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Unified multiple-access performance analysis of several multirate multicarrier spread-spectrum systems

Nikjah, R ; Sharif University of Technology | 2006

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  1. Type of Document: Article
  2. Publisher: Sharif University of Technology , 2006
  3. Abstract:
  4. A unified multiple-access performance analysis and comparison of three multicarrier spread-spectrum multiple-access schemes, namely, MC-CDMA (Multicarrier Code-Division Multiple-Access), MC-FH (Multicarrier Frequency Hopping) and a hybrid of the above systems, called DS-MC-FH (Direct-Sequence MC-FH), in a multirate environment, where each user can have several multirate services, is provided. In MC-CDMA and MC-FH systems, users and their diverse services are differentiated by means of only one kind of signature code. However, in a DS-MCFH scheme, different users and different services of the same user are distinguished through the first and second signature codes, respectively. The performance of the above systems are evaluated and compared, using a unified structure in synchronous and asynchronous nonfading and synchronous correlated Rayleigh fading channels, with a Maximum-Ratio Combining (MRC) receiver. The near-far effect on the systems' performance is also investigated. The (second) signature in the MC-CDMA (D5-MC-FH) scheme is considered to be either a Pseudo-Noise (PN) sequence or a Walsh code. The authors analyses indicate that MC-CDMA systems with Walsh codes outperform the other schemes in different synchronous and asynchronous channels. DS-MC-FH systems with Walsh codes always surpass MC-FH systems. Furthermore, all of the schemes, except synchronous MC-CDMA systems with Walsh codes, are susceptible to a near-far effect with an MRC receiver. © Sharif University of Technology, January 2006
  5. Keywords:
  6. Code division multiple access ; Frequency hopping ; Rayleigh fading ; Maximum-ratio combining receiver ; Multirate multicarrier spread-spectrum systems ; Pseudo-noise sequence ; Signature code ; Walsh code ; Communication channels (information theory) ; Multicarrier modulation ; Radio receivers ; Spread spectrum communication ; Telecommunication services ; Algorithm ; Performance assessment ; Signal processing
  7. Source: Scientia Iranica ; Volume 13, Issue 1 , 2006 , Pages 33-49 ; 10263098 (ISSN)
  8. URL: http://scientiairanica.sharif.edu/article_2561.html