The practical realization of beam steering mechanisms in millimeter wave communications has a large impact on performance. The key challenge is to find a pragmatic trade-off between throughput performance and the overhead of periodic beam sweeping required to improve link quality in case of transient link blockage. This is particularly critical in commercial off-the-shelf devices, which require...

We include the brane curvature scalar to study its cosmological implication in the brane world cosmology. This term is usually introduced to obtain the well-defined stress-energy tensor on the boundary of anti de Sitter-Schwarzschild space. Here we treat this as the perturbed term for cosmological purpose. It is shown that the brane curvature scalar induces some interesting consequences in the ...

The effects of aberration on the Bit-Error-Rate (BER) and reliability of free- space optical (FSO) communication links are investigated. Based on aberrated divergent rectangular partially coherent flat-topped beam formula on the receiver plane and considering the atmosphere losses due to absorption and scattering, numerical values for Power In Bucket (PIB), Signal to Noise Ratio (SNR) and BER a...

Due to high directionality and small wavelengths, 60 GHz links are highly vulnerable to human blockage. To overcome blockage, 60 GHz radios can use a phased-array antenna to search for and switch to unblocked beam directions. However, these techniques are reactive, and only trigger after the blockage has occurred, and hence, they take time to recover the link. In this paper, we propose BeamSpy,...

In this letter, we present a non-mechanical 2D beam-steering system suitable for optical wireless communication. Steering is achieved using polarization gratings combined with nematic liquid crystal cells operating as voltage-controlled shifters. These steering elements are holographic diffuser matched to the discrete angles of grating, enabling continuous angular coverage. Beam-steering also u...

Millimeter wave (mmWave) bands formulate the standalone (SA) operation mode in new radio (NR) access technology of 5G systems. These rely on beamforming architectures to aggregate antenna array gains that compensate for dynamic channel fluctuations and propagation impairments. However, results directional transmission reception, thus resulting beam management challenges, foremost initial access...

Mobile communication on the multi-beam satellite communication has attracted attention, since Digital Video Broadcasting – Return Channel Satellite (DVB-RCS) has been successively implemented. In general, multi beam satellite employs uniform allocation of RF power and bandwidth to multi beams, since it is hard to predict the distribution of traffic requests and the arrival rate of new connectio...

In this paper we propose a new class of sensitive and compact passive stress measurement pattern that uses the piezoresistivity of polysilicon. The proposed measurement pattern utilizes the resistance change of the beam that connects the structures moving in opposite directions. The unit structure is composed of a pair of bent beam actuators with apexes at their mid-points connected by a link b...

It is known that partially (spatial) coherent beams can reduce the effects of scintillation in a free space optical link. However, practical implementations of this type of beam are still under investigation. In this work we apply a wave optics model to analyze the propagation through turbulence of a coherent beam and a particular version of a pseudo-partially coherent beam. The beam we study i...

This paper addresses transmission impairment mechanisms in multiple-beam satellite communications systems that use active phased arrays. The communications link and system aspects are assessed through measurements and analysis. Three link parameters that contribute to transmission impairment are investigated and their effects on the overall carrier-to-interference ratio are quantified. First ar...