Investigation of Prediction Accuracy, Sensitivity, and Parameter Stability of Large-Scale Propagation Path Loss Models for 5G Wireless Communications

This paper compares three candidate large-scale propagation path loss models for use over the entire microwave and millimeter-wave (mmWave) radio spectrum: the alpha-beta-gamma (ABG) model, the close-in (CI) free space reference distance model, and the CI model with a frequency-weighted path loss exponent (CIF). Each of these models have been recently studied for use in standards bodies such as 3GPP, and for use in the design of fifth generation (5G) wireless systems in urban macrocell, urban microcell, and indoor office and shopping mall scenarios. Here we compare the accuracy and sensitivity of these models using measured data from 30 propagation measurement datasets from 2 GHz to 73 GHz over distances ranging from 4 m to 1238 m. A series of sensitivity analyses of the three models show that the physically-based two-parameter CI model and three-parameter CIF model offer computational simplicity, have very similar goodness of fit (i.e., the shadow fading standard deviation), exhibit more stable model parameter behavior across frequencies and distances, and yield smaller prediction error in sensitivity testing across distances and frequencies, when compared to the four-parameter ABG model. Results show the CI model with a 1 m close-in reference distance is suitable for outdoor environments, while the CIF model is more appropriate for indoor modeling. The CI and CIF models are easily implemented in existing 3GPP models by making a very subtle modification -- by replacing a floating non-physically based constant with a frequency-dependent constant that represents free space path loss in the first meter of propagation.Comment: Open access available at: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=743465

Millimeter wave and UWB propagation for high throughput indoor communications

Millimeter-wave systems at 60 GHz and ultra-wideband (UWB) systems in the microwave range of 3-10 GHz have been received with great interest for their high data rate wireless communications. In design, test and optimization of future wireless systems, channel models featuring the relevant characteristics of radiowave propagation are required. Furthermore, detailed understanding of the propagation channel and its interaction with system, creates insights into possible solutions. In this work, both theoretical (ray-tracing) and statistical models of the 60 GHz and UWB channels are studied. Propagation characteristics of the 60 GHz and UWB indoor channels are also compared for providing useful information on design of radio systems. More specifically, based on real-time channel sounder measurements performed in the 60 GHz band, propagation mechanisms including person blocking effect are concluded. Ray-based models in LOS and NLOS indoor corridors are proposed. Multipath power distributions in the 60 GHz band are studied first time. Moreover, propagation interdependencies of path loss, shadowing, number of paths, Rice K-factor and cross polarization discrimination (XPD) with channel delay spread are established. In the UWB propagation channel, frequency- and bandwidth- dependencies are investigated. Multipath and clustering propagation characteristics are analyzed. A new cluster model is proposed and compared with the classical Saleh-Valenzuela model for gaining more understanding of channel general properties. Finally, the performance and capacities of the 60 GHz UWB and MIMO (multiple-in and multiple-out) systems are analyzed for providing reliable parameters for system design and useful information for standardization groups