Institutional Repository
Technical University of Crete
Technical University of Crete
EN
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EL
| URI | http://purl.tuc.gr/dl/dias/E3668D6D-4472-4467-85AB-CBA4C929FBB3 | - |
| Identifier | https://doi.org/10.26233/heallink.tuc.70091 | - |
| Language | en | - |
| Extent | 43 pages | en |
| Title | Asynchronous multi-user detection using inference algorithms | en |
| Title | Ασύγχρονη εκτίμηση πολλαπλών χρηστών με αλγόριθμους συμπερασμού | el |
| Creator | Tsetis Ioannis | en |
| Creator | Τσετης Ιωαννης | el |
| Contributor [Thesis Supervisor] | Bletsas Aggelos | en |
| Contributor [Thesis Supervisor] | Μπλετσας Αγγελος | el |
| Contributor [Committee Member] | Paterakis Michalis | en |
| Contributor [Committee Member] | Πατερακης Μιχαλης | el |
| Contributor [Committee Member] | Karystinos Georgios | en |
| Contributor [Committee Member] | Καρυστινος Γεωργιος | el |
| Publisher | Πολυτεχνείο Κρήτης | el |
| Publisher | Technical University of Crete | en |
| Academic Unit | Technical University of Crete::School of Electrical and Computer Engineering | en |
| Academic Unit | Πολυτεχνείο Κρήτης::Σχολή Ηλεκτρολόγων Μηχανικών και Μηχανικών Υπολογιστών | el |
| Content Summary | This work highlights state-of-the-art probabilistic graphical models and infer- ence algorithms that exploit rather than avoid the symbol-level asynchrony in multi-user wireless communications. More specically, the recently pro- posed inference algorithm SigSag is studied, where multiple users transmit their data packets at the same time and frequency channels, with however random delays; assuming channel state information (CSI) at the receiver, linear equations are formed, which produce a probabilistic graphical model (PGM), amenable to inference algorithms. This work implements the sum- product belief propagation algorithm on the crafted PGM and a) derives the message passing equations, b) studies initialization and c) complements with CSI estimation, using linear minimum mean squared error (LMMSE) estimator. Performance was tested for 2 or 3 users. It was found that per- formance was sensitive to initialization, as expected, due to the inherently loopy nature of the crafted PGM for small packet lengths. On the contrary, bit error rate (BER) decreases with increasing packet length, at the expense of convergence time. Moreover, reduced convergence time results to higher BER. | en |
| Type of Item | Διπλωματική Εργασία | el |
| Type of Item | Diploma Work | en |
| License | http://creativecommons.org/licenses/by/4.0/ | en |
| Date of Item | 2017-11-13 | - |
| Date of Publication | 2017 | - |
| Subject | Networking | en |
| Subject | Inference theory | en |
| Subject | Probabilistic graphical models | en |
| Subject | Detection & estimation theory | en |
| Bibliographic Citation | Ioannis Tsetis, "Asynchronous multi-user detection using inference algorithms", Diploma Work, School of Electrical and Computer Engineering, Technical University of Crete, Chania, Greece, 2017 | en |
| Bibliographic Citation | Ιωάννης Τσέτης, "Ασύγχρονη εκτίμηση πολλαπλών χρηστών με αλγόριθμους συμπερασμού ", Διπλωματική Εργασία, Σχολή Ηλεκτρολόγων Μηχανικών και Μηχανικών Υπολογιστών, Πολυτεχνείο Κρήτης, Χανιά, Ελλάς, 2017 | el |
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