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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Adaptive Space-Time Receiver for DS-CDMA Communication Systems in Time-varying Multipath Channels

Lin, Yu-Fone 20 June 2001 (has links)
As the internet and multimedia transportation are envisaged as inherent functions, the generation CDMA system demands a dramatic bandwidth increase. It becomes an important topic to achieve high spectral efficiency over the limited available spectrum. Combing antenna array and equalizer structure, a space-time signal receiver is developed to overcome multiple access interference and intersymbol interference in DS-CDMA systems. In this paper, a space-time signal receiver based on the algorithm is developed for direct-sequence code-division multiple access (DS-CDMA) communication systems in time-varying multipath channels. At first, the received signal vectors of an antenna array at base station are constructed via the spatio-temporal correlation properties of time-varying multipath channels. The adaptive algorithm is employed to mitigate the Doppler¡¦s affect on the performance of signal detection. However, the computational burden of the algorithm is enormous. To reduce the computational complexity, the subweight partition technique is incorporated into the algorithm. The time-varying path directivity patterns for a receiver at base station are simulated. Computer simulations validate the advantages of the algorithm over the recursive least-squares (RLS) algorithm for the signal detection of the proposed space-time receiver.

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