25-08-2017, 09:32 PM
WCDMA is direct spread technology, which means that it will spread its transmissions over a wide, 5MHz carrier. Hence the name W (wideband) CDMA. WCDMA is the leading 3G wireless standard in the world today. It was adopted as a standard by the ITU under the name "IMT-2000 direct spread." WCDMA is the technology used in the Universal Mobile Telecommunications System (UMTS), and with data rates up to 2Mbits it has the capacity to easily handle bandwidth-intensive applications such as video, data, and image transmission necessary for mobile internet services. Operators such as Vodafone, Singtel, AT&T and TIM have chosen WCDMA/UMTS as their 3G solution. W-CDMA can support mobile/portable voice, images, data, and video communications at up to 2 Mbps (local area access) or 384 Kbps (wide area access).Because of its application in the upcoming new techonolgies in mobile communication such as 3G mobiles WCDMA is gaining popularity.
WCDMA is the successor of CDMA. CDMA employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code) to allow multiple users to be multiplexed over the same physical channel. By contrast, time division multiple access (TDMA) divides access by time, while frequency-division multiple access (FDMA) divides it by frequency. CDMA is a form of "spread-spectrum" signaling, since the modulated coded signal has a much higher data bandwidth than the data being communicated. CDMA technology is being used in GSM mobiles.