Research On Synchronization Technology In Heterogeneous Broadcast/Multicast Radio Networks

Conventional cellular network provides ubiquitous network coverage and convenient services to mobile users,but the data transfer rate is relatively low. Wireless LAN has higher transfer rate compared to the cellular network. Therefore, the convergence of these two heterogeneous networks is one of the technological trends on heterogeneous network development. MBMS proposed by 3GPP has become popular recenly, but the cost to provide MBMS by cellular network is much expensive than that by WLAN.Therefore, research work on MBMS in converged heterogeneous networks becomes an urgent problem to solve.This thesis focuses on the research of synchronization technology based on the scenario of multi-domain wireless broadcast and multicast network. It includes two parts:MBMS content synchronization and OFDM timing synchronization in broadcast network. Both of the research works are based on the converged heterogeneous network.Synchronization is one of the key factors that affect wireless broadcast multicast network performance.By investigating the OFDM timing and frequency synchronization technologies in wireless broadcast network, the thesis focuses on the S&C algorithm which applies the training sequence and maximum likelihood estimation algorithm based on the Cyclix Prefix and an improved algorithm is presented.The improved algorithm effectively eliminates the plateau range exsiting in S&C algorithm by making use of the correlation between the training sequence part and the cyclic prefix part and calculating the start time of new arrival symbols,.The effectiveness of the improved algorithm was evaluated through simulation.In the thesis,MBMS content synchronization mechanism is studied. Firstly, a converged functional architecture between the Evolved Packet System and wireless local area network was provided, an access gateway between the WLAN AP and the EPS core network is introduced to achieve the network convergence function.Secondly, a new MBMS content synchronization mechanism was proposed, and an extension on the 3GPP SYNC protocol was presented.