60 GHz Blockage Study Using Phased Arrays

The millimeter wave (mmWave) frequencies offer the potential for enormous capacity wireless links. However, designing robust communication systems at these frequencies requires that we understand the channel dynamics over both time and space: mmWave signals are extremely vulnerable to blocking and the channel can thus rapidly appear and disappear with small movement of obstacles and reflectors. In rich scattering environments, different paths may experience different blocking trajectories and understanding these multi-path blocking dynamics is essential for developing and assessing beamforming and beam-tracking algorithms. This paper presents the design and experimental results of a novel measurement system which uses phased arrays to perform mmWave dynamic channel measurements. Specifically, human blockage and its effects across multiple paths are investigated with only several microseconds between successive measurements. From these measurements we develop a modeling technique which uses low-rank tensor factorization to separate the available paths so that their joint statistics can be understood.Comment: To appear in the Proceedings of the 51st Asilomar Conference on Signals, Systems, and Computers, 201

5G Millimeter Wave Cellular System Capacity with Fully Digital Beamforming

Due to heavy reliance of millimeter-wave (mmWave) wireless systems on directional links, Beamforming (BF) with high-dimensional arrays is essential for cellular systems in these frequencies. How to perform the array processing in a power efficient manner is a fundamental challenge. Analog and hybrid BF require fewer analog-to-digital converters (ADCs), but can only communicate in a small number of directions at a time,limiting directional search, spatial multiplexing and control signaling. Digital BF enables flexible spatial processing, but must be operated at a low quantization resolution to stay within reasonable power levels. This paper presents a simple additive white Gaussian noise (AWGN) model to assess the effect of low resolution quantization of cellular system capacity. Simulations with this model reveal that at moderate resolutions (3-4 bits per ADC), there is negligible loss in downlink cellular capacity from quantization. In essence, the low-resolution ADCs limit the high SNR, where cellular systems typically do not operate. The findings suggest that low-resolution fully digital BF architectures can be power efficient, offer greatly enhanced control plane functionality and comparable data plane performance to analog BF.Comment: To appear in the Proceedings of the 51st Asilomar Conference on Signals, Systems, and Computers, 201

Channel Dynamics and SNR Tracking in Millimeter Wave Cellular Systems

The millimeter wave (mmWave) frequencies are likely to play a significant role in fifth-generation (5G) cellular systems. A key challenge in developing systems in these bands is the potential for rapid channel dynamics: since mmWave signals are blocked by many materials, small changes in the position or orientation of the handset relative to objects in the environment can cause large swings in the channel quality. This paper addresses the issue of tracking the signal to noise ratio (SNR), which is an essential procedure for rate prediction, handover and radio link failure detection. A simple method for estimating the SNR from periodic synchronization signals is considered. The method is then evaluated using real experiments in common blockage scenarios combined with outdoor statistical models

Disseminated tuberculosis presenting as pneumomediastinum: a case report

This study describes a rare case of a 19 year old girl who presented with features of subcutaneous emphysema and pneumomediastinum to the emergency department in whom further investigation revealed pulmonary and neurotuberculosis. Tuberculosis presenting as pneumomediastinum and subcutaneous emphysema is a rare, but an important entity and a better knowledge of this condition can help in the early diagnosis and adequate management of tuberculosis

Internet addiction, behavioural aspects, and health related problems associated with it: a cross sectional study among engineering students of Jabalpur district

Background: With the rise of new generation gadgets, the risk of “internet addiction” is emerging as a significant behavioral addiction pandemic to be tackled worldwide. Internet addiction can be defined as an impulse disorder. Objective of the study was to determines the level of Internet addiction in Students. To identify the behavioural and any health-related problems associated with internet addiction among students.Methods: This study was a cross sectional study carried out in 7 different engineering colleges of Jabalpur city during the period of 1st July 2016 to 30th September 2016.Results: In present study the prevalence of internet addiction was found to be 74 %. 26 % of the participants were found with no internet addictions whereas 55 % and 17.67 % of the participants were found to be mild and moderate addicted whereas only 1.33 % of the participants were severely addicted to internet addiction. Participant who has internet addiction has 84.8 % of yelling and annoying behavior while 86.5 % participants with internet addiction have secretive and defensive behavior. Association was found to be highly significant (p = <0.001). Ill effects like problem related to eye have significant effect on the participants with internet addiction i.e. 66.17 %. Association of problem related to eye problems with internet addiction was significant with the p = 0.02.Conclusions: The problem is alarming and progressing to an addictive state in the near future Interventions like setting boundaries and detecting early warning signs of underlying psychopathology at the earliest are require

Cellular Wireless Networks in the Upper Mid-Band

The upper mid-band -- roughly from 7 to 24 GHz -- has attracted considerable recent interest for new cellular services. This frequency range has vastly more spectrum than the highly congested bands below 7 GHz while offering more favorable propagation and coverage than the millimeter wave (mmWave) frequencies. Realizing the full potential of these bands, however, will require fundamental changes to the design of cellular systems. Most importantly, spectrum will likely need to be shared with incumbents including communication satellites, military RADAR, and radio astronomy. Also, due to the wide bandwidth, directional nature of transmission, and intermittent occupancy of incumbents, cellular systems will need to be agile to sense and intelligently use large spatial and bandwidth degrees of freedom. This paper attempts to provide an initial assessment of the feasibility and potential gains of wideband cellular systems operating in the upper mid-band. The study includes: (1) a system study to assess potential gains of multi-band systems in a representative dense urban environment; (2) propagation calculations to assess potential cross interference between satellites and terrestrial cellular services; and (3) design and evaluation of a compact multi-band antenna array structure. Leveraging these preliminary results, we identify potential future research directions to realize next-generation systems in these frequencies.Comment: 11 page