Abstract
This paper reviews and proposes blind multiuser detection techniques for space division multiple access systems. In this case, multiple users can be separated due to their spatial position by means of an adaptive antenna array. The constant modulus algorithm is employed in the array weights computation together with the concept of explicit decorrelation, for the sake to recover all users simultaneously. In order to improve the convergence rate and the steady-state error behavior, two new features are introduced. The first contribution is the proposition of a least-squares version of the CMA technique for multiuser detection. Afterwards an adaptive procedure is proposed to provide an improved explicit decorrelation. The performance improvements are confirmed bx some simulation results.
Résumé
Cet article présente et propose des techniques de détection aveugle multiutilisateur pour les systèmes d’accès multiple par répartition dans l’espace. Dans ce cas les utilisateurs peuvent être séparés à partir de leur position dans l’espace, à l’aide d’une antenne en réseau adaptative. L’algorithme du module constant (CMA), employé dans l’adaptation des coefficients de pondération, est combiné avec un concept de décorrélation explicite, dans le but de récupérer tous les utilisateurs. Pour améliorer la vitesse de convergence et l’erreur résiduelle en régime permanent, deux nouvelles approches sont introduites. Une première contribution propose une version en moindres carrés de la technique CMA pour la détection multiutilisateur. Une méthode adaptative est ensuite proposée pour améliorer la décorrélation explicite. Des résultats de simulation illustrent les gains de performances.
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Cavalcanti, R.P., Romano, M.T. Blind multiuser detection in space division multiple access systems. Ann. Télécommun. 54, 411–419 (1999). https://doi.org/10.1007/BF02997763
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DOI: https://doi.org/10.1007/BF02997763
Key words
- Space division multiple access
- Signal detection
- Complex signal
- Nonsupervised learning
- Antenna array
- Adaptive antenna
- Decorrelation
- Least squares method