Research On Discrete Bands Aggregation And Resource Scheduling

In order to improve volume and rate of wireless communication system,multiple bands in different frequency can be aggregrated by spectrum aggregation technology to improve volume and rate.The frequency,bandwidth and wireless environment of bands is very different,so it is a problem to be solved that how to manage raido resource to improve the quality of service(QoS)for different multimedia service in system with spectrum aggregation.So,the target of the research is to improve the QoS for wireless service by utilizing the difference among bands and QoS requirement of various service.And,efficient radio resource scheduling schemes are proposed in different scenarios with spectrum aggregation.The research in this thesis consists of three parts.The first part is to search the radio schudeling scheme in multi-service and multi-user wireless network with carrier aggregation(CA)where bands are licensed.The user equipment(UE)can ulitize multiple bands if they are equipped with spectrum aggregation.Otherwise,UE can only utilize the resource on single band.In order to take full advantage of frequency division and user division,a novel band selection scheme is proposed for single-band UE.Simulation results show that the proposed scheme can decrease latency by 40%and improve throughput by 20%.Then,a novel resource block(RB)scheduling scheme is proposed by using the prority of data packet in buffer.The second part calculate the match factor between band and service based on the difference among bands and variety of QoS requirement where bands are in licensed or unlicensed band.Further,the utilization function with match factor is used to evaluate the performance of radio resource scheduling.Then,a novel scheduling algorithm is proposed to assign RBs in bands by maximizing the total utilization.Compared with existing algorithm,simulation results show that the proposed scheme can signicantly reduce the delay by 80%and packet loss probability(PLR)by 50%.The last part develops system simulation for wireless network with spectrum aggregation to validate the validity of proposed schemes.The topologies of typical deployment scenarios are modeled.Then,physical(PHY)layer,media access control(MAC)layer and access strategy in unlicensed band of LTE which are necessary for simulation are implemented in the simulation platform.The performance parameters can be collected to evaluate the QoS of service,including waiting latency,PLR and throughput.Finally,the research is concluded by pointing out the deficiencies of the proposed research and indicating the direction for improvement in future work.