Wireless Channel Prediction in a Modern Office Building Using an Image-Based Ray Tracing Method

In the last few years, many measurements were made to . characterize indoor wide-band channels [1]-[4]. Based on the measurement results; we have some rough ideas about the path loss and rms delay spread values. in different indoor envirooments. However, more accurate signal prediction techniques are necessary to provide optimum capacity and maximum coverage for future indoor wireless communication systems [5]. Site-specific channel impulse response prediction methods, which can incorporate geometrical information of the envirooment, are desired because measurements are usually costly and time-consuming. Recently, much work in MPRG has focused on development of site-specific propagation models [6][8]. The use of building data base in prediction of three dimensional diffraction has been demonstrated by Russell [6]. A ray tracing algorithm for the microcellular environment has been proposed and implemented by Schaubach [7]. A "brute force" ray tracing method is used in [7] to account for all possible propagation paths. A similar algcrithm is used for in-building predictions [8]. Path loss prediction errors are shown to be within 5 dB for most cases. Therefore, site-specific propagation models show promise for accurate signal prediction.