Short-Range Low-VHF Channel Characterization in Cluttered Environments

Dagefu, Fikadu T.; Verma, Gunjan; Rao, Chirag; Yu, Paul; Fink, Jonathan; Sadler, Brian M.; Sarabandi, Kamal

doi:10.1109/tap.2015.2418346

Cited by 41 publications

(18 citation statements)

References 18 publications

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“…However, the lack of any observable reflections with delays significantly exceeding 1 µs has been remarkable during the field trials. This is in contrast with the findings of several others, as discussed in Section 2, but perhaps does support the findings of [19,20] and extends their applicability. During all the field trials, PDP data has been collected and examples showing close-in views of notable delay profiles on the correlation pulse are presented in Figs.…”

Section: Extracted Delay Profile Modelssupporting

confidence: 77%

Design and field trial measurement results for a portable and low‐cost very‐high‐frequency/ultra‐high‐frequency channel sounder platform for Internet of things propagation research

Ball

2019

IET Microwaves, Antennas & Propagation

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Propagation research is vital for informing the design of reliable very high‐frequency and ultra‐high‐frequency communications systems for the Internet of things. In this study, a cost‐effective and highly portable system is proposed and then used to obtain propagation measurements in city and suburban scenarios at 71 and 869.525 MHz. The system calculates the received power, power delay profile and channel frequency response. The portable sounding receiver uses readily available parts: an RTL‐SDR (covering 27 MHz–1.7 GHz) and a Raspberry Pi with a touchscreen. The Pi implements all the channel sounding signal processing algorithms in Python, in near real time. Extracted propagation data and models are presented, from example city and suburban field trials incorporating pedestrian and car use.

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Section: Extracted Delay Profile Modelssupporting

confidence: 77%

Design and field trial measurement results for a portable and low‐cost very‐high‐frequency/ultra‐high‐frequency channel sounder platform for Internet of things propagation research

Ball

2019

IET Microwaves, Antennas & Propagation

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“…Furthermore, the Tx and Rx antennas are positioned so that they have similar heights in terms of electrical length. The reason for this is to make sure the near‐ground propagation effects, which are dominant when the height of the antennas are less than a wavelength, are similar at the two frequency bands [ Liao and Sarabandi , ; Dagefu et al , ]. Discussion of path loss calculations from the measured data and the results for various types of channels are presented in the rest of this section.…”

Section: Analysis and Resultsmentioning

confidence: 99%

Performance assessment of lower VHF band for short‐range communication and geolocation applications

et al. 2015

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The focus of this paper is to characterize near-ground wave propagation in the lower very high frequency (VHF) band and to assess advantages that this frequency band offers for reliable short-range low-data rate communications and geolocation applications in highly cluttered environments as compared to conventional systems in the microwave range. With the advent of palm-sized miniaturized VHF antennas, interest in low-power and low-frequency communication links is increasing because (1) channel complexity is far less in this frequency band compared to higher frequencies and (2) significant signal penetration through/over obstacles is possible at this frequency. In this paper, we quantify the excess path loss and small-scale fading at the lower VHF and the 2.4 GHz bands based on short-range measurements in various environments. We consider indoor-to-indoor, outdoor-to-indoor, and non-line-of-sight outdoor measurements and compare the results with measurements at higher frequencies which are used in conventional systems (i.e., 2.4 GHz). Propagation measurements at the lower VHF band are carried out by using an electrically small antenna to assess the possibility of achieving a miniaturized, mobile system for near-ground communication. For each measurement scenario considered, path loss and small-scale fading are characterized after calibrating the differences in the systems used for measurements at different frequencies, including variations in antenna performance.

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“…The area consists of residential, parkland and low rise warehouses. A map of the area with measurement and TX locations can be seen in Calculated path-loss measurements for VHF and UHF are shown in Figure 5 along with the calculated log-distance model and shadowing standard deviation given in (8) and (9).…”

Section: Suburban (Wakefield)mentioning

confidence: 99%

IoT focused VHF and UHF propagation study and comparisons

Wright

Ball

2021

IET Microwaves Antenna & Prop

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As the market for internet of things (IoT) is growing and due to Ofcom's decision to reassign parts of the very high frequency (VHF) spectrum in the UK for IoT use, a propagation study has been conducted using the newly released VHF spectrum and the currently commercially operated ultra‐high frequency (UHF) spectrum, in order to compare and contrast the suitability of the VHF spectrum for IoT use. The authors conducted their study in a number of different environments (rural, suburban, urban and dense urban), with measurement equipment deployed in a manner suitable for a portable IoT use case. Results are presented in comparison to other propagation studies available in the literature and widely used propagation models such as the Hata model. Shadowing and noise are also measured and examined. It is found that current propagation models do not provide adequate predictions within the considered use case, but found it is possible to calculate log‐distance based models that provide good predictions. Path‐loss is found to be constantly lower at VHF than UHF, but radio frequency noise is consistently higher. The newly released spectrum is found to be suitable for IoT deployments in all the examined environments.

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Short-Range Low-VHF Channel Characterization in Cluttered Environments

Cited by 41 publications

References 18 publications

Design and field trial measurement results for a portable and low‐cost very‐high‐frequency/ultra‐high‐frequency channel sounder platform for Internet of things propagation research

Design and field trial measurement results for a portable and low‐cost very‐high‐frequency/ultra‐high‐frequency channel sounder platform for Internet of things propagation research

Performance assessment of lower VHF band for short‐range communication and geolocation applications

IoT focused VHF and UHF propagation study and comparisons

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