Wireless local area networks based on IEEE 802.11 standard have been widely deployed to provide pervasive Internet access. In densely deployed WLAN environment, the WLAN can experience severe inter-cell interference which may cause a considerable performance degradation. In addition, to provide high-capacity wireless local area network system, the inter-cell interference should be more carefully managed from the network setup stage of deciding the operating channel. Therefore, in order to mitigate the inter-cell interference, we propose a centralized channel allocation scheme considering the uncontrolled neighboring access points. The proposed scheme estimates the channel utilization based on the received beacon signals without any help from clients. The channel allocation problem is formulated by finding maximum weight matching on bipartite graph. The proposed scheme has been implemented and the performance of the proposed scheme has been evaluated by the experiment. Despite the simplicity of the proposed scheme, it shows the best performance within compared schemes.