Intelligent genetic algorithms for next-generation broadband multi-carrier CDMA wireless networks

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This dissertation proposes a novel intelligent system architecture for next-generation broadband multi-carrier CDMA wireless networks. In our system, two novel and similar intelligent genetic algorithms, namely Minimum Distance guided GAs (MDGAs) are invented for both peak-to-average power ratio (PAPR) reduction at the transmitter side and multi-user detection (MUD) at the receiver side. Meanwhile, we derive a theoretical BER performance analysis for the proposed MC-CDMA system in A WGN channel. Our analytical results show that the theoretical BER performance of synchronized MC-CDMA system is the same as that of the synchronized DS-CDMA system which is also used as a theoretical guidance of our novel MUD receiver design. In contrast to traditional GAs, our MDGAs start with a balanced ratio of exploration and exploitation which is maintained throughout the process. In our algorithms, a new replacement strategy is designed which increases significantly the convergence rate and reduces dramatically computational complexity as compared to the conventional GAs. The simulation results demonstrate that, if compared to those schemes using exhaustive search and traditional GAs, (1) our MDGA-based P APR reduction scheme achieves 99.52% and 50+% reductions in computational complexity, respectively; (2) our MDGA-based MUD scheme achieves 99.54% and 50+% reductions in computational complexity, respectively. The use of one core MDGA solution for both issues can ease the hardware design and dramatically reduce the implementation cost in practice

Intelligent genetic algorithms for next-generation broadband multi-carrier CDMA wireless networks

This dissertation proposes a novel intelligent system architecture for next-generation broadband multi-carrier CDMA wireless networks. In our system, two novel and similar intelligent genetic algorithms, namely Minimum Distance guided GAs (MDGAs) are invented for both peak-to-average power ratio (PAPR) reduction at the transmitter side and multi-user detection (MUD) at the receiver side. Meanwhile, we derive a theoretical BER performance analysis for the proposed MC-CDMA system in A WGN channel. Our analytical results show that the theoretical BER performance of synchronized MC-CDMA system is the same as that of the synchronized DS-CDMA system which is also used as a theoretical guidance of our novel MUD receiver design. In contrast to traditional GAs, our MDGAs start with a balanced ratio of exploration and exploitation which is maintained throughout the process. In our algorithms, a new replacement strategy is designed which increases significantly the convergence rate and reduces dramatically computational complexity as compared to the conventional GAs. The simulation results demonstrate that, if compared to those schemes using exhaustive search and traditional GAs, (1) our MDGA-based P APR reduction scheme achieves 99.52% and 50+% reductions in computational complexity, respectively; (2) our MDGA-based MUD scheme achieves 99.54% and 50+% reductions in computational complexity, respectively. The use of one core MDGA solution for both issues can ease the hardware design and dramatically reduce the implementation cost in practice.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Timing and Carrier Synchronization in Wireless Communication Systems: A Survey and Classification of Research in the Last 5 Years

Timing and carrier synchronization is a fundamental requirement for any wireless communication system to work properly. Timing synchronization is the process by which a receiver node determines the correct instants of time at which to sample the incoming signal. Carrier synchronization is the process by which a receiver adapts the frequency and phase of its local carrier oscillator with those of the received signal. In this paper, we survey the literature over the last 5 years (2010–2014) and present a comprehensive literature review and classification of the recent research progress in achieving timing and carrier synchronization in single-input single-output (SISO), multiple-input multiple-output (MIMO), cooperative relaying, and multiuser/multicell interference networks. Considering both single-carrier and multi-carrier communication systems, we survey and categorize the timing and carrier synchronization techniques proposed for the different communication systems focusing on the system model assumptions for synchronization, the synchronization challenges, and the state-of-the-art synchronization solutions and their limitations. Finally, we envision some future research directions

New detection schemes for DS/CDMA with antenna arrays.

by Siu-Lung Hui, Freeman.Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.Includes bibliographical references (leaves 64-[67]).Abstract also in Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Use of Antenna Arrays in Mobile Communications --- p.1Chapter 1.1.1 --- Overview --- p.1Chapter 1.1.2 --- Beamforming --- p.2Chapter 1.2 --- DS/CDMA System s and Multiple Access Interferences --- p.4Chapter 1.3 --- Multiuser Detection Schemes --- p.7Chapter 1.4 --- Outline of Thesis --- p.11Chapter 2 --- A Blind Adaptive Receiver with Antenna Arrays and M-ary Orthogonal Data Signals --- p.13Chapter 2.1 --- Introduction --- p.13Chapter 2.2 --- System Model --- p.15Chapter 2.3 --- Eigen-Analysis Algorithm --- p.21Chapter 2.4 --- Simulation Results --- p.92Chapter 2.5 --- Adaptive Algorithm --- p.27Chapter 2.6 --- Summary --- p.30Chapter 3 --- Detection with the Use of the Two-Stage Spreading Scheme --- p.32Chapter 3.1 --- Introduction --- p.32Chapter 3.2 --- System Model --- p.34Chapter 3.3 --- Blind Beamforming --- p.36Chapter 3.4 --- Blind Adaptive Multiuser Detection without Antenna Arrays --- p.38Chapter 3.4.1 --- Stochastic Gradient Descent Algorithm --- p.40Chapter 3.4.2 --- Alternative Matrix Approach --- p.41Chapter 3.5 --- Theoretical Combined Receiver Model --- p.41Chapter 3.6 --- Practical Implementation of the Receiver --- p.50Chapter 3.6.1 --- Combined Scheme with Adaptive Algorithms --- p.50Chapter 3.6.2 --- Simplified Structure --- p.52Chapter 3.7 --- Summary --- p.54Chapter 4 --- Conclusions and Future Work --- p.55Chapter A --- Correlation Properties --- p.58Chapter B --- Adaptive Algorithm --- p.62Bibliography --- p.6