SIGNAL DETECTION IN WIRELESS IR COMMUNICATIONS

Abstract

At present, optical wireless communication systems using Infrared (IR) do not enjoy large frequency bands as the RF systems. Thus, the RF techniques have been popular for both outdoor and indoor communications. Over the last decade or so the IR has been studied rather extensively for indoor applications because the light is limited within a room, wherely not interfering with the communications in nearby rooms, and allowing an effective frequency reuse. On the contrary, due to the presence of many obstacles and reflections, the IR communication suffers from the narrowing of the bandwidth and increasing the BER. This paper presents a signal detector working on the feature extraction capability of the wavelet multiresolution analysis, and the recognition capability of the ANN in order to increase the effetiveness of the IR channel. With various signal modulation schemes, different wavelets, and an ANN having variable factors used in our extensive computer simulation, the effectiveness of each combination can be judged. Using of encoding schemes and equalizers to reduce the system BER is not considered in this study.