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See detailThe ABCD of cyclic quadrilaterals
Begalla, Engjell UL; Perucca, Antonella UL

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See detailNon-problematic and problematic binge-watchers do not differ on prepotent response inhibition: A preregistered pilot experimental study
Flayelle, Maèva; Verbruggen, Frederick; Schiel, Julie et al

in Human Behavior and Emerging Technologies (in press)

Binge‐watching (i.e., watching multiple episodes of a TV series back‐to‐back) has become standard viewing practice. Yet, this phenomenon has recently generated concerns regarding its potential negative ... [more ▼]

Binge‐watching (i.e., watching multiple episodes of a TV series back‐to‐back) has become standard viewing practice. Yet, this phenomenon has recently generated concerns regarding its potential negative outcomes on the long run. The presumed addictive nature of this behavior has also received increasing scientific interest, with preliminary findings reporting associations between binge‐watching, self‐control impairments, and heightened impulsivity. Nevertheless, previous studies only relied on self‐report data. The current preregistered study therefore investigated whether non‐problematic and problematic binge‐watchers differ not only in self‐report but also in experimental measures of behavioral impulsivity. Based on their viewing characteristics, 60 TV series viewers were allocated to one of three predetermined groups: non‐binge‐watchers, trouble‐free binge‐watchers (absence of negative impact) and problematic binge‐watchers (presence of negative impact). Participants performed tasks assessing response inhibition (Stop‐Signal Task) and impulsive reward seeking (Delay Discounting Task), and completed self‐reported questionnaires on sociodemographics, affect, symptoms of problematic binge‐watching, and impulsive personality traits. According to the preregistered analytic plan, one‐way analyses of covariance (ANCOVAs) were computed to compare the predetermined groups. With gender being controlled for, no differences were identified in self‐report impulsivity and response inhibition abilities. Trouble‐free binge‐watchers reported higher rates of delay discounting than non‐binge‐watchers. Although preliminary, our results challenge the notion that problematic binge‐watching is characterized by the same neuropsychological impairments as in addictive disorders as, contrary to our preregistered hypotheses, no differences emerged between non‐problematic and problematic binge‐watchers regarding self‐control variables considered as hallmarks of the latter. These results suggest the need for formulating and testing alternative conceptualizations of problematic binge‐watching. [less ▲]

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See detailOptimisation of the mechanical properties of Miscanthus lightweight concrete (Top 10 Journal)
Pereira Dias, Patrick; Waldmann, Danièle UL

in Construction and Building Materials (in press)

In this paper, Miscanthus fibres are used to develop lightweight concrete. The amount of Miscanthus and cement, as well as the water/cement ratio, are varied to analyse the behaviour of the mixture ... [more ▼]

In this paper, Miscanthus fibres are used to develop lightweight concrete. The amount of Miscanthus and cement, as well as the water/cement ratio, are varied to analyse the behaviour of the mixture concerning the physical and mechanical properties. The Miscanthus was pre-treated with a silicate sealant or a cement-based fluid. The current paper analyses the impact of the pre-treatment of the Miscanthus fibres on the compressive strength as well as on the long-term deformations. The specimens with a pre-treatment based on a silicate sealant reached a compressive strength of 19.3 MPa, which is higher than the compressive strength of a conventional LC 16/18, a Young's Modulus above 9.9 GPa and a shrinkage deformation of 2244 μm/m. Nevertheless, considering the density the pre-treatment showed not to be beneficial. [less ▲]

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See detailAutomated Repair of Feature Interaction Failures in Automated Driving Systems
Ben Abdessalem, Raja; Panichella, Annibale; Nejati, Shiva UL et al

in Proceedings of the 29th ACM SIGSOFT International Symposium on Software Testing and Analysis (ISSTA 2020) (2020, July)

In the past years, several automated repair strategies have been proposed to fix bugs in individual software programs without any human intervention. There has been, however, little work on how automated ... [more ▼]

In the past years, several automated repair strategies have been proposed to fix bugs in individual software programs without any human intervention. There has been, however, little work on how automated repair techniques can resolve failures that arise at the system-level and are caused by undesired interactions among different system components or functions. Feature interaction failures are common in complex systems such as autonomous cars that are typically built as a composition of independent features (i.e., units of functionality). In this paper, we propose a repair technique to automatically resolve undesired feature interaction failures in automated driving systems (ADS) that lead to the violation of system safety requirements. Our repair strategy achieves its goal by (1) localizing faults spanning several lines of code, (2) simultaneously resolving multiple interaction failures caused by independent faults, (3) scaling repair strategies from the unit-level to the system-level, and (4) resolving failures based on their order of severity. We have evaluated our approach using two industrial ADS containing four features. Our results show that our repair strategy resolves the undesired interaction failures in these two systems in less than 16h and outperforms existing automated repair techniques. [less ▲]

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See detailMindfulness in everyday life: Between- and within-person relationships to motivational conflicts
Senker, Kerstin; Fries, Stefan; Grund, Axel UL

in Current Psychology (2020)

Mindfulness has shown beneficial relationships with well-being and self-regulation. We aim to improve the understanding of the effects of between- and within-person differences in mindfulness when dealing ... [more ▼]

Mindfulness has shown beneficial relationships with well-being and self-regulation. We aim to improve the understanding of the effects of between- and within-person differences in mindfulness when dealing with situations of motivational conflict. For this purpose, we conducted an experience sampling study with 56 university students who replied to a total of N = 1889 short questionnaires, which they received via their smartphones over a period of eight consecutive days. In addition to a state mindfulness questionnaire with the facets presence and non-judgment (focusing attention on the experience of the current action and a momentary non-judgmental stance towards these, respectively), the participants received questions about their current affective well-being and perceived intensity of want or should conflict experiences. Multi-level analyses revealed that want conflicts were predicted by both state mindfulness facets, even after momentary affect was controlled. In addition, to be non-judgmental (as a trait), and having momentary presence (as a state), related to lower intensity of should conflicts. The results suggest that being mindful might be a particularly beneficial way of dealing with daily motivational conflicts, which is an essential and frequent task of self-regulation. [less ▲]

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See detailIntersectionality and Adolescent Mental Well-being: A Cross-Nationally Comparative Analysis of the Interplay Between Immigration Background, Socioeconomic Status and Gender
Kern, Matthias Robert UL; Duinhof, Elisa L.; Walsh, Sophie D. et al

in Journal of Adolescent Health (2020), 66(6), 12-20

Purpose: Intersectionality theory highlights the importance of the interplay of multiple social group memberships in shaping individual mental well-being. This article investigates elements of adolescent ... [more ▼]

Purpose: Intersectionality theory highlights the importance of the interplay of multiple social group memberships in shaping individual mental well-being. This article investigates elements of adolescent mental well-being (life dissatisfaction and psychosomatic complaints) from an intersectional perspective. It tests mental well-being consequences of membership in combinations of multiple social groups and examines to what extent such intersectional effects depend on the national context (immigration and integration policies, national-level income, and gender equality). Methods: Using Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy, we assessed the role of the national context in shaping the interplay between immigration background, socioeconomic status, and gender, using data from 33 countries from the 2017/2018 Health Behaviour in School-aged Children survey. Results: We found no uniform intersectionality effects across all countries. However, when allowing the interplay to vary by national context, results did point toward some intersectional effects. Some aggravated negative effects were found for members of multiple disadvantaged social groups in countries with low levels of income equality and restrictive migration policies, whereas enhanced positive effects were found for members of multiple advantaged groups in these countries. Similarly, mitigated negative effects of membership in multiple disadvantaged groups were shown in countries with higher levels of income equality and more inclusive migration policies, whereas mitigated positive effects were found for multiply advantaged individuals. Although for national-level gender equality results pointed in a similar direction, girls’ scores were counterintuitive. High national-level gender equality disproportionately benefitted groups of disadvantaged boys, whereas advantaged girls were doing worse than expected, and reversed effects were found for countries with low gender equality. Conclusions: To fully understand social inequalities in adolescent mental well-being, the interplay between individual-level and national-level indicators must be explored. [less ▲]

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See detailMeasurement invariance of the Positive Gains Scale in families of children with and without disabilities
Jess, Mikeda; Bailey, Tom; Pit-Ten Cate, Ineke UL et al

in Research in Developmental Disabilities (2020), 103

Background Despite the high frequency of case-control studies in the developmental disability literature, there is a paucity of research establishing the measurement equivalence of instruments used, and ... [more ▼]

Background Despite the high frequency of case-control studies in the developmental disability literature, there is a paucity of research establishing the measurement equivalence of instruments used, and particularly those relating to positive perceptions and experiences in family disability research. Aims The present study sought to establish measurement invariance for the Positive Gains Scale (PGS) across 1219 mothers of children with developmental disabilities, 234 mothers of children with spina bifida/hydrocephalus, and 157 mothers of children without disabilities. Methods and Procedures A three-step test for measurement invariance across the three groups was conducted using Multigroup Confirmatory Factor Analysis. Outcomes and Results Loadings between the three groups were invariant, suggesting the criteria to assume metric invariance was met. However, the assumption of scalar invariance was not met, suggesting that item intercepts differed between the three groups. Conclusions and Implications Our findings suggest that the PGS cannot be meaningfully used to compare outcomes between mothers of children with developmental disabilities and other mothers. These findings may have wider implications for research utilising well-being measures to make comparisons with carers of children with developmental disabilities. [less ▲]

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See detailAttitudes towards Multiculturalism in Luxembourg: Measurement Invariance and Factor Structure of the Multicultural Ideology Scale
Stogianni, Maria UL; Murdock, Elke UL; He, Jia et al

E-print/Working paper (2020)

The present study examined the dimensionality and the measurement invariance of the Multicultural Ideology Scale (MCI; Berry & Kalin, 1995), and mean differences across different cultural groups within ... [more ▼]

The present study examined the dimensionality and the measurement invariance of the Multicultural Ideology Scale (MCI; Berry & Kalin, 1995), and mean differences across different cultural groups within the multilingual, multicultural context of Luxembourg. With 47% of the citizens being non-nationals, minority and majority are increasingly difficult to define and Luxembourg becomes a unique context to study attitudes towards diversity. Our sample included 1488 participants from diverse ethnic backgrounds who completed the survey in German, French or English. In contrast to previous findings, our analyses revealed a two-dimensional structure, distinguishing between positive and negative attitudes towards multiculturalism. The factor structure was partially invariant across ethnocultural groups: Configural and metric invariance were established across natives and non-natives, scalar invariance only across gender groups. Natives and male participants reported more negative attitudes towards multiculturalism. We discuss the importance of assessing measurement invariance and provide recommendations to improve the assessment of psychological multiculturalism. [less ▲]

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See detailGuidelines for Operationalizing Policy Coherence for Development (PCD) as a Methodology for the Design and Implementation of Sustainable Development Strategies
Koff, Harlan UL; Challenger, Antony; Portillo, Israel

in Sustainability (2020), 12(4055), 1-23

Policy Coherence for Development (PCD) is considered a pillar of the 2030 Sustainable Development Agenda. It aims to promote whole of government approaches to sustainable development. Despite its ... [more ▼]

Policy Coherence for Development (PCD) is considered a pillar of the 2030 Sustainable Development Agenda. It aims to promote whole of government approaches to sustainable development. Despite its prominence in development cooperation discussions, many national development professionals or stakeholders have not heard of PCD, indicating that its effectiveness is significantly limited. This article contends that the impact of PCD has not been maximized because it has been presented as a political objective or a policy tool by multilateral organizations and their member states. Instead, the article argues that PCD should be implemented as a methodology that can be adopted by domestic government and non-governmental actors alike, in order to understand trade-offs and co-benefits within and between policy sectors, thus promoting a participative approach. I-GAMMA is a research project in Mexico that examines data-driven public policy in order to promote PCD. It is based on in-depth reviews of policy documents and interviews with development actors. It is committed to open data, evidence-based policymaking, and collaborative dialogue between academics, government officials, and representatives of civil society organizations in sustainable development discussions. In the results section of this article, the project proposes participative PCD as a methodology for policy analysis through which a plurality of actors can identify mechanisms that either reinforce or undermine sustainable development strategies. This section then applies the methodology to the governance of protected natural areas in Mexico. The discussion section and the conclusions highlight the relevance of this approach for participative policymaking in sustainable development. [less ▲]

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See detailStudent translanguaging: insights into resource combinations and reflections of classroom practices
Degano, Sarah UL

Presentation (2020, May 15)

This presentation adopts a multimodal perspective on translanguaging. It focusses on the extent to which multilingual pupils’ translanguaging practices provide insights into the semiotic repertoires of ... [more ▼]

This presentation adopts a multimodal perspective on translanguaging. It focusses on the extent to which multilingual pupils’ translanguaging practices provide insights into the semiotic repertoires of the students and connect to the classroom practices of their learning environment as well as to those of the larger community. [less ▲]

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See detailClimate SMART Agriculture: How well does the agricultural sector in Luxembourg perform in terms of climate change?
Evelyne, Stoll; Schader, Christian; Bohn, Torsten et al

Scientific Conference (2020, May 04)

In Luxembourg, the agricultural sector was responsible for 711.7 Gg CO2-equivalents in 2016, which corresponds to 6.95 % of the total country greenhouse gas (GHG) emissions. Over 50 % of the farms are ... [more ▼]

In Luxembourg, the agricultural sector was responsible for 711.7 Gg CO2-equivalents in 2016, which corresponds to 6.95 % of the total country greenhouse gas (GHG) emissions. Over 50 % of the farms are specialist grazing livestock farms. The beef and cattle milk production account globally together for over 60 % of the sector’s global emissions. Thus, the climate impact of the whole agricultural sector in Luxembourg can be significantly lowered by reducing the GHG emissions of the specialist grazing livestock sector. However, beyond farm type, the GHG emissions of a farm are also influenced by other factors, such as management systems and farming practices. To enable a transition towards a more climate-positive agriculture, insights into the sustainability performance in terms of climate change are needed. The aim of this study is to determine the current sustainability performance of the Luxembourgish specialist grazing livestock sector in terms of climate change. The climate impact of the different specialist grazing livestock farm types (OTE (orientation technico-économique) 45 - Specialist dairying; OTE 46 - Specialist cattle - rearing and fattening and OTE 47 - Cattle - dairying, rearing and fattening combined) and of different management systems (conventional or organic) was assessed at farm-level. Furthermore, the relationship between the sustainability performance in terms of climate change and other areas of sustainability is being studied. Farming practices of 60 farms typical for Luxembourg in regard to their share of arable land and permanent grassland (OTE 45: 3 farms; OTE 46: 15; OTE 45: 11; Conventional: 44; Organic: 16) and their respective sustainability implications were assessed in 2019 according to the FAO SAFA Guidelines (Guidelines for the Sustainability Assessment of Food and Agriculture Systems, 2014) using the Sustainability Monitoring and Assessment RouTine (SMART)-Farm Tool (v5.0). Organic farms were highly overrepresented, with 26.7 % in the sample compared to 5 % of all Luxembourgish farms. The data was collected during a farm visit and a 3 h interview with the farm manager. The impact of management system and farm type on the SAFA-goal achievement for the sub-theme Greenhouse Gases (GHG) were studied. The results show that the sustainability performances of the participating farms were moderate to good. Goal achievement for the sub-theme GHG was moderate and did not differ significantly between the three farm types (OTE 45: 53.3 % ±3.9 SD goal achievement; OTE 46: 55.6 % ±7.3 SD; OTE 47: 54.6 % ±6.9 SD). Organic farms showed a significantly higher mean goal achievement for GHG than conventional farms (p-value < 0.001) (organic: 58.3 % ±6.0 SD; conventional: 52.6 % ±4.4 SD). For indicators positively impacting GHG, the organic and the OTE 46 farms had generally higher ratings. Correlations between GHG and the other sub-themes were mainly in the Environmental Integrity dimension, showing that implementing climate-positive farming practices can also improve other ecological aspects. The indicator analysis identified the following linchpins: increase in protein autarky, closing of farming cycles and holistic approach with strategic decision making leading to harmonized actions towards a sustainable and climate positive farming system. [less ▲]

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See detailMultichannel Source Separation Using Time-Deconvolutive CNMF
Dias, Thadeu; Alves Martins, Wallace UL; Biscainho, Luiz Wagner

in Journal of Communication and Information Systems (2020), 35(1), 103-112

This paper addresses the separation of audio sources from convolutive mixtures captured by a microphone array. We approach the problem using complex-valued non-negative matrix factorization (CNMF), and ... [more ▼]

This paper addresses the separation of audio sources from convolutive mixtures captured by a microphone array. We approach the problem using complex-valued non-negative matrix factorization (CNMF), and extend previous works by tailoring advanced (single-channel) NMF models, such as the deconvolutive NMF, to the multichannel factorization setup. Further, a sparsity-promoting scheme is proposed so that the underlying estimated parameters better fit the time-frequency properties inherent in some audio sources. The proposed parameter estimation framework is compatible with previous related works, and can be thought of as a step toward a more general method. We evaluate the resulting separation accuracy using a simulated acoustic scenario, and the tests confirm that the proposed algorithm provides superior separation quality when compared to a state-of-the-art benchmark. Finally, an analysis of the effects of the introduced regularization term shows that the solution is in fact steered toward a sparser representation. [less ▲]

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See detailMarché du travail transfrontalier : Quelles équations à résoudre?
Pigeron, Isabelle UL; Belkacem, Rachid

in Les Cahiers de la Grande Région (2020), 2

Après un premier numéro consacré aux évolutions démographiques, ce volume, édité par Rachid Belkacem (Université de Lorraine) et Isabelle Pigeron-Piroth (Université du Luxembourg) interroge les évolutions ... [more ▼]

Après un premier numéro consacré aux évolutions démographiques, ce volume, édité par Rachid Belkacem (Université de Lorraine) et Isabelle Pigeron-Piroth (Université du Luxembourg) interroge les évolutions actuelles et futures du marché du travail transfrontalier. Pour traiter ces différents aspects, cinq articles, constituant des synthèses de travaux réalisés par divers instituts (LISER, ADEM et STATEC) aborderont les questions de compétences recherchées dans la Grande Région, les inadéquations entre offres et demandes de travail, mais aussi les nouveaux modèles d’organisation du travail (télétravail), ou de croissance (croissance qualitative), reflets de ces équations difficiles à résoudre,mais aussi des problématiques d’actualité liées à la crise sanitaire . [less ▲]

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See detailPharmacoresponse in genetic generalized epilepsy: a genome-wide association study
Wolking, Stefan; Schulz, Herbert; Nies, Anne T. et al

in Pharmacogenomics (2020), 0(0),

Aim: Pharmacoresistance is a major burden in epilepsy treatment. We aimed to identify genetic biomarkers in response to specific antiepileptic drugs (AEDs) in genetic generalized epilepsies (GGE ... [more ▼]

Aim: Pharmacoresistance is a major burden in epilepsy treatment. We aimed to identify genetic biomarkers in response to specific antiepileptic drugs (AEDs) in genetic generalized epilepsies (GGE). Materials  methods: We conducted a genome-wide association study (GWAS) of 3.3 million autosomal SNPs in 893 European subjects with GGE – responsive or nonresponsive to lamotrigine, levetiracetam and valproic acid. Results: Our GWAS of AED response revealed suggestive evidence for association at 29 genomic loci (p <10-5) but no significant association reflecting its limited power. The suggestive associations highlight candidate genes that are implicated in epileptogenesis and neurodevelopment. Conclusion: This first GWAS of AED response in GGE provides a comprehensive reference of SNP associations for hypothesis-driven candidate gene analyses in upcoming pharmacogenetic studies. [less ▲]

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See detailPassivation of the CuInSe2 surface via cadmium pre-electrolyte treatment
Kameni Boumenou, Christian UL; Babbe, Finn; Elizabeth, Amala et al

in Physical Review Materials (2020)

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See detailOn Reductions of Hintikka Sets for Higher-Order Logic
Steen, Alexander UL; Benzmüller, Christoph UL

E-print/Working paper (2020)

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See detailCondition assessment of bridge structures by damage localisation based on the DAD-method and close-range UAV photogrammetry
Erdenebat, Dolgion UL

Doctoral thesis (2020)

The provided dissertation presents a so-called “Deformation Area Difference (DAD)” method for condition assessment of existing bridges, especially for the detection of stiffness-reducing damages. The ... [more ▼]

The provided dissertation presents a so-called “Deformation Area Difference (DAD)” method for condition assessment of existing bridges, especially for the detection of stiffness-reducing damages. The method is based on the one hand on conventional static load deflection experiments and on the other hand on a high-precision measurement of the structural deflection. The experimental load on the bridge should be generated within the serviceability limit state in order to enable a non-destructive inspection. In the course of the laboratory tests, the most innovative measuring techniques were applied, whereby the photogrammetry has delivered promising results. With the help of additional studies on the influences of camera quality and calibration, the measuring precision of photogrammetry could be brought to its limits. Both the theoretical investigations and the laboratory tests showed the successful use of the DAD method for the identification of local damages. Therefore, the first in-situ experiment was carried out on a single-span, prestressed bridge in Luxembourg. The knowledge gained from this was combined with statistical investigations based on finite element calculations and artificially generated measurement noise effect in order to determine the application limits, such as the achievable measurement precision, identifiable degree of damage, required number of measurement repetitions, influence of the damage position, optimal size of the structural deformation, etc. The development of the DAD method ready for application usefully supplements the state of the art and contributes to the reliable assessment of the bridge condition. [less ▲]

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See detailThe token’s secret: the two-faced financial incentive of the token economy
Drasch, Benedict J; Fridgen, Gilbert UL; Manner-Romberg, Tobias et al

in Electronic Markets (2020)

Multi-sided platforms are omnipresent in today’s digital world. However, establishing a platform includes challenges: The platform utility usually increases with the number of participants. At an early ... [more ▼]

Multi-sided platforms are omnipresent in today’s digital world. However, establishing a platform includes challenges: The platform utility usually increases with the number of participants. At an early stage, potential participants expect the platform utility to be low and lack an incentive to join (i.e., “chicken and egg” problem). Blockchain-enabled utility tokens hold the promise to overcome this problem. They supposedly provide a suitable financial incentive for their owners to join the platform as soon as possible. In the first half of 2018, investors seemed to believe in the presumption and spent more than US$ 17.6 billion in token sales. To date, we know little about this financial incentive in the context of the token economy. For this purpose, we model the token value development and the associated incentives in a multi-sided blockchain-enabled platform. The resulting findings suggest that blockchain-enabled utility tokens can help to overcome the “chicken and egg” problem. However, these tokens lead to contradictory incentives for platform participants, and can even inhibit platform usage. The contribution of our work is twofold: First, we develop one of the first models for token value development. Second, our research contributes to a deeper understanding of the utility token’s financial incentive. [less ▲]

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See detailRobust SINR-Constrained Symbol-Level Multiuser Precoding With Imperfect Channel Knowledge
Haqiqatnejad, Alireza UL; Kayhan, Farbod UL; Ottersten, Björn UL

in IEEE Transactions on Signal Processing (2020), 68(1), 1837-1852

In this paper, we address robust design of symbol-level precoding (SLP) for the downlink of multiuser multiple-input single-output wireless channels, when imperfect channel state information (CSI) is ... [more ▼]

In this paper, we address robust design of symbol-level precoding (SLP) for the downlink of multiuser multiple-input single-output wireless channels, when imperfect channel state information (CSI) is available at the transmitter. In particular, we consider a well known model for the CSI imperfection, namely, stochastic Gaussian-distributed uncertainty. Our design objective is to minimize the total (per-symbol) transmission power subject to constructive interference (CI) constraints as well as the users’ quality-of-service requirements in terms of signal-to-interference-plus-noise ratio. Assuming stochastic channel uncertainties, we first define probabilistic CI constraints in order to achieve robustness to statistically known CSI errors. Since these probabilistic constraints are difficult to handle, we resort to their convex approximations in the form of tractable (deterministic) robust constraints. Three convex approximations are obtained based on different conservatism levels, among which one is introduced as a benchmark for comparison. We show that each of our proposed approximations is tighter than the other under specific robustness settings, while both of them always outperform the benchmark. Using the proposed CI constraints, we formulate the robust SLP optimization problem as a second-order cone program. Extensive simulation results are provided to validate our analytic discussions and to make comparisons with conventional block-level robust precoding schemes. We show that the robust design of symbol-level precoder leads to an improved performance in terms of energy efficiency at the cost of increasing the computational complexity by an order of the number of users in the large system limit, compared to its non-robust counterpart. [less ▲]

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