43 research outputs found
Algoritmos paralelos segmentados para los problemas de mínimos cuadrados recursivos (RLS) y de detección por cancelación ordenada y sucesiva de interferencia (OSIC)
Dentro del marco de los sistemas de comunicaciones de banda ancha podemos
encontrar canales modelados como sistemas MIMO (Multiple Input
Multiple Output) en el que se utilizan varias antenas en el transmisor (entradas)
y varias antenas en el receptor (salidas), o bien sistemas de un solo
canal que puede ser modelado como los anteriores (sistemas multi-portadora
o multicanal con interferencia entre ellas, sistemas multi-usuario con una o
varias antenas por terminal móvil y sistemas de comunicaciones ópticas sobre
fibra multimodo). Estos sistemas pretenden alcanzar valores de capacidad de
transmisión relativa al ancho de banda muy superiores al de un único canal
SISO (Single Input Single Output).
Hoy en dÍa, existe, desde un punto de vista de implementación del sistema,
una gran actividad investigadora dedicada al desarrollo de algoritmos de
codificación, ecualización y detección, muchos de ellos de gran complejidad,
que ayuden a aproximarse a las capacidades prometidas.
En el aspecto relativo a la detección, las soluciones actuales se pueden
clasificar en tres tipos: soluciones subóptimas, ML (Maximum Likelihood) o
cuasi-ML e iterativas. En estas ultimas, se hace uso explicito de técnicas de
control de errores empleando intercambio de información soft o indecisa entre
el detector y el decodificador; en las soluciones ML o cuasi-ML se lleva
a cabo una búsqueda en árbol que puede ser optimizada llegando a alcanzar
complejidades polinómicas en cierto margen de relación señal-ruido; por
ultimo dentro de las soluciones subóptimas destacan las técnicas de forzado
de ceros, error cuadrático medio y cancelación sucesiva de interferencias SIC
(Succesive Interference Cancellation), esta última con una versión ordenada
-OSIC-. Las soluciones subóptimas, aunque no llegan al rendimiento
de las ML o cuasi-ML son capaces de proporcionar la solución en tiempo
polinómico de manera determinista.
En la presente tesis doctoral, hemos implementado un método basado
en la literatura para lMartínez Zaldívar, FJ. (2007). Algoritmos paralelos segmentados para los problemas de mínimos cuadrados recursivos (RLS) y de detección por cancelación ordenada y sucesiva de interferencia (OSIC) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/1873Palanci
Combined precoding for multiuser Multiple-Input Multiple-Output satellite communications
[EN] Applying Multiple-Input Multiple-Output (MIMO) techniques in satellite communications can increase data rates. However, new signal processing elements have to be taken into account to fully exploit the expected advantages of MIMO communications. In this paper, we evaluate different precoding techniques over the satellite channel. A performance comparison between several precoders in terms of Bit Error Rate (BER) and complexity is given for different channel realizations. Furthermore, a novel hybrid scheme for signal precoding is proposed that optimizes the computation for a required BER. The new scheme is based on the matrix condition number of the satellite MIMO channel.This work has been partially funded by the Spanish MINECO grant RACHEL TEC2013-47141-C4-4-R and through FPU AP-2012/71274.Simarro, MA.; Puig, B.; Martínez Zaldívar, FJ.; Gonzalez, A. (2018). Combined precoding for multiuser Multiple-Input Multiple-Output satellite communications. Computers & Electrical Engineering. 71:704-713. https://doi.org/10.1016/j.compeleceng.2018.08.006S7047137
Multichannel massive audio processing for a generalized crosstalk cancellation and equalization application using GPUs
[EN] Multichannel acoustic signal processing has undergone major development in recent years due to the increased com- plexity of current audio processing applications, which involves the processing of multiple sources, channels, or filters. A gen- eral scenario that appears in this context is the immersive reproduction of binaural audio without the use of headphones, which requires the use of a crosstalk canceler. However, generalized crosstalk cancellation and equalization (GCCE) requires high com- puting capacity, which is a considerable limitation for real-time applications. This paper discusses the design and implementation of all the processing blocks of a multichannel convolution on a GPU for real-time applications. To this end, a very efficient fil- tering method using specific data structures is proposed, which takes advantage of overlap-save filtering and filter fragmentation. It has been shown that, for a real-time application with 22 inputs and 64 outputs, the system is capable of managing 1408 filters of 2048 coefficients with a latency time less than 6 ms. The proposed GPU implementation can be easily adapted to any acoustic environment, demonstrating the validity of these co-processors for managing intensive multichannel audio applications.This work has been partially funded by Spanish Ministerio de Ciencia e Innovacion TEC2009-13741, Generalitat Valenciana PROMETEO 2009/2013 and GV/2010/027, and Universitat Politecnica de Valencia through Programa de Apoyo a la Investigacion y Desarrollo (PAID-05-11).Belloch Rodríguez, JA.; Gonzalez, A.; Martínez Zaldívar, FJ.; Vidal Maciá, AM. (2013). Multichannel massive audio processing for a generalized crosstalk cancellation and equalization application using GPUs. Integrated Computer-Aided Engineering. 20(2):169-182. https://doi.org/10.3233/ICA-130422S16918220
On the use of many-core machines for the acceleration of a mesh truncation technique for FEM
Finite element method (FEM) has been used for years for radiation problems in the
field of electromagnetism. To tackle problems of this kind, mesh truncation techniques
are required, which may lead to the use of high computational resources.
In fact, electrically large radiation problems can only be tackled using massively
parallel computational resources. Different types of multi-core machines are commonly
employed in diverse fields of science for accelerating a number of applications.
However, properly managing their computational resources becomes a very
challenging task. On the one hand, we present a hybrid message passing interface
+ OpenMP-based acceleration of a mesh truncation technique included in a
FEM code for electromagnetism in a high-performance computing cluster equipped
with 140 compute nodes. Results show that we obtain about 85% of the theoretical
maximum speedup of the machine. On the other hand, a graphics processing unit
has been used to accelerate one of the parts that presents high fine-grain parallelism.This work has been fnancially supported by TEC2016-80386-P, TIN2017-82972-R,
CAM S2013/ICE-3004 projects and “Ayudas para contratos predoctorales de Formación del Profesorado
Universitario FPU”
Soft MIMO detection through sphere decoding and box optimization
[EN] Achieving optimal detection performance with low complexity is
one of the major challenges, mainly in multiple-input multiple-output
(MIMO) detection. This paper presents three low-complexity Soft-Output
MIMO detection algorithms
that are based mainly on Box Optimization (BO) techniques. The proposed
methods provide good performance with low computational cost using
continuous constrained optimization techniques. The rst proposed
algorithm is a non-optimal Soft-Output detector of reduced complexity.
This algorithm
has been compared with the Soft-Output Fixed Complexity (SFSD) algorithm,
obtaining lower complexity and similar performance. The two remaining
algorithms are employed in a turbo receiver, achieving the max-log
Maximum a Posteriori (MAP) performance. The two Soft-Input Soft-Output
(SISO) algorithms were proposed in a previous work for soft-output MIMO
detection. This work presents its extension for iterative decoding. The
SISO algorithms presented
are developed and compared with the SISO Single Tree Search algorithm
(STS), in terms of efficiency and computational cost. The results show
that the proposed algorithms are more efficient for high order
constellation than the STS algorithm.Simarro, MA.; García Mollá, VM.; Vidal Maciá, AM.; Martínez Zaldívar, FJ.; Gonzalez, A. (2018). Soft MIMO detection through sphere decoding and box optimization. Signal Processing. 145:48-58. https://doi.org/10.1016/j.sigpro.2017.11.010S485814
Parallel signal detection for generalized spatial modulation MIMO systems
[EN] Generalized Spatial Modulation is a recently developed technique that is designed to enhance the efficiency of transmissions in MIMO Systems. However, the procedure for correctly retrieving the sent signal at the receiving end is quite demanding. Specifically, the computation of the maximum likelihood solution is computationally very expensive. In this paper, we propose a parallel method for the computation of the maximum likelihood solution using the parallel computing library OpenMP. The proposed parallel algorithm computes the maximum likelihood solution faster than the sequential version, and substantially reduces the worst-case computing times.This work has been partially supported by the Spanish Ministry of Science, Innovation and Universities and by the European Union through grant RTI2018- 098085-BC41 (MCUI/AEI/FEDER), by GVA through PROMETEO/2019/109, and by RED 2018-102668-T.
Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.García Mollá, VM.; Simarro, MA.; Martínez Zaldívar, FJ.; Boratto, M.; Alonso-Jordá, P.; Gonzalez, A. (2022). Parallel signal detection for generalized spatial modulation MIMO systems. The Journal of Supercomputing. 78(5):7059-7077. https://doi.org/10.1007/s11227-021-04163-y7059707778
Las Aplicaciones de Extractos de Algas en Lima Persa Aumentan Rendimiento y Calidad de Fruto de Exportación
With the objective of evaluating the quality and yield of export fruit in Persian lime, an experiment was carried out with applications of algae extracts to the foliage in the municipality of Martínez de la Torre, Veracruz, Mexico. The treatment design was randomized blocks with 4 treatments and 7 repetitions. The greatest thickness of the fruit shell was with the 3 % treatment. The maximum number of fruits per tree with first-class export quality was with 3 % algae extract and was statistically higher (P ≤0.05) than the control. The percentage of first export fruit ranged from 56 % in the control to 92 % with seaweed extract. From the results obtained, it is concluded that foliar applications with algae extracts in doses of 3 % increase the yield of the first export fruit in Persian lime.Con el objetivo de evaluar calidad y rendimiento de fruto de exportación en lima Persa se realizó un experimento con aplicaciones al follaje de extractos de algas en el municipio de Martínez de la Torre, Veracruz, México. El diseño de tratamientos fue en bloques al azar con 4 tratamientos y 7 repeticiones. El mayor grosor de cáscara de fruto fue con el tratamiento 3 %. El máximo número de frutos por árbol con calidad de primera de exportación fue con 3 % de extracto de alga y superó estadísticamente (P ≤0.05) al testigo. El porcentaje de fruto de exportación de primera osciló de 56 % en el testigo a 92 % con extracto de alga. Por los resultados obtenidos se concluye que las aplicaciones foliares con extractos de algas en dosis de 3 % aumentan rendimiento de fruto de primera de exportación en lima Persa
Parallel Implementation Strategies for MIMO ID-BICM Systems
[EN] One of the current techniques proposed for multiple transmit and receive antennas wireless communication systems is the use of error control coding and iterative detection and decoding at the receiver. These sophisticated techniques produce a significant increase of the computational cost and require large computational power. The use of modern computer facilities as multicore and multi-GPU (Graphics Processing Unit) processors can decrease the computational time required, representing a promising solution for the receiver implementation in these systems.
In this paper we explain how iterative receivers can improve the performance of suboptimal detectors. We also introduce a novel parallel receiver scheme based on a hybrid computing model where CPUs and GPUs work together to accelerate the detection and decoding steps; this design comes to exploit the features of the GPU NVIDIA Kepler architecture respect to the previous one in order to optimize the communication system performance.This work has been partially funded by PROMETEO/2009/013 project of Generalitat Valenciana, projects TEC2009-13741 of the Ministerio Español de Ciencia e Innovación, TEC2012-38142-C04 of the Ministerio Español de Economía y Competitividad, and PAID-05-2011 of Universitat Politècnica de València.Simarro Haro, MDLA.; Ramiro Sánchez, C.; Martínez Zaldívar, FJ.; Vidal Maciá, AM.; González Téllez, A.; Piñero Sipán, MG.; García Mollá, VM. (2013). Parallel Implementation Strategies for MIMO ID-BICM Systems. Waves. 5-13. http://hdl.handle.net/10251/57906S51
Effects of Maternal Fish Oil and/or 5-MethylTetrahydrofolate Supplementation during Pregnancy on Offspring Brain Resting-State at 10 Years Old: A Follow-Up Study from the NUHEAL Randomized Controlled Trial
Recent studies have shown that maternal supplementation with folate and long-chain
polyunsaturated fatty acids (LC-PUFAs) during pregnancy may affect children’s brain development.
We aimed at examining the potential long-term effect of maternal supplementation with fish oil
(FO) and/or 5-methyl-tetrahydrofolate (5-MTHF) on the brain functionality of offspring at the age
of 9.5–10 years. The current study was conducted as a follow-up of the Spanish participants
belonging to the Nutraceuticals for a Healthier Life (NUHEAL) project; 57 children were divided
into groups according to mother’s supplementation and assessed through functional magnetic
resonance imaging (fMRI) scanning and neurodevelopment testing. Independent component analysis
and double regression methods were implemented to investigate plausible associations. Children
born to mothers supplemented with FO (FO and FO + 5-MTHF groups, n = 33) showed weaker
functional connectivity in the default mode (DM) (angular gyrus), the sensorimotor (SM) (motor and
somatosensory cortices) and the fronto-parietal (FP) (angular gyrus) networks compared to the No-FO
group (placebo and 5-MTHF groups, n = 24) (PFWE < 0.05). Furthermore, no differences were found
regarding the neuropsychological tests, except for a trend of better results in an object recall (memory)
test. Considering the No-FO group, the aforementioned networks were associated negatively with
attention and speed-processing functions. Mother’s FO supplementation during pregnancy seems
to be able to shape resting-state network functioning in their children at school age and appears to
produce long-term effects on children´s cognitive processing.European Union (EU)
212652
007036Commission of the European Community within the 5th Framework Program
QLK1-CT-1999-00888European Research Council (ERC)
322605 META-GROWTHSpanish Ministry of Science, Innovation and Universities
FJCI-2017-3339
Long-Chain Polyunsaturated Fatty Acids, Homocysteine at Birth and Fatty Acid Desaturase Gene Cluster Polymorphisms Are Associated with Children’s Processing Speed up to Age 9 Years
Both pre- and early postnatal supplementation with docosahexaenoic acid (DHA), arachidonic
acid (AA) and folate have been related to neural development, but their long-term effects
on later neural function remain unclear. We evaluated the long-term effects of maternal prenatal
supplementation with fish-oil (FO), 5-methyltetrahydrofolate (5-MTHF), placebo or FO + 5-MTHF,
as well as the role of fatty acid desaturase (FADS) gene cluster polymorphisms, on their offspring’s
processing speed at later school age. This study was conducted in NUHEAL children at 7.5 (n = 143)
and 9 years of age (n = 127). Processing speed tasks were assessed using Symbol Digit Modalities
Test (SDMT), Children Color Trails Test (CCTT) and Stroop Color andWord Test (SCWT). Long-chain
polyunsaturated fatty acids, folate and total homocysteine (tHcy) levels were determined at delivery
from maternal and cord blood samples. FADS and methylenetetrahydrofolate reductase (MTHFR)
677 C > T genetic polymorphisms were analyzed. Mixed models (linear and logistic) were performed.
There were significant differences in processing speed performance among children at different ages
(p < 0.001). The type of prenatal supplementation had no effect on processing speed in children
up to 9 years. Secondary exploratory analyses indicated that children born to mothers with higher
AA/DHA ratio at delivery (p < 0.001) and heterozygotes for FADS1 rs174556 (p < 0.05) showed better
performance in processing speed at 9 years. Negative associations between processing speed scores and maternal tHcy levels at delivery were found. Our findings suggest speed processing development
in children up to 9 years could be related to maternal factors, including AA/DHA and tHcy
levels, and their genetic background, mainly FADS polymorphism. These considerations support
that maternal prenatal supplementation should be quantitatively adequate and individualized to
obtain better brain development and mental performance in the offspring.European Commission
212652
007036
QLK1-CT-1999-00888European Commission
European Commission Joint Research Centre
DYNAHEALTH-633595
Lifecycle-733206European Research Council Advanced Grant META-GROWTH ERC-2012AdG
322605Erasmus Plus Programme Early Nutrition eAcademy Southeast Asia
573651EPP-1-2016-1-DE-EPPKA2-CBHE-JPErasmus Plus Programme Capacity Building to Improve Early Nutrition and Health in South Africa
598488-EPP-1-2018-1-DE-EPPKA2-CBHE-JPEU Interreg Programme Focus in CD-CE111European Joint Programming Initiative Project NutriPROGRAM and EndObesityGerman Ministry of Education and Research, Berlin
01 GI 0825German Research Foundation (DFG)
Ko912/12-1
INST 409/224-1 FUGGElse Kroner-Fresenius-FoundationLMU University Hospital