The Research Of Resource Scheduling Strategy In Wireless Cooperative Communication Network

Cooperative network obtains the cooperative diversity in a distributed way,well against the multi-path fading channel, thus improving the reliability of system andcapacity. Resource scheduling is one important part of the wireless network, takeadvantage of the time-varying characteristics of wireless channel and the quality ofservice requirements of users, schedule and allocate resources reasonable to ensure thedifferent users QOS requirements. So it is critical to do the resource scheduling researchin cooperative relay network. Compared with the conventional cellular network,resource scheduling in cooperative relay network also need to consider more things,likerelay selection, multi-hop wireless link characteristics and so on. This article focus onthe multi-source multi-relay cooperative network model, do the research of thecooperative node resource scheduling, the main research work as follows:1.We design an evolved Max C/I and PF (EMax C/I&EPF) schedule strategy forthe resource allocation of multi-user multi-relay cooperative network. We adopt theEMax C/I algorithm to schedule the source users. Multiply by a relative capacityweighted factor to compute the user schedule priority in order to improve the unfairissue of the conventional Max C/I schedule algorithm. Relay selection adopt EPFschedule algorithm, according to the channel information of the second relay hop linkand add a PF schedule factor to compute the priority of the relay node,thus ensuring theload balance of the relays. Compared EMax C/I&EPF algorithm with the unimprovedalgorithm, simulation results show that this evolved scheme is a tradeoff between systemthroughput and node scheduling fairness.2. We design an evolved round robin (ERR) packet scheduling strategy combingdistributed space-time code. Relays are divided into groups in a round robin manner,then scheduled with RR schedule algorithm. This scheme needn’t any extra signalingoverhead. As for the scheduling scheme of source users, adopted the maximize signal tonoise ratio round robin packet scheduling. Finally, the scheduled users and the selectedrelays use the distributed space-time code to transmit, thus improving the systemspectrum efficiency. We compare the performance of the ERR scheduling algorithmwith that of the ordinary RR algorithm. Simulation results show that this evolved scheme has a better system performance than the ordinary RR algorithm.3. We design an evolved PF resource schedule strategy when considering QOS ofuses. Cooperative system adopt a distributed scheduling scheme, relays have its ownscheduling function. Introducing the concept of QOS to the source users, divided usersinto two groups, called GBR and Non-GBR respectively. According to the differentusers, we design two different evolved PF resource schedule algorithms for the GBR andNon-GBR users. By adding weighted factor which are the parameters used to measurethe users QOS to compute the source users schedule priority, thus ensuring the differentrequirement of users QOS. Compared this evolved scheme with the unimproved threeconventional algorithms, simulation results show that the system throughput and usersscheduling fairness of this evolved scheme is between RR and Max C/I schedulingalgorithms, as we see, evolved scheme also is a tradeoff between system throughput andnode scheduling fairness. When compared with ordinary PF algorithm only, the resultshows that the proposed evolved PF algorithm can allocate resource to users with theirdifferent QOS requirements, thus Achieving the goal of scheduling the limited systemresources reasonable.