A maximum likelihood CDMA receiver using the EM algorithm and the discrete wavelet transform

@inproceedings{citeulike:2355254, abstract = {A maximum likelihood (ML) method for joint estimation of amplitude, phase, time delay, and data demodulation in a single-user direct sequence spread spectrum communication system is developed. The likelihood function is analytically intractable, so a recursive estimation algorithm is considered. The expectation maximization (EM) algorithm has been used in similar problems, however, in this case it is not computationally efficient. A variant of the EM algorithm, called space alternating generalized EM (SAGE), has been derived. We apply the SAGE algorithm to the sequence estimation problem in a way which results in simple sequential updates of all the estimated parameters. An important feature of the proposed algorithm is the use of a discrete wavelet decomposition of the received signal as a sufficient statistic. The consequence is that all the information is still available to the receiver, while the complicated estimation problem is considerably simplified. Computer simulations of a single user system were performed. It is shown that the algorithm has a fast convergence, and essentially achieves optimal performance}, author = {Sharfer, I. and Hero, A. O. }, booktitle = {Acoustics, Speech, and Signal Processing, 1996. ICASSP-96. Conference Proceedings., 1996 IEEE International Conference on}, citeulike-article-id = {2355254}, doi = {10.1109/ICASSP.1996.548010}, journal = {Acoustics, Speech, and Signal Processing, 1996. ICASSP-96. Conference Proceedings., 1996 IEEE International Conference on}, keywords = {algorithm, cdma, ml, receiver, sage, wavelet}, pages = {2654--2657 vol. 5}, posted-at = {2008-02-09 00:58:54}, priority = {2}, title = {A maximum likelihood CDMA receiver using the EM algorithm and the discrete wavelet transform}, url = {http://dx.doi.org/10.1109/ICASSP.1996.548010}, volume = {5}, year = {1996} }

TY - CONF ID - citeulike:2355254 L3 - citeulike-article-id:2355254 TI - A maximum likelihood CDMA receiver using the EM algorithm and the discrete wavelet transform T2 - Acoustics, Speech, and Signal Processing, 1996. ICASSP-96. Conference Proceedings., 1996 IEEE International Conference on JF - Acoustics, Speech, and Signal Processing, 1996. ICASSP-96. Conference Proceedings., 1996 IEEE International Conference on VL - 5 SP - 2654 EP - 2657 vol. 5 N2 - A maximum likelihood (ML) method for joint estimation of amplitude, phase, time delay, and data demodulation in a single-user direct sequence spread spectrum communication system is developed. The likelihood function is analytically intractable, so a recursive estimation algorithm is considered. The expectation maximization (EM) algorithm has been used in similar problems, however, in this case it is not computationally efficient. A variant of the EM algorithm, called space alternating generalized EM (SAGE), has been derived. We apply the SAGE algorithm to the sequence estimation problem in a way which results in simple sequential updates of all the estimated parameters. An important feature of the proposed algorithm is the use of a discrete wavelet decomposition of the received signal as a sufficient statistic. The consequence is that all the information is still available to the receiver, while the complicated estimation problem is considerably simplified. Computer simulations of a single user system were performed. It is shown that the algorithm has a fast convergence, and essentially achieves optimal performance KW - algorithm KW - cdma KW - ml KW - receiver KW - sage KW - wavelet AU - Sharfer, I AU - Hero, AO PY - 1996/// UR - http://dx.doi.org/10.1109/ICASSP.1996.548010 ER -