Fast Double-Directional Full Azimuth Sweep Channel Sounder Using Low-Cost COTS Beamforming RF Transceivers

Abstract

This paper presents a multipath component (MPC) parameter estimator that uses a double-directional (D-D) channel sounding system in WiGig millimeter-wave bands. It employs low-cost commercial-off-the-shelf (COTS) RF transceivers capable of beam steering within an azimuth angle range of ±45 • ; the transmit power is approximately 31 dBm, equivalent isotropic radiated power (EIRP), including a total antenna gain of approximately 19 dBi. The half-power beam widths in the azimuth and elevation planes are 6 • and 45 • , respectively. A fast D-D channel acquisition in 360 • full azimuth range can be achieved by developing a 4 × 4 multiple-input-multiple-output (MIMO) time division-multiplexing (TDM) scheme that enables simultaneous use of four antenna arrays at both sides of the transmitter and receiver. The beam switching for all combinations (48 × 48 = 2304) with 12 beams at each array requires less than 200 ms, excluding optional procedure related to data storage. A high-resolution MPC extraction method was developed from the D-D angular delay power spectra obtained using the sub-grid CLEAN algorithm, which is applicable when phase coherence among multiple snapshots obtained via the beam-switching measurement cannot be guaranteed. Furthermore, the operation of the developed system was validated via a measurement at 58.32 GHz in an office floor of a university laboratory. From the data analysis, the cluster properties and the corresponding scattering processes were identified.

3GPP-Compatible Channel Generation Framework for FR2-2 Indoor Short-Range Communication

“…In addition to standardization activities, measurements and modeling for this scenario were performed in [25][26][27][28][29][30]. In [25], indoor measurements at 60 GHz bands were conducted, where the statistical characteristics of the time of arrival, AoA, and path loss were derived.…”

“…In [27], the angular spread, delay spread, and path loss were measured in the 60 GHz and 80 GHz bands. The characteristics of a measured cluster were reported in [28]. However, these works did not address the channel generation applicable to link-level simulations, where the objective differs from this work.…”

“…To involve a large dispersion of the intra-cluster subpath powers, we propose to add intra-cluster shadow-fading term to the intra-cluster power decay. More formally, (18) in the 3GPP channel generation flow is replaced with the following equation: STUTV , intra-cluster shadow fading (28) where 𝑧 #,& ∼ 𝒩(0, ζ 45 ) denotes the intra-cluster shadow fading term. The standard deviation, ζ 4 , is determined by a linear regression in the dB scale, where the squared error between the regression line and the observed intra-cluster power is minimized.…”

“…As shown in Fig. 9(b), the proposed model overcomes this drawback of the 3GPP channel generation flow in Remark 1 by introducing the dispersion term of the subpath powers in each cluster in (28), thereby simulating the real characteristics of the measured CIR.…”

THz Channel Sounding and Modeling Techniques: An Overview

“…A THz channel has disparate properties from the relatively well-studied cmWave [11] and mmWave channels [140]- [143] which makes studying and modeling such channels a unique proposition. Some of the unique features of a THz channel that augments the challenge can be summarized as • As opposed to other bands for communication, in the THz band significant power is present not only in the LoS path but also in reflected paths (up to double bounce), scattered and diffracted paths, and hence it would not be prudent to simply ignore them while modeling the channel [144].…”