Capacity Performance And Radio Resource Management Algorithms In Multi-service CDMA Cellular Communication Systems

Future wireless communication systems trend to provide multi-services to mobile users. CDMA technique is adopted by the 3rd generation mobile communication systems due to its flexibility in supporting multi-services. How to keep QoS of heterogeneous services and at the meantime utilize the scarce radio spectrum resources is challenging for 3rd generation mobile communication systems and future personal communication systems, especially in error-prone wireless channel and under the situations of users' mobility and their interfering with each other. This dissertation studies the capacity performance of the multi-service CDMA cellular systems and three key radio resource management algorithms, which are power control algorithm, admission control algorithm and packet scheduling algorithm.To study the capacity performance of the multi-service CDMA cellular systems is one of the key elements in procedures of the system capacity planning, meanwhile the exact analysis method is helpful to explore the factors affecting the cell capacity and thus remedies can be found to improve the efficiency of the radio spectrum utilization. The capacity performance of both the uplink and downlink are studied in chapter 2. An exact mathematical approximation method is proposed for the uplink capacity analysis, which uses a log-normal distributed random variable to approximate the statistics of total interference signal at the base station. The simulation results demonstrate that the proposed approximation method is more exact than gaussian approximation one , which have been widely used in literature. Computer simulation is used to study the capacity performance of the downlink, as the statistics of the signals received by the mobile users from different base stations is hard to gain. The call arrival process, active factors, wireless propagation environment and power control error are considered in the analysis, and some simplified or idealized assumptions adopted in current literatures are improved to better sketch the characterizations of practical system.HIPower control is one of the key technologies of reducing interference in cellular systems , especially in CDMA systems. An efficient power control method can reduce the interferences between users and increase capacity, for mobile users it also prolongs the working hours of the handsets. The power control problem in multi-service CDMA cellular systems is studied in chapter 3. The concept of generalized SIR balance is proposed firstly, and a class of centralized and distributed power control algorithms which can only be used in single traffic cellular systems are improved to be applied into the multi-service CDMA cellular systems, and thus the system capacity can be increased. Besides, the problem of SIR balance in single traffic cellular systems is proved to be a just a special instance of the generalized SIR balance, thus the theory about the power control algorithms based on SIR balance is supplemented.The cell capacity of CDMA cellular systems is limited, admitting more users than the capacity into system will make the already admitted users suffer a loss of QoS . Call admission control mechanisms must be adopted by the system to protect the QoS of the heterogeneous traffics and at the same time accommodate more users. The problem of call admission control is studied in chapter 4. Two admission control algorithms based on SIR- measurement are proposed firstly and evaluated through extensive simulations under homogeneous and heterogeneous traffic enviroment. The proposed admission algorithms can be used in multi-service CDMA cellular system and make efficient utilization of system capacity, thus make the improvement over the current admission control algorithms based on SIR- measurement which can not support multi-services with heterogeneous QoS requirements.It's believed that providing Internet-based non-realtime services through packet-switched way can optimize the radio spectrum utilization.In packet-switched networks, proper service disciplines , service ord...