An experimental study of quasi-synchronous multiuser communications in cluttered scenarios at low VHF

Dagefu, Fikadu T.; Verma, Gunjan; Spasojević, Predrag; Sadler, Brian M.

doi:10.1109/icmcis.2017.7956502

Cited by 5 publications

(7 citation statements)

References 19 publications

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Section: Figure 14 Zcz Sdr Experimental Resultmentioning

confidence: 99%

“…Motivated by low frequency CDMA, a comprehensive numerical search was conducted over a large collection of ZCZ code families that examined the best-and worst-achievable performance in terms of frequency-offset induced orthogonality loss. These codes were studied for QS multi-user networking applications at low VHF, including simulations and experiments on software-defined radios that have nontrivial frequency offsets [185], [186].…”

Section: A Quasi-synchronous Multi-carrier Cdmamentioning

confidence: 99%

“…QS-DS-CDMA SDR experiments studied ZCZ performance in and around a large five story building, including constellations up to 256-QAM [186]. The SDR testbed in Figure 12 enabled software control of the signals and system parameters, and cabling was used to vary the physical spacing of the two transmit antennas.…”

Section: B Qs-mc-cdma Indoor/outdoor Experiments With Loosely Synchro...mentioning

confidence: 99%

“…The Tx USRPs are wired to enable programmable offsets, and the Tx antennas are spread using lengthy RF cables. From [186]. ©2017 IEEE Figure 13 depicts the building used for experiments and in-and thru-building test points.…”

Section: Figure 12mentioning

confidence: 99%

Section: Figure 12mentioning

confidence: 99%

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Low Frequency Multi-Robot Networking

Sadler,

Dagefu,

Twigg

et al. 2024

IEEE Access

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Autonomous teams of unmanned ground and air vehicles rely on networking and distributed processing to collaborate as they jointly localize, explore, map, and learn in sometimes difficult and adverse conditions. Co-designed intelligent wireless networks are needed for these autonomous mobile agents for applications including disaster response, logistics and transportation, supplementing cellular networks, and agricultural and environmental monitoring. In this paper we describe recent progress on wireless networking and distributed processing for autonomous systems using a low frequency portion of the electromagnetic spectrum, here defined as roughly 25 to 100 MHz with corresponding wavelengths of 3 to 12 meters. This research is motivated by the desire to support autonomous systems operating in dense and cluttered environments by harnessing low frequency propagation, where meters long wavelengths yield significantly reduced scattering and enhanced penetration of obstacles and structures. This differs considerably from higher frequency propagation, requiring different low frequency propagation models than those widely employed for other bands. Progress in use of low frequency for autonomous systems has resulted from combined advances in low frequency propagation modeling, networking, antennas and electromagnetics, geolocation, multi-antenna array distributed beamforming, and mobile collaborative processing. This article describes the breadth and the depth of interaction between areas, leading to new tools and methods, especially in physically complex indoor/outdoor, dense urban, and other challenging scenarios. We bring together key results, models, measurements, and experiments that describe the state of the art for new uses of low frequency spectrum for multi-agent autonomy.

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Section: Figure 14 Zcz Sdr Experimental Resultmentioning

confidence: 99%

Section: A Quasi-synchronous Multi-carrier Cdmamentioning

confidence: 99%

Section: B Qs-mc-cdma Indoor/outdoor Experiments With Loosely Synchro...mentioning

confidence: 99%

Section: Figure 12mentioning

confidence: 99%

Section: Figure 12mentioning

confidence: 99%

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