scholarly journals The Optimized Cell Configuration Method of Avoiding SRS Inter-Cell Interference

2021 ◽  
Author(s):  
Shin-Hwan Kim ◽  
Kyung-Yup Kim ◽  
Jae-Hyung Koo ◽  
Young-Soo Seo
Keyword(s):  
Reference Signal ◽  
False Alarm Probability ◽  
Control Channel ◽  
Channel State ◽  
Auto Correlation ◽  
Shared Channel ◽  
Communication Method ◽  
Inter Cell Interference ◽  
The Impact ◽  
Conventional Scheme

The issue of cell-to-cell interferences is a serious problem that has always been raised in digital communication system such as NR. The communication method of NR and LTE is OFDM. OFDM has many advantages, but has fatal disadvantage called ICI (Inter-Cell Interference) because resources among cells are always overlapped. For example, NR’s typical interferences are ICIs among PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), PUSCH (Physical Uplink Shared Channel), PUCCH (Physical Uplink Control Channel), CSI-RS (Channel State Information-Reference Signal) and SRS (Sounding Reference Signal). Among them, it is important to determine the correct beamforming weight factor value by estimating the channel with SRS. Therefore, the ICI of SRS degrades the performance of downlink throughput. This paper analyses the impact of SRS’s ICI in conventional scheme, introduces the proposed AC-CS (Auto-Correlation Cyclic Shift) schemes by the Zadoff-Chu sequence to overcome the ICI of SRS and analyses theirs performance. The method used for performance analysis is determined by the detection abilities, which are missing probability and false alarm probability.

Multiplexing SRS with Periodic CSI on Shortened PUCCH Format 2/2a/2b

2014 ◽  
Vol 556-562 ◽  
pp. 6063-6067
Author(s):  
Dan Wang ◽  
Xue Mei Deng ◽  
Xin Ni
Keyword(s):  
Channel State Information ◽  
Reference Signal ◽  
Control Channel ◽  
Channel State ◽  
State Information ◽  
Similar Performance ◽  
Lte Advanced ◽  
Advanced System ◽  
Simultaneous Transmission

In order to avoid dropping the SRS report frequently in case of collision between SRS and a periodic CSI report in LTE-Advanced system, this paper gives shortened PUCCH (Physical Uplink Control Channel) format 2/2a/2b for multiplexing SRS (Sounding Reference Signal) with periodic CSI (Channel State Information). The result of simulation shows that the shortened PUCCH format 2/2a/2b can effectively support simultaneous transmission periodic CSI and SRS. What’s more, on shortened PUCCH format 2/2a/2b with the first and last two encoded bits punctured, periodic CSI and HARQ-ACK feedback have the same performance as on PUCCH format 2/2a/2b without multiplexing SRS. Hence through the shortened PUCCH format 2/2a/2b, we can not only enhance simultaneous transmission of periodic CSI and SRS, but also guarantee the similar performance of periodic CSI and HARQ-ACK feedback as transmitting them on PUCCH format 2/2a/2b without multiplexing SRS.

scholarly journals Fast radio burst detection in the presence of coloured noise

2021 ◽  
Vol 503 (4) ◽  
pp. 5223-5231
Author(s):  
C F Zhang ◽  
J W Xu ◽  
Y P Men ◽  
X H Deng ◽  
Heng Xu ◽  
...  
Keyword(s):  
False Alarm ◽  
Radio Burst ◽  
Pulse Width ◽  
False Alarm Probability ◽  
False Positives ◽  
Parameter Distribution ◽  
Correlated Noise ◽  
Width Distribution ◽  
Fast Radio Burst ◽  
The Impact

ABSTRACT In this paper, we investigate the impact of correlated noise on fast radio burst (FRB) searching. We found that (1) the correlated noise significantly increases the false alarm probability; (2) the signal-to-noise ratios (S/N) of the false positives become higher; (3) the correlated noise also affects the pulse width distribution of false positives, and there will be more false positives with wider pulse width. We use 55-h observation for M82 galaxy carried out at Nanshan 26m radio telescope to demonstrate the application of the correlated noise modelling. The number of candidates and parameter distribution of the false positives can be reproduced with the modelling of correlated noise. We will also discuss a low S/N candidate detected in the observation, for which we demonstrate the method to evaluate the false alarm probability in the presence of correlated noise. Possible origins of the candidate are discussed, where two possible pictures, an M82-harboured giant pulse and a cosmological FRB, are both compatible with the observation.

scholarly journals SPEECH DELAY THERAPY FOR CHILDREN USING THE AAC METHOD

2020 ◽  
Vol 4 (2) ◽  
pp. 172
Author(s):  
Natalina Purba ◽  
Mira Kusumo Astuti
Keyword(s):  
Data Analysis ◽  
Speech Therapy ◽  
Environmental Response ◽  
Speech Delay ◽  
Alternative Communication ◽  
Augmentative Alternative Communication ◽  
Sensory Integration Therapy ◽  
Communication Method ◽  
New Ideas ◽  
The Impact

The purpose of this study (1) The factors that cause speech delay in early childhood (2) The treatment given by Permata Diakonia and parents? (3) The impact of speech therapy performed by Permata Diakonia using the AAC (Augmentative Alternative Communication) method. Methods: This study used a case study method with one child data analysis used qualitative data analysis with Miles and Huberman methods. Results: Sensory therapy that was given every day since the child was diagnosed late speaking had a very significant impact on the child's environmental response. A good response to this environment is a sign that the child can be given speech therapy using the AAC method which is given twice a week. From this study, it can be concluded that speech therapy using the AAC method significantly improves children's speaking ability. It should be noted that the key to success in this therapy is not changing therapists. Implication: speech therapy using the AAC method has implications for new ideas that will give  new ideas to new approaches to enrich speech therapy.Keywords: speech delay, sensory integration therapy, and speech therapy, AAC

scholarly journals The effects of granulation and supergranulation on Earth-mass planet detectability in the habitable zone around F6-K4 stars

2020 ◽  
Vol 642 ◽  
pp. A157 ◽  
Author(s):  
N. Meunier ◽  
A.-M. Lagrange
Keyword(s):  
False Alarm ◽  
Radial Velocity ◽  
Poor Performance ◽  
False Alarm Probability ◽  
False Positives ◽  
High Mass ◽  
Habitable Zone ◽  
Detection Rates ◽  
Temporal Sampling ◽  
The Impact

Context. The detectability of exoplanets and the determination of their projected mass in radial velocity are affected by stellar magnetic activity and photospheric dynamics. Among those processes, the effect of granulation, and even more so of supergranulation, has been shown to be significant in the solar case. The impact for other spectral types has not yet been characterised. Aims. Our study is aimed at quantifying the impact of these flows for other stars and estimating how such contributions affect their performance. Methods. We analysed a broad array of extended synthetic time series that model these processes to characterise the impact of these flows on exoplanet detection for main sequence stars with spectral types from F6 to K4. We focussed on Earth-mass planets orbiting within the habitable zone around those stars. We estimated the expected detection rates and detection limits, tested the tools that are typically applied to such observations, and performed blind tests. Results. We find that both granulation and supergranulation on these stars significantly affect planet mass characterisation in radial velocity when performing a follow-up of a transit detection: the uncertainties on these masses are sometimes below 20% for a 1 MEarth (for granulation alone or for low-mass stars), but they are much larger in other configurations (supergranulation, high-mass stars). For granulation and low levels of supergranulation, the detection rates are good for K and late G stars (if the number of points is large enough), but poor for more massive stars. The highest level of supergranulation leads to a very poor performance, even for K stars; this is both due to low detection rates and to high levels of false positives, even for a very dense temporal sampling over 10 yr. False positive levels estimated from standard false alarm probabilities sometimes significantly overestimate or underestimate the true level, depending on the number of points: it is, therefore, crucial to take this effect into account when analysing observations. Conclusions. We conclude that granulation and supergranulation significantly affect the performance of exoplanet detectability. Future works will focus on improving the following three aspects: decreasing the number of false positives, increasing detection rates, and improving the false alarm probability estimations from observations.

scholarly journals Transactions Volume, Exchange Direction and Asymmetry of Volatility in Emerging Market: Evidence From Tunisian Stock Exchange

2020 ◽  
Vol 11 (6) ◽  
pp. 318
Author(s):  
Jaber Yasmina
Keyword(s):  
Stock Market ◽  
Financial Market ◽  
Stock Exchange ◽  
Emerging Market ◽  
Explanatory Power ◽  
Trading Activity ◽  
Auto Correlation ◽  
The Asymmetry ◽  
The Impact ◽  
The Relationship

This study is an attempt to explain the relationship between intraday return and volume in Tunisian Stock Market. Indeed, former researches avow that the trading activity have the main explanatory power for volatility. However, most theories measure the activity of transactions through the size of exchange or the number of transactions. Nevertheless, these components are not aware enough of the importance of the direction of exchange when explaining the phenomenon of asymmetry of volatility. In the most of studies, the technique “Augmented Tick Test” (ATT) is employed so as to identify the direction of exchange. Such technique is adapted for the markets directed by orders like the Tunisian financial market. Again, this paper shows that the impact of the direction of exchange differs according to the market trend. In other words, if the returns are positive, the transactions of sale (of purchase) generate a decrease (increase) of volatility; whereas, they induce an increase (drop) of volatility if returns are negative. This result stresses the significance of exchange direction in explaning the asymmetry of volatility. Moreover, throughout this study, one may affirm that “Herding trades” are at the origin of the increase of volatility, while the “Contrarian trades” reduce volatility. Similarly, the identification of the direction of exchange enables us to affirm that the transactions of the initiates are characterized by the absence of returns auto- correlation; whereas, the transactions carried out by uninformed investors present an auto- correlation of the returns. In fact, the sign of this correlation varies according to transaction direction.

The Impact of Gaze Controlled Technology on Quality of Life

2012 ◽  
pp. 48-54 ◽  
Author(s):  
Valentina Pasian ◽  
Fulvio Corno ◽  
Isabella Signorile ◽  
Laura Farinetti
Keyword(s):  
Quality Of Life ◽  
Eye Tracking ◽  
Progressive Disease ◽  
Gaze Control ◽  
Communication Method ◽  
Tracking Device ◽  
The Impact

This chapter presents the process of introducing an eye tracking device to impaired users. It reports results from a gaze control user trial conducted with people for whom gaze control is a necessity due to their current condition or for whom it will soon become a necessity because of a progressive disease. Special attention is paid to the impact of this new communication method on their quality of life.

scholarly journals Transmission Scheme with Limited Channel State Information Feedback for 3D MIMO System

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Xing Li ◽  
Hui Zhao ◽  
Long Zhao ◽  
Wenxiu Zhao ◽  
Senyao Zheng
Keyword(s):  
Channel State Information ◽  
Mimo System ◽  
Reference Signal ◽  
Base Station ◽  
Information Feedback ◽  
Transmission Scheme ◽  
Channel State ◽  
State Information ◽  
3D Mimo ◽  
Channel State Information Feedback

Three-dimensional (3D) multiple-input multiple-output (MIMO) system can exploit the spatial degree of freedom in vertical dimension and can significantly improve system performance compared with 2D transmission scheme. However, in the actual frequency division duplex (FDD) transmission mode, the large overhead of the reference signal and channel state information (CSI) feedback would become a barrier for performance improvement of 3D MIMO system with the significantly increased number of transmit antennas. To deal with these problems, this paper proposes a new transmission scheme of the channel state information-reference signal (CSI-RS), where the CSI-RS is precoded with 3D beamforming vectors and composed of two components: long-term CSI-RS and short-term CSI-RS. For the purpose of conducting efficient transmission in widely used FDD system, we also propose a corresponding limited channel state information feedback scheme. Moreover, multiuser pairing and scheduling criteria based on the design of the CSI-RS are proposed to realize the multiuser transmission. We have investigated multiple options for 3D MIMO codebook scheme and finally adopt the Kronecker product-based codebook (KPC) for precoding operation at the base station (BS). Simulation results demonstrate that our proposed scheme for the 3D MIMO system achieves a better tradeoff between resource overhead and throughput performance.

An Improved Physical Downlink Control Channel De-Resource Mapping Method in Long Term Evolution Systems

2014 ◽  
Vol 513-517 ◽  
pp. 3577-3580
Author(s):  
Dan Wang ◽  
Wen Wen Xu ◽  
Jia Luo
Keyword(s):  
Reference Signal ◽  
Long Term Evolution ◽  
Mapping Method ◽  
Control Channel ◽  
Evolution System ◽  
Resource Mapping ◽  
Modified Method ◽  
Term Evolution ◽  
System Resource

In TD-LTE (Time Division-Long Term Evolution) system, Resource Element Group (REG) is the unit of de-resource mapping for Physical Downlink Control Channel (PDCCH), due to the reference signal should be considered, which lead to the large calculation. To solve this problem, a modified method is proposed in this paper to reduce the cycles of de-resource mapping. Calculation and simulation reveal that this scheme can reduce the calculation significantly. At the same time, the feasibility and effectiveness of this modified method have been verified.

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