This study is aimed at solving several important problems relating to power control in CDMA systems. Our focus is on the mobile to basestation (reverse) link. In this study, we propose a new SIR estimator for CDMA systems, using an auxiliary spreading sequence method. The proposed SIR estimator is employed at the basestation to estimate the SIR, which serves as a control parameter in the power control algorithm. The effects of system parameters (step size, power-update rate, feedback delay, SIR measurement error, and command error) on the bit error rate (BER) performance of power control are investigated. Feedback delay is found to be the most critical parameter that causes a serious problem in the loop. To solve this problem, we propose to use a channel prediction technique at the basestation. To further improve the performance of power control, we then propose to use a diversity reception technique using antenna arrays at the basestation. We show that this combination allows solving the problems linked to the use of power control in a real system affected by multiple access interference under fading conditions. / thesis (PhD)--University of South Australia, 2003.
| Identifer | oai:union.ndltd.org:ADTP/173397 |
| Date | January 2003 |
| Creators | Kurniawan, Adit |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright Adit Kurniawan 2003 |
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