UMTS evolved from 2G GSM and 2.5G GPRS; CDMA2000 evolved from the North America Standard IS-95
. The fundamental assumption in the standard is that the mobile devices can support multiple radio interfaces, both wired and wireless, such as Ethernet, Wi-Fi, Bluetooth, WiMax, GSM, GPRS, UMTS, and CDMA2000.
Figure 3 shows ACPR performance at 1960 MHz for IS-95
, while Figure 4 shows ACPR performance at 1840 MHz for CDMA2000 operation.
CDMA is a multiple access method used earlier in IS-95
(1), in which a communication channel is defined as a chip (2) sequence.
The 8650A can measure the peak and average power of TDMA, GSM and CDMA (IS-95
and third-generation 10-MHz wideband) signals.
The multicarrier (MC) mode will be based on cdma2000 standards and will provide an evolution path to 3G for many of the IS-95
operators in the United States.
The TQ3M31 amplifier offers a tri-mode, dual band CDMA (IS-95
standard) operation to enable mobile phones to function in various geographic markets.
and international markets for second-generation wireless networks, and it will support all digital cellular standards, including UMTS and 3G-1X (cdma2000), as well as IS-95
CDMA, GSM, and TDMA.
The company proposed most of what later became Interim Standard 95 (IS-95
) which defines a cellular system that uses direct sequence code division multiple access (CDMA-DS).
The predistorter also improves the adjacent channel power ratio (ACPR) by more than 10 dB for CDMA (IS-95
) 4FA signals.
IS-2000 is designed to support the evolution from today's IS-95
Dobson Cellular Systems will install Nortel Networks digital infrastructure equipment in Maryland, New York, Ohio and Pennsylvania under a three-year, US$30m contract for AMPS, TDMA IS-136 and cdmaOne IS-95
switching and radio equipment.
Figure 10 compares the results of the HPA nonlinear characteristics with and without the predistortor in the case of an IS-95
CDMA 1FA signal.