Research On Packet Scheduling Algorithms For The Forward Link In Cdma2000 1x EV-DO Rev.A

It's very important to schedule multi-user combining with fairness of service and full use of resources while meeting demands of QoS (Quality of Service) of different traffics for mobile system. The available algorithms of packet scheduling have many problems. First, scheduling algorithms for VoIP traffic have bad influences on the capacity of the system and the fairness with other traffics. Second, power efficient scheduling algorithms for stream traffic have bad performance, and the ability of guaranteeing QoS is poor. Under this background, the special researches on the algorithm of packet scheduling are developed for cdma2000 1x EV-DO Rev.A system. The primary contents and work in this thesis are listed as follows:First, for VoIP traffic, an advanced algorithm called Voluntary Dropping-from-front Scheduling is proposed, which emphasizes not only the characteristic of delay sensitive but also the property of loss tolerance. With dropping packet properly, the scheme has good performance not only in fairness but also in system throughput, even in the situation that the system has many VoIP users.Second, for stream traffic, an improved algorithm called Ahead-service Power-efficient Scheduling is proposed. With considering the characteristic of wireless channel, this algorithm sets the length of slot bulk properly to keep the user having good quality of channel when it is scheduled continuously, which helps the base station transfer more data to it, therefore the wireless network interface of access terminal can sleep longer, the ability of saving power and guaranteeing QoS is improved.Third, a program to schedule multi-traffic is designed for the forward link based on the advanced algorithms which are proposed above for special traffic.At last,the thesis summarizes the advantages and shortages of the topic and indicates the direction of the problem which need to be solved further.