Characterization of 60 GHz Shadowing by Human Bodies and Simple Phantoms

The 60 GHz band is very prominsing for high data rate (>1 Gb/s) wireless systems operating at short ranges. However, due to the short wavelengths in this frequency band, the shadowing effects cuased by human bodies and furniture are severe and needs to be modeled properly. In this paper, we present an experimental, measurementbased characterization of the reflection and shadowing effects in the 60 GHz band caused by human bodies and various phantoms, in order to find simple phantoms suitable for use in human shadowing measurements. It is shown that a water-filled human phantom serves as a good choice for this purpose

Time- and Frequency-Varying KK-Factor of Non-Stationary Vehicular Channels for Safety Relevant Scenarios

Vehicular communication channels are characterized by a non-stationary time- and frequency-selective fading process due to fast changes in the environment. We characterize the distribution of the envelope of the first delay bin in vehicle-to-vehicle channels by means of its Rician $K$-factor. We analyze the time-frequency variability of this channel parameter using vehicular channel measurements at 5.6 GHz with a bandwidth of 240 MHz for safety-relevant scenarios in intelligent transportation systems (ITS). This data enables a frequency-variability analysis from an IEEE 802.11p system point of view, which uses 10 MHz channels. We show that the small-scale fading of the envelope of the first delay bin is Ricean distributed with a varying $K$-factor. The later delay bins are Rayleigh distributed. We demonstrate that the $K$-factor cannot be assumed to be constant in time and frequency. The causes of these variations are the frequency-varying antenna radiation patterns as well as the time-varying number of active scatterers, and the effects of vegetation. We also present a simple but accurate bi-modal Gaussian mixture model, that allows to capture the $K$-factor variability in time for safety-relevant ITS scenarios.Comment: 26 pages, 12 figures, submitted to IEEE Transactions on Intelligent Transportation Systems for possible publicatio

Estimation of Spherical Wave Coefficients From 3-D Positioner Channel Measurements

Electromagnetic vector spherical waves have been used recently to model antenna channel interaction and the available degrees of freedom in MIMO systems. However, there are no previous accounts of a method to estimate spherical wave coefficients from channel measurements. One approach, using a 3D positioner, is presented in this letter, both in theory and practice. Measurement results are presented and discussed. One conclusion is that using randomly positioned measurements within a volume is less sensitive to noise than using only measurements on the surface

Directional analysis of measured 60 GHz indoor radio channels using SAGE

Abstract in Undetermined Directional properties of the radio channel are of high importance for the development of reliable wireless systems operating in the 60 GHz frequency band. Using transfer functions measured from 61 to 65 GHz in a conference room we have extracted estimates of the multi-path component parameters using the SAGE algorithm. In the paper we compare results for line-of-sight (LOS) scenarios and the corresponding non-line-of-sight (NLOS) scenarios and present values of the direction spread at the Tx and the Rx

Immunospecific Antibody Concentration in Egg Yolk of Chickens Orally Immunised with Varying Doses of Bovine Serum Albumin and the Mucosal Adjuvant, RhinoVax®, using Different Immunization Regimes

Antibody harvested from eggs of immunised chickens, IgY, has proven to be a non-invasive alternative to  antibodies purified from serum of mammals. Taking the non-invasive concept further, the development of  oral immunization techniques combined with IgY harvest from chicken eggs may subsequently eliminate  all regulated procedures from polyclonal antibody production. In the present study, we report the effects of  varying the temporal administration mode of the antigen (immunogen) comparing dosing on three consecutive  days with dosing on five consecutive days, and of incorporating a mucosal adjuvant. Two antigen  doses were compared: 30 mg bovine serum albumin (BSA) and 300 mg BSA, with and without the mucosal  adjuvant, RhinoVax®, administered to laying chickens. The egg yolk of chickens dosed with BSA in combination  with 20% RhinoVax®, contained significantly higher concentrations of immunospecific IgY than  did egg yolks of chickens fed with BSA without adjuvant. The most efficient dose in the RhinoVax®-treated  groups was 300 mg BSA regardless of whether the chickens were initially immunised daily for three or  five days. A 3-day dosing regime with BSA alone also induced immunospecific IgY production. This study  confirms that RhinoVax® is an efficient oral adjuvant. It also demonstrates the efficacy of daily immunizations  on three or five consecutive days on immunospecific IgY production. The chickens received oral  booster immunizations one and two months after the initial immunization. No real effect could be recorded  after the second and third immunization, although the study did provide some evidence of memory  based on an optimum IgY concentration recorded after the 2nd immunization.

Ultrawideband MIMO Channel Measurements and Modeling in a Warehouse Environment

This paper presents a detailed description of a propagation channel measurement campaign performed in a warehouse environment and provide a comprehensive channel model for this environment. Using a vector network analyzer (VNA), we explored both Line-of-sight(LOS) and Non-Line-of-sight (NLOS) scenarios over a 2-8 GHz frequency range. We extracted both small-scale and large-scale channel parameters such as distance-dependent pathloss exponent (n), frequency-dependent pathloss exponent (k), shadowing variance, and amplitude fading statistics of the channel. We also provide the clustering analysis of the channel impulse responses by using a modified Saleh-Valenzuela approach. Our model is validated by comparing the distributions of the root-mean-square (RMS) delay spread obtained from our model and measurement data, respectively. The model developed can be used for realistic performance evaluations of ultrawideband (UWB) communications and localization systems in warehouse environments