The paper deals with an analysis of multipath propagation environment in the 60 GHz band using a pseudo-random binary sequence-based time-domain channel sounder with 8 GHz bandwidth. The main goal of this work is to analyze the multipath components (MPCs) propagation between a moving car carrying a transmitter with an omnidirectional antenna and a fixed receiver situated in a building equipped with a manually steered directional horn antenna. The paper briefly presents the time dependence of the dominant MPC magnitudes, shows the effect of the surrounding vegetation on the RMS delay spread and signal attenuation, and statistically evaluates the reflective properties of the road which creates the dominant reflected component. To understand how the MPCs propagate through the channel we measured and analyzed the power and the RMS delay spread distributions in the static environment surrounding the car using an automated measuring system with a controlled receiver antenna tracking system. We give some examples of how the MPC magnitudes change during the antenna tracking and demonstrate that a building and a few cars parked close to the measuring car create a lot of MPCs detectable by the setup with a dynamic range of about 50 dB.
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Programmable Radio Environments for Smart Spaces
Smart spaces, such as smart homes and smart offices, are common Internet of Things (IoT) scenarios for building automation with networked sensors. In this paper, we suggest a different notion of smart spaces, where the radio environment is programmable to achieve desirable link quality within the space. We envision deploying low-cost devices embedded in the walls of a building to passively reflect or actively transmit radio signals. This is a significant departure from typical approaches to optimizing endpoint radios and individual links to improve performance. In contrast to previous work combating or leveraging per-link multipath fading, we actively reconfigure the multipath propagation. We sketch design and implementation directions for such a programmable radio environment, highlighting the computational and operational challenges our architecture faces. Preliminary experiments demonstrate the efficacy of using passive elements to change the wireless channel, shifting frequency "nulls" by nine Wi-Fi subcarriers, changing the 2 x 2 MIMO channel condition number by 1.5 dB, and attenuating or enhancing signal strength by up to 26 dB.
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- Award ID(s):
- 1763309
- NSF-PAR ID:
- 10177062
- Date Published:
- Journal Name:
- HotNets-XVI
- Page Range / eLocation ID:
- 36 to 42
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Data files were used in support of the research paper titled "“Experimentation Framework for Wireless
Communication Systems under Jamming Scenarios" which has been submitted to the IET Cyber-Physical Systems: Theory & Applications journal.Authors: Marko Jacovic, Michael J. Liston, Vasil Pano, Geoffrey Mainland, Kapil R. Dandekar
Contact: krd26@drexel.edu---------------------------------------------------------------------------------------------
Top-level directories correspond to the case studies discussed in the paper. Each includes the sub-directories: logs, parsers, rayTracingEmulation, results.
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logs: - data logs collected from devices under test
- 'defenseInfrastucture' contains console output from a WARP 802.11 reference design network. Filename structure follows '*x*dB_*y*.txt' in which *x* is the reactive jamming power level and *y* is the jaming duration in samples (100k samples = 1 ms). 'noJammer.txt' does not include the jammer and is a base-line case. 'outMedian.txt' contains the median statistics for log files collected prior to the inclusion of the calculation in the processing script.
- 'uavCommunication' contains MGEN logs at each receiver for cases using omni-directional and RALA antennas with a 10 dB constant jammer and without the jammer. Omni-directional folder contains multiple repeated experiments to provide reliable results during each calculation window. RALA directories use s*N* folders in which *N* represents each antenna state.
- 'vehicularTechnologies' contains MGEN logs at the car receiver for different scenarios. 'rxNj_5rep.drc' does not consider jammers present, 'rx33J_5rep.drc' introduces the periodic jammer, in 'rx33jSched_5rep.drc' the device under test uses time scheduling around the periodic jammer, in 'rx33JSchedRandom_5rep.drc' the same modified time schedule is used with a random jammer.--------------------------------
parsers: - scripts used to collect or process the log files used in the study
- 'defenseInfrastructure' contains the 'xputFiveNodes.py' script which is used to control and log the throughput of a 5-node WARP 802.11 reference design network. Log files are manually inspected to generate results (end of log file provides a summary).
- 'uavCommunication' contains a 'readMe.txt' file which describes the parsing of the MGEN logs using TRPR. TRPR must be installed to run the scripts and directory locations must be updated.
- 'vehicularTechnologies' contains the 'mgenParser.py' script and supporting 'bfb.json' configuration file which also require TRPR to be installed and directories to be updated.--------------------------------
rayTracingEmulation: - 'wirelessInsiteImages': images of model used in Wireless Insite
- 'channelSummary.pdf': summary of channel statistics from ray-tracing study
- 'rawScenario': scenario files resulting from code base directly from ray-tracing output based on configuration defined by '*WI.json' file
- 'processedScenario': pre-processed scenario file to be used by DYSE channel emulator based on configuration defined by '*DYSE.json' file, applies fixed attenuation measured externally by spectrum analyzer and additional transmit power per node if desired
- DYSE scenario file format: time stamp (milli seconds), receiver ID, transmitter ID, main path gain (dB), main path phase (radians), main path delay (micro seconds), Doppler shift (Hz), multipath 1 gain (dB), multipath 1 phase (radians), multipath 1 delay relative to main path delay (micro seconds), multipath 2 gain (dB), multipath 2 phase (radians), multipath 2 delay relative to main path delay (micro seconds)
- 'nodeMapping.txt': mapping of Wireless Insite transceivers to DYSE channel emulator physical connections required
- 'uavCommunication' directory additionally includes 'antennaPattern' which contains the RALA pattern data for the omni-directional mode ('omni.csv') and directional state ('90.csv')--------------------------------
results: - contains performance results used in paper based on parsing of aforementioned log files
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Abstract In this paper presents terahertz (THz) channel propagation characterization and generalized channel model for a desktop environment. Path loss and power delay profiles (PDPs) measured on the motherboard in both free space and desktop‐like metal cavity are compared. To characterize the large scale fading of the channel, a mean path loss model as a function of antenna height is proposed by treating the motherboard desktop environment as a partially dielectric filled resonant cavity. The measured and modeled mean path loss achieve 98.5% R‐squared goodness of fit. For the shadowing, a Gamma‐mixture model is applied to characterize the oscillations of in‐cavity measured path loss. Results show that with proper choice of the number of mixed Gamma distributions
k , the goodness of fit between the model and the probability density function (PDF) can be greater than 97%. Multipath components are characterized by cluster‐based channel modeling. Modifications were made on the conventional Saleh‐Valenzuela (S‐V) model to accurately characterize the channel by rewriting the cluster power decay with step‐wise functions and each sub‐function is expressed exponentially in dB, and the ray power decay with power law approach. It is shown that measured and simulated multipath components match well with each other with at least 98.2% goodness of fit. -
Mobility tracking of IoT devices in smart city infrastructures such as smart buildings, hospitals, shopping centers, warehouses, smart streets, and outdoor spaces has many applications. Since Bluetooth Low Energy (BLE) is available in almost every IoT device in the market nowadays, a key to localizing and tracking IoT devices is to develop an accurate ranging technique for BLE-enabled IoT devices. This is, however, a challenging feat as billions of these devices are already in use, and for pragmatic reasons, we cannot propose to modify the IoT device (a BLE peripheral) itself. Furthermore, unlike WiFi ranging - where the channel state information (CSI) is readily available and the bandwidth can be increased by stitching 2.4GHz and 5GHz bands together to achieve a high-precision ranging, an unmodified BLE peripheral provides us with only the RSSI information over a very limited bandwidth. Accurately ranging a BLE device is therefore far more challenging than other wireless standards. In this paper, we exploit characteristics of BLE protocol (e.g. frequency hopping and empty control packet transmissions) and propose a technique to directly estimate the range of a BLE peripheral from a BLE access point by multipath profiling. We discuss the theoretical foundation and conduct experiments to show that the technique achieves a 2.44m absolute range estimation error on average.more » « less
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Sub-Terahertz (THz) frequencies between 100 GHz and 300 GHz are being considered as a key enabler for the sixthgeneration (6G) wireless communications due to the vast amounts of unused spectrum. The 3rd Generation Partnership Project (3GPP) included the indoor industrial environments as a scenario of interest since Release 15. This paper presents recent sub- THz channel measurements using directional horn antennas of 27 dBi gain at 142 GHz in a factory building, which hosts equipment manufacturing startups. Directional measurements with copolarized and cross-polarized antenna configurations were conducted over distances from 6 to 40 meters. Omnidirectional and directional path loss with two antenna polarization configurations produce the gross cross-polarization discrimination (XPD) with a mean of 27.7 dB, which suggests that dual-polarized antenna arrays can provide good multiplexing gain for sub-THz wireless systems. The measured power delay profile and power angular spectrum show the maximum root mean square (RMS) delay spread of 66.0 nanoseconds and the maximum RMS angular spread of 103.7 degrees using a 30 dB threshold, indicating the factory scenario is a rich-scattering environment due to a massive number of metal structures and objects. This work will facilitate emerging sub-THz applications such as super-resolution sensing and positioning for future smart factories.more » « less
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1145/3152434.3152456
