In this thesis, we discuss multi-user detectors for synchronous and asynchronous DS-CDMA system. In synchronous case, we investigates the application of linear reinforcement learning stochastic approximation to the synchronous CDMA radio channels in the presence of multiple access interference (MAI) and additive Gaussian noise. However, the ODFD receiver requires the knowledge of the receiver energies. In order to overcome this problem, we apply well-known LSA algorithm to estimate all the user¡¦s energies. Numerical simulation shows that the performance of the ODFD-LSA is the same of origined ODFD with known user¡¦s energies.
In asynchronous case, we propose a blind adaptive approach to asynchronous DS-CDMA over multipath fading channels, termed GSCMCMA Approach. The GSCMCMA Approach use modified CMA algorithm in GSC structure with multipath constrained matrix. The CMA algorithm can not converge to unity When using constrained matrix in GSC structure. So we proposed modified CMA (MCMA) algorithm in GSC structure which can overcome such problem. In computer simulation, we will compare performance with existing MCMV and MMCMV detectors.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0611101-150439 |
| Date | 11 June 2001 |
| Creators | Chang, Chao-Hsi |
| Contributors | Shiunn-Jang Chern, Ching-Tai Chiang, Zhao-Hong Chen, Jun-Nan Li |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0611101-150439 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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