Research And Implement On Wireless Resource Scheduling In LTE-Advanced Relay System

With the continuous development of wireless communication, the new technologies based on OFDM have been applied to the next generation mobile communication systems. In particular, the Release 10 version completed in early 2011 marked the communication technology is upgraded and mobile communication has entered into LTE-Advanced stage. A large number of new technologies are introduced into LTE-A standard, including relay technology.In the conventional LTE network, there is only one link between the base station and the user,leading to problems: the communication quality of the users is poor at the cell edge due to the inter-cell interference or the position being far away from the base station, another case is since the large density or blocked by obstacles, the communication quality of users in the hot or blind site is also poor. In order to solve these problems, the relay technology has been paid more attention to study.At present, the schemes of the majority articles related to one-way relay are that the relay users of the second hop link are firstly scheduled for resources, and then the instantaneous data rates of the second hop relay users are polymerized to instantaneous data rate of relay node in the first hop,finally the direct users and relay node of first hop are scheduled for resources based on seeking to maximize system throughput, but the deathful shortcoming of these schemes is only to ensure the fairness of relay users in the second hop, leading to ignoring the fairness between direct users and relay users, while the throughput of the system is not very high. Therefore, based on the traditional schemes this paper proposes an algorithm named NPFA firstly. When allocating resource blocks in the second hop, this scheme takes account into not only relay users but also direct users. Under the premise of ensuring the fairness of the relay users, the scheme also improves the fairness of direct users. Then based on NFPA scheme, this article also proposed the NPFA-ATS scheme. The data rate matching problem between the two hops is not considered into the NPFA scheme, resulting in the waste of resources. Through a transmission scale factor, NPFA-ATS scheme makes the data rate of two hop link equal and finally maximizes the utilization of wireless resource.Theoretical analysis and simulation show that: compared with some existing conventional schedule schemes of relay systems and systems without the use of relay, on the premise of guaranteeing fairness between users, the two scenarios have both improved the throughput and spectrum efficiency of the system.