Research On Applications And Network Optimization Of EVDO Technology

In the process of CDMA development from the second generation to the third generation, EVDO (Evolution Data Only) serves as a technical standard which is likely to be widely used in the future. Compared to the Second Generation Mobile Communication System standard CDMA IX,the EVDO standard uses a series of critical technologies to optimize the packet data service and improve the frequency spectrum utilization. It can achieve a downlink peak rate of 3.1Mbps and uplink peak rate of 1.8Mbps. The critical technologies of EVDO standard mainly include: TDM (Time Division Multiplexer) in the forward link; adaptive modulation and coding; multi-user scheduling and virtual soft switch; rate control in the reverse link.Combined with some typical cases, A further research is made in this thesis about the principle and network application of EVDO standard. The main contents include:(1) Give a brief introduction of EVDO standard including the evolution process, the present situation of network development, the core design idea, and the functions of important units and interfaces of EVDO system. Moreover, aiming at the critical technologies to satisfy the demand of high speed packet data service, a detailed analysis is carried out in this thesis.(2) Based on the practical cases, the typical network model of EVDO system is presented. We focus on the function of each node equipment and the standard configuration of network ability.(3) Combined with the network optimization of CDMA 1X standard, this thesis investigates and summarizes the EVDO network optimization including the basic flow, key measures and optimization tips. Among them, the power limitation problem of the repeater in EVDO network environment is emphasized.(4) Data rate optimization and network coverage optimization are further studied, which are the most critical parts in EVDO network optimization. In the investigation of data rate optimization, several optimization methods are analyzed for the solutions of network coverage, skipping coverage and pilot frequency pollution. And some typical cases are given.(5) Aimed at the most common faults (mainly interference and noise), complete solutions are presented according to the causes such as the quality of antenna, the interference of users, the equipment malfunction, etc.Through this paper, wireless network engineers can quickly master the key principles of EVDO technology, typical networking architecture, and network optimization and so on, and can effectively deal with universal issues exposed in the process of network operations, especially typical faults. The research work in this thesis makes a solid foundation for constructing the EVDO network into a network with high quality.