Αντιμετώπιση παρεμβολών και έλεγχος πρόσβασης σε σύγχρονα ασύρματα τηλεπικοινωνιακά συστήματα

Μυριδάκης, Νικόλαος Ι.

Doctoral Thesis

Author

Μυριδάκης, Νικόλαος Ι.

Date

2013-06-10

Abstract

This dissertation addresses the problem of interference management in modern wireless telecom-munication networks. Particularly, the study is focused on systems that support orthogonal transmission in the domain of frequency, space and code, solely or jointly. The developed ap-proach is established in two frameworks. The main objective of the first framework is the anal-ysis, the evaluation and the optimization of the successive interference cancellation technique. The objective of the second one is the admission control and the radio resource management in such systems. Both frameworks are implemented in a receiver-centric regime. Firstly, the basic features of the transceiver and the wireless channel along with the interfer¬ence effect are analytically described. Furthermore, a detailed evaluation of the most important successive interference cancellation techniques is performed with respect to the receiver's per¬formance and complexity. Afterwards, a new technique is presented, which utilizes jointly two different equalization strategies for the signal detection, according to the appropriate switch¬ing method. The main objective at this point is the optimization of the performance-complexity tradeoff at the receiver side. Moreover, a theoretical performance analysis of the successive interference cancellation technique is provided and useful statistical metrics are derived in closed-form mathematical expressions. More specifically, some already published results are generalized, whereas the potential error propagation effect, caused by this technique, is analytically evaluated for the first time in the bibliography. Finally, a new admission control algorithm is presented, where the radio resource man¬agement to the system's users and the overall interference reduction are accomplished at the receiver. The main benefits of this approach are the optimization of the signal's robustness in terms of the error rate during the transmission and the reduction of the signaling overhead between the transmitter and the receiver.