Measured channel parameters for the disturbed wide‐bandwidth HF channel

Nissen, C.A.; Bello, P.

doi:10.1029/2002rs002746

Cited by 5 publications

(6 citation statements)

References 8 publications

(7 reference statements)

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“…An estimation of the SNR is calculated as: where A sp represents the area spread factor which is the area of the scattering function over the multipath and Doppler spreads as expressed by Nissen and Bello [],

P {true|}_{A_{sp}}

is the power in the area spread factor,

\overset{A_{italicsp}}{true}

is the area outside the area of spread factor,

P |_{\overset{A_{italicsp}}{true}}

represents the power in the area outside the spread factor area, and ρ n is the noise power per unit of area in the scattering function.…”

Section: Wideband Analysismentioning

confidence: 99%

A comprehensive sounding of the ionospheric HF radio link from Antarctica to Spain

et al. 2013

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[1] Since 2003, our group has been investigating the performance of different transmission techniques for low-power low-interference High Frequency (HF) ionospheric communication systems. Specifically, we have focused on the link between the Spanish Antarctic Station (SAS) Juan Carlos I in Livingston Island and Ebro Observatory (OE) in Spain, in order to transmit the data gathered from some geomagnetic sensors. These transmission techniques require a valuable knowledge of the channel behavior, thus a comprehensive narrowband and wideband sounding of the ionospheric channel is needed. Some significant improvements both in the system and in the signal processing have been done to achieve this goal. The analysis time and the frequency band have been extended to 24 hours per day and to the whole HF band (2-30 MHz). Moreover, new measurements of the absolute propagation time and the Doppler frequency shift are introduced. In this paper, the sounding results obtained using the new system are presented.

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P {true|}_{A_{sp}}

is the power in the area spread factor,

\overset{A_{italicsp}}{true}

is the area outside the area of spread factor,

P |_{\overset{A_{italicsp}}{true}}

represents the power in the area outside the spread factor area, and ρ n is the noise power per unit of area in the scattering function.…”

Section: Wideband Analysismentioning

confidence: 99%

A comprehensive sounding of the ionospheric HF radio link from Antarctica to Spain

et al. 2013

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“…This measure is called composite Doppler spread (u eff ) by Warrington and Stocker [2003]. Then, the area spread factor is defined as the area enclosed by the composite multipath and Doppler spreads in the scattering function [Nissen and Bello, 2003].…”

Section: Measurement Techniquesmentioning

confidence: 99%

An Antarctica‐to‐Spain HF ionospheric radio link: Sounding results

2008

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[1] Our research group in Electromagnetism and Communications is involved in a project dealing with the channel characterization of an ionospheric radio link from the Spanish Antarctic Base (62.6°S, 60.4°W) to the Observatori de l'Ebre (40.8°N, 0.5°E) in Spain. Since the link was established for the first time on December 2003, the sounder and measurement techniques have been improved on the basis of the preliminary results. In this paper, the final results of the project corresponding to the 2006/2007 sounding survey are presented. First the hardware and measurement techniques used to probe the channel are described. Then the results in terms of channel availability (and its daily, hourly, and frequency variation), multipath and Doppler spreads, and signal-to-noise ratio are discussed. These results are being used to design the physical layer of a low data rate transmission system intended to send the information acquired by a geomagnetic sensor in the Antarctica.

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“…Again, we make an adjustment in sign convention due to the fact that we are estimating a scattering function and not a true 2-D spectrum. It is simple to show that the resulting equation is exactly (20), except that Because both a direct estimate of and an estimate of the ACF are required for the different methods of AR model estimation, both will be derived. We will first formulate the problem in terms of the linear model and then address the task of estimating .…”

Section: Ar Approachmentioning

confidence: 99%

“…Given a known scattering function, receiver and transmitter parameters may be optimized for detection [18], [19]. Recently, channel scattering functions have been used in radio communications for modeling the wideband HF (WBHF) channel impulse response over a high-latitude auroral path [20] and for the HF skywave channel [21]. Methods have been developed to predict performance of a WBHF communications system derived from the channel scattering function [22].…”

Section: Introductionmentioning

confidence: 99%

Rapid estimation of the range-doppler scattering function

Kay

Doyle

2003

IEEE Trans. Signal Process.

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Under wide sense stationary uncorrelated scattering (WSSUS) conditions, the signal spreading due to a random channel may be described by the scattering function (SF). In an active acoustic system, the received signal is modeled as the superposition of delayed and Doppler spread replicas of the transmitted waveform. The SF completely describes the second-order statistics of a WSSUS channel and can be considered a density function that characterizes the average spread in delay and Doppler experienced by an input signal as it passes through the channel. The SF and its measurement will be reviewed. An estimator is proposed based on a two-dimensional (2-D) autoregressive (AR) model for the scattering function. In order to implement this estimator, we derive the conditional minimum variance unbiased estimator of the time-varying frequency response of a linear channel. Unlike conventional Fourier methods, the AR approach does not suffer from the usual convolutional smoothing due to the signal ambiguity function. Simulation results are given.

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Measured channel parameters for the disturbed wide‐bandwidth HF channel

Cited by 5 publications

References 8 publications

A comprehensive sounding of the ionospheric HF radio link from Antarctica to Spain

A comprehensive sounding of the ionospheric HF radio link from Antarctica to Spain

An Antarctica‐to‐Spain HF ionospheric radio link: Sounding results

Rapid estimation of the range-doppler scattering function

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