Optimal Allocation Of Resources In Two-tier Heterogeneous Network Based On Non-ideal Channel And Hybrid Access Mode

With the progress of the times and the development of mobile communication technology,in order to achieve the public's demand for higher rate,the network is upgrading towards the direction of high rate and low delay.Now 5G network based on two-tier heterogeneous network has entered the actual experimental stage.The two-tier heterogeneous network basically covers all the technologies and key problems of the hierarchical three-dimensional network.Because the two-tier heterogeneous network is based on the existing network plus one layer of network,it will bring new problems while improving the system speed,including:(1)It is difficult to solve the problem of co-channel interference caused by sharing spectrum in two-tier heterogeneous networks;(2)With the development of economy,the high-rise building becomes inevitable,the communication environment will be more complex and changeable,which leads to the uncertain channel gain;(3)When some macrocell user(MUE)are located in the blind area covered by macrocell base station(MBS),these users will not be able to communicate.How to effectively improve the communication experience and network performance of these users is a difficult problem.Therefore,combining with the above three points,this paper studies the resource optimization of two-tier heterogeneous network based on non-ideal channel and hybrid access mode,and designs a robust communication scheme to deal with the more complex and changeable communication environment.The main research work of this paper is as follows:First of all,aiming at the situation that some MUEs are in the dead zone in the fast fading communication environment,this paper studies the problem of user switching service and improves the quality of service(QoS)of user.The framework of optimization problem is constructed by using hierarchical game.The channel gain of communication link is modeled as the multiplication of average channel gain and exponential distribution,and the uncertain channel gain is described by using outage probability.Non-convex problems are dealt with by mathematical methods such as continuous convex approximation,and a robust power control algorithm is given to obtain the optimal solution,which not only reduces the outage probability of users,but also improves the transmission rate.Then,aiming at the selfishness of the femtocell base station(FBS)in the fast fading communication environment,the Stackelberg game is used to construct the optimization problem,which gives the FBS certain benefit return to encourage it to use the hybrid access mode.The probability constraint method is used to meet the QoS requirements of users,and convex optimization method is used to solve the optimal solution of the problem,which realizes the normal communication of users and improves the system throughput.At last,for the slow fading communication environment,a practical sub-channel incentive mechanism is designed to encourage FBS to use the hybrid access mode to provide services for the MUE located in the MBS coverage blind area and improve the QoS of the MUE located in the MBS coverage blind area.By constructing an optimization problem that includes 0-1 planning with energy efficiency as the goal,the optimal solution is obtained by dinkelbach,worst-case and other methods.A robust algorithm combining sub-channel allocation and power optimization is designed to ensure the communication quality of users.