Research On Fractional Frequency Reuse And Downlink Resource Scheduling Algorithm In LTE

In addition to meeting the needs of users and providing fair services to all users,the LTE system provides more reliable performance in terms of higher throughput,less latency,and lower packet loss rate.In order to meet the explosive growth of packet data service in wireless network,it is necessary to design the efficient and reasonable resource allocation algorithms in LTE system by increasing the system capacity and satisfying QoS requirements to maximize the use of scarce radio resources.The main contents of this paper are as follows:(1)Aiming at the significant problem of inter-cell cross-layer interference under LTE Macro-Femto two-layer heterogeneous network scenario,this paper proposes a flexible spectrum allocation scheme based on traditional Fractional Frequency Reuse,by using the method of spectrum sensing and querying spectrum database in cognitive radio to obtain the available resources in cellular network.This method effectively reduces the cross-layer interference in LTE heterogeneous network and improves the spectrum utilization rate.(2)For the characteristics of real-time multimedia services(such as Video,VoIP flow,etc.),which are sensitive to delay and packet loss rate,considering that the Earliest Deadline First(EDF)strategy can effectively solve the problem of discarding of packets due to the deadline expiration,this paper proposes two new downlink scheduling algorithms based on channel-aware and QoS-aware scheduling algorithms by using Earliest Deadline First(EDF)strategy,thus better guaranteeing the QoS requirements of real-time traffics.(3)By building the LTE-Sim system-level simulation platform,the improved scheduling algorithms in this paper are simulated and analyzed.The simulation results show that in terms of real-time flows,the improved algorithms are able to decrease the packet loss rate,and increase the throughput while ensuring delay and fairness.