Dynamic Double Directional Propagation Channel Measurements at 28 GHz

TL;DR

This study provides the first dynamic double-directional mm-wave channel measurements in outdoor microcell scenarios, revealing how moving objects affect signal propagation and beam adjustments.

Contribution

It introduces a real-time phased array measurement setup capable of tracking multi-path components in dynamic environments at 28 GHz.

Findings

Time-varying path-loss and delay spread observed

Vehicle and pedestrian movements impact channel characteristics

Dynamic beam steering reduces excess losses

Abstract

This paper presents results from the (to our knowledge) first dynamic double-directionally resolved measurement campaign at mm-wave frequencies for an outdoor microcellular scenario. The measurements are performed with USC's real-time channel sounder equipped with phased array antennas that can steer beams electrically in microseconds, allowing directional measurements in dynamic environments. Exploiting the phase coherency of the setup, the multi-path components can be tracked over time to investigate the temporal dependencies of the channel characteristics. We present results for time-varying path-loss, delay spread, mean angles and angular spreads observed at the transmitter (TX) and receiver (RX) in the presence of moving vehicles and pedestrians. Additionally, we investigate excess losses observed due to blockage by vehicles and compare the cases when TX and RX are using fixed beams or when they are capable of adjusting beam directions dynamically.