Phase Rotation Based Precoding for MISO DCO-OFDM LiFi with Highly Correlated Channels

2021 ◽  
Author(s):  
Qiong Wang ◽  
Yufei Jiang ◽  
Xu Zhu ◽  
Tong Wang
Keyword(s):  
Correlated Channels ◽  
Phase Rotation ◽  
Highly Correlated

scholarly journals The Role of Correlation in the Performance of Massive MIMO Systems

2021 ◽  
Vol 4 (3) ◽  
pp. 54
Author(s):  
Marwah Abdulrazzaq Naser ◽  
Mustafa Ismael Salman ◽  
Muntadher Alsabah
Keyword(s):  
Channel Model ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Interference Management ◽  
Base Station ◽  
Rectangular Array ◽  
High Data ◽  
Correlated Channels ◽  
Physical Channel ◽  
Highly Correlated

Massive multiple-input multiple-output (m-MIMO) is considered as an essential technique to meet the high data rate requirements of future sixth generation (6G) wireless communications networks. The vast majority of m-MIMO research has assumed that the channels are uncorrelated. However, this assumption seems highly idealistic. Therefore, this study investigates the m-MIMO performance when the channels are correlated and the base station employs different antenna array topologies, namely the uniform linear array (ULA) and uniform rectangular array (URA). In addition, this study develops analyses of the mean square error (MSE) and the regularized zero-forcing (RZF) precoder under imperfect channel state information (CSI) and a realistic physical channel model. To this end, the MSE minimization and the spectral efficiency (SE) maximization are investigated. The results show that the SE is significantly degraded using the URA topology even when the RZF precoder is used. This is because the level of interference is significantly increased in the highly correlated channels even though the MSE is considerably minimized. This implies that using a URA topology with relatively high channel correlations would not be beneficial to the SE unless an interference management scheme is exploited.

scholarly journals Selective Feature Generation Method Based on Time Domain Parameters and Correlation Coefficients for Filter-Bank-CSP BCI Systems

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3769 ◽  
Author(s):  
Yongkoo Park ◽  
Wonzoo Chung
Keyword(s):  
Time Domain ◽  
Filter Bank ◽  
Correlation Coefficients ◽  
Channel Selection ◽  
Classification Performance ◽  
Selection Methods ◽  
Common Spatial Pattern ◽  
Correlated Channels ◽  
Fisher Ratio ◽  
Highly Correlated

This paper presents a novel motor imagery (MI) classification algorithm using filter-bank common spatial pattern (FBCSP) features based on MI-relevant channel selection. In contrast to existing channel selection methods based on global CSP features, the proposed algorithm utilizes the Fisher ratio of time domain parameters (TDPs) and correlation coefficients: the channel with the highest Fisher ratio of TDPs, named principle channel, is selected and a supporting channel set for the principle channel that consists of highly correlated channels to the principle channel is generated. The proposed algorithm using the FBCSP features generated from the supporting channel set for the principle channel significantly improved the classification performance. The performance of the proposed method was evaluated using BCI Competition III Dataset IVa (18 channels) and BCI Competition IV Dataset I (59 channels).

scholarly journals Limited-Search Chase Decoding Algorithm for LDPC Coded Underwater Acoustic Multiuser Channels

2021 ◽  
pp. 76-81
Author(s):  
Xingming Li ◽  
◽  
Zhiliang Qin ◽  
Yuanhao Sun ◽  
Qidong Lu ◽  
...  
Keyword(s):  
Code Division Multiple Access ◽  
Multiple Access ◽  
Low Complexity ◽  
Underwater Acoustic ◽  
Correlated Channels ◽  
Multiuser Detector ◽  
Acoustic Networks ◽  
Lower Complexity ◽  
Highly Correlated ◽  
Code Division Multiple

In this paper, we propose a low-complexity soft-input/soft-output (SISO) Chase multiuser detector that has a polynomial computational complexity in terms of the number of the least reliable bit positions for low-density parity-check (LDPC) coded code-division multiple-access (CDMA) systems, which is a potentially competitive technology for underwater acoustic networks (UWAN). Simulation results over highly correlated channels show that the proposed detector can afford searching over a larger number of the least reliable bit positions and achieve better bit-error-rate (BER) performance as compared with the Chase-II detector at much lower complexity.

Cannabis use in Switzerland: The role of attribution of drug use to friends, urbanization and repression 1The study was supported by the Swiss Federal Office of Public Health (Bundesamt für Gesundheit BAG) Grant 316.96.5980.

2001 ◽  
Vol 60 (2) ◽  
pp. 99-107 ◽  
Author(s):  
Holger Schmid
Keyword(s):  
Drug Use ◽  
Urban Areas ◽  
Hierarchical Linear Model ◽  
Cannabis Use ◽  
School Aged Children ◽  
Structural Variables ◽  
Hbsc Study ◽  
Nationally Representative ◽  
Highly Correlated ◽  
Individual Use

Cannabis use does not show homogeneous patterns in a country. In particular, urbanization appears to influence prevalence rates, with higher rates in urban areas. A hierarchical linear model (HLM) was employed to analyze these structural influences on individuals in Switzerland. Data for this analysis were taken from the Switzerland survey of Health Behavior in School-Aged Children (HBSC) Study, the most recent survey to assess drug use in a nationally representative sample of 3473 15-year-olds. A total of 1487 male and 1620 female students indicated their cannabis use and their attributions of drug use to friends. As second level variables we included address density in the 26 Swiss Cantons as an indicator of urbanization and officially recorded offences of cannabis use in the Cantons as an indicator of repressive policy. Attribution of drug use to friends is highly correlated with cannabis use. The correlation is even more pronounced in urban Cantons. However, no association between recorded offences and cannabis use was found. The results suggest that structural variables influence individuals. Living in an urban area effects the attribution of drug use to friends. On the other hand repressive policy does not affect individual use.

The Difficulties in Emotion Regulation Scale (DERS)

2013 ◽  
Vol 72 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Elise S. Dan-Glauser ◽  
Klaus R. Scherer
Keyword(s):  
Emotion Regulation ◽  
Well Being ◽  
French Translation ◽  
French Version ◽  
Inappropriate Behaviors ◽  
Initial Validation ◽  
Difficulties In Emotion Regulation ◽  
Instrument Measuring ◽  
Highly Correlated ◽  
Psychopathological Disorders

Successful emotion regulation is a key aspect of efficient social functioning and personal well-being. Difficulties in emotion regulation lead to relationship impairments and are presumed to be involved in the onset and maintenance of some psychopathological disorders as well as inappropriate behaviors. Gratz and Roemer (2004 ) developed the Difficulties in Emotion Regulation Scale (DERS), a comprehensive instrument measuring emotion regulation problems that encompasses several dimensions on which difficulties can occur. The aim of the present work was to develop a French translation of this scale and to provide an initial validation of this instrument. The French version was created using translation and backtranslation procedures and was tested on 455 healthy students. Congruence between the original and the translated scales was .98 (Tucker’s phi) and internal consistency of the translation reached .92 (Cronbach’s α). Moreover, test-retest scores were highly correlated. Altogether, the initial validation of the French version of the DERS (DERS-F) offers satisfactory results and permits the use of this instrument to map difficulties in emotion regulation in both clinical and research contexts.

Automated Latex Agglutination and ELISA Testing Yield Equivalent D-Dimer Results in Patients with Recent Myocardial Infarction

1999 ◽  
Vol 82 (11) ◽  
pp. 1412-1416 ◽  
Author(s):  
Wojciech Zareba ◽  
John Horan ◽  
Arthur Moss ◽  
Joel Kanouse ◽  
◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Elisa Test ◽  
Mean Value ◽  
Latex Agglutination ◽  
Test Results ◽  
Coronary Death ◽  
Elisa Testing ◽  
Strong Linear Correlation ◽  
Highly Correlated ◽  
D Dimer

SummaryOur previous prospective study of post-infarction patients described a strong and significant association of increased plasma D-dimer concentrations in those who experienced a subsequent coronary death or non-fatal myocardial infarction. In the present study, we compare results on stored plasma obtained two months after the index myocardial infarction from 1,038 patients of this trial, using a simple automated latex agglutination (LA) assay in parallel with the standard ELISA test. Results show a somewhat higher mean value for the LA assay (702 ± 1092 vs. 638 ± 986 ng/ml, p = 0.0002), a strong linear correlation of the two assays (r = 0.86) and 88% agreement for values below 500 ng/ml by the ELISA test. D-dimer concentrations determined by each assay were highly correlated in patients with subsequent coronary artery events (p = 0.93) and quartile values for both the LA and ELISA were equally predictive of such events (p = 0.003 and p = 0.001, respectively). This is the first demonstration that a latex agglutination assay for D-dimer can be used to assess the prognostic risk of recurrent coronary thrombotic disease after myocardial infarction

Do Extra-Platelet Sources Contribute to the Plasma Level of Thrombospondin?

1988 ◽  
Vol 59 (02) ◽  
pp. 273-276 ◽  
Author(s):  
J Dawes ◽  
D A Pratt ◽  
M S Dewar ◽  
F E Preston
Keyword(s):  
Platelet Count ◽  
Background Concentration ◽  
Serum Concentrations ◽  
Bone Marrow Depression ◽  
Serial Sampling ◽  
Control Serum ◽  
Platelet Release ◽  
Highly Correlated ◽  
The Relationship

SummaryThrombospondin, a trimeric glycoprotein contained in the platelet α-granules, has been proposed as a marker of in vivo platelet activation. However, it is also synthesised by a range of other cells. The extraplatelet contribution to plasma levels of thrombospondin was therefore estimated by investigating the relationship between plasma thrombospondin levels and platelet count in samples from profoundly thrombocytopenic patients with marrow hypoplasia, using the platelet-specific α-granule protein β-thromboglobulin as control. Serum concentrations of both proteins were highly correlated with platelet count, but while plasma β-thromboglobulin levels and platelet count also correlated, there was no relationship between the number of platelets and thrombospondin concentrations in plasma. Serial sampling of patients recovering from bone marrow depression indicated that the plasma thrombospondin contributed by platelets is superimposed on a background concentration of at least 50 ng/ml probably derived from a non-platelet source, and plasma thrombospondin levels do not simply reflect platelet release.

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