Non-orthogonal frequency division multiplexing with turbo equalization
Also available in printed version
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| Autres auteurs: | |
| Format: | Doctoral thesis |
| Langue: | anglais |
| Publié: |
Universiti Teknologi Malaysia
2025
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| Sujets: | |
| Accès en ligne: | https://utmik.utm.my/handle/123456789/60170 |
| Abstract | Abstract here |
| _version_ | 1854975091193937920 |
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| author | Norulhusna Ahmad |
| author2 | Norsheila Fisal, supervisor |
| author_facet | Norsheila Fisal, supervisor Norulhusna Ahmad |
| author_sort | Norulhusna Ahmad |
| description | Also available in printed version |
| format | Doctoral thesis |
| id | utm-123456789-60170 |
| institution | Universiti Teknologi Malaysia |
| language | English |
| publishDate | 2025 |
| publisher | Universiti Teknologi Malaysia |
| record_format | dspace |
| record_pdf | Abstract |
| spelling | utm-123456789-601702025-08-21T06:57:00Z Non-orthogonal frequency division multiplexing with turbo equalization Norulhusna Ahmad Norsheila Fisal, supervisor Electrical engineering Also available in printed version Bandwidth scarcity is one of the main concerns in telecommunication field and research on enhancing the efficiency of the bandwidth has attracted a lot of interest recently. The established Orthogonal Frequency Division Multiplexing (OFDM) technique can transmit high bit rate transmission, however it consumes high bandwidth. In order to enhance the bandwidth efficiency, non-OFDM (n-OFDM) technique has been introduced by reducing the subcarriers frequency spacing and/or shortening the symbol transmission time at the expense of losing the subcarriers orthogonality. As a result, the n-OFDM will suffer from severe Intercarrier Interference (ICI) and thus it increases the complexity of signal detection at the receiver. This thesis proposes a new Generalized Inverse Discrete Fourier Transform n-OFDM (GIDFT-nOFDM) system to further enhance the bandwidth efficiency and increase data rate transmission while minimizing interference. In the GIDFT-nOFDM system, non orthogonal signal is generated at the transmitter and detected using turbo equalization at the receiver. The Soft-Interference Cancellation Minimum Mean Squared Error (SC-MMSE) turbo equalization is developed to mitigate the problem of severe ICI in GIDFT-nOFDM. Then recursive systematic convolutional code (RSCC) and Repetition Code (RC) channel coding are applied to further enhance the error rate performance. The Doped Accumulator (DACC) is proposed to curtail the distance of GIDFT-nOFDM performance to theoretical limits. The results show that at bandwidth efficiency factor n = 2, the bandwidth efficiency of GIDFT-nOFDM system enhances up to 50% more efficient than OFDM system. It has been proven that with the same bandwidth usage, GIDFT-nOFDM can transmit 2.8 bits/s/Hz more than conventional n-OFDM. This is due to high mutual information totalling over subcarriers (MITS) achieved as more overlapping of non-orthogonal subcarriers being transmitted. The Bit-Error-Rate (BER) of 1 x 10-5 is achieved at Eb/N0 = 5 dB and bandwidth efficiency factor n = 5 due to the matching between RSCC and SC-MMSE turbo equalization. With further aid of DACC in GIDFT-nOFDM system, the Eb/N0 gain is improved by almost 9.5 dB and the distance to the theoretical limits is closer by 50% compared to the GIDFT-nOFDM without DACC. The use of RC as the channel coding in GIDFT-nOFDM with DACC shows the best matching with SC-MMSE-DACC. The overall result shows that GIDFT-nOFDM system ensures high bandwidth efficiency closer to theoretical limit. The GIDFT-nOFDM system has the potential to be applied in high bit rate future wireless communication system atiff UTM 179 p. Thesis (Ph.D (Kejuruteraan Elektrik)) - Universiti Teknologi Malaysia, 2014 2025-03-17T06:32:15Z 2025-03-17T06:32:15Z 2014 Doctoral thesis https://utmik.utm.my/handle/123456789/60170 valet-20170502-151512 vital:98571 ENG Closed Access UTM Complete Unpublished application/pdf Universiti Teknologi Malaysia |
| spellingShingle | Electrical engineering Norulhusna Ahmad Non-orthogonal frequency division multiplexing with turbo equalization |
| thesis_level | PhD |
| title | Non-orthogonal frequency division multiplexing with turbo equalization |
| title_full | Non-orthogonal frequency division multiplexing with turbo equalization |
| title_fullStr | Non-orthogonal frequency division multiplexing with turbo equalization |
| title_full_unstemmed | Non-orthogonal frequency division multiplexing with turbo equalization |
| title_short | Non-orthogonal frequency division multiplexing with turbo equalization |
| title_sort | non orthogonal frequency division multiplexing with turbo equalization |
| topic | Electrical engineering |
| url | https://utmik.utm.my/handle/123456789/60170 |
| work_keys_str_mv | AT norulhusnaahmad nonorthogonalfrequencydivisionmultiplexingwithturboequalization |