Time-frequency Resource Allocation Research In HetNets Based On Self-backhaul Technology

With the rapid development of mobile communications,mobile data traffic has burst out.To cope with the major challenge of data traffic surge,the industry has proposed the heterogeneous network architecture.In heterogeneous networks,low-power small base stations are deployed under the coverage of macro base stations.As the density of small cells in a heterogeneous network increases,the backhaul link connecting the small base station to the macro base station needs to be densely deployed.At the same time,it carries a large amount of data traffic.In this scenario,traditional wired backhaul links are no longer applicable due to high cost and lack of flexibility.In contrast,wireless backhaul links have low cost and flexible deployment.So they are more advantageous in heterogeneous networks where small cells are densely deployed.Among the many wireless backhaul technologies,self-backhaul technology has attracted a lot of attention,since it has low deployment cost,high flexibility,no additional spectrum,and low hardware overhead.This thesis is devoted to analyzing the existing defects in self-backhaul technology research.Then it proposes three time-frequency resource allocation schemes based on self-backhaul technology.The main inn ovations of this thesis are as follows:(1)A time-frequency resource block allocation scheme for heterogeneous networks based on self-backhaul technology is proposed.Current research on self-backhaul technology is usually based on full-duplex communication,but the half-duplex mode has higher engineering application value.This thesis considers a half-duplex self-backhaul heterogeneous network.It is dedicated to solving the interference management problem and the data rate matching problem with self-backhaul technology.The proposed scheme achieves the data rate matching of access links and backhaul links while satisfying the uplink and downlink data rate requirements of all users.It achieves the goal of maximizing the total system throughput through dynamic resource block allocation.The simulation results show that compared with the benchmark scheme,the proposed time-frequency resource block allocation scheme based on self-backhaul technology can effectively improve the total system throughput.At the same time,the match of access links with backhaul links in data rate is also well achieved.(2)A joint uplink and downlink scheduling scheme in heterogeneous network based on self-backhaul technology is proposed.In mobile communication systems in the future,the number of resource blocks included in each frame tends to increase.In this case,resource block allocation scheme in the first research point can improve system performance,but it also faces problems of high computational overhead and signaling overhead.In order to balance system performance,signaling overhead and computational overhead,this thesis proposes a joint uplink and downlink scheduling scheme based on self-backhaul technology.The semi-persistent scheduling method is used to complete the scheduling signaling interaction in the signaling interaction phase.After that,no additional signaling overhead is needed.And the granularity of resource allocation is not refined to each resource block,but through time slots and sub-channel scheduling.The interference management is implemented by using a common transmission gain matrix.The simulation results show that compared with the benchmark scheme,the proposed scheduling scheme can effectively improve the downlink throughput of the system,and the match of access links with backhaul links in data rate is also well achieved.(3)A joint cache and spectrum resource allocation scheme based on self-backhaul technology and context awareness is proposed.Irn the existing research on self-backhaul technology,how to combine the improving of spectral efficiency with the reduction of the backhaul link load is still an open question.There is no significant research result yet.On the one hand,the joint cache and spectrum resource allocation scheme completes the matching of content files with small base stations according to the context information.On the other hand,it performs the spectrum resource allocation of access links and backhaul links.So it improves the spectral efficiency and at the same time reduces the traffic load on the backhaul link.The simulation results show that the caching strategy and the inter-cell interference management strategy in the proposed scheme have obvious effects on the system throughput improvement.