scholarly journals Exploiting Capture Diversity for Performance Enhancement of ALOHA-Based Multi-Static Backscattering Systems in the 6G Perspective

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5070
Author(s):  
Roberto Valentini ◽  
Piergiuseppe Di Marco ◽  
Fortunato Santucci
Keyword(s):  
Communication Systems ◽  
Performance Enhancement ◽  
Multiple Access Interference ◽  
Wireless Channel ◽  
Cross Layer ◽  
Framed Slotted Aloha ◽  
Normalized Throughput ◽  
Log Normal ◽  
Aloha Protocol ◽  
The Impact

In this paper, we consider the emerging context of ALOHA-based multi-static backscattering communication systems. By assuming an architecture consisting of a set of passive backscattering nodes, an illuminator, and a set of spatially dislocated receivers, we firstly propose a cross-layer framework for performance analysis. The model jointly accounts for the shared wireless channel, including fading and capture effect, and channel contention strategy, which is regulated by a Framed Slotted ALOHA protocol. Furthermore, based on the inherent macroscopic diversity offered by the multi-static settings, we introduce the concept of capture diversity, which is shown to enable multiple packet detection in slots with multiple transmissions. In order to characterize the multiple access interference and approximate the capture probabilities, we enforce a log-normal approximation of the inverse Signal-to-Interference Ratio that relies on moment matching. Numerical results show the impact of deployment scenarios and the relative positions of illuminator, backscattering nodes, and receivers on the system normalized throughput. We show how the number of detection points impacts the system performance under various channel conditions. Moreover, the accuracy of the proposed approximation rationale is validated via Monte Carlo simulations. Finally, we analyze the optimal frame length in the presence of capture diversity.

Blind Multiuser Receivers for Chaos Based Communications

2003 ◽  
Vol 13 (08) ◽  
pp. 2353-2359 ◽  
Author(s):  
Francisco Argüello ◽  
Manuel Bugallo ◽  
Juan López
Keyword(s):  
Communication Systems ◽  
Multiple Access ◽  
Good Deal ◽  
Multiple Access Interference ◽  
Detection Techniques ◽  
Multiuser Receivers ◽  
Cdma Systems ◽  
Blind Receivers ◽  
Code Division Multiple ◽  
The Impact

Recently, there has been a good deal of interest in the use of chaotic signals for direct sequence code division multiple access (DS-CDMA) communication systems. The capacity of DS-CDMA systems is interference-limited, and can therefore be increased by techniques that suppress interference. This letter is devoted to the evaluation of the impact of blind multiuser detection techniques on chaos based DS-CDMA systems. Blind receivers can suppress multiple access interference and do not require knowledge of the code sequences and propagation channels of the interference. We demonstrate that, for chaotic sequence-based communications, blind multiuser receivers significantly improve the BER with respect to single-user receivers, and that their use is practically essential with a high number of users.

scholarly journals Cross-Layer Analysis of Multi-Static RFID Systems Exploiting Capture Diversity

2021 ◽  
Author(s):  
Roberto Valentini ◽  
Piergiuseppe Di Marco ◽  
Roberto Alesii ◽  
Fortunato Santucci
Keyword(s):  
Mac Protocol ◽  
Wireless Channel ◽  
Cross Layer ◽  
Mac Layer ◽  
Medium Access ◽  
Rfid Systems ◽  
Layer Analysis ◽  
Passive Rfid ◽  
The Impact ◽  
Collision Mechanism

In this paper, we propose a framework for cross-layer analysis of multi-static passive RFID systems. The model takes into account details of the shared wireless channel, including fading and capture effect, whereas, at the medium access control (MAC) layer, the anti-collision mechanism proposed in the EPC Generation 2 standard is taken as a reference.<br>To address the complexity of the system model, we rely on a semi-analytical approach, that combines a moment matching approximation method to abstract the physical layer and Monte-Carlo simulations to describe the MAC dynamics.<br>Furthermore, based on the space diversity feature offered by the multi-static settings, we introduce the concept of capture deiversity and propose a modification to the standard to fully support this form of diversity.<br>Numerical results show the impact of deployment conditions and the relative positions of interrogator, tags, and detection points on the performance of tags' identification. We show how the number of detection points impacts the system performance under various channel conditions and MAC parameters' settings. Finally, we validate the proposed update of the MAC protocol, showing substantial performance improvement with respect to the standard collision resolution policy.

A Cross-Layer Design to Wireless/Mobile Video Streaming

2011 ◽  
pp. 125-146
Author(s):  
Yongjin Cho ◽  
C. Jay Kuo
Keyword(s):  
Video Streaming ◽  
Communication Systems ◽  
Performance Enhancement ◽  
Cross Layer ◽  
Cross Layer Design ◽  
Mobile Video ◽  
Mobile Video Streaming ◽  
The Cross ◽  
Wireless Mobile Communication ◽  
Wireless Mobile

This chapter introduces a cross-layer approach to wireless/mobile video streaming system design to meet its flexibility and adaptability requirements. On one hand, with the rapid development of wireless/mobile communication infrastructure, wireless video applications are gaining more popularity. On the other hand, there exist many new challenges due to the inherent characteristics of wireless networks and communication systems. This is especially true for video delivery under a stringent time constraint. To address these issues, flexibility and adaptability of communication systems, which are the objectives of cross-layer design, have been extensively studied for performance enhancement. In this chapter, we begin with the motivation of the cross-layer approach, which is needed in response to several challenges of efficient wireless/mobile video streaming. Then, some fundamental issues of the cross-layer design are introduced followed by video-specific system requirements. Furthermore, we examine a couple of cross-layer design ideas proposed in the past. Finally, we consider issues associated with the practical employment along with software simulations, and demonstrate the benefit of the cross-layer approach.

Performance Analysis of Amplify-and-Forward Relaying FSO/SC-QAM Systems over Weak Turbulence Channels and Pointing Error Impairments

2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Ha Duyen Trung
Keyword(s):  
Atmospheric Turbulence ◽  
Communication Systems ◽  
Symbol Error Rate ◽  
Aperture Size ◽  
Free Space Optical ◽  
Amplify And Forward ◽  
Pointing Error ◽  
Log Normal ◽  
The Impact ◽  
Af Relaying

AbstractIn this paper, the end-to-end performance of free-space optical (FSO) communication system combining with Amplify-and-Forward (AF)-assisted or fixed-gain relaying technology using subcarrier quadrature amplitude modulation (SC-QAM) over weak atmospheric turbulence channels modeled by log-normal distribution with pointing error impairments is studied. More specifically, unlike previous studies on AF relaying FSO communication systems without pointing error effects; the pointing error effect is studied by taking into account the influence of beamwidth, aperture size and jitter variance. In addition, a combination of these models to analyze the combined effect of atmospheric turbulence and pointing error to AF relaying FSO/SC-QAM systems is used. Finally, an analytical expression is derived to evaluate the average symbol error rate (ASER) performance of such systems. The numerical results show that the impact of pointing error on the performance of AF relaying FSO/SC-QAM systems and how we use proper values of aperture size and beamwidth to improve the performance of such systems. Some analytical results are confirmed by Monte-Carlo simulations.

scholarly journals Cross-Layer Analysis of Multi-Static RFID Systems Exploiting Capture Diversity

2021 ◽  
Author(s):  
Roberto Valentini ◽  
Piergiuseppe Di Marco ◽  
Roberto Alesii ◽  
Fortunato Santucci
Keyword(s):  
Mac Protocol ◽  
Wireless Channel ◽  
Cross Layer ◽  
Mac Layer ◽  
Medium Access ◽  
Rfid Systems ◽  
Layer Analysis ◽  
Passive Rfid ◽  
The Impact ◽  
Collision Mechanism

In this paper, we propose a framework for cross-layer analysis of multi-static passive RFID systems. The model takes into account details of the shared wireless channel, including fading and capture effect, whereas, at the medium access control (MAC) layer, the anti-collision mechanism proposed in the EPC Generation 2 standard is taken as a reference.<br>To address the complexity of the system model, we rely on a semi-analytical approach, that combines a moment matching approximation method to abstract the physical layer and Monte-Carlo simulations to describe the MAC dynamics.<br>Furthermore, based on the space diversity feature offered by the multi-static settings, we introduce the concept of capture deiversity and propose a modification to the standard to fully support this form of diversity.<br>Numerical results show the impact of deployment conditions and the relative positions of interrogator, tags, and detection points on the performance of tags' identification. We show how the number of detection points impacts the system performance under various channel conditions and MAC parameters' settings. Finally, we validate the proposed update of the MAC protocol, showing substantial performance improvement with respect to the standard collision resolution policy.

Performance Analysis of FSO DF Relays with Log-Normal Fading Channel

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Ha Duyen Trung
Keyword(s):  
Performance Analysis ◽  
Error Rate ◽  
Communication Systems ◽  
Free Space Optical ◽  
Error Performance ◽  
Relay Nodes ◽  
Decode And Forward ◽  
Log Normal ◽  
Optimal Average ◽  
The Impact

AbstractThis paper studies the bit error performance analysis of decode-and-forward (DF) relays-based free-space optical (FSO) communication systems using avalanche photodiode (APD). The system uses subcarrier intensity binary phase shift keying (BPSK) modulated signals and subjects to scintillation due to optical turbulence. A log-normal random process is considered to model the received signal intensity fluctuation for a clear-air condition (weak atmospheric turbulence) scenario. Mathematical expressions of the average bit error probability and bit error rate (BER) are derived by taking into account the impact of atmospheric loss, thermal-noise and shot-noise limited conditions. It can be inferred from the numerical results that using DF relay nodes can extend the transmission distance and minimize BER performance of FSO system significantly compared with the direct transmission. Moreover, the selection of APD’s gain values is essential to minimize the system’s error rate performance. Therefore, the system could achieve the minimal BER by selecting an optimal average APD gain value appropriately. Moreover, the optimal average gain values of APD significantly depend on various conditions, such as the bit rate, total transmitted power, and the number of relay nodes.

The Effect of Information Technology on Fluidity of Contemporary Architectural Space

2019 ◽  
Vol 7 (1) ◽  
pp. 62-72
Author(s):  
Shatha Abbas Hassan ◽  
Noor Ali Aljorani
Keyword(s):  
Information Technology ◽  
Communication Systems ◽  
Research Problem ◽  
Architectural Space ◽  
Human Thought ◽  
Technological Developments ◽  
Ease Of Access ◽  
The Impact ◽  
Role Of Information

The increasing importance of the information revolution and terms such as ‘speed’, ‘disorientation’, and ‘changing the concept of distance’, has provided us with tools that had not been previously available. Technological developments are moving toward Fluidity, which was previously unknown and cannot be understood through modern tools. With acceleration of the rhythm in the age we live in and the clarity of the role of information technology in our lives, as also the ease of access to information, has helped us to overcome many difficulties. Technology in all its forms has had a clear impact on all areas of daily life, and it has a clear impact on human thought in general, and the architectural space in particular, where the architecture moves from narrow spaces and is limited to new spaces known as the ‘breadth’, and forms of unlimited and stability to spaces characterized with fluidity. The research problem (the lack of clarity of knowledge about the impact of vast information flow associated with the technology of the age in the occurrence of liquidity in contemporary architectural space) is presented here. The research aims at defining fluidity and clarifying the effect of information technology on the changing characteristics of architectural space from solidity to fluidity. The research follows the analytical approach in tracking the concept of fluidity in physics and sociology to define this concept and then to explain the effect of Information Technology (IT) to achieve the fluidity of contemporary architectural space, leading to an analysis of the Skidmore, Owings and Merrill (SOM) architectural model. The research concludes that information technology achieves fluidity through various tools (communication systems, computers, automation, and artificial intelligence). It has changed the characteristics of contemporary architectural space and made it behave like an organism, through using smart material.

scholarly journals WON-OCDMA System Based on MW-ZCC Codes for Applications in Optical Wireless Sensor Networks

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 539
Author(s):  
Saleh Seyedzadeh ◽  
Andrew Agapiou ◽  
Majid Moghaddasi ◽  
Milan Dado ◽  
Ivan Glesk
Keyword(s):  
Optical Networks ◽  
Video Surveillance ◽  
Multiple Access ◽  
Optical Sensing ◽  
Multiple Access Interference ◽  
Service Differentiation ◽  
Sensor Data ◽  
Variable Weight ◽  
Code Division Multiple ◽  
The Impact

The growing demand for extensive and reliable structural health monitoring resulted in the development of advanced optical sensing systems (OSS) that in conjunction with wireless optical networks (WON) are capable of extending the reach of optical sensing to places where fibre provision is not feasible. To support this effort, the paper proposes a new type of a variable weight code called multiweight zero cross-correlation (MW-ZCC) code for its application in wireless optical networks based optical code division multiple access (WON-OCDMA). The code provides improved quality of service (QoS) and better support for simultaneous transmission of video surveillance, comms and sensor data by reducing the impact of multiple access interference (MAI). The MW-ZCC code’s power of two code-weight properties provide enhanced support for the needed service differentiation provisioning. The performance of this novel code has been studied by simulations. This investigation revealed that for a minimum allowable bit error rate of 10−3, 10−9 and 10−12 when supporting triple-play services (sensing, datacomms and video surveillance, respectively), the proposed WON-OCDMA using MW-ZCC codes could support up to 32 simultaneous services over transmission distances up to 32 km in the presence of moderate atmospheric turbulence.

scholarly journals Influence of Aircraft Power Electronics Processing on Backup VHF Radio Systems

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 777
Author(s):  
Jan Leuchter ◽  
Radim Bloudicek ◽  
Jan Boril ◽  
Josef Bajer ◽  
Erik Blasch
Keyword(s):  
Power Electronics ◽  
Electromagnetic Interference ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Intermediate Frequency ◽  
Radio Communication ◽  
Very High Frequency ◽  
Switching Power ◽  
Radio Systems ◽  
The Impact

The paper describes the influence of power electronics, energy processing, and emergency radio systems (ERS) immunity testing on onboard aircraft equipment and ground stations providing air traffic services. The implementation of next-generation power electronics introduces potential hazards for the safety and reliability of aircraft systems, especially the interferences from power electronics with high-power processing. The paper focuses on clearly identifying, experimentally verifying, and quantifiably measuring the effects of power electronics processing using switching modes versus the electromagnetic compatibility (EMC) of emergency radio systems with electromagnetic interference (EMI). EMI can be very critical when switching power radios utilize backup receivers, which are used as aircraft backup systems or airport last-resort systems. The switching power electronics process produces interfering electromagnetic energy to create problems with onboard aircraft radios or instrument landing system (ILS) avionics services. Analyses demonstrate significant threats and risks resulting from interferences between radio and power electronics in airborne systems. Results demonstrate the impact of interferences on intermediate-frequency processing, namely, for very high frequency (VHF) radios. The paper also describes the methodology of testing radio immunity against both weak and strong signals in accordance with recent aviation standards and guidance for military radio communication systems in the VHF band.

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