Multi-carrier code-division multiple access: Difference between revisions

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{{Short description|Multiple access scheme in telecommunications}}

'''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.

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== Downlink: MC-CDM ==

In the downlink (one base station transmitting to one or more terminals), MC-CDMA typically reduces to Multi-Carrier Code Division Multiplexing. All user signals can easily be synchronized, and all signals on one subcarrier experience the same radio channel properties. In such case a preferred system implementation is to take N user bits (possibly but not necessarily for different destinations), to transform these using a Walsh [[Hadamard Transformtransform]], followed by an IFFT.

== Variants ==

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# [[OFDMA]] with time spreading ([[MC-DS-CDMA]] and [[MT-CDMA]])

# [[OFDMA]] with both time and frequency spreading (Orthogonal Frequency Code Division Multiple Access([[OFCDMA]]))

==See also==

* [[OFDMA]], an alternative multiple access scheme for OFDM systems, where the signals of different users are separated in the [[frequency ___domain]] by allocating different sub-carriers to different users.

==References==

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* Wireless Communication Reference Web Site, section about [http://www.wirelesscommunication.nl/reference/chaptr05/mccdma/mccdma.htm''MC-CDMA''], 2001.

==See also==

* [[OFDMA]], an alternative multiple access scheme for OFDM systems, where the signals of different users are separated in the [[frequency ___domain]] by allocating different sub-carriers to different users.

{{cdma}}

{{Channel access methods}}

[[Category:Code division multiple access]]