3D Wideband Channel Characterization Using Ray-based Technique

To improve the performance of industrial processes, it has become crucial to properly model wireless channels in industrial settings. This enables a means of new applications including building control and industrial automation and integration. The paper presents a comprehensive 3D indoor industrial channel characterization to represent the IEEE 802.15.4a channel model CM 7. Using a ray-based recipe, this is achieved by considering a general wave with horizontal and vertical polarizations. The field evaluation is performed ray-by-ray and is thus affected by the transfer functions of both the transmitting and receiving antennas. In addition, a deterministic procedure to evaluate the magnitude and phase of the voltage captured by each receiving antenna in a 3D wideband massive MIMO channel is proposed. The channel conditioning is evaluated via the cumulative distribution function (CDF) of both the channel matrix singular value spread (SVS) and the correlation coefficient among users' channels, and the sum-rate capacity. The assessment is carried out by using a uniform rectangular array (URA) and a uniform linear array (ULA) at the base station. It is found that URAs provide enhanced channel conditioning and therefore higher capability for spatial separation of users' channels is guaranteed with respect to analogous ULAs. Moreover, due to the improved spatial diversity of the URAs, constructed by combining two orthogonal ULAs, the achieved sum-rate for a URA setup is higher than that for the corresponding ULA. The implemented 3D ray tracing scheme is simple, modular and shows a full agreement with the experimental results in the literature.