Using Wcdma Simulation Of Multi-user Detection

Along with the development of the society and communication technology, we are no longer satisfied with the services and quality, which are provided by the First and Second Cellular Systems. A wide variety of communication services such as high speed data, video, and multimedia traffic as well as voice signals must be integrated in the next generation of mobile communication systems. WCDMA as radio access technique for the 3G had many advantages such as highly efficient spectrum utilization and high system capacity. The multi-path signals produced by multi-path propagation can be used as a diversity to improve the system performance. All users can share the same frequency when the signals are transmitted through mobile radio channel. This also creates the question, multiple access interference. So, the system is an interfered limited system. Multi-user detection technologies are very important for counteracting MAI. Simulation is an important tool to get insight into these problemsIn this thesis a WCDMA uplink signal simulator is implemented according to the physical layer specification of the IMT-2000 WCDMA system. Employing indoor channel, four different instances are considered in the simulator which are AWGN channel, Rayleigh channel, Rayleigh channel with channel coding and Rayleigh channel with MUD. Theoretical analysis of the uplink simulator is also shown. Multi-user detector is investigated, which is one of the key techniques to enhance system performance. A simulation environment in C language is developed in this work.The simulation and theoretical analysis all indicates WCMDA shows good performance in counteracting multi-path fading and ISI. Channel coding, Rake receiver and multi-user detection are important techniques to improve performance of WCDMA system.The simulator developed can be an invaluable tool for investigating the design and implementation of WCDMA system: It can be easily extended to the downlink simulation and the simulation employing different types of multi-path channel. The key techniques, for example, MUD, smart antenna and space-time code, which are suggested by 3GPP, can be conveniently embedded in the simulator to analyze their benefits to WCDMA system. It also gives a direction for link-level simulation and system-level simulation using other languages and software such as: Matlab, System View, COSSAP and SPW.