Network Planning Based on Interference Alignment in Density WLANs

In high-density scenarios, wireless local area networks (WLANs) encounter serious interference. Interference alignment (IA) is an effective manner to control interference and improve system capacity in the interference channel. However, interference channels interact with each other in existing network planning manners and the network throughput cannot be improved significantly through the IA. In order to control interference and improve the network throughput more efficiently, we propose a network planning scheme based on the IA in high-density WLANs. The whole network is divided into a plurality of subregions, and neighbor subregions use different channels. Each subregion is considered as an interference channel, and the IA is utilized to control interference in a single subregion. Meanwhile, inter-subregion interference is controlled by channel allocation. The appropriate size of subregions and the optimal channel allocation will be selected according to the principle of maximizing the degree of freedom (DoF) of the whole network. The DoF describes the number of messages transmitted at the same time, therefore, this manner will make high-density WLANs more competitive by improving the average DoF. In the simulations, the proposed network planning manner is compared to the traditional manner in different scales of the WLANs, and the results show that the proposed manner can improve the average DoF in high-density WLANs.