• Design and Calibration of a Double-directional 60 GHz Channel Sounder for Multipath Component Tracking

Ruoyu Sun (National Institute of Standards and Technology, USA); Peter Papazian and Jelena Senic (NIST, USA); Yeh Lo (NTIA, USA); Jae-Kark Choi (National Institute of Standards and Technology, USA); Kate A. Remley and Camillo Gentile (NIST, USA)

The 60 GHz band is being considered for many high-bandwidth wireless applications. To support standards development for these applications, NIST has developed an untethered 60 GHz, 8×16 MIMO channel sounder. It employs a pseudorandom bit sequence with a bandwidth of 4 GHz. The sounder can precisely measure radio propagation channel characteristics such as path loss, small-scale fading, delay dispersion, absolute delay, angle-of-arrival (AoA), angle-of-departure (AoD), and Doppler power spectrum. Its ability to measure the time dynamics of the millimeter-wave radio channel, when untethered and in motion, is unique. It employs electronically-switched MIMO antenna arrays, a robot for moving measurements and an automated one-dimensional positioner for precision measurements at fixed locations. Sounder performance is improved by use of pre-distortion filters and precision calibration of the RF and timing systems. Data showing initial AoD and AoA estimation error are presented along with initial test results for ground-plane reflection.

• Polarimetric Analysis of Reverberation Times for 94 GHz Indoor Communication

Brecht Hanssens (Ghent University, Belgium); Maria Teresa Martinez-Ingles (University Centre of Defence at the Spanish Air Force Academy, MDE-UPCT, Spain); Emmeric Tanghe (Ghent University, Belgium); David Plets (Ghent University – iMinds, Belgium); Jose-Maria Molina-Garcia-Pardo (Universidad Politécnica de Cartagena, Spain); Claude Oestges (Université Catholique de Louvain, Belgium); Luc Martens (Ghent University, Belgium); Wout Joseph (Ghent University/IMEC, Belgium)

This paper presents a measurement-based analysis of both the specular- and dense multipath components (SMC and DMC) at 94 GHz in an indoor environment. A total of 15 positions were measured with a virtual antenna array system, from which we have calculated Power Delay Profiles (PDP). A method was developed that allowed for the full-polarimetric estimation of the specular propagation paths, after which the remainder was regarded as the diffuse spectrum. The behavior of the reverberation time, known from the theory of room electromagnetics, was analyzed based on this diffuse spectrum.

• A Comparison of Indoor Channel Properties in V and E Bands

Aliou Bamba (CEA-LETI & Université Grenoble-Alpes, France); Francesco Mani (Università degli studi di Bologna, Italy); Raffaele D’Errico (CEA, LETI, Minatec Campus & Univ\. Grenoble-Alpes, France)

This paper presents wideband channel measurements in an office environment in the 62 GHz and 83 GHz frequency bands. Measurements were performed with a VNA and the mechanical steering of directive antennas at both the transmitter and receiver side, allowing a double-directional angular characterization. A comparison of propagation characteristics such as the path loss, multipaths clusters’ dispersion properties in the delay and angular domains are provided. Results show that similar propagation characteristics are attainable in the two bands considered.

• 11 GHz Band MIMO Channel Characteristics in a Street Micro-Cell Environment

Kentaro Saito and Jun-ichi Takada (Tokyo Institute of Technology, Japan); Minseok Kim (Niigata University, Japan)

Recently, the fifth-generation mobile communication system (5G) has been widely investigated to accommodate increasing mobile users’ traffic. In the 5G system, although the utilization of the higher frequency band above the 6 GHz band is expected, the detailed investigation for the applicability to the mobile communication is still necessary because of different radio channel characteristics compared with microwave bands. In this paper, 11 GHz band MIMO channel measurements were conducted in a street micro-cell environment. The result shows that the delay and the angular spreads of the specular paths were smaller compared with the results in the microwave band. The scattered signal component was weak compared with measurement results of indoor environments. The result is expected to utilize for the MIMO channel modeling in the higher frequency band.

• Indoor Channel Characteristics in Atrium Entrance Hall Environment at Millimeter-wave Band

Minseok Kim, Tatsuki Iwata and Kento Umeki (Niigata University, Japan); Jun-ichi Takada (Tokyo Institute of Technology, Japan); Shigenobu Sasaki (Niigata University, Japan)

This paper presents indoor channel characteristics in atrium entrance hall environment at millimeter-wave band. In this measurement campaign, the base stations (BS) were mounted at a height of approximately 2.8 m on the walls and the user equipment (UE) was located at multiple positions on the floor.

• A Model for the Reflection of Terahertz Signals From Printed Circuit Boards

Alexander Fricke and Thomas Kürner (Technische Universität Braunschweig, Germany); Mounir Achir (Canon Research Centre France, France); Philippe Le Bars (Canon CRF, France)

Based on Vector Network Analyzer (VNA) measurements, a model for the specular reflection behavior of printed circuit boards (PCB) in the Terahertz range has been derived. It has been calibrated to suit the behavior of the measurements using a simulated annealing algorithm. The model has been tailored for the integration to ray-tracing based propagation modeling.

• Comparison of Path Loss Models for Indoor 30 GHz, 140 GHz, and 300 GHz Channels

Chia-Lin Cheng and Seunghwan Kim (Georgia Tech, USA); Alenka Zajic (Georgia Institute of Technology, USA)

This paper compares performance of the single-frequency floating-intercept model, the single-frequency close-in model, the multi-frequency alpha-beta-gamma model, and the multi-frequency close-in frequency-dependent model at 30 GHz, 140 GHz, and 300 GHz. For comparison purposes, extensive propagation measurements at 30 GHz (26.5–40 GHz), D-band (110–170 GHz), and 300 GHz (300–316 GHz) are conducted in the indoor line-of-sight (LoS) environments. The results show that if no measurement error is present in the channel impulse response, all four models have very similar performance and the model with the smallest number of parameters would be the optimal choice. On the other hand, the results show that in the presence of measurement errors or lack of detailed antenna gain characterization, models without physical anchor outperform models with physical anchor and correctly predict the reason for path loss mismatch between model and theoretical values.

• Investigations on Fading Scaling with Bandwidth and Directivity at 60 GHz

Diego Dupleich (Ilmenau University of Technology, Germany); Naveed Iqbal (Huawei Technologies, Germany); Christian Schneider (Ilmenau University of Technology, Germany); Stephan Haefner (Technische Universität Ilmenau, Germany); Robert Müller and Sergii Skoblikov (TU Ilmenau, Germany); Jian Luo (Huawei Technologies Duesseldorf GmbH, Germany); Reiner S. Thomä (Ilmenau University of Technology, Germany)

In the present paper we analyse small-scale fading of reflections at 60 GHz using different antennas and bandwidths. The aim is to investigate the deterministic property of the channel in view of modelling and deployment of systems with larger bandwidths and higher directivity. We have investigated the scattering effect of a reflection on a wall emulating a beam-former in a NLOS condition. The results show that the distribution of the amplitudes fit better with a Rician than a Rayleigh distribution. Furthermore, we show that an increasing bandwidth and directivity increases the K-factor, supporting the idea of deterministic paths apart from the LOS.

• Multi-frequency Power Angular Spectrum Comparison for an Indoor Environment

Usman Tahir Virk, Sinh Nguyen and Katsuyuki Haneda (Aalto University, Finland)

This paper presents the comparison of power angular spectra at frequencies below and above 6 GHz, i.e., 2, 15, 28, 60 GHz. With the increased focus on millimeter wave frequencies for ultra-high data rates, a detailed understanding of channel frequency dependence has become crucial. The analysis in this paper is based on multi-frequency radio channel measurements in an indoor coffee room environment for both line-of-sight (LOS) and non-LOS scenarios. For multipath extraction, two different methodologies are used at below and above 6 GHz frequency bands, respectively. The results indicate that LOS channels demonstrate a similar spatial spread at all the frequencies considered, and hence can be spatially modeled in a similar fashion. The NLOS channels exhibit larger spatial spread overall. The paths at above 6 GHz channels appear to be spatially more consistent compared to those that are below 6 GHz, where penetrated and the diffracted paths also exist.

• Path Loss Model in Typical Outdoor Environments in the 50-73 GHz Band

Sana Salous, Xavier Raimundo and Adnan Cheema (Durham University, United Kingdom)

Results of path loss in typical outdoor environments in two frequency bands identified in WRC15 for future 5G radio systems are presented. These include angular path loss as estimated from the strongest component, the main beam, the back beam and from the synthesized omni-directional beam.