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  1. en.wikipedia.org › wiki › UMTSUMTS - Wikipedia

    Though W-CDMA does use a direct-sequence CDMA transmission technique like CDMA2000, W-CDMA is not simply a wideband version of CDMA2000 and differs in many aspects from CDMA2000. From an engineering point of view, W-CDMA provides a different balance of trade-offs between cost, capacity, performance, and density [ citation needed ...

  2. Code-division multiple access ( CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communication channel. This allows several users to share a band of frequencies (see bandwidth ).

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  4. Freedom of Mobile Multimedia Access (FOMA) is the brand name of the W-CDMA-based 3G telecommunications services being offered by the Japanese telecommunications service provider NTT DoCoMo. It is an implementation of the Universal Mobile Telecommunications System (UMTS) and was the world's first 3G mobile data service to commence ...

  5. en.wikipedia.org › wiki › CDMA2000CDMA2000 - Wikipedia

    CDMA2000 compares to UMTS, a competing set of 3G standards, which is developed by 3GPP and used in Europe, Japan, China, and Singapore. The name CDMA2000 denotes a family of standards that represent the successive, evolutionary stages of the underlying technology. These are: Voice: CDMA2000 1xRTT, 1X Advanced.

  6. Multi-carrier code-division multiple access ( MC-CDMA) is a multiple access scheme used in OFDM -based telecommunication systems, allowing the system to support multiple users at the same time over same frequency band. MC-CDMA spreads each user symbol in the frequency domain.

  7. en.wikipedia.org › wiki › 3G3G - Wikipedia

    3G is the third generation of wireless mobile telecommunications technology. It is the upgrade over 2G, 2.5G, GPRS and 2.75G Enhanced Data Rates for GSM Evolution networks, offering faster data transfer, and better voice quality. [1] This network was superseded by 4G, and later on by 5G. This network is based on a set of standards used for ...

  8. Code-division multiple access (CDMA) This uses a digital modulation called spread spectrum which spreads the voice data over a very wide channel in pseudorandom fashion using a user or cell specific pseudorandom code. The receiver undoes the randomization to collect the bits together and produce the original data.