The Study Of The Power Control And Rate Control In The Modern Mobile Communications Systems

In recent years, along with the rapid development and meshwork integration of the mobile communication systems, data communication and internet networks, the mobile users not only need the high-quality basic voice service, but also expect wide-band multimedia services which can be realized by their working computers. Therefore, the 2G mobile communication systems, which mainly offers voice service, lagged far behind the current people's expectation of handling more information and messages. And at this time, modern mobile communication systems which may provide wide-band multimedia services and can be linked into internet networks come into the stage.Different services in modern mobile communication systems need different transmission rates and have different QoS requirements, such as time delay, throughput, bit error rate and so on, which means that the systems should have more wireless resources to go round and more complicated mechanism to deal with them. However, the wireless resources (like radio frequency, transmission power, transmission rate, time slots and spreading code) in communication systems are really scarce, and thus the control and optimization of the wireless resources become one of the important issues in the research of the mobile communication systems.According to the needs of the optimization of the wireless resources in the communication systems, this thesis mainly studies two important issues of radio control problem: the power control and rate control. The main innovative work and contributions in the thesis are as follows:A new power control method based on the genetic algorithm is proposed. Comparing with the traditional iterative power control algorithms, the new power control algorithm fully takes advantage of the overall search and optimization ability of the genetic algorithm when it was applied to the study of the power control issues in the modern mobile communication systems. The simulation results show that the new algorithm may considerably speed up the converge and calculation in resolving the power control issues.An improved rate control algorithm suitable for the reverse link data transmission of 3G-1X EVDO system is presented. To deal with the problem that it's difficult for the reverse link transmission to effectively restrain the traffic overload, the thesis suggests an improved rate control algorithm for the reverse link data transmission by studying the original rate control algorithm, simulates this...