Empirical Effects of Dynamic Human-Body Blockage in 60 GHz Communications

TL;DR

This work presents a novel spatial dynamic channel sounding system based on phased array transmitters and receivers operating at 60 GHz that can measure multiple directions rapidly at high speed to provide detailed spatial dynamic measurements of complex scenarios.

Abstract

The millimeter wave (mmWave) bands and other high frequencies above 6~GHz have emerged as a central component of Fifth-Generation (5G) cellular standards to deliver high data rates and ultra-low latency. A key challenge in these bands is blockage from obstacles, including the human body. In addition to the reduced coverage, blockage can result in highly intermittent links where the signal quality varies significantly with motion of obstacles in the environment. The blockages have widespread consequences throughout the protocol stack including beam tracking, link adaptation, cell selection, handover and congestion control. Accurately modeling these blockage dynamics is therefore critical for the development and evaluation of potential mmWave systems. In this work, we present a novel spatial dynamic channel sounding system based on phased array transmitters and receivers operating at 60 GHz. Importantly, the sounder can measure multiple directions rapidly at high speed to provide detailed spatial dynamic measurements of complex scenarios. The system is demonstrated in an indoor home-entertainment type setting with multiple moving blockers. Preliminary results are presented on analyzing this data with a discussion of the open issues towards developing statistical dynamic models.

Figures (6)

• Figure 1: Example blockage event obtained from our measurements.
• Figure 2: Photograph of the transmitter side of our measurement setup, including the SiBeam array which forms the RF portion and the PXIe chassis for baseband processing.
• Figure 3: Layout of the measurement environment and trajectories of moving blockers.
• Figure 4: Received power for different numbers of human blockers. The single blocker measurement has a lower received power because the arrays were both pointing toward a wall and therefore fewer pointing angle combinations directed a substantial amount of energy to the LOS path.
• Figure 5: Received power for each AoD index (choosing the AoA with the largest received power) from a measurement with a single human blocker. Only one NLOS path is clearly visible.