25-08-2017, 09:32 PM
The world is demanding more from wireless communication technologies than ever before. More people around the world are subscribing to wireless services and consumers are using their phones more frequently. Exciting Third-Generation (3G) wireless data services and applications - such as wireless email, web,digital picture taking/sending and assisted-GPS position location applications - and wireless networks have also arrived and asked to do much more than just a few years ago. This is where CDMA technology fits in. CDMA consistently provides better capacity for voice and data communications than other commercial mobile technologies, allowing more subscribers to connect at any given time, and it is the common platform on which 3G technologies are built. Two transmission modes?the frequency division duplex FDD) mode and the time division duplex (TDD) mode?are considered in the CDMA proposals for IMT-2000. Among these, the CDMA system with TDD mode (CDMA/TDD system) has become highly attractive for supporting multimedia services under micro/pico cell environments. . It is believed that while 1G and 2G systems were dominated by the FDD mode, 3G and 4G systems will be mostly based on the TDD mode of communications.