Modulation-mode assignment for SVD-assisted and iteratively detected downlink multiuser MIMO transmission schemes

In this contribution we jointly optimize the number of multiple-input multiple-output (MIMO) layers and the number of bits per symbol within an iteratively-detected multiuser MIMO downlink (DL) transmission scheme under the constraint of a given fixed data throughput and integrity. Instead of treating all the users jointly as in zero-forcing (ZF) multiuser transmission techniques, the investigated singular value decomposition (SVD) assisted DL multiuser MIMO system takes the individual user's channel characteristics into account. In analogy to bit-interleaved coded irregular modulation, we introduce a MIMO-BICM scheme, where different user-specific signal constellations and mapping arrangement were used within a single codeword. Extrinsic information transfer (EXIT) charts are used for analyzing and optimizing the convergence behaviour of the iterative demapping and decoding. Our results show that in order to achieve the best bit-error rate, not necessarily all user-specific MIMO layers have to be activate

EXIT chart analysis of iteratively detected and SVD-assisted broadband MIMO-BICM schemes

In this contribution the number of activated MIMO layers and the number of bits per symbol are jointly optimized under the constraint of a given fixed data throughput and integrity. In general, non-frequency selective MIMO links have attracted a lot of research and have reached a state of maturity. By contrast, frequency selective MIMO links require substantial further research, where spatio-temporal vector coding (STVC) introduced by Raleigh seems to be an appropriate candidate for broadband transmission channels. In analogy to bit-interleaved coded irregular modulation, a broadband MIMO-BICM scheme is introduced, where different signal constellations and mappings are used within a single codeword. Extrinsic Information Transfer (EXIT) charts are used for analyzing and optimizing the convergence behaviour of the iterative demapping and decoding. Our results show that in order to achieve the best bit-error rate, not necessarily all MIMO layers have to be activated

Modulation-mode and power-assignment for SVD-assisted downlink multiuser MIMO systems

Multiuser multiple-input multiple-output (MIMO) downlink (DL) transmission schemes experience both multiuser interference as well as inter-antenna interference. However, instead of treating all the users jointly as in zero-forcing (ZF) multiuser transmission techniques, the investigated singular value decomposition (SVD) assisted DL multiuser MIMO system takes the individual user's channel characteristics into account. The performed joint optimization of the number of activated MIMO layers and the number of bits per symbol along with the appropriate allocation of the transmit power shows that not necessarily all user-specific MIMO layers has to be activated in order to minimize the overall BER under the constraint of a given fixed data throughput

Soil moisture initialization effects in the Indian monsoon system

Towards the goal to understand the role of land-surface processes over the Indian sub-continent, a series of soil-moisture sensitivity simulations have been performed using a non-hydrostatic regional climate model COSMO-CLM. The experiments were driven by the lateral boundary conditions provided by the ERA-Interim (ECMWF) reanalysis. The simulation results show that the pre-monsoonal soil moisture has a significant influence on the monsoonal precipitation. Both, positive and negative soil-moisture precipitation (S-P) feedback processes are of importance. The negative S-P feedback process is especially influential in the western and the northern parts of India

Modulation-mode and power-assignment for SVD-and GMD-assisted downlink MIMO systems

Multiuser multiple-input multiple-output (MIMO) downlink (DL) transmission schemes experience both multiuser interference (MUI) as well as inter-antenna interference. However, instead of treating all the users jointly as in zero-forcing (ZF) multiuser transmission techniques, the investigated singular value decomposition (SVD) and geometric mean decomposition (GMD) assisted DL multiuser MIMO systems take the individual user's channel characteristics into account. The performed joint optimization of the number of activated MIMO layers and the number of bits per symbol along with the appropriate allocation of the transmit power shows that not necessarily all user-specific MIMO layers have to be activated in order to minimize the overall BER under the constraint of a fixed data throughpu

Performance Analysis of SVD-assisted Downlink Multiuser MIMO Systems

Multiuser multiple-input multiple-output (MIMO) downlink (DL) transmission schemes experience both multiuser interference as well as inter-antenna interference. Instead of treating all the users jointly as in zero-forcing (ZF) multiuser transmission techniques, the investigated singular value decomposition (SVD) assisted DL multiuser MIMO system takes the individual user’s channel characteristics into account. This translates to a choice of modulation constellation and transmitter power and, in our proposed system, to a choice of number of activated user-specific MIMO layers. The performed joint optimization of the number of activated MIMO layers and the number of bits per symbol along with the appropriate allocation of the transmit power shows that not necessarily all user-specific MIMO layers has to be activated in both frequency-selective and non-frequency selective MIMO channels in order to minimize the overall BER under the constraint of a given fixed data throughput

Regional climate projections in two alpine river basins: Upper Danube and Upper Brahmaputra

Projections from coarse-grid global circulation models are not suitable for regional estimates of water balance or trends of extreme precipitation and temperature, especially not in complex terrain. Thus, downscaling of global to regionally resolved projections is necessary to provide input to integrated water resources management approaches for river basins like the Upper Danube River Basin (UDRB) and the Upper Brahmaputra River Basin (UBRB). This paper discusses the application of the regional climate model COSMO-CLM as a dynamical downscaling tool. To provide accurate data the COSMO-CLM model output was post-processed by statistical means. This downscaling chain performs well in the baseline period 1971 to 2000. However, COSMO-CLM performs better in the UDRB than in the UBRB because of a longer application experience and a less complex climate in Europe. Different climate change scenarios were downscaled for the time period 1960–2100. The projections show an increase of temperature in both basins and for all seasons. The values are generally higher in the UBRB with the highest values occurring in the region of the Tibetan Plateau. Annual precipitation shows no substantial change. However, seasonal amounts show clear trends, for instance an increasing amount of spring precipitation in the UDRB. Again, the largest trends for different precipitation statistics are projected in the region of the Tibetan Plateau. Here, the projections show up to 50% longer dry periods in the months June to September with a simultaneous increase of about 10% for the maximum amount of precipitation on five consecutive days. For the Assam region in India, the projections also show an increase of 25% in the number of consecutive dry days during the monsoon season leading to prolonged monsoon breaks

Principles of Sampling in Educational Research in Higher Education

Innovation and creativity in European society are fostered via a dynamic and flexible European higher education based on the integration between education and research at all levels (Communiqué, 2009). The synergy between education and research is effeciently driven via educational research. Sampling as an element of the educational research has a two-fold role: sample size is inter-connected with statistical analysis of the data and generalisation. Against this background, little attention has been given to principles of sampling in educational research. The research question is as follows: what principles form sampling in educational research? The aim of the research is to analyse scientific literature and work out principles of sampling in educational research underpinning elaboration of a new research question for further studies in educational research. The present research involves a process of analysing the meaning of the key concept “principle”. In the empirical study, explorative research was employed. Interpretive research paradigm was used. The empirical study involved six experts from different countries in February 2013 – July 2014. The findings of the research allow drawing the conclusions on the elaborated principles of sampling in educational research. Directions of further research are proposed

SOCIAL INNOVATION IN ENGINEERING EDUCATION

Traditionally, engineering students are provided with new knowledge by educatorstudent interaction based on educator’s academic (social) knowledge or student-student interaction based on their practical (individual) knowledge. That is why engineering students lack the inter-connection between the academic and practical knowledge. However, engineering education should lead to the transformation of students’ knowledge from external (social) to internal (individual) perspective. Social innovation that has become the dominant response to challenges in all the domains of modern life includes peer-learning as the subphase to create socially shared knowledge in the transformation of students’ knowledge from external to internal perspective and Enterprise 3.0 as a component of social media integrated into the teaching and learning process. This allows the novel transformation of students’ knowledge from external to internal perspective, as introduced in this contribution, that proceeds from teaching through peer-learning to learning to be integrated in the environments of engineering education

POST-COVID-19 UNIVERSITY GOVERNANCE IN GERMANY

Researchers admit that there will not be a quick return to “business as usual”, especially related to internationalization, the financing of studies and universities, research and administration. The enabling research question is formulated as following: What is the relationship between the COVID-19 pandemic and university governance? The aim of the article is to examine the relationship between the COVID-19 pandemic and university governance underpinning the elaboration of implications for higher education. The study was of the qualitative nature. The exploratory study was implemented. The study was carried out in Germany on the 22nd September 2020. Focus group interview served as a method of data collection. The data were interpreted via structuring and summarising content analysis. The theoretical finding is that the COVID-19 pandemic is a factor that influences the university governance. The COVID-19 pandemic is an external factor in regard to university governance. Factor impact can be regulated. Factor impact can be increased or decreased according to the situation requirements. The empirical data allow concluding that the COVID-19 pandemic fastens the changes in governing the universities in Germany. Implications for higher education are presented. Research limitations are identified. Directions of further research are proposed