On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels
In the downlink of a synchronous direct sequence code division multiple access (DS-CDMA) system utilising orthogonal codes, intersymbol interference (ISI) arises due to multipath propagation, which destroys the code orthogonality and in turn, gives rise to multiple access interference (MAI). Therefo...
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| Format: | Article |
| Language: | English |
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INST ENGINEERING TECHNOLOGY-IET
2007
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| Online Access: | http://shdl.mmu.edu.my/3027/ http://shdl.mmu.edu.my/3027/1/1052.pdf |
| _version_ | 1848790214490718208 |
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| author | Ng, Y.H. Mohamad, H. Chuah, T.C. |
| author_facet | Ng, Y.H. Mohamad, H. Chuah, T.C. |
| author_sort | Ng, Y.H. |
| building | MMU Institutional Repository |
| collection | Online Access |
| description | In the downlink of a synchronous direct sequence code division multiple access (DS-CDMA) system utilising orthogonal codes, intersymbol interference (ISI) arises due to multipath propagation, which destroys the code orthogonality and in turn, gives rise to multiple access interference (MAI). Therefore if the ISI can be mitigated through channel equalisation, the MAI can be effectively reduced. However, existing channel equalisers are plagued with different performance and complexity issues. A sub-band adaptive chip equalising (SACE) receiver is proposed as an effective solution for performance enhancement over time-dispersive DS-CDMA downlinks. The SACE receiver exploits the pre-whitening effect of the filter banks to reduce the eigenvalue spread of the input signal covariance matrix. Results based on the popular COST-207 channel models for bad urban and hilly terrain areas are presented with varying loaded conditions. It is observed that in highly dispersive channels, the proposed SACE receiver significantly outperforms the correlation receiver and the full-band equaliser while retaining the desirable attribute of graceful degradation in CDMA networks. |
| first_indexed | 2025-11-14T18:09:03Z |
| format | Article |
| id | mmu-3027 |
| institution | Multimedia University |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T18:09:03Z |
| publishDate | 2007 |
| publisher | INST ENGINEERING TECHNOLOGY-IET |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | mmu-30272014-02-25T03:09:48Z http://shdl.mmu.edu.my/3027/ On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels Ng, Y.H. Mohamad, H. Chuah, T.C. T Technology (General) QA75.5-76.95 Electronic computers. Computer science In the downlink of a synchronous direct sequence code division multiple access (DS-CDMA) system utilising orthogonal codes, intersymbol interference (ISI) arises due to multipath propagation, which destroys the code orthogonality and in turn, gives rise to multiple access interference (MAI). Therefore if the ISI can be mitigated through channel equalisation, the MAI can be effectively reduced. However, existing channel equalisers are plagued with different performance and complexity issues. A sub-band adaptive chip equalising (SACE) receiver is proposed as an effective solution for performance enhancement over time-dispersive DS-CDMA downlinks. The SACE receiver exploits the pre-whitening effect of the filter banks to reduce the eigenvalue spread of the input signal covariance matrix. Results based on the popular COST-207 channel models for bad urban and hilly terrain areas are presented with varying loaded conditions. It is observed that in highly dispersive channels, the proposed SACE receiver significantly outperforms the correlation receiver and the full-band equaliser while retaining the desirable attribute of graceful degradation in CDMA networks. INST ENGINEERING TECHNOLOGY-IET 2007-08 Article NonPeerReviewed text en http://shdl.mmu.edu.my/3027/1/1052.pdf Ng, Y.H. and Mohamad, H. and Chuah, T.C. (2007) On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels. IET Communications, 1 (4). pp. 802-809. ISSN 17518628 http://dx.doi.org/10.1049/iet-com:20060529 doi:10.1049/iet-com:20060529 doi:10.1049/iet-com:20060529 |
| spellingShingle | T Technology (General) QA75.5-76.95 Electronic computers. Computer science Ng, Y.H. Mohamad, H. Chuah, T.C. On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels |
| title | On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels |
| title_full | On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels |
| title_fullStr | On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels |
| title_full_unstemmed | On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels |
| title_short | On sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels |
| title_sort | on sub-band adaptive chip equalisation for direct sequence code division multiple access downlink over dispersive channels |
| topic | T Technology (General) QA75.5-76.95 Electronic computers. Computer science |
| url | http://shdl.mmu.edu.my/3027/ http://shdl.mmu.edu.my/3027/ http://shdl.mmu.edu.my/3027/ http://shdl.mmu.edu.my/3027/1/1052.pdf |