【作者】 王维民；

【导师】 刘志新；

【作者基本信息】 燕山大学 ， 控制科学与工程， 2020， 硕士

【摘要】 随着时代的进步和移动通信技术的发展,为了实现大众对于更高速率需求的目标,网络正在朝着高速率、低延时的方向升级,现在以双层异构网络为基础的5G网络已经进入实际实验阶段。双层异构网络基本涵盖了分层立体网络的所有技术与关键问题,由于双层异构网络是在已有网络的基础上再加一层网络,在提升系统速率的同时也将带来新的难题,这其中就包括:(1)双层异构网络共享频谱导致的共信道干扰问题难以解决;(2)随着经济的发展,楼房的高层化成为了必然,通信环境将更复杂、更多变,导致了不确定性的信道增益;(3)当某些宏用户(MUE:Macrocell User)位于宏基站(MBS:Macrocell Base Station)覆盖盲区时,这些用户将无法通信,如何有效地提高这些用户的通信体验、增强网络性能是个难题。因此,结合上述三点,本文对基于非理想信道和混合接入模式的双层异构网络进行了资源优化分配,设计了具有鲁棒性的通信方案,以应对更复杂多变的通信环境。本文主要研究工作如下:首先,针对快衰落通信环境部分MUE位于死区的情况,研究用户切换服务问题,提升用户服务质量(QoS:Quality of Service)。用分层博弈构建了优化问题框架,将通信链路信道增益建模为平均信道增益和指数分布相乘的形式,并用中断概率对不确定性信道增益加以描述。采用连续凸逼近等数学方法对非凸问题进行处理,给出了获得最优解的鲁棒功率控制算法,既降低了用户的中断概率,又提升了传输速率。其次,针对快衰落通信环境下家庭基站(FBS:Femtocell Base Station)的自私性,采用Stackelberg博弈构建了优化问题,给FBS一定的效益回报来激励其使用混合接入模式。用概率约束方法满足用户的QoS要求,并通过凸优化等方法解出了问题的最优解,实现了用户的正常通信,提高了系统吞吐量。最后,针对慢衰落的通信环境,设计了一个实用的子信道激励机制,激励FBS采用混合接入模式为位于MBS覆盖盲区的MUE提供服务,提升位于MBS覆盖盲区MUE的QoS。通过构建以能效为目标包含0-1规划的优化问题,利用丁克尔巴赫、worst-case等方法求得最优解。设计了联合子信道分配和功率优化的鲁棒算法,保证了用户的通信质量。更多还原

【Abstract】 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.更多还原