ELAA Channel Measurements and Characteristics Analysis for 6G Upper Mid-Band Communications

Abstract

The sixth generation (6G) upper mid-band at 7–24 GHz, combined with extremely large-scale antenna arrays (ELAA) is critical for future wireless networks. However, the large physical aperture introduces complex channel characteristics that require thorough empirical investigation. In this paper, indoor ELAA channel measurements are conducted at 7 GHz and 10 GHz in a mixed indoor environment, covering lineof-sight (LoS), non-LoS (NLoS), and obstructed-LoS (OLoS) scenarios. Comprehensive statistical properties are analyzed, including delay power spectral density (PSD), angular PSD, root mean square (RMS) delay spread (DS), RMS azimuth spread of arrival (ASA), and the coherence distance. Based on empirical data, the statistical distributions of RMS DS and ASA are evaluated to quantify multipath dispersion. The spatial evolution of propagation mechanisms along the large aperture is further investigated, including spherical wavefront effects and spatial nonstationarity. In addition, the spatial decorrelation behaviors across different scenarios are examined, and the statistical differences between 7 GHz and 10 GHz bands are evaluated. These findings provide essential insights for 6G upper mid-band ELAA channels.