Macor- and Micro-diveristy for W-CDMA System Employing Smart Antennas
| Autor: | Ching-Ten Song, 宋經天 |
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| Rok vydání: | 2002 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 90 The macro- and micro-diversity schemes for the W-CDMA base stations deployed with smart antennae are investigated and their performances in terms of the improvement in the received bit energy to interference PSD ratio are evaluated, where both the adaptive and fixed beam schemes are considered for smart antenna systems. The macro-diversity scheme is employed to compensate the decrease of antenna gain when mobiles are located in the overlapping areas between two adjacent beams, while the micro-diversity is employed to collect the multi-path signals. A multi-path collecting algorithm is proposed to perform micro-diversity, and associate simulations are performed to evaluate its’ performance. We find that, for intra-cell macro-diversity, the average reduction of transmitted power is 30% for a beamwidth of 120 and a macro-diversity threshold of -1dB; while it is 8% for inter- cell macro-diversity for a threshold of +3dB. Consequently, the interference generated by mobiles is reduced and the bit-energy-to-interference PSD ratio is improved. In the micro-diversity, the proposed algorithm can provide at least 70% reduction in the number of search. For four resolvable paths, there is improvement on the received bit energy to interference PSD ratio in terms of a 3 dB increase in the mean value and a at least 1 dB decrease in the standard deviation. In general, both macro- and micro-diversity are indeed can be used to enhance the performance of CDMA systems deployed with smart antennae. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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