Title :
EM-based blind demodulation of synchronous CDMA
Author :
Yao, Yingwei ; Poor, H. Vincent
Author_Institution :
Dept. of Electr. Eng., Princeton Univ., NJ, USA
Abstract :
The problem of blind detection in a synchronous CDMA system when there is no knowledge of the users´ spreading sequences is considered. An EM-based algorithm which exploits the finite alphabet property of the digital communications source is proposed. Simulations show that this approach, which makes use of knowledge of the subspace spanned by the signaling multiplex, achieves the Cramer-Rao lower bound. The issues of subspace estimation and timing acquisition are also considered
Keywords :
code division multiple access; demodulation; digital communication; maximum likelihood estimation; parameter estimation; spread spectrum communication; synchronisation; Cramer-Rao lower bound; EM-based algorithm; EM-based blind demodulation; blind detection; digital communications source; expectation maximization; finite alphabet property; signaling multiplex; simulations; spreading sequences; subspace estimation; synchronous CDMA; timing acquisition; Algorithm design and analysis; Array signal processing; Blind source separation; Code division multiplexing; Demodulation; Digital communication; Eigenvalues and eigenfunctions; Multiaccess communication; Signal processing; Timing;
Conference_Titel :
Spread Spectrum Techniques and Applications, 2000 IEEE Sixth International Symposium on
Conference_Location :
Parsippany, NJ
Print_ISBN :
0-7803-6560-7
DOI :
10.1109/ISSSTA.2000.876532
