple Access) technology from the beginning has been increased of extraordinary capacity improvement.
Over narrowband multiple access wireless technologies. Simple models suggest that the capacity improvement may be more than 20 times that of the existing narrowband cellular standards, such as AMPS in North America,NMT in Scandinavia,TACS in the United Kingdom.Historically,the capacity was calculated using simple parameters.Reality,of course, is much more complicated than the idealized models. Real cell coverage areas are highly irregular, not the neat hexagons found in textbook models. Offered load is not spatially uniform, changes dramatically with time-of-day, and is often subject to other uncontrollable influences.