Relay Deployment in Single Frequency Network

Future wireless communication systems would have to support very high data rates. As this vision is not feasible with the conventional cellular architecture without increasing the density of the base stations, in order to increase the capacity, different transmit diversity schemes have been heavily investigated in the past years. Relaying has been one of those areas investigated and has been proposed as a costly advantageous method to increase the radio coverage area. The scope of this thesis is to build a Matlab simula-tor for Digital Video Broadcasting-Handheld/Terrestrial (DVB-H/T) and Multimedia Broadcast Multicast Service (MBMS) in 3G systems and evaluate the performance of different relaying concepts. The simulated network is a single-frequency network (SFN) using orthogonal frequency-division multiplexing (OFDM) and the program is a physical layer simulator. The performance metric is the cumulative distribution function of the signal-to-interference-plus-noise-ratio (SINR) for different user positions in the network. Different simulations have been run to assess the impact of inter-site distance, asyn-chronity, and other factors such as distance from the border of two SFNs and effect of possible holes in the SFN grid. Then, the focus is on the impact of fixed relaying deployment using the amplify and forward protocol. The impact on the SINR is compared for different relaying gain and densities of relays, as well as different transmission protocol such as the full-duplex and half-duplex protocols. An investigattion is also made of where the relays should be located in the cells to obtain the best performance. Analysis is done at the center of the network and at the border of two SFNs. Acknowledgements The research work for this thesis was mostly carried out in the Signal Processing Laboratory at Helsinki University of Technology (TKK) during the years 2007 to 2008 in parallel with my studies as a degree student of the International Master in Communication Engineering. I wish to express my gratitude to my supervisor, Prof. Risto Wichman, for offering me the opportunity to work with him, his understanding and patience during the writing process, and all the academic helps he provided me. Many thanks go to my instructor, M.Sc. Taneli Riihonen, for his advices, support and numerous comments. Among the contributors to this thesis, I thank sincerely William Martin for the language comments. I would like also to thank my former French professors Jerome Mars and Jocelyn Chanussot, and the international student advisor of ENSIEG Max Ginier-Gillet for all their help, …