DocumentCode :
1192385
Title :
Synchronous CDMA based on the cyclical translations of a CAZAC sequence
Author :
Carni, Enrico ; Spalvieri, Arnaldo
Author_Institution :
Dipt. di Elettron. e Inf., Politec. di Milano, Milan
Volume :
8
Issue :
3
fYear :
2009
fDate :
3/1/2009 12:00:00 AM
Firstpage :
1144
Lastpage :
1147
Abstract :
A new scheme of synchronous CDMA is introduced in the paper. The new scheme is based on a code made by all the cyclical translations of a basic sequence having constant amplitude and white discrete spectrum. Such a code is proposed here for the first time as a code for CDMA. According to the proposed scheme, a cyclic prefix is appended to the multiplexed signal. The proposed scheme has a property that none of the known CDMA schemes has: in a multipath environment, it allows multiuser interference to become cyclic intersymbol interference. Noticeably, the memory of the finite state machine that describes the ISI model is equal to memory of the multipath channel. The main advantage of our proposed scheme is that optimal and suboptimal detectors can be obtained from detectors proposed in the past for the ISI channel, which are much easier to implement than conventional multiuser detectors of classical CDMA schemes. Another advantage of our scheme is that it leads naturally to a signal processing architecture similar to that of OFDM systems, hence based on the efficient FFT/IFFT algorithm.
Keywords :
channel coding; code division multiple access; cyclic codes; fast Fourier transforms; intersymbol interference; multipath channels; multiuser channels; sequences; signal detection; CAZAC sequence; FFT algorithm; IFFT algorithm; ISI model; cyclic intersymbol interference; cyclic prefix; cyclical translations; finite state machine; multipath channel; multiuser interference; optimal detectors; signal processing architecture; suboptimal detectors; synchronous CDMA; Automata; Code division multiplexing; Detectors; Intersymbol interference; Multiaccess communication; Multipath channels; Multiuser detection; OFDM; Signal detection; Signal processing algorithms; CAZAC sequences; ISI; MUI; Synchronous CDMA; cyclic prefix;
fLanguage :
English
Journal_Title :
Wireless Communications, IEEE Transactions on
Publisher :
ieee
ISSN :
1536-1276
Type :
jour
DOI :
10.1109/TWC.2009.080435
Filename :
4801461
Link To Document :
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