Cyclic Delay Diversity (CDD) is a
diversity scheme used in
OFDM
In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital commu ...
-based telecommunication systems, transforming spatial diversity into frequency diversity and thus avoiding
intersymbol interference
In telecommunication, intersymbol interference (ISI) is a form of distortion of a signal in which one symbol interferes with subsequent symbols. This is an unwanted phenomenon as the previous symbols have a similar effect as noise, thus making ...
.
CDD was introduced in 2001 and can gain frequency diversity at the receiver without changing the
SISO receiver structure.
The idea of CDD for OFDM had previously also been submitted as a patent application in September 2000.
References
* Louay M.A. Jalloul and Sam. P. Alex, "Evaluation Methodology and Performance of an IEEE 802.16e System", Presented to the IEEE Communications and Signal Processing Society, Orange County Joint Chapter (ComSig), December 7, 2006. Available at: https://web.archive.org/web/20110414143801/http://chapters.comsoc.org/comsig/meet.html
* A. Dammann and S. Kaiser
Performance of low complex antenna diversity techniques for mobile OFDM systems In Proceedings 3rd International Workshop on Multi-Carrier Spread-Spectrum & Related Topics (MC-SS 2001), Oberpfaffenhofen, Germany, pages 53–64, Sept. 2001. .
* P. Larsson, US-6842487 B1, WO/2002/025857, "Cyclic Delay Diversity for Mitigating ISI in OFDM systems", filed 22 September 200
''First filed patent application'' PCT Biblio. data fro
''WIPO''
See also
*
OFDM
In telecommunications, orthogonal frequency-division multiplexing (OFDM) is a type of digital transmission and a method of encoding digital data on multiple carrier frequencies. OFDM has developed into a popular scheme for wideband digital commu ...
*
diversity scheme
Radio resource management
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