Research On User-centered Wireless Collaborative Communication Technology

In general,ultra-dense networking(UDN)is considered as a promising technology for 5G.However,with the continuous development of wireless networks,base station types,user equipment types,and service requirements are rapidly increasing.Irregular multi-layer heterogeneous dense networking replaces traditional wireless networks,which causes the following problems:(1)There are multiple accessible wireless networks or cellular base stations around each user equipment.So a user-oriented flexible and efficient dynamic networking strategy which is gradually changing to the service-centric connection mode is needed to determine the final connection for the user equipment.(2)Flexible cooperative transmission strategy brings more challenges to resource management.It is necessary to design a joint resource optimization algorithm for coordinated multiple points(CoMP)joint transmission in UDN.(3)In order to solve the sudden traffic demand caused by temporary hot events,collaborative networking mode and dynamic deployment of drones need to be studied.In order to meet these challenges,this thesis makes an exploratory study on analyzing and promoting the performances of wireless ultra-dense heterogeneous networks with coordinated transmission.First,we will carry out the user-centered dynamic networking technology research of UDN,such as dynamic multi-cell association service and enhancement mobile management strategy,and resource joint optimization problem.Our focuses are the key technical issues such as adaptive dynamic business cell formation method and collaborative member updating strategy.In addition,the dynamic cooperative networking and on-demand coverage issues are discussed in drone-assisted UDN.The maj or content of this thesis includes:(1)First,we propose a user-centric dynamic networking method for UDN.Based on the analysis of challenges and requirements of UDN,a new architecture is presented that breaks through the traditional cellular architecture of the network controlling user.Dynamic access points grouping(DAPGing)is proposed as the core function of the new user-centric architecture,through which a user could enjoy satisfactory following its movement.Furthermore,we also apply DAPGing technology to user mobility management in dense environment and design corresponding mobility management signaling process design.System demonstration and simulation results show that the proposed method achieves performance gains in user interruption rate and regional spectral efficiency.(2)Second,we studied on resource allocation problems in UDN based on DAPGing.Based on the constructed CoMP-JT transmission models,we mathematically formulated a joint optimization problem involving both subchannel and power resources,which aims at maximize the system throughput while maintaining data rate fairness among users.Accordingly,due to resource allocation constraints unbounded among the overlapped access points(APs)group,and which results resource allocation optimization problem being nonconvex.To address this issue,the resource allocation problem is divided into subchannel(SC)allocation subproblem and power allocation subproblem.With the SC allocation results,an iterative power allocation algorithm is carried out over all SCs at each AP to get an optimal power allocation.Simulation results evaluate evaluate the performance of edge users,spectral efficiency and system throughput achieved by the proposed joint optimization algorithm,which proves the better benefits in UDN.(3)Third,user demand based air-to-ground networking model is proposed using multiple drone as air drone access point(DAP).In order to solve the deployment of DAP,we intend to find the proactive coverage area(PCA)for being covered by the supplied DAPs that maximize the number of covered users while ensuring the minimum cost.The data field theory is introduced,in which the potential value method is used to determine the PCA.In each PCA,on-demand coverage radius is considered to determine the optimal height of DAP.Moreover,we design a user access policy based on maximizing the association degree,and proposed CoMP scheduling algorithms for edge users.