A Comprehensive Spatial-Temporal Channel Propagation Model for the Ultrawideband Spectrum 2–8 GHz

Gentile, Camillo; Lopez, Sofia Martinez; Kik, Alfred

doi:10.1109/tap.2010.2046834

Cited by 19 publications

(8 citation statements)

References 29 publications

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“…Several solutions to mitigate the signal loss in the coaxial cables in VNA-based channel sounders have been proposed in the literature. In [21]- [23], an low-noise amplifier (LNA) is added to the Rx chain, and a radio-frequency (RF) power amplifier is added to the Tx chain to improve the signal dynamic range. To minimize the signal loss in the RF chain and effectively increase the system dynamic range, a novel technique addressed in the literature is the application of the heterodyne principle.…”

Section: Introductionmentioning

confidence: 99%

Phase-Compensated Optical Fiber-Based Ultrawideband Channel Sounder

Mbugua

Fan

Olesen

et al. 2020

IEEE Trans. Microwave Theory Techn.

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In this article, a novel vector network analyzer (VNA)-based ultrawideband (UWB) channel sounder using radio-over-fiber (RoF) techniques is presented. Benefiting from the usage of optical fiber cable, the measurement range and the dynamic range are significantly increased compared with the conventional coaxial-based VNA system. Specifically, using RoF increases the dynamic range to a maximum of 112 dB at 30 GHz for the back-to-back connection with an optical fiber cable of length 300 m. Moreover, a state-of-the-art phase compensation scheme using optical circulators is proposed for the first time. The novel scheme renders the channel sounder immune to stochastic phase changes in the optical fiber cable due to thermal changes and mechanical stress, thus permitting the remoting of virtual antenna arrays. The proposed channel sounder is experimentally validated in back-to-back measurements, an anechoic chamber, and practical indoor scenarios. The indoor channel measurements are conducted using a virtual uniform rectangular array (URA) at the millimeter-wave (mm-wave) band from 26.5 to 30 GHz. The measured results demonstrate the developed channel sounder's capability to perform UWB large-scale antenna array measurements with a long measurement range.

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Section: Introductionmentioning

confidence: 99%

Phase-Compensated Optical Fiber-Based Ultrawideband Channel Sounder

Mbugua

Fan

Olesen

et al. 2020

IEEE Trans. Microwave Theory Techn.

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“…This slight degradation exhibited in CRB for the LOS model is derived from the fact that the vector of unknown parameters included a new parameter to estimate [26], and due to the fact that this new LOS parameter did not disturb emporal dispersion statistics in the model. However, it is important to point out, that a LOS condition is associated with a less dispersed signal both temporally and spatially [15,17,42], and this fact has to be considered in the analysis to extract proper conclusions from these results. Furthermore, from a positioning viewpoint, timing is the most relevant parameter, and the coherence bandwidth can be considered a nuisance parameter.…”

Section: Crbs For Timing and Normalized Coherence Bandwidth For The Lmentioning

confidence: 99%

“…This result is provided for a SNR of 10 dB, an ICD source (α = 0), 75 channel vector estimates available; the sampling rate set to twice the chip rate, delay spread set to 2T c , angular spread set to 5°, and four sensors to discriminate the LOS component from the dispersed signal. Figure 12 exhibits the TOA-MV power spectrum computed using (62) for a NLOS signal model as described by (17) and (19) for an ICD source, when SNR=10 dB, K=75 channel estimates, and N s = 4 sensors for a sampling of twice the chip rate. The threshold has been computed properly [62] over the noise floor to avoid an early detection due to the first side lobe.…”

Section: Crbs For Timing and Normalized Coherence Bandwidth For The Lmentioning

confidence: 99%

“…Permanent efforts have been made to characterize wireless channels [14][15][16][17], and practical estimators have been derived. For instance, Bengtsson [18], Besson [19], and Valaee [20] have described several techniques based on signal subspace to estimate DOA and angular spread for wireless dispersed signal, whereas Raleigh [21] and Wax [22], among others [23] have studied the problem of Joint Space-Time Estimation in a multipath environment.…”

Section: Introductionmentioning

confidence: 99%

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Cramer-Rao bounds in the estimation of time of arrival in fading channels

Jativa

Vidal

2018

EURASIP J. Adv. Signal Process.

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This paper computes the Cramer-Rao bounds for the time of arrival estimation in a multipath Rice and Rayleigh fading scenario, conditioned to the previous estimation of a set of propagation channels, since these channel estimates (correlation between received signal and the pilot sequence) are sufficient statistics in the estimation of delays. Furthermore, channel estimation is a constitutive block in receivers, so we can take advantage of this information to improve timing estimation by using time and space diversity. The received signal is modeled as coming from a scattering environment that disperses the signal both in space and time. Spatial scattering is modeled with a Gaussian distribution and temporal dispersion as an exponential random variable. The impact of the sampling rate, the roll-off factor, the spatial and temporal correlation among channel estimates, the number of channel estimates, and the use of multiple sensors in the antenna at the receiver is studied and related to the mobile subscriber positioning issue. To our knowledge, this model is the only one of its kind as a result of the relationship between the space-time diversity and the accuracy of the timing estimation.

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“…In fact, LBS are a key piece of this dynamism, not just because LBS are hunger of more resources from network devices but also because they take advantage of the virtuosities of new communication technologies to construct new possibilities of relation among users, between users and service providers, and also between providers and third parties such as contents' providers. Neither it is strange that all these systems' elements are object of permanent research and keep in permanent revision [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. This paper focuses in network based positioning technologies and particularly in the mitigation of an important issue, which strongly degrades the accuracy of the subscriber due to the specific propagation conditions of the wireless signals, known as Non Line Of Sight (NLOS) condition.…”

Section: Introductionmentioning

confidence: 99%

Mitigación de la Condición NLOS para Sistemas de Posicionamiento de Suscriptor Móvil usando Ponderación de Medidas y Restricciones Geométricas

Játiva

Sanchez

Vidal

2015

Av. Cienc. Ing. (Quito)

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This paper studies the Non-Line-Of-Sight condition mitigation issue in mobile subscriber positioning systems by weighting Time-Of-Arrival measures and applying geometrical restrictions. Particularly, this work departs from a more exact characterization of the signal statistics to achieve weighting factors able to reach a more effective mitigation, and consequently a more accurate mobile subscriber positioning. In addition, restrictions based on the cell geometry are incorporated as a complementary refinement method. Therefore, three new methods with better properties than those taken from the literature and used as reference are introduced. These approaches are evaluated within a realistic simulation scenario.

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A Comprehensive Spatial-Temporal Channel Propagation Model for the Ultrawideband Spectrum 2–8 GHz

Cited by 19 publications

References 29 publications

Phase-Compensated Optical Fiber-Based Ultrawideband Channel Sounder

Phase-Compensated Optical Fiber-Based Ultrawideband Channel Sounder

Cramer-Rao bounds in the estimation of time of arrival in fading channels

Mitigación de la Condición NLOS para Sistemas de Posicionamiento de Suscriptor Móvil usando Ponderación de Medidas y Restricciones Geométricas

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