Radio Propagation Measurements and Cluster-Based Analysis for 5G Millimeter-Wave Cellular Systems in Dense Urban Environments

Abstract

Empirical channel modeling is necessary for the deployment of the fifth-generation (5G) millimeter-wave (mmWave) cellular system in actual environments. In this paper, cluster-based analyses of mmWave channel characteristics in two typical dense urban environments are performed. First, radio propagation measurement campaigns are conducted at two primary 5G bands of 28 GHz and 39 GHz in a central business district and a dense residential area. The custom-designed channel sounder supports high-efficiency directional scanning sounding, which helps to collect sufficient data for statistical channel modeling. Next, using an improved autoclustering algorithm, multipath clusters and their scattering sources are identified. Mapping results show that multiple reflections from exterior walls and diffraction over building corners or rooftops enhance the coverage for non-line-of-sight (NLoS) links and the influences of these propagation mechanisms are intuitively embodied as changes in the topologies of deployment environments. Finally, an appropriate measure for cluster-level channel characteristics is provided including cluster number, Ricean K-factor, root mean squared (RMS) delay spread, RMS angular spread, and their correlations. Comparisons of these parameters across two mmWave bands are also given. The measurement and modeling results shed light on a fully understanding of mmWave channels in dense urban environments across multiple bands.

Standard Propagation Channel Models for MIMO Communication Systems

“…A simple illustration of the twin cluster rotation at the MT and the transmitter end is shown in Figure 10. In [108], the twin-cluster idea was used to suggest a technique for modeling multiple interactions of MPCs with dynamic objects in the BS-MS paths [177]. A standard example of a geometry-based stochastic channel model showing how black dots within each cluster reflects the individual multipath components is shown in Figure 11 [173].…”

“…25 Wireless Communications and Mobile Computing First, conducting large-scale channel measurements is a major concern. It is still very difficult to carry out large-scale channel measurements, due partly to the complex nature of the dynamic environment, especially for outdoor scenarios, and the sophisticated equipment that is required for such measurements in the mmWave [177,220] and Terahertz (THz) [221] bands. In the case of double-directional channel measurements, switched channel sounders have been used.…”