CNR estimation under man-made radio noise environment and its application to noise reduction technique using sector antenna

Man-made noise emitted from Industrial, Scientific and Medical (ISM) apparatus is known to be one of the major causes of errors in ISM-band wireless Local Area Network (LAN) systems. Although many kinds of countermeasures to improve the performance of ISM-band wireless LAN systems have been proposed, most of these countermeasures are required to estimate the statistical characteristics of man-made noise in advance. In this paper, as the basic parameter characterizing the statistics of of man-made noise the received Carrier to Noise power Ratio (CNR) is employed, we discuss the CNR estimation under man-made noise environment. Moreover, CNR estimation is applied to noise reduction technique using angle diversity reception with sector antenna, and the improvement in bit error rate performance is evaluated.