This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

In general, Micropower Impulse Radar (MIR) depends on Ultra-Wideband (UWB) transmission systems. UWB technology can supply innovative new systems and products that have an obvious value for radar and communications uses. Important applications include bridge-deck inspection systems, ground penetrating radar, mine detection, and precise distance resolution for such things as liquid level measurement. Most of these UWB inspection and measurement methods have some unique qualities, which need to be pursued. Therefore, in considering changes to Part 15 the FCC needs to take into account the unique features of UWB technology. MIR is applicable to two general types of UWB systems: radar systems and communications systems. Currently LLNL and its licensees are focusing on radar or radar type systems. LLNL is evaluating MIR for specialized communication systems. MIR is a relatively low power technology. Therefore, MIR systems seem to have a low potential for causing harmful interference to other users of the spectrum since the transmitted signal is spread over a wide bandwidth, which results in a relatively low spectral power density.

/pdf/response-to-fcc-98-208-notice-of-inquiry-in-the-matter-of-3attixctl7.pdf

Response to FCC 98-208 notice of inquiry in the matter of revision of part 15 of the commission's rules regarding ultra-wideband transmission systems

Wireless body area sensor network is a sub-field of wireless sensor network. Wireless body area sensor network has come into existence after the development of wireless sensor network reached some ...

https://journals.sagepub.com/doi/pdf/10.1177/1550147718768994

The state-of-the-art wireless body area sensor networks: A survey:

This paper presents a planar monopole backed with a 2 × 1 array of electromagnetic bandgap (EBG) structures. The reflection phase of a single EBG unit cell has been studied and exploited toward efficient radiation of a planar monopole antenna, intended for wearable applications. The shape of the EBG unit cell and the gap between the ground and the EBG layer are adjusted so that the antenna operates at 2.45 GHz. The proposed antenna retains its impedance matching when placed directly upon a living human subject with an impedance bandwidth of 5%, while it exhibits a measured gain of 6.88 dBi. A novel equivalent array model is presented to qualitatively explain the reported radiation mechanism of the EBG-backed monopole. The proposed antenna is fabricated on a 68 × 38 × 1.57 mm
 3
 board of semiflexible RT/duroid 5880 substrate. Detailed analysis and measurements are presented for various cases when the antenna is subjected to structural deformation and human body loading, and in all cases, the EBG-backed monopole antenna retains its high performance. The reported efficient and robust radiation performance with very low specific absorption rate, compact size, and high gain make the proposed antenna a superior candidate for most wearable applications used for off-body communication.

https://pureadmin.qub.ac.uk/ws/files/138746400/TAP2635588.pdf

Compact EBG-Backed Planar Monopole for BAN Wearable Applications

In this paper, we propose a beam-oriented digital predistortion (BO-DPD) technique for power amplifiers (PAs) in hybrid beamforming massive multiple-input multiple-output (MIMO) transmitters, which can achieve linearization of the transmitted signal in the main beam direction and address the DPD implementation issue in the hybrid beamforming array. In massive MIMO hybrid beamforming transmitters, the conventional DPD to linearize each PA is impractical to implement for that the number of digital chains is less than the number of PAs; however, the BO-DPD can resolve this issue by constructing and linearizing the “virtual” main beam signal rather than single PAs. According to the beamforming weights for array elements, the feedback path combines all PA’s outputs to estimate the main beam signal for DPD processing. In addition, an average estimation method is also presented to broaden the linearized angle range around the main beam direction. A $4 \times 16$ (four subarrays and 16 antennas in each subarray) uniform linear array (ULA) simulation along with a $1 \times 2$ ULA at 2.5 GHz and a $2 \times 2$ ULA at 3.5-GHz experimental tests was performed. The experimental results show that the proposed technique and linearization angle range broadening method achieve up to 15-dB adjacent channel power ratio improvement and 10° linearization angle range in the main beam direction.

Beam-Oriented Digital Predistortion for 5G Massive MIMO Hybrid Beamforming Transmitters

The purpose of this communication is to present the design of an artificially anisotropic antenna substrate (AAAS) for the generation of circular polarization (CP) for a linearly polarized antenna. The AAAS can be manufactured by assembling thin sheets with certain relative permittivities for the host or environment $\varepsilon _{e}$ and inclusion $\varepsilon _{i}$ materials as a stack. Using two different stacking materials enables the generation of different effective permittivities $\varepsilon _{{{x{'}}}}$ and $\varepsilon _{{{y{'}}}}$ for the wave components propagating in-between an antenna and a ground. The idea is to modify the antenna polarization by exploiting reflections from a ground in a way that CP operation is obtained. By properly designing the AAAS, the radiator shape can be maintained simple. The operation of AAAS is demonstrated for substrates made of homogeneous anisotropic and thin sheets. It is shown that by using sufficient high inclusion permittivity (e.g., $\varepsilon _{i} = 15$ ), the AAAS is observed to even show axial ratio <2 dB with over 25 dBi higher right-hand CP gain than left-hand CP in the main beam of the antenna. A prototype with available low-lossy materials is manufactured and successful correlation with theory and simulation results is observed.

An Artificially Anisotropic Antenna Substrate for the Generation of Circular Polarization

Considerations of biological effects, executed as the bio-heat and bio-thermal simulations, in terms of a specific absorption rate (SAR) and temperature rise in human body tissues for ultra wideband (UWB) wireless body area network (WBAN) applications are studied in this paper. 3D-electromagnetic (EM) simulation software, utilizing finite integration technique (FIT), is used in order to obtain temperatures and power losses by thermal stationary and transient solvers (TSS, TTS) in the vicinity of the modelled dispersive medium. Two different UWB antennas having excellent radiation properties are experimented on contact with tissues. The effect of the antenna input power on the temperature and maximum SARs over 1 g and 10 g averaging masses are evaluated. Obtained results are compared with the restrictions set by the institute of Electrical and Electronics Engineers (IEEE) and International Commission on Non-Ionizing Radiation Protection (I CNIRP). This paper investigates generally how much power should be fed to the UWB antenna in order to cross the maximum SAR limits in WBANs or in order the antenna start to heat the tissues significantly, both in the stationary conditions and further as the transient solutions.

On the evaluation of biological effects of wearable antennas on contact with dispersive medium in terms of SAR and bio-heat by using FIT technique

Investigations of wave propagation in the proximity of human body tissues are required in order to design a reliable wireless body area network (WBAN). This paper shows creeping wave (CW) propagation properties along a skin tissue surface at 2.45 GHz for three antenna types. Dipole, discone and patch antennas with different pattern properties are examined. In this study, antenna polarization is normal, tangential or their mixture relatively to the surface. Performance is compared in free space and close to the skin models. The polarization normal to a tissue surface is by far shown to outperform the tangentially polarized counterpart, as expected, for channel paths along the cylindrical models. It is efficient for links around a body (abdomen-spine), as over 40 dB gain improvements were seen in this study. The present paper provides perspective for the eligible properties of on-body antennas.

http://ieeexplore.ieee.org/iel7/6888545/6901672/06902129.pdf

The effect of antenna pattern and polarization for launching creeping waves on a skin surface

This paper presents a generic small scale channel model for ultra wideband wireless body area network communications. It is based on static on-body measurements in an anechoic chamber by using a vector network analyzer within a 2--8 GHz bandwidth. Two antenna types are used for the examination: dipole and double loop. From the existing data, a generic average channel impulse response (CIR) was extracted resulting 11 and 12 resolvable paths for the dipole and the double loop antenna, respectively, when a dynamic range of 25 dB was used. The CIR envelopes were modelled by using the polynomial least squares (LS) fitting with orders one to five. The 5th order LS model was noted to follow the CIR envelope most precisely. The CIR decays slightly faster for the dipole antenna. The statistical properties of the CIR bins were solved by fitting the data for 17 continuous distributions and ranking them by using the second order Akaike information criterion. To model the CIR amplitudes exactly, four different distributions were needed for the dipole but for an approximate model Weibull and lognormal distributions suffice. For the double loop, all CIR bins follow the inverse Gaussian distribution. The distributions of the CIR bin indexes were found to follow the negative binomial distribution for both antennas.

/pdf/generic-small-scale-channel-model-for-on-body-uwb-wban-2bkwe0zn0b.pdf

Generic small scale channel model for on-body UWB WBAN communications

Comprehensive knowledge of the channel and accurate channel models are essential in the optimized system design. In the Wireless Body Area Network (WBAN) applications, use of Ultra Wideband (UWB) transmission as well as close presence of human body, bring their own major challenges in the channel modeling. Several channel models have been proposed and numerous channel measurement campaigns have been performed for WBAN applications, but they are only approximations for certain situations. The main challenge in this field is to find a method to generate realistic channel models for new different purposes quickly and flexibly without excessive computational efforts. In this paper, applicability of Finite Integration Technique (FIT) is studied in the modeling the channel characteristics of WBAN on-off body communication link. The validity of the FIT-based channel modeling is verified by comparing the FIT simulation results with the measurement results using three different Ultra Wide Band (UWB) printed planar antennas. The analysis is performed both in frequency and time domains. It is shown that there is a clear agreement between the simulated and measured channel responses. Hence, FIT can be considered as a promising technique in the modeling of realistic on-off body communications channel characteristics for the cases where there is no analytical model available.

Tommi Tuovinen

Papers

An Artificially Anisotropic Antenna Substrate for the Generation of Circular Polarization

On the evaluation of biological effects of wearable antennas on contact with dispersive medium in terms of SAR and bio-heat by using FIT technique

The effect of antenna pattern and polarization for launching creeping waves on a skin surface

Generic small scale channel model for on-body UWB WBAN communications

Channel modeling for UWB WBAN on-off body communication link with finite integration technique