Micro Base-station Association Algorithms In Mobile Scenarios

Micro base station technology is a kind of network access technology which has been developed rapidly in recent years.With the rapid development of 3G and 4G networks,more and more users choose to access the network through mobile devices.To meet the growing needs of users,improve the communication quality of users in popular cell,and reduce the macrocell load pressure,a variety of micro base stations have been developed.Typical micro base stations include Wi-Fi,Femtocell,MicroCell,to name a few.To solve problems such as base station allocation and bursty mobile data traffic,load balancing has become a hot topic in wireless network research.A number of challenges need to be addressed,mainly related to infrastructure coorperation and user mobility.In this dissertation,we design and implement the micro base-station association algorithm for mobile scenario.The micro base-station association algorithm is a distributed base-station access algorithm based on the auction algorithm.A user bids on a base station with the related dependence.And a base station selects the user with the highest bid and gives the connection right.We compare the performance of this algorithm with two classical algorithms such as College and RAT-game.Experiments show that our algorithm achieves an average Jain's fairness index greater than 0.83,and the user loss rate of our algorithm is less than 12%.In addition,we also propose a method to determine the mobility state of user by channel state information,and realize the sensorless method to perceive the mobility state of user.The results show that our approach can achieves an average accuracy of 96.6%.We apply the user's mobility state information to the access process of the micro base-station micro base-station association algorithm,which reduces the execution time to 65%.The main contributions of this dissertation include:Firstly,we propose the discount algorithm based on the characteristics of the mobile scenario to solve the chain cascade caused by a new user or the switching base station users.It extends the micro base-station micro base-station association algorithm for the mobile scenario.The discount algorithm can reduce the length of the influence chain and ensures the quality of service(QoS)in the mobile scenario.It makes the connection between the user and the base station tends to be stable without frequent switching.Secondly,we propose a new base-station repricing algorithm for the mobile scenario.Because of the characteristics of the micro base-station micro base-station association algorithm in the static scenario,the price of base station will progressively increases in the continuous bidding of the users.This leads to the price of the micro base station over estimated in non-peak time.We propose a repricing strategy for such a problem,so that the micro base-station price can reflect the current demand for communication resources,but also enables to call back to a reasonable level in non-peak time.This method ensures that the micro base-station association algorithm can run in the mobile scenario stably for a long time.Thirdly,we propose a method to detect the mobility state of a user by using the channel state information(CSI)which provided by the mirco base station.We denoise the channel state information through the principal component analysis method,and detect the mobility state of a user by logistic regression classifier.This method subverts the traditional way of user's mobility state detection by sensor and other methods.It reduces the bandwidth occupation of the control information,and promptly reflect the user's mobility state.