know friends should know WCDMA mobile phone network, we can often see some people say that WCDMA mobile phone, so is WCDMA is what mean?A lot of friends may have experienced the question.Simple say WCDMA is a kind of wireless communication technology, widely used in communication field, at present China unicom is the WCDMA technology of 3 g communication standards, and this is why a lot of people say WCDMA mobile phone just know is China unicom brand.China mobile is using another telecommunications technology (GSM) here but, more detailed below what is the meaning of WCDMA.What is
wcdma is what meaning, wcdma network?
wcdma is English Wideband Code Division Multiple Access (Wideband Code Division Multiple Access) English abbreviation, is a third generation wireless technology.W - CDMAWideband CDMA is a kind of set by the 3 GPP concrete, based on the GSM core network MAP, UTRAN (UMTS terrestrial radio access network) for the wireless interface of the third generation mobile communication system.At present there are Release 99, Release 4, WCDMA Release version 5, and 6 Release, etc.China unicom has used this kind of 3 g communication standards.
wcdma (wideband code division multiple access) is an ITU (international telecommunication union) standards, it is from the code points evolved multiple access (CDMA), look from the official is believed to be direct extension of IMT - 2000, compared with the EDGE, it can be for mobile and portable wireless devices to provide higher data rate.WCDMA USES the direct sequence spread spectrum code division multiple access (DS - CDMA), frequency division duplex (FDD), code rate is 3.84 Mcps, carrier bandwidth for 5 MHZ. Based on the Release 99 version/Release 4, available in 5 MHZ bandwidth, provide up to 384 KBPS user data transmission rate.WCDMA can support mobile/portable devices between the voice, image, data and video communications, rate can be up to 2 MB/s (indoor static) or 384 KB/s (outdoor mobile).Input signal by digital first, and then in a wider range of spectrum code spread spectrum model for transmission.Narrowband CDMA is using a 200 KHZ carrier frequency width, and the use of WCDMA is a carrier of the width of the 5 MHZ.
wcdma by ETSI NTT DoCoMo as wireless interface for their FOMA development of 3 g networks.Later NTTDocomo itu-t is submitted to a detailed specification as a like IMT - 2000 as a candidate of the 3 g standards.The international telecommunication union (ITU) eventually accept w-cdma as part of the 3 g standard of the family of IMT - 2000.Later the WCDMA was chosen for UMTS wireless interface, as inheritance GSM 3 g technology or solution.Misunderstanding as name with CDMA is similar, but the WCDMA CDMA has little to do with.The standpoint of how big or small depends on different people.Term in the field of mobile phone, CDMA can generation refers to the CDMA spread spectrum reuse technology, can also refer to the United States Qualcomm, Qualcomm development including the IS - 95 / CDMA1X and CDMA2000 (IS - 2000) of CDMA standards.
wcdma has become the most widely used in countries and regions in the world, one of the most abundant types of terminal 3 g standard.538 WCDMA carriers in 246 countries and regions opened the WCDMA network, 3 g commercial market share of over 80%, and WCDMA downward compatible GSM network has covered 184 countries, all over the world, WCDMA users has exceeded 600 million.
now after China unicom's efforts to research and investment have now can be upgraded to HSPA +, 4 g system, has opened in Shanghai laboratories, speeds up to 21.9 MBPS transmission rate.The introduce WCDMA mobile phone
China's three big 3 g network is: China mobile, China unicom and China telecom, China unicom in WCDMA is, there are a lot of smart phone has indicated support WCDMA, then illustrates the smartphone is suitable for unicom WCDMA network.Such as: apple iPhone 4 s, samsung I9300, lenovo le Phone and so on.