On Resource Scheduling In LTE-A Systems With Mobile Relay Under High Mobility Scenario

Broadband access system for high speed railway networks attracts huge attention, due to the wide deployment of high speed railway at 350 kilometers per hour, together with the development of the broadband multimedia services. LTE-A(Long Term Evolution-Advanced) introduced mobile relay to overcome the penetration loss and the Doppler frequency shift caused by high speed railway. Meanwhile, as a key element of LTE-A’s radio resource management, resource scheduling has a significant effect on LTE-A systems’ performance. This paper has a research on resource scheduling in LTE-A systems with mobile relay under high mobility scenario. Especially, we focus on the resource scheduling between users in high speed railway and users moving at pedestrian speeds in the same cellular.Firstly, we study the traffic model and analyze the penetration of different kinds of traffic under high mobility scenario. Traffic model indicates the statistical characterization of users’ behavior. Thus, it can help us make a sense of the amount of resources that users demand for. In this paper, we take Shenzhen and Shanghai as examples, and analyze the traffic of these two cities. Concerning Shanghai, we collect the traffic of base stations nearby high speed railway and highway scenarios. Results show that among all kinds of traffic, web browsing, streaming media and insant communication rank the first three. The number of users playing e-commerce and gaming entertainment is also increasing. What’s more, with the popularization of high speed railway, users have an increasing demand for wireless communication under high mobility scenario.Secondly, we study the resource scheduling in LTE-A systems with mobile relay under high mobility scenario. When a high speed train with mobile relay installed comes across a cellular, the originally established resource allocation method would be broken. Concening this scenario, traditional resource scheduling algorithms can not fulfill this problem. Therefore, based on MLWDF, we propose a modified resource scheduling algorithm. Results show that our proposed algorithm can not only enhance the throughput of high speed users, but also improve the system’s fairness. Besides, our proposed alorithm can also achieve a higher system’s throughput. Taking the delay of time-varying channels’ CQI(Channel Quality Indicator) into consideration, we further propose a resource scheduling algorithm with CQI prediction of high speed users.Finally, we have a research on the resource scheduling algorithm for multi-operators’ collaboration. With the increase of users in high speed train, limited to the spectrum resource, the performance of communication system has an upper floor. To address this problem, based on the VNO(Virtual Network Operator), we introduce the resource scheduling strategy of multi-operators’ collaboration. We also design a reource scheduling algorithm for this scenario, which is based on the load prediction of base stations belong to different operators. With the newly proposed algorithm, the performance of LTE-A systems with mobile relay under high mobility scenario gets better.