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Improved MUSIC algorithm for the code-timing estimation of DS-CDMA multipath-fading channels in multiantenna systems
- Source :
- IEEE Transactions on Vehicular Technology. Sept, 2004, Vol. 53 Issue 5, p1354, 16 p.
- Publication Year :
- 2004
-
Abstract
- A multiple-signal-classification (MUSIC) approach of estimating the code timings of a desired user is considered for direct-sequence code-division multiple-access (DS-CDMA) multipath-fading channels when exploiting multiple receive antennas with either spatially uncorrelated or fully correlated fading. The acquisition performance of the conventional MUSIC timing estimator employing a single antenna is not good for the small size of observation windows and low signal-to-noise ratios (SNRs). Multiple antennas allow for rapid acquisition and lowers the range of detectable SNR. An efficient and improved MUSIC algorithm of estimating the multipath timings of a desired user for DS-CDMA systems is presented. In multipath-fading channels, the solution of the proposed algorithm is based on successively optimizing the cost function for increasing numbers of multipath delays, which does not require a multidimensional search for multidelay paths. Furthermore, the estimate of code timing at each path is obtained by finding the zeros of second-order polynomials, which is computationally efficient. The proposed MUSIC algorithm significantly improves the acquisition performance of conventional MUSIC algorithm in the presence of multipath time-varying Rayleigh-fading channels with arbitrary time delays. The acquisition performance of multiple antennas-based MUSIC timing estimators is much better than that of a single-antenna-based timing estimator. The Cramer-Rao bound for the code-timing estimator based on multiple antennas is presented. Index Terms--Code-division multiple access (CDMA), code-timing estimation, Cramer-Rao bound, multiantenna, multipath fading, synchronization.
Details
- Language :
- English
- ISSN :
- 00189545
- Volume :
- 53
- Issue :
- 5
- Database :
- Gale General OneFile
- Journal :
- IEEE Transactions on Vehicular Technology
- Publication Type :
- Academic Journal
- Accession number :
- edsgcl.123322945