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https://ptsldigital.ukm.my/jspui/handle/123456789/486947Full metadata record
| DC Field | Value | Language |
|---|---|---|
| dc.contributor.advisor | Mahamod Ismail, Assoc. Prof. Dr. | - |
| dc.contributor.author | Hussain Falih Mahdi (P54867) | - |
| dc.date.accessioned | 2023-10-11T02:26:50Z | - |
| dc.date.available | 2023-10-11T02:26:50Z | - |
| dc.date.issued | 2017-05-06 | - |
| dc.identifier.other | ukmvital:118429 | - |
| dc.identifier.uri | https://ptsldigital.ukm.my/jspui/handle/123456789/486947 | - |
| dc.description | Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Division Multiple Access (OFDMA) have gained incredible interest in last decade since it is spectrally efficient, inherent to Inter-System Interference (ISI), and robustness against multipath fading. This can be achieved by having efficient channel estimation (CE) methods such as Minimum Mean Square Error (MMSE) estimation that produces accurate channel information based on previously known channel statistical information but introduce higher computational complexity, using Blind, Semi-Blind and Pilot Assisted CE techniques. Moreover, low complexity channel state information (CSI) estimation techniques, such as Least Square (LS), are not efficient and may degrade bit error rate (BER) performance. Thus, in order to increase the spectrum efficiency and reducing computational complexity in OFDM/OFDMA based wireless system such as long term evolution/long term evolution-advanced (LTE/LTE-A), the minimum number of pilots should be determined. The main objective of the research is to develop and evaluate a low complexity and spectrally efficient channel estimation methods using intelligent swarm optimization for OFDM/OFDMA based wireless system. Different optimization methods are listed in the literature such as genetic algorithms. Three intelligent swarm's optimization methods have been adopted; Particle Swarm Optimization (PSO), Flower Pollination Optimization (FPO), and Cuckoo Search (CS) due to their simplicity as compared to MMSE with respect to the number of mathematical operations. The three optimization methods have been integrated in channel estimation model. The integrated channel model been simulated using MATLAB and the performance been evaluated based on BER and number of iteration to represent system spectral efficiency and computational complexity respectively. The pilot symbols in MMSE, PSO, and flower pollination methods are equally-spaced resulted in non-optimal performance. Therefore, CS method is used to determine the non-equally-spaced pilot distribution that minimize the BER. PSO and flower pollination based algorithms achieved almost similar performance as MMSE, however the number of pilot carriers used in the both algorithms reduced at most by halved. For instance, an OFDM with 1024 subcarriers,16-QAM mapping and BER of 10-3, the PSO computational complexity reduction factor (CCRF) is 89.73% and the SNR reduction is around 6 dB compared with MMSE method while the flower pollination CCRF and signal to noise ratio (SNR) reduction are 84.7% and 4 dB respectively. On the other hand, ELS-CS outperforms the LS with respect to SNR, when BER = 10-3, for instance, an OFDM symbol of size N = 1024 with 64-QAM mapping, the SNR was reduced from 40 dB to 28 dB. Hence, the performance of the OFDM system was enhanced more by using the ELS-CS algorithm.,"Certification of Masters/Doctoral Thesis" is not available,Ph.D. | - |
| dc.language.iso | eng | - |
| dc.publisher | UKM, Bangi | - |
| dc.relation | Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina | - |
| dc.rights | UKM | - |
| dc.subject | Swarm intelligence | - |
| dc.subject | Orthogonal frequency division multiplexing | - |
| dc.subject | Wireless communication systems | - |
| dc.subject | Universiti Kebangsaan Malaysia -- Dissertations | - |
| dc.subject | Dissertations, Academic -- Malaysia | - |
| dc.title | Channel estimation for wireless orthogonal frequency division multiplexing systems using intelligent swarm optimization | - |
| dc.type | Theses | - |
| dc.format.pages | 141 | - |
| dc.identifier.callno | Q337.3.M334 2017 3 tesis | - |
| dc.identifier.barcode | 004599(2020) | - |
| Appears in Collections: | Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina | |
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| File | Description | Size | Format | |
|---|---|---|---|---|
| ukmvital_118429+SOURCE1+SOURCE1.0.PDF Restricted Access | 601.26 kB | Adobe PDF |  View/Open |
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