In this thesis, a precoding scheme is proposed for channel estimation in orthogonal frequency-division multiplexing (OFDM) systems. The precoding scheme utilizes a special code matrix before the inverse fast Fourier transform (IFFT) at the transmitter. The row vectors of the matrix have constant amplitudes in both time domain and frequency domain. With the prcoding scheme, a semi-blind channel estimation method is proposed by using the characteristics of the row code sequences. In the proposed scheme, the channel frequency responses of all sub-carriers can be obtained by using only one pilot sub-carrier, and the proposed architecture can not only increase the data rate, but also avoid interpolation error in channel estimation. In addition, the normalized mean square error (NMSE) function is derived and parameters are optimized to improve system performance. The proposed precoding architecture and channel estimation scheme are shown to have better performances in bit error rate by conducting computer simulation experiments.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0728106-132830 |
| Date | 28 July 2006 |
| Creators | Chen, Sheng-wen |
| Contributors | Mao-Ching Chiu, Chin-Liang Wang, Tsang-Yi Wang, Jyh-Horng Wen, Chih-Peng 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-0728106-132830 |
| Rights | withheld, Copyright information available at source archive |
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