28-08-2017, 12:20 PM
In this section we offer a high level overview of the main radio interfaces of 3G systems and their properties. We turn first to CDMA2000 and the evolution of the North American CDMA system to 3G, and then we describe UMTS and the evolution of the GSM to 3G system.
CDMA2000, often called CDMA 3G, is a next generation of original IS-95A and IS-95B CDMA cellular systems. It has already been deployed in America, as well as in parts of Asia and Eastern Europe. CDMA2000 (RTT) radio transmission technology includes enhancements that effectively double the CDMA IS-95 spectral efficiency, as well as the number of simultaneous voice calls the system can handle. CDMA2000 uses transmission chip speeds, which are multiple of 1.2288 Mcps, which means that CDMA2000 cellular systems are compatible with the large installed base of CDMA IS-95 systems and CDMA2000 mobile terminals may be compatible with legacy systems . The CDMA 2000 deployment can support multiple bandwidths and frequency band plans, including PCS and IMT2000. CDMA2000 RTMA support for the 1.25 MHz deployment capability is especially important in North America where it enables CDMA companies to reuse their existing spectrum to offer CDMA2000 service by upgrading the equipment without the need to purchase new spectrum. This version of CDMA2000 had been called CDMA2000 phase one, or CDMA2000-1x RTT. The other version of CDMA2000 technology, called CDMA2000-3x, which represents the logical evolution of CDMA2000-1x, employs 5 MHz of bandwidth.
CDMA2000-1x will provide subscribers with the ability to transfer and receive packets at raw data rates of 153.6 Kbps or an effective data rate of up to 144 Kbps. CDMA2000-lx, like its predecessor, provides support for voice and data. The CDMA2000-1x physical layer incorporates a number of important enhancements that provide higher data rates and better spectral efficiency than second-generation CDMA systems. A burst mode capability is defined to allow better management of interference and capacity utilization. An active high-speed packet data mobile always has a traffic channel that uses a fundamental code. This channel is called the fundamental channel (FCH). An active high speed packet (HSPD) data call with the need for greater bandwidth, either forward or backward, could be assigned an additional channel for the duration of a data burst, which is order of seconds. The additional channel during this state is called Supplementary Channel (SCH), which allows a wide range of data rates; Unprocessed data rates from 9.6 Kbps to 307.2 Kbps are supported on each SCH. Although the numerology of the proposed CDMA2000-1x standard supports raw SCH data rates of up to 307.2 Kbps, it is envisaged that the maximum effective data rate that can be supported over a wide coverage area - with a single carrier of 1 , 25 MHz - About 150 Kbps. A SCH is usually assigned per data service. A SCH with a data rate of 19.2 Kbps or higher is equivalent to multiple voice calls from consideration of the air interface capability.
CDMA2000, often called CDMA 3G, is a next generation of original IS-95A and IS-95B CDMA cellular systems. It has already been deployed in America, as well as in parts of Asia and Eastern Europe. CDMA2000 (RTT) radio transmission technology includes enhancements that effectively double the CDMA IS-95 spectral efficiency, as well as the number of simultaneous voice calls the system can handle. CDMA2000 uses transmission chip speeds, which are multiple of 1.2288 Mcps, which means that CDMA2000 cellular systems are compatible with the large installed base of CDMA IS-95 systems and CDMA2000 mobile terminals may be compatible with legacy systems . The CDMA 2000 deployment can support multiple bandwidths and frequency band plans, including PCS and IMT2000. CDMA2000 RTMA support for the 1.25 MHz deployment capability is especially important in North America where it enables CDMA companies to reuse their existing spectrum to offer CDMA2000 service by upgrading the equipment without the need to purchase new spectrum. This version of CDMA2000 had been called CDMA2000 phase one, or CDMA2000-1x RTT. The other version of CDMA2000 technology, called CDMA2000-3x, which represents the logical evolution of CDMA2000-1x, employs 5 MHz of bandwidth.
CDMA2000-1x will provide subscribers with the ability to transfer and receive packets at raw data rates of 153.6 Kbps or an effective data rate of up to 144 Kbps. CDMA2000-lx, like its predecessor, provides support for voice and data. The CDMA2000-1x physical layer incorporates a number of important enhancements that provide higher data rates and better spectral efficiency than second-generation CDMA systems. A burst mode capability is defined to allow better management of interference and capacity utilization. An active high-speed packet data mobile always has a traffic channel that uses a fundamental code. This channel is called the fundamental channel (FCH). An active high speed packet (HSPD) data call with the need for greater bandwidth, either forward or backward, could be assigned an additional channel for the duration of a data burst, which is order of seconds. The additional channel during this state is called Supplementary Channel (SCH), which allows a wide range of data rates; Unprocessed data rates from 9.6 Kbps to 307.2 Kbps are supported on each SCH. Although the numerology of the proposed CDMA2000-1x standard supports raw SCH data rates of up to 307.2 Kbps, it is envisaged that the maximum effective data rate that can be supported over a wide coverage area - with a single carrier of 1 , 25 MHz - About 150 Kbps. A SCH is usually assigned per data service. A SCH with a data rate of 19.2 Kbps or higher is equivalent to multiple voice calls from consideration of the air interface capability.