Game Theoretic Approaches For Interference Management In Hetnets

The rapid spread of the intelligent terminals and theincreasing numberof people for pursuiong the growing high speed, high bandwidth and diverse service, all of whichprofoundlychallenge the network architecture and key technologies of the fifth generation(5G). Heterogeneouscellularnetworks have become one of the key technologies to enhance system capacity and improve the user experiencequalilty. The multiple involvedcells in heterogeneous networks share the samefrequencyspectrum with the macro station, which leads to the serious interference in the same layers and crossdifferentlayers. Meanwhile, green communication has become one of the key directions of future wireless network for sustainable development.However, in the face of the challenges such as interference, spectrum efficiency, energy efficiency, and enhancing the quality of the user experience,the multiple cellulars in heterogeneous networks and the macro station can be formed cooperation agreement.This paper aims to tap cooperation gain realized interference suppression and performance improvements.Nash bargaining cooperative game is an effective mathematical tool to describe the behavior and strategy selection of partners. To address the challenge and cooperation gain above, this paper based on cooperative game theory, taking into account the overall system performance and each users’ performance. First it explores the interference management techniques of Long Term Evolution(LTE) in homogeneous, and then extends it to the heterogeneous networks.Because of the characteristics of cooperative games, the power allocation based on cooperative game has been studied extensively. Then, the paper studies the problem of the LTE homogeneous uplink interference. In actual communication scenario, the cell edge user can easily cause uplink interference to other cell users, which is often associated with a user profile position.So the paper designs a utility function taking into account the distance factor, which defined as a utility function with balance factor. The balance factor could effectively describe the interference between the multiple base stations and multiple uses which near and far away from the base station. At the same time closed-form mathematical derivation shows: it can reduce the transmission power of the users, especially the user far away, thereby reduce the interference to each other. Simulation results show that: the design algorithm to meet thequality of service of all users, and reduces the inter-cell interference, achievesthe purposes that a small power for additional performance improvement.Subsequently, the paper studies the layers and cross-layers interference in heterogeneous networks. Build a cooperative game model in heterogeneous networks, and define the uses in macrocell and femtocells as the players. Based on the analysis above in homogeneous, we can draw the Nash equilibrium and design a distributed interference management method. Simulation results show that: the proposed algorithm can not only guarantee the macrocell user Qo S, but also enables home users to reach their lowest SINR. Compared with the traditional cooperative game algorithm, the proposed algorithm significantly reduces the user’s transmission power, reducing interference, so that the proposed algorithm is superior to the traditional cooperative game algorithm to improve network performance.In summary, by using cooperative game model, this paper designs a suitableutility function in homogeneous and heterogeneous networks, and to a certain extent, it reduces the interference of the system and improve system performance.