Research On Resource Management Algorithms In Macro-femto Heterogeneous Networks

With the rapid development of wireless communication requirement in the indoor enviroment,the Macro-Femto heterogeneous wireless network is presented.Wireless resource management is the key technology to realize the network resource optimization and guarantee the quality of service(QoS)for users.This dissertation focuses on the wireless resource management algorithms in Macro-Femto heterogeneous integrated networks,which include a long-term-based handover decision algorithm for dense Macro-Femto and mobile hotspot coexistence networks,a hybrid transmission and access control algorithm assisted with the relay node in Femtocell network,a dynamic hybrid-access control in multi-user and multi-femtocell networks via Stackelberg game competition and a fair resource allocation for multiple types of services in Macro-Femto heterogeneous network.The main contributions of this dissertation are as follows.1.For the scenario where the dense Macro-Femto coexistence networks,a Long-Term-based Handover Decision(LTHD)algorithm is proposed.The handover decision algorithm is jointly determined by the angle of handover(AHO)and the Time-to-Stay(TTS)to reduce the unnecessary handover numbers.In order to decrease the huge computation complexity leading by increasing with the numbers of the multiple candidate base stations(CBSs)for each handover user,the proposed AHO parameter is used to decrease the dimensionality of the CBSs set to effectively reduce the handover decision computation complexity.Then,two types of the TTS parameters are given for the fixed base stations and mobile base stations,respectively,to decide which one among multiple CBSs should be accessed by each handover user aiming at a long term stay in its serving base station.System simulation results show that the proposed algorithm can effectively reduce the unnecessary numbers of handover in the dense Macro-Femto networks coexisting with the Mobile-BSs.2.A Femtocell hybrid access control algorithm assisted with relay note is proposed to supply higher performance for the Femtocell neighboring users(NUEs)in heterogeneous networks.Deploying relay outside the Femtocell networks is used and Amplify-and-Forward(AF)relaying protocol or direct link protocol is alternated to use for the data transmission of the Feintocell NUEs.An optimization problem is formulated with the constraints of the required transmission rates thresholds of the Femtocell registered users(FUEs),the thresholds of the cross-tier interferences to the Macrocell users(MUEs),and the total transmit powers of the Femtocell base station(FBS).By using the dual decomposition method,a Femtocell hybrid access control algorithm is given based on the combination of the direct mode and relay mode.Simulation results have shown that the proposed scheme can not only protect the transmission rate required by the FUEs,but also decrease the cross-tier interferences suffered by the MUEs.It also illustrates the better performance of the NUEs through the dynamic and flexible access mechanism.3.In this study,the hybrid-access problem in multi-Femtocell networks,where multiple Femtocell registered users(FRUs)and unregistered users(FURUs)coexist,is solved based on the optimal resource allocation using Stackelberg game.Firstly,theFBS allocating resources to FRUs freely to guarantee their transmission rate,and then obtaining the compensation for offering the hybrid access through selling the remaining resources to FURUs with high motivation.Based on the Stackelberg game involving the non-cooperative competition among the FBS and multiple FURUs,a dynamic hybrid-access control scheme is proposed and analysed for Femtocell access.Simulation results show that the proposed schemes have the FBS not only protect FRUs’ transmission rate,but also dynamically determine the list of accessible FURUs according to the channel power gains of FURUs and the change of FRUs’QoS demands,through pricing the FURUs.4.The problem about how to allocate the FBS resource fairly among multiple services(constant-rate services and variable-rate services)in Femtocell network is considered.Using the proportional fair to allocate the FBS transmit power for different variable-rate users is proposed to achieve fair allocated transmit rates in Macro-Femto heterogeneous network.The problem can be formulated as an optimization problem with the objective of finding the solutions for the variable-rate users subject to a set of users’ rate constraints,a set of FBS power constraints and the cross-tier interferences constraints from the FBS to the MUEs.Based on the fact that the formulated problem is a concave maximization problem,the dual decomposition method is employed to find the optimal solution.Finally,the simulation results show that,besides protecting the individual minimal transmission rate for each user,the proposed algorithm can not only provide fair resource allocation among variable-rate users,but also restrict the cross-tier interference to the MUEs.