A review of adaptive decorrelating detector techniques for direct-sequence code division multiple access (CDMA) signals is given. The goal is to improve CDMA system performance and capacity by reducing interference between users. The techniques considered are implementations of multiuser receivers, for which background material is given. Adaptive algorithms improve the feasibility of such receivers. An adaptive multiuser receiver for CDMA system has been proposed to increase system capacity. The adaptive decorrelator can be used to eliminate interference from known interferers, though it is prone to noise enhancement. However the receiver is basically designed for synchronous CDMA over AWGN channels. In order to confirm the robustness of the receiver for the asynchronous cases, experimental evaluations are displayed when the relative user delays are small compared to the symbol duration and when the channel is Rayleigh multipath fading as in micro-cellular scenarios. In addition to the efficient implementation of the decorrelating detector of [1], the receiver also can be adapted to incorporate decision feedback. Successive interference cancellation techniques reduce interference by cancellation of one detected signal from another. And an efficient incorporation of decorrelator with RAKE and (DF) decision feedback receiver for frequency-selective Rayleigh fading multipath channels is also proposed. Performance evaluation of the detector via computer simulation scenarios is conducted to substantiate it's potential for real-time operation.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0630100-150324 |
| Date | 30 June 2000 |
| Creators | Chang, Jr-Wen |
| Contributors | none, none, Shiuun-Jang Chern, none |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0630100-150324 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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