A study on the CNR estimation under man-made noise and multipath fading environments and its application to improvement of 2.4GHz band wireless LAN system with sector antenna

摘要

With the increase of demands for Wireless Local Area Network (WLAN) systems, 2.4GHz band WLAN system has been taking a great attention, as it provides the attractive features such as relative high-speed transmission, low cost, and unnecessary of the license. However, the performance of 2.4GHz band WLAN system is seriously degraded by man-made noise emitted from ISM apparatus and multipath fading caused by multipath propagation of transmitted signal. Since radio channel is varied with time under man-made noise and multipath fading environments, it is effective to estimate channel condition for the improvement which adapt to time varying of the channel. In this paper, we focus on Carrier-to-Noise Power Ratio (CNR) as the most basic parameter which characterizes radio channel condition, and evaluate performance of CNR estimation under man-made noise and multipath fading environments. And next, we evaluate the improvement in Bit Error Rate performance of 2.4GHz band WLAN system using sector antenna with CNR estimation.