scholarly journals The Design of Deploying RIS for Millimetre-Wave Signal in Outdoor Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Wenming Shi ◽  
Yang Liu ◽  
Zhangyou Peng ◽  
Mengnan Xu ◽  
Zhonghao Zhang
Keyword(s):  
Wireless Communication ◽  
Optimal Solution ◽  
Low Complexity ◽  
Outdoor Environment ◽  
Coverage Problem ◽  
Coverage Area ◽  
Millimetre Wave ◽  
Cell Network ◽  
Very High

The power coverage of wireless communication is crucial for the quality of communication and cell network evaluation. In this letter, by taking the layout of Reconfigurable Intelligent Surface (RIS) into count, the power coverage area is proposed for a typical outdoor scenario, which has many rectangular buildings. In this approach, via designing the deploying angle, we introduce finding the optimal horizontal and elevation angles of RIS; we adjust RIS so as to get more power coverage. Since the computational complexity of the optimal solution is very high, a low-complexity method is proposed for solving the optimization problem. More specifically, the coverage is showed in the urban environment with RIS assisting. Presenting the numerical results, we can find the power coverage notably improved. It clearly indicates that our experiment is useful to solve the coverage problem for wireless communication.

scholarly journals A high throughput architecture for a low complexity soft-output demapping algorithm

2015 ◽  
Vol 13 ◽  
pp. 73-80 ◽  
Author(s):  
I. Ali ◽  
U. Wasenmüller ◽  
N. Wehn
Keyword(s):  
Wireless Communication ◽  
High Throughput ◽  
Turbo Code ◽  
Low Complexity ◽  
Implementation Cost ◽  
Qam Modulation ◽  
Iterative Systems ◽  
Very High ◽  
Complexity Algorithm ◽  
Hardware Performance

Abstract. Iterative channel decoders such as Turbo-Code and LDPC decoders show exceptional performance and therefore they are a part of many wireless communication receivers nowadays. These decoders require a soft input, i.e., the logarithmic likelihood ratio (LLR) of the received bits with a typical quantization of 4 to 6 bits. For computing the LLR values from a received complex symbol, a soft demapper is employed in the receiver. The implementation cost of traditional soft-output demapping methods is relatively large in high order modulation systems, and therefore low complexity demapping algorithms are indispensable in low power receivers. In the presence of multiple wireless communication standards where each standard defines multiple modulation schemes, there is a need to have an efficient demapper architecture covering all the flexibility requirements of these standards. Another challenge associated with hardware implementation of the demapper is to achieve a very high throughput in double iterative systems, for instance, MIMO and Code-Aided Synchronization. In this paper, we present a comprehensive communication and hardware performance evaluation of low complexity soft-output demapping algorithms to select the best algorithm for implementation. The main goal of this work is to design a high throughput, flexible, and area efficient architecture. We describe architectures to execute the investigated algorithms. We implement these architectures on a FPGA device to evaluate their hardware performance. The work has resulted in a hardware architecture based on the figured out best low complexity algorithm delivering a high throughput of 166 Msymbols/second for Gray mapped 16-QAM modulation on Virtex-5. This efficient architecture occupies only 127 slice registers, 248 slice LUTs and 2 DSP48Es.

scholarly journals Microbial air contamination with air borne bacteria in the outdoor environment at Janakpurdham, Nepal

2018 ◽  
Vol 6 (2) ◽  
pp. 37-43
Author(s):  
Nagendra Prasad Yadav ◽  
Rakesh Yadav ◽  
Ambu Thakur
Keyword(s):  
Allergic Asthma ◽  
Bacterial Load ◽  
Outdoor Environment ◽  
Microbial Count ◽  
Outdoor Air ◽  
Spring Season ◽  
Air Contamination ◽  
Seasonal Allergies ◽  
Very High

Background and Objectives: Bacteria can cause allergic asthma and seasonal allergies, diseases which are increasingly prevalent in developing nations. Allergic asthma is currently affecting millions of people in Nepal. Therefore, the objective of this study was designed to measure the bacterial load in outdoor air. Materials and Methods: Airborne outdoor bacteria were assessed during the spring season using conventional methods to investigate the enumeration of airborne microorganisms. This was determined by sampling air using the ‘settle plate technique’. The air samples were collected during the spring season (February-March) from 10 different areas of Janakpur. Counts of airborne bacteria were measured as CFUs collected by gravity onto Nutrients Agar plates. Samples were taken periodically over a period of 2 months of February and March 2017. Results: A total of 7,404 bacterial colonies were counted on 30 Petri plates that were exposed for 1 hour. The maximum number of colonies of bacteria was 412. Similarly, the least number of bacterial colonies was 32. Higher numbers of CFUs were found in the petri plates which were exposed for 1 hour in comparison to the petri plates which were exposed for 30 minutes. According to the measurement, 36.6% of total CFUs of bacteria were collected during morning hours, 28.4% during day time and 35% during evening hours. Also, the highest numbers of colonies of bacteria were found in the petri plates that were exposed in ward number 7 and the least number of bacterial colonies were obtained in ward number 9. Conclusion: The bacteriological quality of air in janakpur was very poor. Very high microbial load was found in the outdoor air in Janakpur. The microbial count was found higher in morning than the noon and evening.

Analysis of Dropped-Call Probability in Relay-Based High Speed Railway Environment

2015 ◽  
Vol 738-739 ◽  
pp. 1129-1132
Author(s):  
Yun Ze Li ◽  
Xin Yu Jin ◽  
Duan Po Wu
Keyword(s):  
Wireless Communication ◽  
High Speed ◽  
Base Stations ◽  
Call Rate ◽  
Coverage Area ◽  
High Speed Railway ◽  
Ping Pong ◽  
Order Of Magnitude

In poor coverage area of high-speed railway, the frequent handoff will increase the dropped-call rate. An approach to improving the quality of wireless communication is adding a relay between two base stations. Paper is about analyzing the dropped-call caused by handoff in this scene. This paper proposed a model for dropped-call probability through analyzing the handoff probability, same frequency interference and ping-pong handoff. Based on the simulation and comparison of the dropped-call model, we found that putting a relay between the base stations can significantly improve the dropped-call problem, and the peek rate of dropped-call decreased by an order of magnitude.

Efficient Receiver Implementation for Mobile Applications

2009 ◽  
pp. 271-298
Author(s):  
Costas Chaikalis ◽  
Felip Riera-Palou
Keyword(s):  
Communication Systems ◽  
Low Complexity ◽  
Wireless Communication Systems ◽  
Channel Decoding ◽  
High Data ◽  
Data Rates ◽  
Channel Effects ◽  
Environment Simulation ◽  
Very High

Modern and future wireless communication systems such as UMTS and beyond 3G systems (B3G) are expected to support very high data rates to/from mobile users. This poses important challenges on the handset design as they should be able to attain an acceptable operating bit error rate (BER) while employing a limited set of resources (i.e. low complexity, low power) and often, with tight processing delay constraints. In this chapter we study how channel decoding and equalisation, two widely used mechanisms to combat the deleterious channel effects, can be made adaptable in accordance to the instantaneous operating environment. Simulation results are given demonstrating how receiver reconfigurability is a promising method to achieve complexity/delay efficient receivers while maintaining prescribed quality of service (QoS) constraints.

scholarly journals Joint Placement and Device Association of UAV Base Stations in IoT Networks

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2157 ◽  
Author(s):  
Ashfaq Ahmed ◽  
Muhammad Awais ◽  
Tallha Akram ◽  
Selman Kulac ◽  
Musaed Alhussein ◽  
...  
Keyword(s):  
Optimization Problem ◽  
Optimal Solution ◽  
Cost Effective ◽  
Low Complexity ◽  
Base Stations ◽  
Large Area ◽  
Significant Research ◽  
Minimum Number ◽  
Efficient Scheme

Drone base stations (DBSs) have received significant research interest in recent years. They provide a flexible and cost-effective solution to improve the coverage, connectivity, quality of service (QoS), and energy efficiency of large-area Internet of Things (IoT) networks. However, as DBSs are costly and power-limited devices, they require an efficient scheme for their deployment in practical networks. This work proposes a realistic mathematical model for the joint optimization problem of DBS placement and IoT users’ assignment in a massive IoT network scenario. The optimization goal is to maximize the connectivity of IoT users by utilizing the minimum number of DBS, while satisfying practical network constraints. Such an optimization problem is NP-hard, and the optimal solution has a complexity exponential to the number of DBSs and IoT users in the network. Furthermore, this work also proposes a linearization scheme and a low-complexity heuristic to solve the problem in polynomial time. The simulations are performed for a number of network scenarios, and demonstrate that the proposed heuristic is numerically accurate and performs close to the optimal solution.

Ground water quality of selected areas of Punjab and Sind Provinces, Pakistan: Chemical and microbiological aspects

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Ionic Concentration ◽  
Chloride Ions ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
High Concentration ◽  
Phosphate Ions ◽  
Sodium Magnesium ◽  
Very High ◽  
Microbiological Aspects

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura & Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.

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.

Quality-of-Life Measurement in Advanced Cancer: Assessing the Individual

1999 ◽  
Vol 17 (11) ◽  
pp. 3603-3611 ◽  
Author(s):  
Dympna Waldron ◽  
Ciaran A. O'Boyle ◽  
Michael Kearney ◽  
Michael Moriarty ◽  
Desmond Carney
Keyword(s):  
Quality Of Life ◽  
Advanced Cancer ◽  
Internal Validity ◽  
Semistructured Interview ◽  
Incurable Cancer ◽  
Life Measurement ◽  
The Difference ◽  
The Individual ◽  
Very High

PURPOSE: Despite the increasing importance of assessing quality of life (QoL) in patients with advanced cancer, relatively little is known about individual patient's perceptions of the issues contributing to their QoL. The Schedule for the Evaluation of Individual Quality of Life (SEIQoL) and the shorter SEIQoL–Direct Weighting (SEIQoL-DW) assess individualized QoL using a semistructured interview technique. Here we report findings from the first administration of the SEIQoL and SEIQoL-DW to patients with advanced incurable cancer. PATIENTS AND METHODS: QoL was assessed on a single occasion using the SEIQoL and SEIQoL-DW in 80 patients with advanced incurable cancer. RESULTS: All patients were able to complete the SEIQoL-DW, and 78% completed the SEIQoL. Of a possible score of 100, the median QoL global score was as follows: SEIQoL, 61 (range, 24 to 94); SEIQoL-DW, 60.5 (range, 6 to 95). Psychometric data for SEIQoL indicated very high levels of internal consistency (median r = .90) and internal validity (median R2 = 0.88). Patients' judgments of their QoL were unique to the individual. Family concerns were almost universally rated as more important than health, the difference being significant when measured using the SEIQoL-DW (P = .002). CONCLUSION: Patients with advanced incurable cancer were very good judges of their QoL, and many patients rated their QoL as good. Judgments were highly individual, with very high levels of consistency and validity. The primacy given to health in many QoL questionnaires may be questioned in this population. The implications of these findings are discussed with regard to clinical assessment and advance directives.

scholarly journals Galileo L10 Satellites: Orbit, Clock and Signal-in-Space Performance Analysis

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1695
Author(s):  
Constantin-Octavian Andrei ◽  
Sonja Lahtinen ◽  
Markku Poutanen ◽  
Hannu Koivula ◽  
Jan Johansson
Keyword(s):  
Performance Indicators ◽  
Satellite System ◽  
Short Term ◽  
Orbital Inclination ◽  
Navigation Data ◽  
Periodic Signals ◽  
Global Navigation Satellite ◽  
Minor Correction ◽  
Very High

The tenth launch (L10) of the European Global Navigation Satellite System Galileo filled in all orbital slots in the constellation. The launch carried four Galileo satellites and took place in July 2018. The satellites were declared operational in February 2019. In this study, we report on the performance of the Galileo L10 satellites in terms of orbital inclination and repeat period parameters, broadcast satellite clocks and signal in space (SiS) performance indicators. We used all available broadcast navigation data from the IGS consolidated navigation files. These satellites have not been reported in the previous studies. First, the orbital inclination (56.7±0.15°) and repeat period (50680.7±0.22 s) for all four satellites are within the nominal values. The data analysis reveals also 13.5-, 27-, 177- and 354-days periodic signals. Second, the broadcast satellite clocks show different correction magnitude due to different trends in the bias component. One clock switch and several other minor correction jumps have occurred since the satellites were declared operational. Short-term discontinuities are within ±1 ps/s, whereas clock accuracy values are constantly below 0.20 m (root-mean-square—rms). Finally, the SiS performance has been very high in terms of availability and accuracy. Monthly SiS availability has been constantly above the target value of 87% and much higher in 2020 as compared to 2019. Monthly SiS accuracy has been below 0.20 m (95th percentile) and below 0.40 m (99th percentile). The performance figures depend on the content and quality of the consolidated navigation files as well as the precise reference products. Nevertheless, these levels of accuracy are well below the 7 m threshold (95th percentile) specified in the Galileo service definition document.

scholarly journals Low-Complexity High-Throughput QC-LDPC Decoder for 5G New Radio Wireless Communication

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 516
Author(s):  
Tram Thi Bao Nguyen ◽  
Tuy Nguyen Tan ◽  
Hanho Lee
Keyword(s):  
Wireless Communication ◽  
High Throughput ◽  
Low Complexity ◽  
Ldpc Decoder ◽  
Processor Architectures ◽  
New Radio ◽  
Decoder Architecture ◽  
Check Node ◽  
Information Update ◽  
Wireless Standards

This paper presents a pipelined layered quasi-cyclic low-density parity-check (QC-LDPC) decoder architecture targeting low-complexity, high-throughput, and efficient use of hardware resources compliant with the specifications of 5G new radio (NR) wireless communication standard. First, a combined min-sum (CMS) decoding algorithm, which is a combination of the offset min-sum and the original min-sum algorithm, is proposed. Then, a low-complexity and high-throughput pipelined layered QC-LDPC decoder architecture for enhanced mobile broadband specifications in 5G NR wireless standards based on CMS algorithm with pipeline layered scheduling is presented. Enhanced versions of check node-based processor architectures are proposed to improve the complexity of the LDPC decoders. An efficient minimum-finder for the check node unit architecture that reduces the hardware required for the computation of the first two minima is introduced. Moreover, a low complexity a posteriori information update unit architecture, which only requires one adder array for their operations, is presented. The proposed architecture shows significant improvements in terms of area and throughput compared to other QC-LDPC decoder architectures available in the literature.

Sign in / Sign up

Export Citation Format

Share Document