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Manuel Garcia Sanchez - One of the best experts on this subject based on the ideXlab platform.

  • RMS Delay Spread vs. Coherence Bandwidth from 5G Indoor Radio Channel Measurements at 3.5 GHz Band.
    Sensors (Basel Switzerland), 2020
    Co-Authors: Wout Debaenst, Manuel Garcia Sanchez, Inigo Cuinas, Arne Feys, Jo Verhaevert
    Abstract:

    Our society has become fully submersed in fourth generation (4G) technologies, setting constant connectivity as the norm. Together with self-driving cars, augmented reality, and upcoming technologies, the new generation of Internet of Things (IoT) devices is pushing the development of fifth generation (5G) communication systems. In 5G architecture, increased capacity, improved data rate, and decreased latency are the objectives. In this paper, a measurement campaign is proposed; we focused on studying the propagation properties of microwaves at a center frequency of 3.5 GHz, commonly used in 5G cellular networks. Wideband measurement data were gathered at various indoor environments with different dimensions and characteristics. A ray-tracing analysis showed that the power spectrum is dominated by the line of sight component together with reflections on two sidewalls, indicating the practical applicability of our results. Two wideband parameters, root mean square delay spread and Coherence Bandwidth, were estimated for the considered scenarios, and we found that they are highly dependent on the physical dimension of the environment rather than on furniture present in the room. The relationship between both parameters was also investigated to provide support to network planners when obtaining the Bandwidth from the delay spread, easily computed by a ray-tracing tool.

  • Experimental distribution functions for analysis of Coherence Bandwidth fluctuations for a fixed broadband wireless access system
    IET Microwaves Antennas & Propagation, 2012
    Co-Authors: Ana Vazquez Alejos, Manuel Garcia Sanchez, Inigo Cuinas
    Abstract:

    In this study the authors propose three methods of analysis in order to develop an in-depth study of the temporal or spatial Coherence Bandwidth fluctuations in a real environment. Firstly, the authors review the classical Coherence Bandwidth (CB) estimation that offers constant single values under the assumption of an ergodic radio channel model. Secondly, the authors introduce the estimation of the experimental cumulative distribution function for CB as a method to characterise and parameterise the fluctuations that this frequency channel parameter can undergo in real environments where the ergodicity condition cannot be fully ensured. Finally, the authors estimate the probability distribution functions regarding the correlation level α in order to determine the operations quality to be expected of a specific channel Bandwidth. The CB trial values are the result of experimental measurements conducted in diverse scenarios which used different antenna pattern and polarisations within the frequency band of 40 GHz. The proposed statistical analysis reveals important information about this channel parameter that can determine the accurate design and performance of a broadband system operating within this spectrum region; besides, this method can also be extrapolated to other frequencies.

  • RMS delay and Coherence Bandwidth measurements in indoor radio channels in the UHF band
    IEEE Transactions on Vehicular Technology, 2001
    Co-Authors: Mercedes Sánchez Varela, Manuel Garcia Sanchez
    Abstract:

    A study of time dispersion in different indoor line-of-sight radio channels in the 492-862 MHz band is presented in this paper. A combined method to filter the noise in the measured impulse response is described. The effect of frequency windowing on the impulse responses and the root mean square (rms) delay spread is also investigated. It has been found that, in general, the use of windows with lower side-lobe levels yields larger values of the rms delay spread. The relation between the mean delay and the rms delay spread has also been studied for copolar and crosspolar channels. The dependence of the Coherence Bandwidth on the rms delay spread has been considered, and an inverse relation has been tested for both components.

  • Coherence Bandwidth characterization in an urban microcell at 62.4 GHz
    IEEE Transactions on Vehicular Technology, 2000
    Co-Authors: Manuel Garcia Sanchez, Akram Hammoudeh, E. Grindrod, Jean-philippe Kermoal
    Abstract:

    Results of experiments made at 62.4 GHz in an urban mobile radio environment to characterize the Coherence Bandwidth are presented. The correlation coefficients between signal envelopes separated in frequency are measured and expressed as functions of distance from the base station. Due to the high variation of this coefficient with distance and in order to provide accurate estimates of the Coherence Bandwidth in the microcell, the correlation coefficient has to be measured over large sections. Two methods to calculate the Coherence Bandwidth are presented and compared. It is shown that estimating this parameter from the frequency correlation function obtained at each position may yield incorrect results. The Coherence Bandwidths for correlation levels of 0.5, 0.7, and 0.9 are given. A ray-tracing tool has been used to assist in interpreting experimental results.

  • Study of a frequency diversity system for indoor digital TV
    IEEE Transactions on Broadcasting, 2000
    Co-Authors: Mercedes Sánchez Varela, Manuel Garcia Sanchez
    Abstract:

    A wide band measurement campaign has been carried out in the DVB-T frequency band. The Coherence Bandwidth has been measured and its variation with the antennas separation is studied. Also, the relation between the Coherence Bandwidth and the RMS delay spread is investigated.

Philip Constantinou - One of the best experts on this subject based on the ideXlab platform.

  • PIMRC - Delay spread measurements and characterization in a special propagation environment for PCS microcells
    The 13th IEEE International Symposium on Personal Indoor and Mobile Radio Communications, 1
    Co-Authors: Nektarios Moraitis, G. Pantos, Athanasios G. Kanatas, Philip Constantinou
    Abstract:

    This paper reports the measurement and analysis of a wideband radio channel at 1900 MHz within a special propagation environment such as the Olympic Stadium of Athens. RMS delay spread values are evaluated as well as the Coherence Bandwidth of the channel is derived by the frequency correlation function. The mean delay spread is found to be 0.314 /spl mu/s and 0.731 /spl mu/s for LOS and NLOS conditions respectively. The mean Coherence Bandwidth that characterizes the entire area reaches 3.463 MHz providing wide transmission data rates. The correlation Bandwidth is found to be inversely proportional to the RMS delay spread and modeled in a minimum mean square error sense.

  • WiMob (2) - Wideband indoor channel measurements at 60 GHz for wireless LANs
    WiMob'2005) IEEE International Conference on Wireless And Mobile Computing Networking And Communications 2005., 1
    Co-Authors: Nektarios Moraitis, Philip Constantinou
    Abstract:

    This paper presents the measurements and the statistical results extracted by impulse response measurements of an indoor 60 GHz radio channel. The mean excess delay is in the range of 3.84 to 8.18 ns for hallways and 3.52 to 14.69 ns for offices. The rms delay spread varies from 12.34 to 15.04 ns in corridors and from 12.56 to 21.09 ns inside the offices. The Coherence Bandwidth varies between 13.88 and 30.49 MHz in corridors with a mean value of 22.8 MHz. Inside offices the mean Coherence Bandwidth is 22.80 MHz for LoS locations while drops to 7.05 MHz for NLoS.

  • Wideband characterization of microcellular suburban mobile radio channels at 1.89 GHz
    Proceedings IEEE 56th Vehicular Technology Conference, 1
    Co-Authors: Athanasios G. Kanatas, G. Pantos, Nektarios Moraitis, Philip Constantinou
    Abstract:

    This paper reports the measurement and analysis of a wideband radio channel at 1.89 GHz within a suburban propagation environment. Mean delay spread was found to be 2.000 /spl mu/s and 1.928 /spl mu/s for LoS and NLoS conditions respectively. The Coherence Bandwidth that characterizes the area varies from 123 kHz in NLoS cases to 103 kHz in LoS cases, providing significant data rates. Measured delay spread was found to be highly variable with increasing separation between transmitter and receiver. Finally, Coherence Bandwidth is found to be inversely proportional to the RMS delay spread and modeled in a minimum mean square error sense.

Jean-philippe Kermoal - One of the best experts on this subject based on the ideXlab platform.

  • Coherence Bandwidth characterization in an urban microcell at 62.4 GHz
    IEEE Transactions on Vehicular Technology, 2000
    Co-Authors: Manuel Garcia Sanchez, Akram Hammoudeh, E. Grindrod, Jean-philippe Kermoal
    Abstract:

    Results of experiments made at 62.4 GHz in an urban mobile radio environment to characterize the Coherence Bandwidth are presented. The correlation coefficients between signal envelopes separated in frequency are measured and expressed as functions of distance from the base station. Due to the high variation of this coefficient with distance and in order to provide accurate estimates of the Coherence Bandwidth in the microcell, the correlation coefficient has to be measured over large sections. Two methods to calculate the Coherence Bandwidth are presented and compared. It is shown that estimating this parameter from the frequency correlation function obtained at each position may yield incorrect results. The Coherence Bandwidths for correlation levels of 0.5, 0.7, and 0.9 are given. A ray-tracing tool has been used to assist in interpreting experimental results.

  • Coherence Bandwidth MEASUREMENTS IN AN INDOOR MICROCELL AT 62.4 GHZ
    Electronics Letters, 1998
    Co-Authors: Akram Hammoudeh, Jean-philippe Kermoal, Manuel Garcia Sanchez
    Abstract:

    Results of experiments made at 62.4 GHz in a long narrow corridor to measure the Coherence Bandwidth are presented. The correlation coefficients between envelopes separated in frequency are measured and expressed as functions of distance between terminals. They are found to be highly variable with the location of the terminals in the microcell. From these data the frequency correlation function is computed and used to calculate the Coherence Bandwidth. The Coherence Bandwidths for correlation levels of 0.5, 0.7, and 0.9 are given for 90% of the time.

  • A Comparison of Coherence Bandwidth Measurements at 11.2 and 62.4GHz for Indoor Line of Sight Microcells
    28th European Microwave Conference 1998, 1998
    Co-Authors: Jean-philippe Kermoal, Akram Hammoudeh, Manuel Garcia Sanchez
    Abstract:

    A series of mobile radio measurements were made at 11.2GHz in a number of indoor environments to characterise the Coherence Bandwidth. The cumulative distribution function of the received signal envelope is modelled as Rician and the power spectrum is shown as a function of distance. The correlation coefficients between signal envelopes, separated in frequency by a few MHz and symmetrically disposed about the 11.2GHz, are measured and expressed as functions of distance between terminals. The frequency correlation functions are also presented and used to calculate the Coherence Bandwidth. The Coherence Bandwidths for correlation levels of 0.5, 0.7 and 0.9 are given. Measurements were repeated under identical conditions but using a 62.4GHz transceiver. A comparison between results obtained at both frequencies is given.

Nektarios Moraitis - One of the best experts on this subject based on the ideXlab platform.

  • PIMRC - Delay spread measurements and characterization in a special propagation environment for PCS microcells
    The 13th IEEE International Symposium on Personal Indoor and Mobile Radio Communications, 1
    Co-Authors: Nektarios Moraitis, G. Pantos, Athanasios G. Kanatas, Philip Constantinou
    Abstract:

    This paper reports the measurement and analysis of a wideband radio channel at 1900 MHz within a special propagation environment such as the Olympic Stadium of Athens. RMS delay spread values are evaluated as well as the Coherence Bandwidth of the channel is derived by the frequency correlation function. The mean delay spread is found to be 0.314 /spl mu/s and 0.731 /spl mu/s for LOS and NLOS conditions respectively. The mean Coherence Bandwidth that characterizes the entire area reaches 3.463 MHz providing wide transmission data rates. The correlation Bandwidth is found to be inversely proportional to the RMS delay spread and modeled in a minimum mean square error sense.

  • Time delay and Coherence Bandwidth measurements at 60 GHz in an indoor environment for WLANs
    2004 IEEE 59th Vehicular Technology Conference. VTC 2004-Spring (IEEE Cat. No.04CH37514), 1
    Co-Authors: A. Pekou, Nektarios Moraitis, V. Nastos, P. Constantitiou
    Abstract:

    This work presents measurement results and characterization of a wideband radio channel at 60 GHz in an indoor environment. Time delay values are evaluated while the Coherence Bandwidth of the channel is derived by the frequency correlation function. The mean excess delay ranges from 1.13 to 29.26 ns and the rms delay spread from 4.28 to 35.92 ns for the entire laboratory environment. The Coherence Bandwidth of the channel yielded for 0.9-correlation varies from 3.77 to 49.37 MHz with a mean value of 19.08 MHz.

  • WiMob (2) - Wideband indoor channel measurements at 60 GHz for wireless LANs
    WiMob'2005) IEEE International Conference on Wireless And Mobile Computing Networking And Communications 2005., 1
    Co-Authors: Nektarios Moraitis, Philip Constantinou
    Abstract:

    This paper presents the measurements and the statistical results extracted by impulse response measurements of an indoor 60 GHz radio channel. The mean excess delay is in the range of 3.84 to 8.18 ns for hallways and 3.52 to 14.69 ns for offices. The rms delay spread varies from 12.34 to 15.04 ns in corridors and from 12.56 to 21.09 ns inside the offices. The Coherence Bandwidth varies between 13.88 and 30.49 MHz in corridors with a mean value of 22.8 MHz. Inside offices the mean Coherence Bandwidth is 22.80 MHz for LoS locations while drops to 7.05 MHz for NLoS.

  • Wideband characterization of microcellular suburban mobile radio channels at 1.89 GHz
    Proceedings IEEE 56th Vehicular Technology Conference, 1
    Co-Authors: Athanasios G. Kanatas, G. Pantos, Nektarios Moraitis, Philip Constantinou
    Abstract:

    This paper reports the measurement and analysis of a wideband radio channel at 1.89 GHz within a suburban propagation environment. Mean delay spread was found to be 2.000 /spl mu/s and 1.928 /spl mu/s for LoS and NLoS conditions respectively. The Coherence Bandwidth that characterizes the area varies from 123 kHz in NLoS cases to 103 kHz in LoS cases, providing significant data rates. Measured delay spread was found to be highly variable with increasing separation between transmitter and receiver. Finally, Coherence Bandwidth is found to be inversely proportional to the RMS delay spread and modeled in a minimum mean square error sense.

Nathan J. Gomes - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of radio over multimode fiber links using Coherence Bandwidth
    IEEE Photonics Technology Letters, 2005
    Co-Authors: Anthony Nkansah, Nathan J. Gomes
    Abstract:

    Experimental measurements have been carried out on 62.5/12- and 50/125-/spl mu/m multimode fiber links using 850-nm vertical-cavity surface-emitting lasers transmitters for their Coherence Bandwidth, a parameter commonly used for wireless systems. It is shown that characterization using the Coherence Bandwidth over any given signal band provides reliable indications of the performance of radio over fiber systems for the transmission of different wireless radio signals (GSM, UMTS, WLAN) without the need to test using modulated signals.