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Errorless codes for over-loaded CDMA with active user detection

Pad, P ; Sharif University of Technology | 2009

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  1. Type of Document: Article
  2. DOI: 10.1109/ICC.2009.5199003
  3. Publisher: 2009
  4. Abstract:
  5. In this paper we introduce a new class of codes for over-loaded synchronous wireless CDMA systems which increases the number of users for a fixed number of chips without introducing any errors. In addition these codes support active user detection. We derive an upper bound on the number of users with a fixed spreading factor. Also we propose an ML decoder for a subclass of these codes that is computationally implementable. Although for our simulations we consider a scenario that is worse than what occurs in practice, simulation results indicate that this coding/decoding scheme is robust against additive noise. As an example, for 64 chips and 88 users we propose a coding/decoding scheme that can obtain an arbitrary small probability of error which is computationally feasible and can detect active users. Furthermore, we prove that for this to be possible the number of users cannot be beyond 230. ©2009 IEEE
  6. Keywords:
  7. Fixed numbers ; ML decoder ; Probability of errors ; Simulation result ; Spreading factor ; Upper Bound ; User detection ; Wireless CDMA ; Wireless telecommunication systems ; Code division multiple access
  8. Source: 2009 IEEE International Conference on Communications, ICC 2009, Dresden, 14 June 2009 through 18 June 2009 ; 2009 ; 05361486 (ISSN); 9781424434350 (ISBN)
  9. URL: https://ieeexplore.ieee.org/document/5199003