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

Abstract

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.

Real-Time Digital Video Streaming at Low-VHF for Compact Autonomous Agents in Complex Scenes

“…To understand the complexity of this specific scenario, we first carry out path-loss comparison measurements at two different frequency bands with a different combination of antennas (low-VHF vs. Wi-Fi). Unlike other complex environments in [7]- [9], the path-loss difference between the two bands is not as high as other complex environments previously tested where we observed well above 30 dB improvement at low VHF. Furthermore, a significantly higher level of received signal fluctuation at Wi-Fi band is observed.…”

“…Recent research on channel characterization of the low Very High Frequency (VHF) band [7]- [8] reveals favorable propagation properties when compared to conventional microwave frequency bands (e.g., Wi-Fi band) especially in Non-Line-of-Sight (NLoS) indoor and outdoor scenarios. Communications experiments have also been carried out with ZigBee radios at 40 MHz using a full-duplex frequency conversion circuit [9].…”

Short-Range Low-VHF Channel Characterization in Cluttered Environments

“…Our reported measurements in Scenario 3 are a challenging case with a significant number of structures in the typical LoS path. A more extensive measurement-based pathloss characterization for VHF indoor/outdoor channels, as well as comparison against measurements at 2.4 GHz, is presented in [18]. Although the measurements were carried out in different indoor and outdoor scenarios, the path-loss results presented in [18] are comparable to the path-loss results discussed in this paper.…”

“…Note, however, that while the pathloss exponent is relatively high, the overall attenuation is much less than expected at higher frequencies due to lower penetration loss through the walls [18]. It should also be noted that other measurements in Scenario 3 (with different Tx locations) have resulted in path-loss exponent values ranging from 4 to 5 (partly due to the lower antenna heights).…”

Reliability evaluation for vhf and uhf bands under different scenarios via propagation loss model

“…Reliable radio communication is very important for the military to perform tasks or for normal civil operation. Under different propagation scenarios, such as small city, large city, suburban, and rural environments, the reliability of VHF and UHF communications is largely influenced by the path loss [6]. As the popularization of the VHF and UHF bands, many research groups pay attention to reliability evaluation method for the radio communication.…”