Characteristics of the polarised off-body channel in indoor environments

Abstract

This paper addresses the depolarisation effect in off-body body area networks channels, based on measurements performed at 2.45 GHz in an indoor environment. Seven different scenarios, involving both static and dynamic users, were considered, taking a statistical perspective. The analysis of the cross-polarisation discrimination is performed, as well as the analysis of path loss in co- and cross-polarised channels. Results show a strong dependence of the cross-polarisation discrimination and of channel characteristics on the polarisation and propagation condition, i.e. line-of-sight (LoS), non-LoS or quasi-LoS. Distance, varied between 1 and 6 m in the considered scenarios, is observed to have very little impact on the cross-polarisation discrimination. In the considered dynamic scenario, the channel is characterised by lognormal-distributed shadowing and Nakagami-distributed multipath fading. Parameters of the Nakagami distribution have essentially different values in the co- and cross-polarised channels, showing a trend towards Rice in the former and Rayleigh in the latter. Based on results, a model is proposed for a dynamic off-body channel.

Characterization of Slow and Fast Fading in Off-Body Communication at 2.45 GHz with Space Diversity Scheme in an Indoor Environment

“…The χ 2 , χ 2 crit , and AIC stand for the χ 2 test statistics, the critical value of this statistics for the significance level of 5%, and the AIC statistic, respectively. It should be reminded that the χ 2 test is passed when the value of χ 2 statistics is below the critical value, and the lowest AIC value indicates the best-fitted PDF [15]. The name of the distributions with the best-fitting results for each configuration has been bolded in the Table 3.…”

An RSS-Based Classification of User Equipment Usage in Indoor Millimeter Wave Wireless Networks Using Machine Learning

“…0 • for LOS, 90 • /270 • for QLOS and 180 • for NLOS cases, respectively. The relationship between the orientation angles (0 • , 90 • /270 • and 180 • ) relative to the wireless AP and the user orientations (LOS, QLOS and NLOS) was investigated in [34], [35]. We have followed this convention for the UE orientations in the measurement set-up within this work.…”

Measurement Stand and Methodology for Research of the Off-Body and Body-to-Body Radio Channels in WBANs with Different Diversity Schemes

“…The XPD (in a linear domain) may be calculated as the ratio between the Rx powers received in the copolarized (CP) and cross-polarized (XP) channels [24], p CP r and p XP r , respectively. Additionally, for a given vertical linear polarization of the Tx antenna, XPD can be obtained from the system loss values observed in the XP and CP channels [9] as…”

“…Measurement equipment and selected scenarios for space diversity in on-body channels at the same frequency band have been presented in [7,8]. On the other hand, in [9], a testbed has been presented that may be used for polarization diversity measurements in off-body channels. In [10,11], one can find description of experimental facilities and scenarios for on-body channels at 2.45 GHz that can be used for analysis of correlation between signals received by two antennas placed in different positions on the body.…”