| Mobile communication is the result of connect among development of economy and technology and communication. In last decade of 20th century, mobile communication especially digital mobile communication developed unexpectedly faster and applied more widely. Mobile communication live two phase: simulation communication and digital communication. In digital mobile communication system , the most wide use of application is TDMA(Time Division Multiple Access) and CDMA(Code Division Multiple Access). CDMA is later than TDMA in business, but it appears good vitality. CDMA is representation of the 3G mobile communication system. The paper introduces the development history of mobile communication technology and gives summary of the compose for CDMA system structure, then describes each pivotal technology in CDMA system. The paper summarize several questions in CDMA system which needs to research more deeply and includes the management of wireless channel resource, the policy for soft handoff, research in wireless access, control of power and control of load etc. Then I mention the background of QoS(Quality of Service ) research in CDMA network which I will discuss about. Through review every rules in CDMA network's QoS standard, the paper introduce all kinds of mechanism in QoS management and analysis the QoS management of application in CDMA network. Based on some access model in CDMA network which I mentioned , I provides a new forecast model to forecast the load change, depend on the change the CDMA system adjust the QoS parameters in order to gain better performance in QoS management. Another when system is busy, the system can depress whole QoS performance properly to ensure that system can run placidly. The policy rely on the result of forecast model strongly. But the result of sampling data is discrete and the continuous model can not calculate directly on it. So we must give interplation conversion result in the increase of calculate cost and made imprecise calculate result. In order to resolve this problem I provide this new discrete model. It can avoid the difficulty of calculating based on interplation and it has good self-adapt ability in simple or complex environment. At the same time, it can obtain good effect in deal with paroxysmal access request. I also introduce each parameter's characteristic that can impact the soft handoff QoS feature in CDMA network and then describe it's use. During soft handoff process, some questions are often occur, such as the paroxysmal speed change to mobile station and it's ping-pong moving and tail drag in cell because of slow speed. It can lead soft handoff lost and outage during wireless communication. Traditional soft handoff arithmetic choose a policy to exchange the success of macrodiversity through depressing the capability of the whole system. That is a mobile station occupy several channel to avoid the fail on soft handoff. When system is not busy, this policy is a good method. But when system is busy all of these conditions can not be met. The paper describe an arithmetic in the condition of single queue at first, it manage the soft handoff request through give priority mark to the that the guidance signal that mobile station bring on. It identify the illusive handoff request effectively. And then I describe an double queue arithmetic that in order to avoid the bug of scorching response with single queue arithmetic on illusive handoff. This method manage illusive handoff dynamically, and can change illusive handoff request to real handoff request when the system need and ensure the soft handoff process can be run correctly. The queue arithmetic solve the illusive question but should solve the other question ulteriorly such as mentions above. The paper give a definiens of dynamic threshold value. The threshold value can be made dynamically depend on exigency level of macrodiversity and soft handoff. It make balance between macrodiversity and soft handoff, not only ensure the soft handoff succ...
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