A. Fort's research while affiliated with Vrije Universiteit Brussel and other places

Publications (20)

Article
Full-text available
Using wireless sensors worn on the body to monitor health information is a promising new application. To realize transceivers targeted for these applications, it is essential to understand the body area propagation channel. Several numerical, simulated, and measured body area propagation studies have recently been conducted. While many of these stu...
Conference Paper
The presentation of slide shows that the decrease of rho<sub>12,13</sub> as d<sub>23</sub> increases is observed in the measurement results. A simple on-body propagation model indicates that the limited number of MPCs in on-body propagation can still show correlation and decorrelation of propagation channels. The model needs to be improved, e.g. in...
Conference Paper
In this paper we developed a body area propagation model by considering an infinite circular lossy cylinder instead of a human body and solving the Helmholtz equations inside and around the cylinder. The wave propagations around and inside the body have been studied for line source, point source, and plane wave excitations.
Article
Using wireless sensors placed on a person to continuously monitor health information is a promising new application. At the same time, new low-power wireless standards such as Bluetooth and Zigbee have been proposed for short range, low data-rate communication matching the requirements of these bio-medical applications. However, there are currently...
Conference Paper
Ultra-wideband (UWB) impulse radio is a promising technique for low-power body area communication systems. While a range of analog and digital UWB transceiver architectures exist, a mostly-digital approach without analog downconversion would enable better technology scaling and signal processing flexibility. Furthermore, recently proposed subsampli...
Conference Paper
Ultra-wideband (UWB) impulse radio is a promising technique for low-power bio-medical communication systems. While a range of analog and digital UWB architectures exist, the mostly-digital approach without analog down-conversion enables better technology scaling and signal processing flexibility. Furthermore, recently proposed sub-sampling schemes...
Conference Paper
Using wireless sensors worn on the body to monitor health information is a promising new application. To realize transceivers targeted for these applications, it is essential to understand the body area propagation channel. Several numerical, simulated, and measured body area propagation studies have recently been conducted. While many of these stu...
Article
Full-text available
A comprehensive statistical model is described for ultrawideband (UWB) propagation channels that is valid for a frequency range from 3-10 GHz. It is based on measurements and simulations in the following environments: residential indoor, office indoor, builtup outdoor, industrial indoor, farm environments, and body area networks. The model is indep...
Article
Body worn wireless sensors for monitoring health information is a promising new application. In developing these sensors, a communication channel model is essential. However, there are currently few measurements or models describing propagation around the body. To address this problem, we have measured electromagnetic waves near the torso and deriv...
Conference Paper
Using wireless sensors placed on a person to continuously monitor health information is a promising new application. Furthermore, ultra-wideband is a promising air interface for short-range low data rate communication scenarios matching the requirements of wireless bio-medical applications. However, the performance and complexity tradeoffs of ultra...
Article
Using ultra-wideband (UWB) wireless sensors placed on a person to continuously monitor health information is a promising new application. However, there are currently no detailed models describing the UWB radio channel around the human body making it difficult to design a suitable communication system. To address this problem, we have measured radi...
Article
The successful realization of a wireless body area network (WBAN) requires innovative solutions to meet the energy consumption budget of the autonomous sensor nodes. The radio interface is a major challenge, since its power consumption must be reduced below 100 μW (energy scavenging limit). The emerging ultra-wide-band (UWB) technology shows strong...
Conference Paper
Using wireless sensors placed on a person to continuously monitor health information is a promising new application. In developing these sensors, detailed knowledge of the communication channel is essential. However, there are currently very few measurements describing propagation around the body. To address this problem, we have measured electroma...
Conference Paper
Using wireless sensors placed on a person to continuously monitor health information is a promising new application. However, there are currently no models describing the radio channel around the human body making it difficult to design a suitable communication system. To address this problem, we have simulated electromagnetic wave propagation arou...
Conference Paper
Full-text available
This paper describes a comprehensive statistical model for UWB propagation channels that is valid for a frequency range from 3-10 GHz. It is based on measurements and simulations in the following environments: residential indoor, office indoor, built-up outdoor, industrial indoor, farm environments, and body area networks. The model is independent...
Article
Full-text available
This is a discussion document for the IEEE document of the IEEE 802.15.4a channel modeling subgroup. It provides models for the following frequency ranges and environments: for UWB channels dovering the frequency range from 2 to 10 GHz, it covers indoor residential, indoor office, industrial, outdoor, and open outdoor environments (usually with a d...
Conference Paper
Synchronization is critical in the design of an OFDM receiver. Large timing offsets result in a loss of orthogonality between subcarriers, ISI, and severe bit error degradation. To minimize this degradation, standards incorporate preambles intended for all OFDM acquisition functions including automatic gain control (AGC) and synchronization. Severa...
Conference Paper
Zero-IF receivers are gaining interest because they enable low-cost WLAN OFDM terminals. However, zero-IF receivers introduce IQ imbalance which may have a huge impact on performance. Rather than increasing component cost to decrease the IQ imbalance, an alternative is to tolerate the IQ imbalance and compensate it digitally. Current solutions conv...
Conference Paper
The wireless communications world is moving towards the so-called 4G pictures, by integrating many different subsystems. Some of them have to provide short-range connectivity at very low power, in order to enable battery-operated sensors or devices. This low-power requirement can be achieved by selecting channel codes of high coding gain. However,...
Conference Paper
A symbol timing synchronization scheme is critical in the design of an OFDM receiver. Large timing errors can result in a loss of orthogonality between subcarriers, ISI and severe bit error degradation. To minimize this degradation, standards incorporate preambles suitable for two kinds of synchronization algorithms: auto-correlation and crosscorre...

Citations

... Each IWSN unit is equipped with advanced sensors that collect information from the environment and transmit it to a receiver, controller or sink node. Our IWSN devices are configured with IEEE 802.15.4 communication [42], which uses an omnidirectional antenna. An omnidirectional antenna does not form a clear-cut disc. ...
... Using measured or simulated results, complete statistical ultrawideband and narrowband models have been developed in [9]–[11] and standardized by the IEEE [12]. These approaches are entirely appropriate for body area propagation modeling and have already proven effective for evaluating body area communication system proposals [13], [14]. However, measurements do not directly consider the physical propagation mechanism, forcing researchers to rely on some ad-hoc modeling approaches that are not always motivated by fundamental principles. ...
... Using measured or simulated results, complete statistical ultrawideband and narrowband models have been developed in [9]–[11] and standardized by the IEEE [12]. These approaches are entirely appropriate for body area propagation modeling and have already proven effective for evaluating body area communication system proposals [13], [14]. However, measurements do not directly consider the physical propagation mechanism, forcing researchers to rely on some ad-hoc modeling approaches that are not always motivated by fundamental principles. ...
... L. An, M. J. Bentum [15], have investigated propagation around the human body and proposed the channel modeling for various scenarios. That channel modeling is done in the way to understand wave propagation in and around human body. ...
... On-body channels are defined between communication nodes on or above the skin of limited height and are usually restricted over short distances, for example, 1-2 m. An on-body channel is jointly formed by near field propagation and body scattering effects [3], leading to complex electromagnetic (EM) field distribution on the skin. This propagation mechanism is also modelled by surface wave or creeping wave assumption where the on-body propagation path is defined on the skin surface, allowing the radio waves to travel around the body [4]. ...
... Sensors 2016, 16, x 2 of 28 optimization [5,6]. However, due to many assumptions in the analytical derivations, the models often are not realistic. ...
... As confirmed by numerous studies, the most-tested statistical model that reflects the small-scale properties of the UWB channel, including in indoor spaces with small volume, is the modified Saleh-Valenzuela parametric model [18], which, as it turned out, corresponded best of all to the experimental data [19][20][21][22]. ...
... In addition to the impact of the on-body sensors placement on the path loss, the body movements as well as the surrounding environment have a big influence on signal propagation and subsequently on the packets transmissions. The authors in [127], for example, studied the influence of arm motions, while the authors in [128] considered the impact of various types of activities (still, walking, and running) on the path loss depending on the location of the transceivers. On this matter, Table 7 illustrates the shadowing standard deviation depending on the respective position of transmitters and receivers. ...
... The two models: EQS propagation at 80 MHz and surface wave model at 450 MHz are compared in Figure 3. These two models are also compared to a UWB around-body model [22] to emphasize how UWB, and more generally over-the-air radio transmissions, suffers from the body shadowing effect, causing important path loss compared to c-BCC. The path loss models are normalized at 5 cm distance from the antenna/electrode as the insertion loss (loss at 5 cm distance) depends on the antenna/electrode impedance matching. ...
... Besides, according to [44], phase noise, frontend components' non-linearities, and IQ-imbalance are considered as the most important phenomena that degrade the performance of wireless communication systems. Based on the system model presented in [44] and [45], the baseband hardware received signal, corrupted by the hardware noise component is given by: y[n] = K 1 y[n] + K 2 y * [n] + DC + n th + n f + n q , (29) ...