Quality of Service aspects : low BER and low delay time
New Services and Capabilities in new generations
Enabling new voice and data service that are not currently available with 1G and 2G technology
High bandwidth services (data, image, multimedia)
0.2 Development of CDMA :
Spread spectrum communications originate from MIT Lincoln Labs since 1920’s.
The theory of spread spectrum communications has been well known since the late 1940's.
It has been used somewhat intensively in the field of secure military communications since 1950's, but in commercial applications it is a relatively new technique.
The spread spectrum technique has been released from military since 1970’s.
The first major commercial application of spread spectrum techniques was the Global Positioning System (GPS).
R.G. Cooper and Nettleton proposed the North American DS-CDMA systems in 1977. It is further commercialized by Qualcomm as narrowband CDMA(IS-95)
0.3 3G development history :
In 1985 ITU (International Telecommunication Union) proposed the 3G specification, which is called FPLMTS (Future Public Land Mobile Telecommunication Systems). In 1996 it is renamed as IMT-2000 (International Mobile Telecommunication) and defines the specifications
144K bps in fast moving speed
384K bps in walking, slow moving speed
2M bps in standstill environment
Proposals for 3G Standards
CDMA-2000 (North American)
It is proposed by Ericsson (Sweden) and NTT DoCoMo (Japan) which is an extension of GSM systems. In 2001, The first W-CDMA 3G service is proposed in Japan by the DoCoMo company.
It is an extension of narrowband CDMA (IS-95)
CDMA-2000 1X, wideband service, 307K bps in 1.25M Hz BW