scholarly journals Impact of IQ Imbalance on RIS-Assisted SISO Communication Systems

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Asma Bouhlel ◽  
Anis Sakly
Keyword(s):  
System Performance ◽  
Communication Systems ◽  
Wireless Channel ◽  
Standard Ml ◽  
Hardware Impairments ◽  
Iq Imbalance ◽  
Transmission Technique ◽  
Quadrature Phase ◽  
Analytical Approaches ◽  
Identical Performance

Reconfigurable intelligent surface (RIS) for wireless networks has emerged as a promising future transmission technique to create smart radio environments that improve the system performance by turning the wireless channel into an adjustable system block. However, transceivers come with various hardware impairments, such as phase noise and in-phase/quadrature-phase imbalance (IQI). Hence, for robust configuration of RIS-based communication under practical conditions, assuming the identical performance analysis when subject to IQI, will lead to inaccurate analysis. In this paper, the implementation of this novel transmission technique is thoroughly investigated under intensive realistic circumstances. For this purpose, based on the maximum likelihood (ML) detector, a novel analytical expression of average pairwise error probability under IQI is proposed and compared to the standard ML detector. Further, the proposed analytical approaches are confirmed by numerical simulations.

scholarly journals Impact of Hardware Impairment Analysis on Channel Capacity Bounds of MIMO Antenna Configurations

2020 ◽  
Vol 9 (3) ◽  
pp. 1981-1985
Keyword(s):  
Channel Capacity ◽  
System Performance ◽  
Communication Systems ◽  
Mimo Systems ◽  
Mimo System ◽  
Mimo Antenna ◽  
Hardware Impairments ◽  
Hardware Impairment ◽  
The Impact ◽  
Capacity Performance

with the increasing demand f the higher data reates the utilization of the MIMO system have exponentially increased in the cellular communication systems. There are many reasons due to which the performance of the MIMO systems degrades in real time. The major challenge is the any kind of noise or erro in the system due to hardware issues and problems. The any kind of hardware error is called as hardware impairment in the systems. These impairments are represented by Kapa values in the systems. Paper is primarily focused to define and evaluate the impact of the hardware impairment on the system performance of MIMO. The paper first defines the basic MIMO systems antenna configurations and then the channel capacity performance is compared with and without hardware impairments. the antenna configurations depends on the number of input and output antenna in the system. As the number of antennas increases the probability of having hardware impairment also increases. This may reduce the capacity performance significantly. New channel capacity formulation is given for antenna configurations. Paper evaluated the performance under the different channel sizes on the capacity. Finally the capacity of the channel is plotted as the function of the different Signal to noise ratios. It is concluded the MIMO system performance is degraded under the presence of the hardware impairments.

scholarly journals Broadband Wireless Channel in Composite High-Speed Railway Scenario: Measurements, Simulation, and Analysis

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Jianwen Ding ◽  
Lei Zhang ◽  
Jingya Yang ◽  
Bin Sun ◽  
Jiying Huang
Keyword(s):  
Ray Tracing ◽  
Communication Systems ◽  
High Speed ◽  
Channel Model ◽  
High Reliability ◽  
Rapid Development ◽  
Path Loss ◽  
Wireless Channel ◽  
Delay Spread ◽  
High Speed Railway

The rapid development of high-speed railway (HSR) and train-ground communications with high reliability, safety, and capacity promotes the evolution of railway dedicated mobile communication systems from Global System for Mobile Communications-Railway (GSM-R) to Long Term Evolution-Railway (LTE-R). The main challenges for LTE-R network planning are the rapidly time-varying channel and high mobility, because HSR lines consist of a variety of complex terrains, especially the composite scenarios where tunnels, cuttings, and viaducts are connected together within a short distance. Existing researches mainly focus on the path loss and delay spread for the individual HSR scenarios. In this paper, the broadband measurements are performed using a channel sounder at 950 MHz and 2150 MHz in a typical HSR composite scenario. Based on the measurements, the pivotal characteristics are analyzed for path loss exponent, power delay profile, and tap delay line model. Then, the deterministic channel model in which the 3D ray-tracing algorithm is applied in the composite scenario is presented and validated by the measurement data. Based on the ray-tracing simulations, statistical analysis of channel characteristics in delay and Doppler domain is carried out for the HSR composite scenario. The research results can be useful for radio interface design and optimization of LTE-R system.

scholarly journals Genetic Algorithm-Based Beam Refinement for Initial Access in Millimeter Wave Mobile Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Hao Guo ◽  
Behrooz Makki ◽  
Tommy Svensson
Keyword(s):  
Genetic Algorithm ◽  
Millimeter Wave ◽  
Mobile Networks ◽  
System Performance ◽  
Multiple Input Multiple Output ◽  
Hardware Impairments ◽  
Mimo Networks ◽  
Multiple Input ◽  
Input Multiple Output ◽  
High Carrier

Initial access (IA) is identified as a key challenge for the upcoming 5G mobile communication system operating at high carrier frequencies, and several techniques are currently being proposed. In this paper, we extend our previously proposed efficient genetic algorithm- (GA-) based beam refinement scheme to include beamforming at both the transmitter and the receiver and compare the performance with alternative approaches in the millimeter wave multiuser multiple-input-multiple-output (MU-MIMO) networks. Taking the millimeter wave communications characteristics and various metrics into account, we investigate the effect of different parameters such as the number of transmit antennas/users/per-user receive antennas, beamforming resolutions, and hardware impairments on the system performance employing different beam refinement algorithms. As shown, our proposed GA-based approach performs well in delay-constrained networks with multiantenna users. Compared to the considered state-of-the-art schemes, our method reaches the highest service outage-constrained end-to-end throughput with considerably less implementation complexity. Moreover, taking the users’ mobility into account, our GA-based approach can remarkably reduce the beam refinement delay at low/moderate speeds when the spatial correlation is taken into account. Finally, we compare the cases of collaborative users and noncollaborative users and evaluate their difference in system performance.

Introduction to Wireless Endogenous Security and Safety: Problems, Attributes, Structures and Functions

2021 ◽  
Author(s):  
Xiaoyan Hu ◽  
Liang Jin ◽  
Yangming Lou ◽  
Zhou Zhong ◽  
Xiaoli Sun
Keyword(s):  
Wireless Communication ◽  
Communication System ◽  
Communication Systems ◽  
Wireless Channel ◽  
Communication Security ◽  
Wireless Communication Systems ◽  
Functional Safety ◽  
Wireless Communication System ◽  
Safety Technology ◽  
Safety Attributes

Abstract: The information security and functional safety of wireless communication systems have become the focus of current research. The endogenous security principle based on Dynamic Heterogeneous Redundancy provides a direction for the development of wireless communication security and safety technology. This paper introduces the concept of wireless endogenous security from the following four aspects. First, we sorts out the endogenous security problems faced by the current wireless communication system, and then analyzes the endogenous security and safety attributes of the wireless channel. After that, the endogenous security and safety structure of the wireless communication system is given, and finally the applications of the existing wireless communication endogenous security and safety functions are listed. <br>

Data Transmission Oriented on the Object, Communication Media, Application, and State of Communication Systems

2011 ◽  
Vol 3 (2) ◽  
pp. 51-65
Author(s):  
Mike Sabelkin ◽  
François Gagnon
Keyword(s):  
Data Transmission ◽  
Channel Coding ◽  
Communication Systems ◽  
Reference Model ◽  
Image Transmission ◽  
Wireless Channel ◽  
Superior Performance ◽  
Communication Media ◽  
Fast Analysis ◽  
Wide Range

The proposed communication system architecture is called TOMAS, which stands for data Transmission oriented on the Object, communication Media, Application, and state of communication Systems. TOMAS could be considered a Cross-Layer Interface (CLI) proposal, since it refers to multiple layers of the Open Systems Interconnection Basic Reference Model (OSI). Given particular scenarios of image transmission over a wireless LOS channel, the wireless TOMAS system demonstrates superior performance compared to a JPEG2000+OFDM system in restored image quality parameters over a wide range of wireless channel parameters. A wireless TOMAS system provides progressive lossless image transmission under influence of moderate fading without any kind of channel coding and estimation. The TOMAS system employs a patent pending fast analysis/synthesis algorithm, which does not use any multiplications, and it uses three times less real additions than the one of JPEG2000+OFDM.

Impact of Wireless Channel Parameters on Quality of Video Streaming

1970 ◽  
Vol 108 (2) ◽  
pp. 27-30 ◽  
Author(s):  
S. Paulikas ◽  
P. Sargautis ◽  
V. Banevicius
Keyword(s):  
Video Streaming ◽  
Communication Systems ◽  
Video Quality ◽  
Human Perception ◽  
Wireless Channel ◽  
End User ◽  
Processing Power ◽  
Channel Parameters ◽  
Assess Quality

The problem of estimation of video quality obtained by end-user for mobile video streaming is addressed. Widely spreading mobile communication systems and increasing data transmission rates expand variety of multimedia services. One of such services is video streaming. So it is important to assess quality of this service. Consumers of video streaming are humans, and quality assessment must account human perception characteristics. Existing methods for user experienced video quality estimation as quality metrics usually usebit-error rate that has low correlation with by human perceived video quality. More advanced methods usually require too much processing power that cannot be obtained in handled mobile devices or intrusion into device firmware and/or hardware to obtain required data. However, recent research shows that channels throughput dedicated to some service (e.g. video streaming) can be tied to QoS perceived by an end-user indicator. This paper presents a research on impact of wireless channel parameters such as throughput and jitter on quality of video streaming. These wireless channel parameters can be easily obtained by monitoring IP level data streams in end-user’s device by fairly simple software agent for indication of video streaming QoS. Ill. 5, bibl. 10 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.108.2.138

scholarly journals Enhancing the Performance of Medical Implant Communication Systems through Cooperative Diversity

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Barnabás Hegyi ◽  
János Levendovszky
Keyword(s):  
Cooperative Communication ◽  
System Performance ◽  
Communication Systems ◽  
Communication Channel ◽  
Cooperative Diversity ◽  
Communication Link ◽  
Medical Implants ◽  
Medical Implant ◽  
Cardioverter Defibrillators ◽  
Implant Communication

Battery-operated medical implants—such as pacemakers or cardioverter-defibrillators—have already been widely used in practical telemedicine and telecare applications. However, no solution has yet been found to mitigate the effect of the fading that the in-body to off-body communication channel is subject to. In this paper, we reveal and assess the potential of cooperative diversity to combat fading—hence to improve system performance—in medical implant communication systems. In the particular cooperative communication scenario we consider, multiple cooperating receiver units are installed across the room accommodating the patient with a medical implant inside his/her body. Our investigations have shown that the application of cooperative diversity is a promising approach to enhance the performance of medical implant communication systems in various aspects such as implant lifetime and communication link reliability.

Technology for EDFA Gain Flattening Based on Long Period Fiber Grating

2012 ◽  
Vol 443-444 ◽  
pp. 484-487
Author(s):  
Kai Xian Liu
Keyword(s):  
Optical Communication ◽  
System Performance ◽  
Communication Systems ◽  
Fiber Grating ◽  
Long Period Fiber Grating ◽  
Long Period ◽  
Optical Communication Systems ◽  
Gain Flattening ◽  
Period Fiber Grating ◽  
Effective Transmission

EDFA is an important component in WDM optical communication systems. But the uneven characteristic will lead to reduced effective transmission bandwidth and system performance degradation. This paper studies on issues of EDFA gain flattering based on long period fiber grating, and provides detailed analysis of the method of using LPFG to achieve flat EDFA output gain. Numerical simulation result shows that this method can reduce unevenness to 0.2dB and below.

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