Measurement-Based Ultra-Massive MIMO Statistical Channel Characterization and System Performance Evaluation for UMi Environments at 15 GHz FR3 Spectrum

TL;DR

This study conducts detailed measurements and analysis of 15 GHz ultra-massive MIMO channels in urban microcell environments, providing empirical data and insights for 6G network design.

Contribution

It offers the first comprehensive measurement campaign and analysis of UM-MIMO channels at 15 GHz in UMi environments, including channel characteristics and system performance evaluation.

Findings

Channel characteristics like path loss and angular spread are characterized.

Near-field effects, spatial non-stationarity, and channel hardening are quantitatively analyzed.

Channel capacity varies significantly with propagation conditions in UMi environments.

Abstract

This paper presents a detailed measurement campaign and a comprehensive analysis of 15 GHz ultra-massive multiple-input multiple-output (UM-MIMO) channels tailored for the urban microcell (UMi) environment. Channel sounding is performed over 14.875-15.125 GHz using a time-domain platform comprising a 128-element L-shaped transmit array and a 64-element square receive array. Four representative scenarios are investigated, namely near-field line-of-sight (LoS), near-field foliage-shaded, far-field foliage-shaded, and far-field LoS street canyon scenarios, resulting in 81 distinct transmit-receive links. Based on the measured data, conventional channel characteristics, including path loss, power delay angle profiles, delay spread, and angular spread, are characterized, while UM-MIMO-specific phenomena associated with near-field effects, spatial non-stationarity (SNS), and channel hardening (CHD) are quantitatively analyzed. Channel capacity is further evaluated to reveal the effects of different UMi propagation conditions on system performance. The reported results provide empirical support for the new mid-band spectrum (6-24 GHz, including Frequency Range 3 (FR3)) UM-MIMO channel modeling and offer practical guidance for the design and deployment of future sixth-generation (6G) microcell networks.