Open AccessBlind Adaptive Multiuser Detection for the MC‐CDMA Systems Using Orthogonalized Subspace Tracking
Author(s) -
Ali Imran,
Kim Doug Nyun,
Lim Jong Soo
Publication year - 2009
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.09.0108.0278
Subject(s) - multiuser detection , orthogonalization , code division multiple access , subspace topology , computer science , algorithm , convergence (economics) , eigenvalues and eigenvectors , artificial intelligence , telecommunications , physics , quantum mechanics , economics , economic growth
In this paper, we study the performance of subspace‐based multiuser detection techniques for multicarrier code‐division multiple access (MC‐CDMA) systems. We propose an improvement in the PASTd algorithm by cascading it with the classical Gram‐Schmidt procedure to orthonormalize the eigenvectors after their sequential extraction. The tracking of signal subspace using this algorithm, which we call OPASTd, has a faster convergence as the eigenvectors are orthonormalized at each discrete time sample. This improved PASTd algorithm is then used to implement the subspace blind adaptive multiuser detection for MC‐CDMA. We also show that, for multiuser detection, the complexity of the proposed scheme is lower than that of many other orthogonalization schemes found in the literature. Extensive simulation results are presented and discussed to demonstrate the performance of the proposed scheme.