Elevation Dependent Shadowing Model for Mobile Communications via High Altitude Platforms in Built-Up Areas

Holis, Jaroslav; Pechač, Pavel

doi:10.1109/tap.2008.919209

Cited by 312 publications

(211 citation statements)

References 14 publications

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“…We are aware that the low sample size of five Motes limits the power and reliability of linear regressions performed in this preliminary study. Nevertheless, even a qualitative assessment of the data seems to indicate that the underlying trends match expectations: because elevation overcomes the curvature of the earth and other potential obstacles in the line of sight [25], higher Motes understandably received more messages per unit of time when coverage areas and reception distances increased (Fig. 4).…”

Section: Factors Affecting Motes Performancementioning

confidence: 76%

Motes enhance data recovery from satellite-relayed biologgers and can facilitate collaborative research into marine habitat utilization

et al. 2017

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Background:The fields of biologging and telemetry have triggered significant advances in the understanding of animal behavior, physiological ecology and habitat utilization. Biologging devices ("tags") can also measure aspects of the physical and biological characteristics of the animals' environment. As marine ecosystems are less accessible than terrestrial ones and marine animals more elusive and difficult to study, data collected by tags attached to marine animals often have to be relayed via satellite. However, satellite availability is not continuous and decreases with decreasing latitude. Consequently, collection of sufficient data is even more challenging in the tropics and mid-latitudes than at the poles. To overcome this limitation and increase data throughput from biologgers, new land-based receiving stations (called Motes) that can receive, log and relay messages from devices transmitting on the Argos satellite frequency have been developed. Methods:We investigated the performance of Motes as enhancers of recovery of signals transmitted by tags normally destined for satellite relay. We quantified Mote reception range, coverage area, data throughput and data corruption rates and examined factors that might impact these parameters. To do so, we used all signals detected by two arrays of Motes installed in the Hawaiian Islands and in Southern California between latitudes 22 and 33°N. Second, using data from 12 sharks and 12 whales tagged near the two Mote arrays, we assessed how increased data recovery translated into improved ability to interpret the behavior of the tagged animals.Results: Motes were capable of receiving up to 100% of messages transmitted within their reception range and overall presented a ~three-to fivefold increase in data message recovery compared to satellites alone. Message reception performance of Motes depended on their coverage area which in turn was affected by station elevation, the presence or not of obstacles within their line of sight, and the directionality of antennas. Conclusions:The increased quantity of data enabled improved biological interpretation of the animals studied. As such, Motes can improve our knowledge of marine animals' ecology in relation to their physical and biological environments. Large-scale Mote arrays could potentially facilitate collaborative multi-disciplinary research projects, resulting in better ecosystem conservation and management.

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Section: Factors Affecting Motes Performancementioning

confidence: 76%

Motes enhance data recovery from satellite-relayed biologgers and can facilitate collaborative research into marine habitat utilization

et al. 2017

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“…As the train moves along its coverage area, the elevation angle between the HAP and the train influence the Doppler shift, factor, and shadowing [11][12][13]. The Doppler shift is defined as in Eq.…”

Section: Doppler Modelmentioning

confidence: 99%

Performance Improvement of LeastSquares Adaptive Filter for High-Speed Train Communication Systems

Zakia

Kurniawan

2017

J. ICT Res. Appl.

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Abstract. The downlink communication channel from high-altitude platform (HAP) to high-speed train (HST) in the Ka-band is a slowly time-varying Rician distributed flat fading channel with 10-25 dB Rician K factor. In this respect, the received signal is mainly affected by the Doppler shift of the line-of-sight (LOS) link. In order to increase receiver performance, we propose to firstly compensate the Doppler shift of the received signal before least-squares (LS) adaptive filtering is pursued. Implementing the proposed method requires a priori knowledge of the time-varying phase of the LOS component. This is justified since signalling between the train and the controller exists such that the train velocity and location are predictable. Implementing the proposed method to the recursive LS (RLS) received beamforming algorithm shows reduction of mean square error (MSE) and bit error rate (BER).

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“…We shall assume a frequency reuse factor of 1, i.e., all users in all other cells will be cochannel users. Each of the M users is equipped with Nr receive antennas and is served by Nt transmit antennas hanged in the HAP payload [6].…”

Section: Multi User Configurationmentioning

confidence: 99%

On the capacity of multicell coverage MIMO systems in High Altitude Platform channels

Raafat

Fattah

El-Motaafy

2012

The First International Conference on Future Generation Communication Technologies

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This paper is a comparative study between the performances of conventional terrestrial multicell Multiple Input Multiple Output (MIMO) working in a Rayleigh fading environment and its corresponding High Altitude Platform (HAP) system working under a different Path Loss (PL) model with the capacity as the performance metric of interest, calculated using the Singular Value Decomposition (SVD). Both systems are assumed to be affected by cochannel interference users in other cells .Simulation results show that the performance of multicell MIMO HAP dependent system outperforms its corresponding that works in terrestrial environment in terms of per user channel capacity.

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Elevation Dependent Shadowing Model for Mobile Communications via High Altitude Platforms in Built-Up Areas

Cited by 312 publications

References 14 publications

Motes enhance data recovery from satellite-relayed biologgers and can facilitate collaborative research into marine habitat utilization

Motes enhance data recovery from satellite-relayed biologgers and can facilitate collaborative research into marine habitat utilization

Performance Improvement of LeastSquares Adaptive Filter for High-Speed Train Communication Systems

On the capacity of multicell coverage MIMO systems in High Altitude Platform channels

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