Research On Interference Mitigation Based On Power Control Under High-Density WLAN

WLAN network has now become the main approach to offload mobile data traffic because of its low cost, high flexibility and easy-to-deploy feature. As the deploying density of WLAN gets higher and higher, the interference between adjacent APs becomes more and more severe. Besides, with the increase of connection density, the interference between users under MU-MIMO scenario also becomes a serious issue. As a result, finding an appropriate power control scheme to mitigate interference is necessary. The main work of this article is as follows:In the study of power control between multi-cell APs under high-density WLAN, firstly, a wireless transformation model of the system is conducted based on classic wireless transformation theory,meanwhile, a mathematical relation between power and SINR is established. Then, focusing on video services, an appropriate QoE evaluating method is chosen, in which SINR is mapped to MOS. Finally,according to the system model conducted and the mathematical mapping relation, a self-adapting power control algorithm is proposed based on QoE. The algorithm takes the average QoE of the network as the assessment criteria, considers the current condition of APs and its surrounding area, and adjusts automatically with the change of the network condition, which effectively improves the average QoE and fairness of the users under WLAN.Under IEEE 802.11ac MU-MIMO scenario, an inference mitigation system model using zero-force pre-coding algorithm is conducted for single cell condition. The performance loss due to channel feedback delay under time-varying channel condition is analyzed. For the incomplete interference mitigation under this condition, an optimization model aimed at optimizing the overall network throughput is established, and the Zoutendijk method is used to get the power of each user and reduce the interference between users, which highly improve the overall throughput of the network.