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  2. Code-division multiple access - Wikipedia

    en.wikipedia.org/wiki/Code-division_multiple_access

    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 ).

  3. Comparison of mobile phone standards - Wikipedia

    en.wikipedia.org/wiki/Comparison_of_mobile_phone...

    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.

  4. CDMA2000 - Wikipedia

    en.wikipedia.org/wiki/CDMA2000

    CDMA2000 1X (IS-2000), also known as 1x and 1xRTT, is the core CDMA2000 wireless air interface standard.The designation "1x", meaning 1 times radio transmission technology, indicates the same radio frequency (RF) bandwidth as IS-95: a duplex pair of 1.25 MHz radio channels. 1xRTT almost doubles the capacity of IS-95 by adding 64 more traffic channels to the forward link, orthogonal to (in ...

  5. List of CDMA2000 networks - Wikipedia

    en.wikipedia.org/wiki/List_of_CDMA2000_networks

    Operator Country Technology Frequency (MHz) Launch date End of service Notes Movicel Angola CDMA2000 1xRTT, EV-DO Rev. A 800 Apr 2004: Mar 2016 [39] [40] [41]Hutchison 3

  6. UMTS - Wikipedia

    en.wikipedia.org/wiki/UMTS

    TD-CDMA, an acronym for Time-Division-Code-Division Multiple Access, is a channel-access method based on using spread-spectrum multiple-access (CDMA) across multiple time slots . TD-CDMA is the channel access method for UTRA-TDD HCR, which is an acronym for UMTS Terrestrial Radio Access-Time Division Duplex High Chip Rate.

  7. Chip (CDMA) - Wikipedia

    en.wikipedia.org/wiki/Chip_(CDMA)

    Chip (CDMA) In digital communications, a chip is a pulse of a direct-sequence spread spectrum (DSSS) code, such as a pseudo-random noise (PN) code sequence used in direct-sequence code-division multiple access (CDMA) channel access techniques. In a binary direct-sequence system, each chip is typically a rectangular pulse of +1 or −1 amplitude ...

  8. Channel access method - Wikipedia

    en.wikipedia.org/wiki/Channel_access_method

    The code-division multiple access (CDMA) scheme is based on spread spectrum, meaning that a wider radio channel bandwidth is used than the data rate of individual bit streams requires, and several message signals are transferred simultaneously over the same carrier frequency, utilizing different spreading codes.

  9. Spread spectrum - Wikipedia

    en.wikipedia.org/wiki/Spread_spectrum

    v. t. e. In telecommunication, especially radio communication, spread spectrum are techniques by which a signal (e.g., an electrical, electromagnetic, or acoustic) generated with a particular bandwidth is deliberately spread in the frequency domain over a wider frequency band. Spread-spectrum techniques are used for the establishment of secure ...