CDMA is the abbreviation of code-division multiple Access technology, it is a kind of advanced wireless spread spectrum communication technology in the process of digital mobile communication, it can satisfy the demand of the market for the capacity and quality of mobile communication, has high spectrum utilization, Good voice quality, confidentiality, low rate of drop, electromagnetic radiation small, large capacity, covering a wide range of characteristics, can greatly reduce investment and reduce operating costs.
CDMA was first introduced by Qualcomm, the same as GSM, CDMA also has 2 generations, 2.5 and 3 generations of technology. China Unicom will launch in the second half of this year CDMA belongs to 2.5 generation technology. CDMA is considered as the first choice for the 3rd generation Mobile communication technology, and the current standard has WCDMA, CDMA2000 and TD-SCDMA.
What is CDMA2000?
CDMA2000 is the name of the TIA standard organization used to refer to the third generation CDMA. The TIA specification for 3G CDMA is called IS-2000, and the technology itself is called CDMA2000.
The first phase of CDMA2000, also known as 1x, enables communications companies with existing IS-95 systems to increase their overall system capacity by one fold and increase the data rate to up to 614kbps.
Higher CDMA2000 technology than the 1x includes 1xEV (high-speed data rate).
The msm5000™ chipset CDMA2000 solution, launched by QCT, is backward-compatible cdmaone (IS-95 CDMA).
The CDMA2000 standard is developed by the 3GPP2 organization, and the release 0, releases A, ev-do and ev-dv,release 0 are mainly characterized by the use of a ansi-41d based core network to increase network entities that support packet operations in wireless access networks and core networks, This version has been stabilized. Unicom will soon open the second phase of the CDMA project is this version, single carrier maximum up and down line speed can reach 153.6kbit/s. Release A is the enhancement of release 0, the single carrier highest rate can reach 307.2kbit/s, and support voice service and packet business concurrency. Ev-do uses a separate carrier support data service, can be in the 1.25MHZ standard carrier, while providing voice and high-speed packet data services, the highest rate of up to 3.1mbit/s.