scholarly journals Wireless Terrestrial Backhaul for 6G Remote Access: Challenges and Low Power Solutions

2021 ◽  
Vol 2 ◽  
Author(s):  
Harri Saarnisaari ◽  
Abdelaali Chaoub ◽  
Marjo Heikkilä ◽  
Amit Singhal ◽  
Vimal Bhatia
Keyword(s):  
Low Power ◽  
Digital Divide ◽  
Communication Systems ◽  
Remote Access ◽  
Small Radius ◽  
Large Area ◽  
Access Points ◽  
Wireless Backhaul ◽  
Rural And Remote Areas ◽  
Backhaul Link

Despite developments in communication systems over the last few decades, a digital divide exists in the unconnected part of the world. The latter is characterized by large distances to internet access points, underdeveloped infrastructure, sparse populations, and low incomes. This concern of digital divide is raised in the sixth generation’s (6G) initial vision as an extremely important topic. However, it is important to understand affiliated challenges and potential solutions to achieve this vision. Motivated by the recent backhaul link forecasts that expect a dominance of the microwave technology within the backhauling market, this paper studies the potential of a low-power terrestrial microwave backhaul from the sufficient-data-rate and solar powering perspective. Competing technologies (e.g., fiber) may not be energy efficient and commercially viable for global connectivity. Since rural and remote areas may not have grid power, we look at the viability of alternative sustainable sources, in particular solar power, to power the wireless backhaul in 6G. In addition, we also explore services for the operators and users to use the system efficiently. Since the access points are connected to backhaul, we also compare the two prominent solutions based on low-power small-radius cells and a mega-cell that covers a large area and show insights on the power autonomy of the systems. In the end, we propose directions for research and deployment for an inclusive connectivity as a part of future 6G networks.

Design and Implementation of an Efficient Parallel LFSR Architecture for Wireless Communication Systems

2019 ◽  
Vol 14 ◽  
Author(s):  
A. Suresh Babu ◽  
B. Anand
Keyword(s):  
Wireless Communication ◽  
Power Consumption ◽  
Low Power ◽  
Communication Systems ◽  
High Speed ◽  
Design Tool ◽  
Shift Register ◽  
Linear Feedback ◽  
Wireless Communication Systems ◽  
Coverage Area

: A Linear Feedback Shift Register (LFSR) considers a linear function typically an XOR operation of the previous state as an input to the current state. This paper describes in detail the recent Wireless Communication Systems (WCS) and techniques related to LFSR. Cryptographic methods and reconfigurable computing are two different applications used in the proposed shift register with improved speed and decreased power consumption. Comparing with the existing individual applications, the proposed shift register obtained >15 to <=45% of decreased power consumption with 30% of reduced coverage area. Hence this proposed low power high speed LFSR design suits for various low power high speed applications, for example wireless communication. The entire design architecture is simulated and verified in VHDL language. To synthesis a standard cell library of 0.7um CMOS is used. A custom design tool has been developed for measuring the power. From the results, it is obtained that the cryptographic efficiency is improved regarding time and complexity comparing with the existing algorithms. Hence, the proposed LFSR architecture can be used for any wireless applications due to parallel processing, multiple access and cryptographic methods.

scholarly journals The Photodetectors Based on Lateral Monolayer MoS2/WS2 Heterojunctions

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Caihong Li ◽  
Juntong Zhu ◽  
Wen Du ◽  
Yixuan Huang ◽  
Hao Xu ◽  
...  
Keyword(s):  
Communication Systems ◽  
Transition Metal Dichalcogenides ◽  
Chemical Vapor ◽  
Large Area ◽  
Optical Signals ◽  
Metal Dichalcogenides ◽  
One Step ◽  
The One ◽  
Charge Carrier Trapping ◽  
Sharp Interfaces

AbstractMonolayer transition metal dichalcogenides (TMDs) show promising potential for next-generation optoelectronics due to excellent light capturing and photodetection capabilities. Photodetectors, as important components of sensing, imaging and communication systems, are able to perceive and convert optical signals to electrical signals. Herein, the large-area and high-quality lateral monolayer MoS2/WS2 heterojunctions were synthesized via the one-step liquid-phase chemical vapor deposition approach. Systematic characterization measurements have verified good uniformity and sharp interfaces of the channel materials. As a result, the photodetectors enhanced by the photogating effect can deliver competitive performance, including responsivity of ~ 567.6 A/W and detectivity of ~ 7.17 × 1011 Jones. In addition, the 1/f noise obtained from the current power spectrum is not conductive to the development of photodetectors, which is considered as originating from charge carrier trapping/detrapping. Therefore, this work may contribute to efficient optoelectronic devices based on lateral monolayer TMD heterostructures.

scholarly journals Low Power Digital Multimedia Telecommunication Designs

VLSI Design ◽  
2001 ◽  
Vol 12 (3) ◽  
pp. 301-315 ◽  
Author(s):  
Koon-Shik Cho ◽  
Jun-Dong Cho
Keyword(s):  
Motion Estimation ◽  
Low Power ◽  
Communication Systems ◽  
Matched Filter ◽  
Optimization Technique ◽  
Low Power Design ◽  
Multimedia Systems ◽  
Wireless Multimedia ◽  
Design Constraint ◽  
Power Capability

The increasing prominence of wireless multimedia systems and the need to limit power capability in very-high density VLSI chips have led to rapid and innovative developments in low-power design. Power reduction has emerged as a significant design constraint in VLSI design. The need for wireless multimedia systems leads to much higher power consumption than traditional portable applications. This paper presents possible optimization technique to reduce the energy consumption for wireless multimedia communication systems. Four topics are presented in the wireless communication systems subsection which deal with architectures such as PN acquisition, parallel correlator, matched filter and channel coding. Two topics include the IDCT and motion estimation in multimedia application.These topics consider algorithms and architectures for low power design such as using hybrid architecture in PN acquisition, analyzing the algorithm and optimizing the sample storage in parallel correlator, using complex matched filter that analog operational circuits controlled by digital signals, adopting bit serial arithmetic for the ACS operation in viterbi decoder, using CRC to adaptively terminate the SOVA iteration in turbo decoder, using codesign in RS codec, disabling the processing elements as soon as the distortion values become great than the minimum distortion value in motion estimation, and exploiting the relative occurrence of zero-valued DCT coefficient in IDCT.

scholarly journals Transmission of wireless backhaul signal in a cellular system with small moving cells

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Hyoung-Keon Kim ◽  
Yong-Suk Byun ◽  
Geon-Woong Jung ◽  
Yong-Hwan Lee
Keyword(s):  
Signal Transmission ◽  
Cellular Systems ◽  
Base Stations ◽  
Wireless Backhaul ◽  
Backhaul Link ◽  
Channel Information ◽  
Short And Long Term ◽  
Water Filling ◽  
Noise Ratio

Abstract Deployment of small moving cells (SMCs) has been considered in advanced cellular systems, where wireless backhaul links are required between base stations and SMCs. In this paper, we consider signal transmission by means of multiuser beamforming in the wireless backhaul link. We generate the beam weight in an eigen-direction of weighted combination of short- and long-term channel information of the backhaul link. The beam weight can maximize the average signal-to-leakage-plus-noise ratio (SLNR), while providing the transmission robust to SMC mobility. We analyze the performance of the proposed scheme in terms of the average signal-to-interference-plus-noise ratio (SINR) and optimize the transmit power by iterative water-filling. Finally, we verify the performance of the proposed scheme by computer simulation.

scholarly journals Energy Optimization of a Laser-Powered Hovering-UAV Relay in Optical Wireless Backhaul

2021 ◽  
Author(s):  
Muhammad Salman Bashir ◽  
Mohamed-Slim Alouini
Keyword(s):  
Quality Of Service ◽  
Communication Systems ◽  
Low Cost ◽  
Base Stations ◽  
Achievable Rate ◽  
Optical Wireless ◽  
Free Space Optical ◽  
Decode And Forward ◽  
Wireless Backhaul

<div>Due to their flexibility and low cost deployment, unmanned aerial vehicles (UAV) will most likely act as base stations and backhaul relays in the next generation of wireless communication systems. However, these UAVs---in the untethered mode---can only operate for a finite time due to limited energy they carry in their batteries. In free-space optical communications, one solution is to transport both the data and the energy from the source to the UAV through the laser beam---a concept known as <i>simultaneous lightwave information and power transfer</i> (SLIPT). In this study, we have analyzed the SLIPT scheme for laser-powered decode-and-forward UAV relays in an optical wireless backhaul. The major goal of this study is to optimally allocate the received beam energy between the decoding circuit, the transmitting circuit and the rotor block of the relay in order to maximize a quality-of-service metric such as maximum achievable rate, outage or error probabilities. As expected, we note that the optimal power allocation depends heavily on the source-relay and relay-destination channel conditions. In the final part of this study, we have maximized the operational time of the UAV relay given that the maximum achievable rate stays above a certain threshold in order to meet a minimum quality-of-service requirement.</div>

scholarly journals Reversible logic in pipelined low power vedic multiplier

2019 ◽  
Vol 16 (3) ◽  
pp. 1265
Author(s):  
Ansiya Eshack ◽  
S. Krishnakumar
Keyword(s):  
Low Power ◽  
Communication Systems ◽  
Large Scale ◽  
Optical Computing ◽  
Digital Signal ◽  
Logic Gates ◽  
Reversible Logic ◽  
Large Scale Integration ◽  
Time Required ◽  
Scale Integration

<span>With an ever growing demand for low-power devices, it is a general trend to search for ways to reduce the power consumption of a system. Multipliers are an important requirement in applications linked to Digital Signal Processing, Communication Systems, Optical Computing, Nanotechnology, Low-Power Very Large Scale Integration and Quantum Computing. Conventional mathematics makes multiplication a very long and time consuming process. The use of Vedic mathematics has led to great reduction in the time required for such calculations. The excessive use of Urdhava Tiryakbhyam sutra in multiplication surely proves its effectiveness and simplicity in this domain. This sutra supports the process of pipelining, a method employed in reduction of the power used by a system. Reversible logic has been gaining demand due to its low-power capabilities and is currently being used in many computing applications. The paper proposes two multiplier systems: one design employs the Urdhava Tiryakbhyam sutra along with pipelining and the second uses reversible logic gates into the first design. These proposed systems provide very less delay for result computation and low hardware utilization when compared to non-pipelined Vedic multipliers.</span>

scholarly journals A low complexity digital frequency calibration with high jitter immunity for ultra-low-power oscillators

2019 ◽  
Vol 17 ◽  
pp. 145-150
Author(s):  
Markus Scholl ◽  
Ralf Wunderlich ◽  
Stefan Heinen
Keyword(s):  
Low Power ◽  
Communication Systems ◽  
Calibration Method ◽  
Low Complexity ◽  
Frequency Stability ◽  
Wireless Communication Systems ◽  
Ultra Low Power ◽  
Wireless Transceiver ◽  
Digital Frequency ◽  
Frequency Calibration

Abstract. This paper presents a highly efficient digital frequency calibration method for ultra-low-power oscillators in wireless communication systems. This calibration method locks the ultra-low-power oscillator's output frequency to the reference clock of the wireless transceiver during its send- and receive-state to achieve frequency stability over process variation and temperature drifts. The introduced calibration scheme offers high jitter immunity and short locking periods overcoming frequency calibration errors for typical ultra-low-power oscillator's by utilizing non-linear segmented feedback levels. In measurements the proposed calibration method improves the frequency stability of an ultra-low-power 32 kHz oscillator from 53 to 10 ppm ∘C−1 over a wide temperature range for temperature drifts of less than 1 ∘C s−1 with an estimated power consumption of 185 nW while coping with relocking periods of 7 ms.

A Femtocellular-Cabled Solution for Broadband Wireless Access

2011 ◽  
Vol 3 (2) ◽  
pp. 38-50 ◽  
Author(s):  
Dario Di Zenobio ◽  
Massimo Celidonio ◽  
Lorenzo Pulcini ◽  
Arianna Rufini
Keyword(s):  
Digital Divide ◽  
Frequency Band ◽  
Mobile Networks ◽  
Wireless Access ◽  
Mobile Technologies ◽  
Innovative Approach ◽  
Broadband Wireless Access ◽  
End User ◽  
Broadband Wireless ◽  
Access Points

Broadband Wireless Access is a strategic opportunity for mobile operators which aim to provide connectivity in digital divide areas, in order to accelerate speed of deployment and save in installation costs. This paper presents an innovative approach to access the end user, relying on infrastructural integration of femtocellular technology with existing cabled network. Usually, the adoption of Femtocell Access Points, operating in the licensed cellular bands typically designed to be used in SOHO, improves the radio coverage and the building penetration of the existing mobile networks, based on macrocells. In the proposed solution, the peculiar functionality of femtocells is further improved using a MATV/SMATV cabled infrastructure which facilitates the signal connection inside the building. The potentiality of the solution is even more evident, taking into account the growing interest towards the possible deployment of new mobile technologies, like LTE in both the last portion of the UHF band V and the GSM frequency band, resulting from the re-farming process.

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