Title :
Estimation of time delays in multirate asynchronous DS-CDMA systems
Author :
Östman, Thomas ; Ottersten, Bjöm E. ; Milstein, Laurence B.
Author_Institution :
Signal Process., R. Inst. of Technol., Stockholm, Sweden
Abstract :
This article treats the problem of time delay estimation in a multirate asynchronous direct-sequence code-division multiple access (DS-CDMA) system in a near-far scenario. A subspace based algorithm for the time delay estimation problem is proposed. The algorithm is a minor modified version of the MUSIC estimator proposed by Ostman, Parkvall and Ottersten (see Proceedings of the 31st Asilomar Conference on Signals, Systems and Computers, 1997). Through theoretical analysis and simulations it is shown that the subspace approach to time delay estimation in a multirate DS-CDMA system is applicable when the algorithm is applied in a way such that the low-rank structure of the system is conserved
Keywords :
AWGN channels; code division multiple access; delay estimation; multiuser channels; pseudonoise codes; spread spectrum communication; AWGN channel; MUSIC estimator; direct-sequence code-division multiple access; low-rank structure; multirate asynchronous DS-CDMA systems; near-far problem; short spreading codes; simulations; subspace based algorithm; time delay estimation; AWGN; Delay effects; Delay estimation; Direct-sequence code-division multiple access; Filters; Multiaccess communication; Multiple signal classification; Niobium; Signal processing; Signal processing algorithms;
Conference_Titel :
Spread Spectrum Techniques and Applications, 1998. Proceedings., 1998 IEEE 5th International Symposium on
Conference_Location :
Sun City
Print_ISBN :
0-7803-4281-X
DOI :
10.1109/ISSSTA.1998.726204
