Reuse Partitioning Based Radio Resource Management In Relay Enhanced Cellular Networks

Higher data rate and ubiquitous coverage are main objectives of future mobile communication systems. To simultaneously satisfy these requirements, the concept of infrastructure-based relaying cellular network was proposed and has been widely believed to be a promising effective solution to above technical challenges.The benefits of relay enhanced cellular network include: enlarging cell coverage, covering areas otherwise shadowed from BSs, power saving, balancing load between cells, etc. However, the facts of extra radio resource consumption and more complicated interference distribution both caused by relaying nodes, put forward new challenges to radio resource management. This dissertation put the focus of research on radio resource allocation, routing, inter-cell interference management in two-hop fixed relaying cellular networks.Reuse partitioning is a resource allocation technology which can effectively improve spectrum utilization. The key idea therein is to divide the cell into several concentric zones and assign these zones different frequency reuse factors. This dissertation initiatively introduces the basic concept of reuse partitioning into relay enhanced cellular network. Different resource allocation schemes and routing algorithms are designed to serve two main design objectives, i.e., cell capacity enhancement and high data rate coverage enlargement, from different perspectives including: inter- and intra-cell optimization, static and dynamic resource allocation, presence and absence of cooperation among cells, etc.In particular, fixed reuse partitioning-based, soft reuse partitioning-based and dynamic reuse partitioning-based inter-cell radio resource allocation schemes are designed. Under these schemes, by optimizing spectrum reuse factors used in base station– mobile station links, base station– relaying node links and relaying node– mobile station links, spectrum resources are utilized effectively and severe inter-cell co-channel interference is mitigated as well. Moreover,“effective reuse factor”is introduced as an index to optimize the intra-cell resource partitioning, and different link bandwidth allocation schemes as well as their impacts on system performance are investigated. Simulation results demonstrate that, in comparison with traditional network, the relay enhanced cellular network adopting these resource allocation schemes obtains higher performance both on cell capacity and high data rate coverage.Routing is an indispensable issue in research of multihop relay network. However, simple and user-centric routing strategies are applied to fixed relay enhanced cellular network in current literatures. To further improve system performance, system-centric routing mechanisms are proposed under reuse partitioning-based resource allocation framework. In addition, two fast routing algorithms are designed by introducing the concept of utility function, which can jointly consider the degree of user’s satisfaction and system performance. By applying the routing algorithms, each user is assigned an appropriate access point (base station or relaying node). The cell capacity and link qualities of cell edge users are further improved by adopting these routing algorithms in comparison with those simple routing strategies.Furthermore, a MAC frame structure in half duplex FDD mode-based relay enhanced cellular network is designed, which can enable joint resource allocation from time domain and frequency domain. An inter-cell dynamic reuse partitioning based spectrum allocation scheme is proposed by taking the interference tolerating abilities of different users into account. By the coordination between cells, in this allocation scheme the spectrum resources can be further reused in local cell, which means the reuse factor can be less than 1. Guaranteeing the minimum data rate requirement of each user, this scheme can improve spectrum utilization more efficiently, and consequently further enhance system throughput and coverageBesides, a reconfigurable multi-hop cellular network architecture framework and a hybrid channel-aware-based radio resource management protocol framework are also proposed creatively in this dissertation. Intellectual property rights have been applied for based on these two proposals.