Efficient 2-D ray-tracing method for narrow and wideband channel characterisation in microcellular configurations
Channel characterisation is an essential step to the development of outdoor or indoor wireless networks. Indeed, for multimedia applications, new radio mobile systems must accurately take into account channel behaviour. An efficient 2-D ray-tracing method is proposed to characterise the narrowband and wideband radio channels for a very large number of receivers in microcellular configurations. It is based on a quick precalculation of an exact 2-D visibility graph. The proposed method follows an ITU recommendation, which advocates, for wideband characterisation, consideration only of the paths included in a 18-dB dynamic range of power impulse response. Contrary to the classical approach, which consists of thresholding the complete impulse response in a post-treatment, this method only computes the significant paths. The interest of the proposed method resides in its significant computation time reduction factor, in comparison with the classical approach, without any significant loss in accuracy. Received power and wideband parameter maps are computed for about 40 000 receivers in a dense urban environment, and are provided with an approximate reduction factor of four and 80% of the null estimation error in comparison to a classical approach.
