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The objective of this study was to evaluate the effects of a cognitive stimulation software on attention, memory, reasoning, planning, and frequency of activities of daily living, in Mexican older adults. To carry out this research, an experimental research design was used, comprising two groups (experimental, n = 28 and control on a waiting list, n = 33) with pre- and post-evaluation, where adults over 60 years of age gathered in meeting centers to complete a sociodemographic data sheet, a psychometric test that evaluates attention, memory, reasoning, planning, and an inventory of activities of daily living of the elderly. The participants interacted with the software via touchscreens for 12 cognitive stimulation exercises. The results indicate improvements in the participants’ attention and concentration, and in the types of work, logic, and spontaneous memory, as well as a significant increase in the frequency of instrumental activities in the home by participants of both sexes, and in the social activities of the men. It was concluded that cognitive stimulation software can be used in Mexican older adults to achieve improvements in cognitive functioning. This is justified due to the importance of maintaining cognitive abilities in old age since their deterioration affects activities of daily living, which are essential for an independent life.
Christian O. Acosta; Ramón R. Palacio; Joaquín Cortez; Sonia B. Echeverría; María José Rodríguez-Fórtiz. Effects of a cognitive stimulation software on attention, memory, and activities of daily living in Mexican older adults. Universal Access in the Information Society 2020, 1 -11.
AMA StyleChristian O. Acosta, Ramón R. Palacio, Joaquín Cortez, Sonia B. Echeverría, María José Rodríguez-Fórtiz. Effects of a cognitive stimulation software on attention, memory, and activities of daily living in Mexican older adults. Universal Access in the Information Society. 2020; ():1-11.
Chicago/Turabian StyleChristian O. Acosta; Ramón R. Palacio; Joaquín Cortez; Sonia B. Echeverría; María José Rodríguez-Fórtiz. 2020. "Effects of a cognitive stimulation software on attention, memory, and activities of daily living in Mexican older adults." Universal Access in the Information Society , no. : 1-11.
Diabetes mellitus (DM) is a metabolic disorder characterized by blood glucose levels above normal limits. The impact of this disease on the population has increased in recent years. It is already a public health problem worldwide and one of the leading causes of death. Recently, several proposals have been developed for better and regular monitoring of glucose. However, theses proposals do not discard erroneous readings and they are not able to anticipate a critical condition. In this work, we propose an algorithm based on the double moving average supported by an IoT architecture to prevent possible complications in elderly patients. The algorithm uses historical readings to construct a series. Given a number of periods, it is possible to calculate averages of different subsets and trends for the next periods and, in this way, the prognosis is obtained. With the prognosis, it is possible to notify the doctor and relatives in advance about a possible critical condition in the patient. The aim of our work is to validate the architecture and prognosis algorithm used for elderly persons. Tests of the algorithm and the architecture were performed with different readings and it was shown that the system generated corresponding notifications before the glucose values were higher than those defined by the WHO (World Health Organization), thus avoiding unnecessary alarms.
Francisco Valenzuela; Armando García; Erica Ruiz.; Mabel Vázquez; Joaquín Cortez; Adolfo Espinoza. An IoT-Based Glucose Monitoring Algorithm to Prevent Diabetes Complications. Applied Sciences 2020, 10, 921 .
AMA StyleFrancisco Valenzuela, Armando García, Erica Ruiz., Mabel Vázquez, Joaquín Cortez, Adolfo Espinoza. An IoT-Based Glucose Monitoring Algorithm to Prevent Diabetes Complications. Applied Sciences. 2020; 10 (3):921.
Chicago/Turabian StyleFrancisco Valenzuela; Armando García; Erica Ruiz.; Mabel Vázquez; Joaquín Cortez; Adolfo Espinoza. 2020. "An IoT-Based Glucose Monitoring Algorithm to Prevent Diabetes Complications." Applied Sciences 10, no. 3: 921.
This paper presents a proposal for an architecture in FPGA for the implementation of a low complexity near maximum likelihood (Near-ML) detection algorithm for a multiple input-multiple output (MIMO) quadrature spatial modulation (QSM) transmission system. The proposed low complexity detection algorithm is based on a tree search and a spherical detection strategy. Our proposal was verified in the context of a MIMO receiver. The effects of the finite length arithmetic and limited precision were evaluated in terms of their impact on the receiver bit error rate (BER). We defined the minimum fixed point word size required not to impact performance adversely for n T transmit antennas and n R receive antennas. The results showed that the proposal performed very near to optimal with the advantage of a meaningful reduction in the complexity of the receiver. The performance analysis of the proposed detector of the MIMO receiver under these conditions showed a strong robustness on the numerical precision, which allowed having a receiver performance very close to that obtained with floating point arithmetic in terms of BER; therefore, we believe this architecture can be an attractive candidate for its implementation in current communications standards.
Ismael Lopez; L. Pizano-Escalante; Joaquin Cortez; O. Longoria-Gandara; Armando Garcia. Fast Scalable Architecture of a Near-ML Detector for a MIMO-QSM Receiver. Electronics 2019, 8, 1509 .
AMA StyleIsmael Lopez, L. Pizano-Escalante, Joaquin Cortez, O. Longoria-Gandara, Armando Garcia. Fast Scalable Architecture of a Near-ML Detector for a MIMO-QSM Receiver. Electronics. 2019; 8 (12):1509.
Chicago/Turabian StyleIsmael Lopez; L. Pizano-Escalante; Joaquin Cortez; O. Longoria-Gandara; Armando Garcia. 2019. "Fast Scalable Architecture of a Near-ML Detector for a MIMO-QSM Receiver." Electronics 8, no. 12: 1509.
Recently, there has been an increase in the development of new intelligent transportation systems. Specifically, this technology was proposed with the aim of increasing road safety and improving traffic flow management by information interchange among vehicles. In this sense, the dedicated radio short-range communication (DSRC) technology enables reliable vehicle-to-vehicle (V2V) and vehicleto-infrastructure (V2I) communication. However, in order to guarantee the correct operation of the radio transmission systems, it is necessary to test the transmitter and receiver devices under controlled conditions. A channel emulator offers a fast and non-expensive solution to perform these tests. This paper presents a new non wide-sense stationary uncorrelated scattering (non-WSSUS) channel emulator for vehicle communications, which is based on software defined radios (SDR). Implementation results show that the proposed channel emulator can reproduce propagation environment corresponding to non-WSSUS channels with exactness. This will allow testing of communications systems under development using the SDR-based V2V-V2I channel emulator.
Ángel E. Ruiz-García; Carlos A. Gutierrez; Javier Vazquez-Castillo; Joaquin Cortez. SDR-Based Channel Emulator for Vehicular Communications. 2019 IEEE Colombian Conference on Communications and Computing (COLCOM) 2019, 1 -6.
AMA StyleÁngel E. Ruiz-García, Carlos A. Gutierrez, Javier Vazquez-Castillo, Joaquin Cortez. SDR-Based Channel Emulator for Vehicular Communications. 2019 IEEE Colombian Conference on Communications and Computing (COLCOM). 2019; ():1-6.
Chicago/Turabian StyleÁngel E. Ruiz-García; Carlos A. Gutierrez; Javier Vazquez-Castillo; Joaquin Cortez. 2019. "SDR-Based Channel Emulator for Vehicular Communications." 2019 IEEE Colombian Conference on Communications and Computing (COLCOM) , no. : 1-6.
Francisco R. Castillo-Soria; Joaquin Cortez; C.A. Gutiérrez; M. Luna-Rivera; A. Garcia-Barrientos. Extended quadrature spatial modulation for MIMO wireless communications. Physical Communication 2019, 32, 88 -95.
AMA StyleFrancisco R. Castillo-Soria, Joaquin Cortez, C.A. Gutiérrez, M. Luna-Rivera, A. Garcia-Barrientos. Extended quadrature spatial modulation for MIMO wireless communications. Physical Communication. 2019; 32 ():88-95.
Chicago/Turabian StyleFrancisco R. Castillo-Soria; Joaquin Cortez; C.A. Gutiérrez; M. Luna-Rivera; A. Garcia-Barrientos. 2019. "Extended quadrature spatial modulation for MIMO wireless communications." Physical Communication 32, no. : 88-95.
Localization is a fundamental problem in Wireless Sensor Networks, as it provides useful information regarding the detection of an event. There are different localization algorithms applied in single-hop or multi-hop networks; in both cases their performance depends on several factors involved in the evaluation scenario such as node density, the number of reference nodes and the log-normal shadowing propagation model, determined by the path-loss exponent (η) and the noise level (σdB) which impact on the accuracy and precision performance metrics of localization techniques. In this paper, we present a statistical analysis based on the 2k factorial methodology to determine the key factors affecting the performance metrics of localization techniques in a single-hop network to concentrate on such parameters, thus reducing the amount of simulation time required. For this proposal, MATLAB simulations are carried out in different scenarios, i.e., extreme values are used for each of the factors of interest and the impact of the interaction among them in the performance metrics is observed. The simulation results show that the path-loss exponent (η) and noise level (σdB) factors have the greatest impact on the accuracy and precision metrics evaluated in this study. Based on this statistical analysis, we recommend estimating the propagation model as close to reality as possible to consider it in the design of new localization techniques and thus improve their accuracy and precision metrics.
Joaquin Mass-Sanchez; Erica Ruiz-Ibarra; Ana Gonzalez-Sanchez; Adolfo Espinoza-Ruiz; Joaquin Cortez-Gonzalez. Factorial Design Analysis for Localization Algorithms. Applied Sciences 2018, 8, 2654 .
AMA StyleJoaquin Mass-Sanchez, Erica Ruiz-Ibarra, Ana Gonzalez-Sanchez, Adolfo Espinoza-Ruiz, Joaquin Cortez-Gonzalez. Factorial Design Analysis for Localization Algorithms. Applied Sciences. 2018; 8 (12):2654.
Chicago/Turabian StyleJoaquin Mass-Sanchez; Erica Ruiz-Ibarra; Ana Gonzalez-Sanchez; Adolfo Espinoza-Ruiz; Joaquin Cortez-Gonzalez. 2018. "Factorial Design Analysis for Localization Algorithms." Applied Sciences 8, no. 12: 2654.
Vehicle-to-vehicle (V2V)doubly-dispersive channels cause loss of orthogonality in multi-carrier systems, resulting in inter-carrier interference (ICI). In order to suppress ICI in orthogonal frequency division multiplexing (OFDM)systems, the techniques of forward error correction (FEC)and nonlinear detection of data are usually employed, requiring low coding rates and high decoding computational complexity. In this paper, different configurations for reception of OFDM signals with frequency dispersion, discrete Fourier transform-spread-OFDM (DFTS-OFDM)are explored including FEC techniques and linear/nonlinear detection. The results show that the use of turbo encoding and non-linear detection of ordered successive interference cancellation (OSIC)in the DFTS-OFDM system offers significant gains in terms of performance when compared to conventional OFDM receivers, obtaining a performance in terms of bit error rate (BER)of 10 -4 with a signal-to-noise ratio (SNR)close to 7 dB over doubly selective channel with 1 kHz Doppler spread. The results found can be applied in the design of communication systems with high mobility.
J. Alberto Del-Puerto-Flores; Lennin C. Yllescas; R. Parra-Michel; F. Pena-Campos; Joaquin Cortez. Performance Evaluation of Turbo Decoding in DFTS-OFDM Systems Over V2V Channel. 2018 IEEE 10th Latin-American Conference on Communications (LATINCOM) 2018, 1 -5.
AMA StyleJ. Alberto Del-Puerto-Flores, Lennin C. Yllescas, R. Parra-Michel, F. Pena-Campos, Joaquin Cortez. Performance Evaluation of Turbo Decoding in DFTS-OFDM Systems Over V2V Channel. 2018 IEEE 10th Latin-American Conference on Communications (LATINCOM). 2018; ():1-5.
Chicago/Turabian StyleJ. Alberto Del-Puerto-Flores; Lennin C. Yllescas; R. Parra-Michel; F. Pena-Campos; Joaquin Cortez. 2018. "Performance Evaluation of Turbo Decoding in DFTS-OFDM Systems Over V2V Channel." 2018 IEEE 10th Latin-American Conference on Communications (LATINCOM) , no. : 1-5.
Computational complexity and spectral efficiency are key components on the implementation of vehicular communication systems. However, in order to counteract the intercarrier interference (ICI) in orthogonal frequency division multiplexing (OFDM) systems, it's usual to resort receivers with high computational complexity or reduced spectral efficiency. This paper analyzes the inclusion of virtual carriers (V C) as a mean to reduce the ICI and the computational complexity required by the nonlinear ordered successive interference cancellation (OSIC). From the simulation results, it is demonstrated that using VC provides 90% reduction in the computational cost required for executing data detection, as well as a gain of 5 dB compared to conventional OFDM system with linear detection. In addition, the system is tested for different rates of channel coding obtaining results that show VC to be a convenient technique for reducing system complexity with low impact on the system throughput.
J. Alberto Del-Puerto-Flores; R. Parra-Michel; F. Pena-Campos; Joaquin Cortez; E. Romero-Aguirre. Evaluation of OFDM Systems With Virtual Carriers Over V2V Channels. 2018 IEEE 9th Annual Information Technology, Electronics and Mobile Communication Conference (IEMCON) 2018, 882 -886.
AMA StyleJ. Alberto Del-Puerto-Flores, R. Parra-Michel, F. Pena-Campos, Joaquin Cortez, E. Romero-Aguirre. Evaluation of OFDM Systems With Virtual Carriers Over V2V Channels. 2018 IEEE 9th Annual Information Technology, Electronics and Mobile Communication Conference (IEMCON). 2018; ():882-886.
Chicago/Turabian StyleJ. Alberto Del-Puerto-Flores; R. Parra-Michel; F. Pena-Campos; Joaquin Cortez; E. Romero-Aguirre. 2018. "Evaluation of OFDM Systems With Virtual Carriers Over V2V Channels." 2018 IEEE 9th Annual Information Technology, Electronics and Mobile Communication Conference (IEMCON) , no. : 882-886.
This paper presents a new decoder algorithm for the double space–time transmit diversity (DSTTD) system. The decoder is based on the QRD-M algorithm, which performs a breadth-first search of possible solutions tree. The search is simplified by skipping unlikely candidates, and it is stopped when no promising candidates are left. Furthermore, the search is divided into three concurrent iterations, making possible a fast, parallel implementation either in hardware or software. After presenting an analysis of the capacity and diversity of DSTTD, we present performance results showing that the proposed decoder is capable of achieving near maximum likelihood performance. We also show that the proposed algorithm exhibits lower computational complexity than other existing maximum likelihood detectors.
Joaquín Cortez; Miguel Bazdresch; Julio Ramírez; Ramón Palacio; Erica Ruiz. Low complexity maximum-likelihood detector for DSTTD architecture based on the QRD-M algorithm. Telecommunication Systems 2018, 70, 55 -66.
AMA StyleJoaquín Cortez, Miguel Bazdresch, Julio Ramírez, Ramón Palacio, Erica Ruiz. Low complexity maximum-likelihood detector for DSTTD architecture based on the QRD-M algorithm. Telecommunication Systems. 2018; 70 (1):55-66.
Chicago/Turabian StyleJoaquín Cortez; Miguel Bazdresch; Julio Ramírez; Ramón Palacio; Erica Ruiz. 2018. "Low complexity maximum-likelihood detector for DSTTD architecture based on the QRD-M algorithm." Telecommunication Systems 70, no. 1: 55-66.
This paper investigates the effects of correlated multiple-input multiple-output (MIMO) channels on the performance of spatial modulation (SM) techniques. Bit error rate (BER) performance for SM, quadrature SM (QSM), and generalized QSM transmission schemes over correlated MIMO vehicle-to-vehicle (V2V) channels are presented. The results are compared with the conventional spatial multiplexing (SMux) transmission schemes. For all cases, the optimal maximum likelihood (ML) detection criterion is used to detect the symbols at the receiver. Performace degradation due to the effects of spatial correlation of the MIMO V2V channels are then evaluated. The simulation results show significant degradations when SM techniques operate over correlated MIMO channels. Therefore, it can be concluded that SM techniques are very sensitive to the adverse effects of the propagation channels of modern mobile communication systems such as vehicular communications.
Joaquin Cortez; Carlos A. Gutierrez; Francisco R. Castillo-Soria; J. M. Luna-Rivera; F. M. Maciel-Barboza; Erica Ruiz. Performance Evaluation of Spatial Modulation Techniques in Correlated MIMO V2V Channels. 2018 IEEE Colombian Conference on Communications and Computing (COLCOM) 2018, 1 -6.
AMA StyleJoaquin Cortez, Carlos A. Gutierrez, Francisco R. Castillo-Soria, J. M. Luna-Rivera, F. M. Maciel-Barboza, Erica Ruiz. Performance Evaluation of Spatial Modulation Techniques in Correlated MIMO V2V Channels. 2018 IEEE Colombian Conference on Communications and Computing (COLCOM). 2018; ():1-6.
Chicago/Turabian StyleJoaquin Cortez; Carlos A. Gutierrez; Francisco R. Castillo-Soria; J. M. Luna-Rivera; F. M. Maciel-Barboza; Erica Ruiz. 2018. "Performance Evaluation of Spatial Modulation Techniques in Correlated MIMO V2V Channels." 2018 IEEE Colombian Conference on Communications and Computing (COLCOM) , no. : 1-6.
This paper presents a novel generalized quadrature spatial modulation (GQSM) transmission scheme using antenna grouping. The proposed GQSM scheme combines QSM and conventional spatial multiplexing (SMux) techniques in order to improve the spectral efficiency (SE) of the system. Analytical and simulation results show that the proposed transmission scheme has minimal losses in terms of the average bit error probability along with the advantage of an increased SE compared with previous SM and QSM schemes. For the case studies, this advantage represents a reduction of up to 81% in terms of the number of required transmit antennas compared with QSM. In addition, a detection architecture based on the ordered successive interference cancellation scheme and the QR decomposition is presented. The proposed QRD‐M adaptive algorithm showed a near‐maximum‐likelihood performance with a complexity reduction of approximately 90%.
Francisco R. Castillo-Soria; Joaquín Cortez-González; Raymundo Ramirez-Gutierrez; Fermín Marcelo Maciel-Barboza; Leonel Soriano-Equigua. Generalized Quadrature Spatial Modulation Scheme Using Antenna Grouping. ETRI Journal 2017, 39, 707 -717.
AMA StyleFrancisco R. Castillo-Soria, Joaquín Cortez-González, Raymundo Ramirez-Gutierrez, Fermín Marcelo Maciel-Barboza, Leonel Soriano-Equigua. Generalized Quadrature Spatial Modulation Scheme Using Antenna Grouping. ETRI Journal. 2017; 39 (5):707-717.
Chicago/Turabian StyleFrancisco R. Castillo-Soria; Joaquín Cortez-González; Raymundo Ramirez-Gutierrez; Fermín Marcelo Maciel-Barboza; Leonel Soriano-Equigua. 2017. "Generalized Quadrature Spatial Modulation Scheme Using Antenna Grouping." ETRI Journal 39, no. 5: 707-717.
This article proposes a methodology for the classification of fractal signals as stationary or nonstationary. The methodology is based on the theoretical behavior of two-parameter wavelet entropy of fractal signals. The wavelet (q,q′)-entropy is a wavelet-based extension of the (q,q′)-entropy of Borges and is based on the entropy planes for various q and q′; it is theoretically shown that it constitutes an efficient and effective technique for fractal signal classification. Moreover, the second parameter q′ provides further analysis flexibility and robustness in the sense that different (q,q′) pairs can analyze the same phenomena and increase the range of dispersion of entropies. A comparison study against the standard signal summation conversion technique shows that the proposed methodology is not only comparable in accuracy but also more computationally efficient. The application of the proposed methodology to physiological and financial time series is also presented along with the classification of these as stationary or nonstationary.
Julio César Ramírez-Pacheco; Joel Antonio Trejo-Sánchez; Joaquin Cortez-González; Ramón R. Palacio. Classification of Fractal Signals Using Two-Parameter Non-Extensive Wavelet Entropy. Entropy 2017, 19, 224 .
AMA StyleJulio César Ramírez-Pacheco, Joel Antonio Trejo-Sánchez, Joaquin Cortez-González, Ramón R. Palacio. Classification of Fractal Signals Using Two-Parameter Non-Extensive Wavelet Entropy. Entropy. 2017; 19 (5):224.
Chicago/Turabian StyleJulio César Ramírez-Pacheco; Joel Antonio Trejo-Sánchez; Joaquin Cortez-González; Ramón R. Palacio. 2017. "Classification of Fractal Signals Using Two-Parameter Non-Extensive Wavelet Entropy." Entropy 19, no. 5: 224.
En el presente trabajo se presenta una nueva arquitectura para detección de sistemas híbridos MIMO en canales con desvanecimiento Rayleigh. El esquema propuesta consiste de un módulo Alamouti más antenas operando con diversidad espacial en el transmisor. El receptor propuesto está basado en el algoritmo Sorted QR decomposition (SQRD) presentado en (Wubben et al., 2001). Nuestra propuesta disminuye significativamente la complejidad manteniendo las ventajas del esquema SQRD, obteniéndose una considerable ganancia en términos de Tasa de Error de Bit (BER), sacrificando una disminución en la tasa de trasmisión.
Joaquín Cortez González; Ramón René Palacio Cinco; Erica C. Ruíz Ibarra; Adolfo Espinoza; Armando García Berumen. Detection scheme for linear dispersion space-time block codes using modified SQRD decomposition. Nova Scientia 2017, 9, 239 -256.
AMA StyleJoaquín Cortez González, Ramón René Palacio Cinco, Erica C. Ruíz Ibarra, Adolfo Espinoza, Armando García Berumen. Detection scheme for linear dispersion space-time block codes using modified SQRD decomposition. Nova Scientia. 2017; 9 (18):239-256.
Chicago/Turabian StyleJoaquín Cortez González; Ramón René Palacio Cinco; Erica C. Ruíz Ibarra; Adolfo Espinoza; Armando García Berumen. 2017. "Detection scheme for linear dispersion space-time block codes using modified SQRD decomposition." Nova Scientia 9, no. 18: 239-256.
José I. De La Rosa; Jesús Villa-Hernández; Joaquin Cortez; Hamurabi Gamboa; José G. Arceo; Efrén González. On the comparison of different kernel functionals and neighborhood geometry for nonlocal means filtering. Multimedia Tools and Applications 2017, 77, 1205 -1235.
AMA StyleJosé I. De La Rosa, Jesús Villa-Hernández, Joaquin Cortez, Hamurabi Gamboa, José G. Arceo, Efrén González. On the comparison of different kernel functionals and neighborhood geometry for nonlocal means filtering. Multimedia Tools and Applications. 2017; 77 (1):1205-1235.
Chicago/Turabian StyleJosé I. De La Rosa; Jesús Villa-Hernández; Joaquin Cortez; Hamurabi Gamboa; José G. Arceo; Efrén González. 2017. "On the comparison of different kernel functionals and neighborhood geometry for nonlocal means filtering." Multimedia Tools and Applications 77, no. 1: 1205-1235.
Long-memory processes, in particular fractional Gaussian noise processes, have been applied as models for many phenomena occurring in nature. Non-stationarities, such as trends, mean level-shifts, etc., impact the accuracy of long-memory parameter estimators, giving rise to biases and misinterpretations of the phenomena. In this article, a novel methodology for the detection and location of mean level-shifts in stationary long-memory fractional Gaussian noise (fGn) signals is proposed. It is based on a joint application of the wavelet-Tsallis q-entropy as a preprocessing technique and a peak detection methodology. Extensive simulation experiments in synthesized fGn signals with mean level-shifts confirm that the proposed methodology not only detects, but also locates level-shifts with high accuracy. A comparative study against standard techniques of level-shift detection and location shows that the technique based on wavelet-Tsallis q-entropy outperforms the one based on trees and the Bai and Perron procedure, as well.
Julio Cesar Ramírez-Pacheco; Luis Rizo-Domínguez; Joaquin Cortez-Gonzalez. Wavelet-Tsallis Entropy Detection and Location of Mean Level-Shifts in Long-Memory fGn Signals. Entropy 2015, 17, 7979 -7995.
AMA StyleJulio Cesar Ramírez-Pacheco, Luis Rizo-Domínguez, Joaquin Cortez-Gonzalez. Wavelet-Tsallis Entropy Detection and Location of Mean Level-Shifts in Long-Memory fGn Signals. Entropy. 2015; 17 (12):7979-7995.
Chicago/Turabian StyleJulio Cesar Ramírez-Pacheco; Luis Rizo-Domínguez; Joaquin Cortez-Gonzalez. 2015. "Wavelet-Tsallis Entropy Detection and Location of Mean Level-Shifts in Long-Memory fGn Signals." Entropy 17, no. 12: 7979-7995.
STBC-VBLAST MIMO space-time codes combine spatial multiplexing with diversity gain to achieve both high spectral efficiency and link reliability. In this work, we present a new near maximum-likelihood detector based on QRD-M algorithm for DSTTD architecture. We analyze its performance in terms of Bit Error Rate and complexity. We use an uncorrelated MIMO channel model to prove the code performance and decoder complexity. We show that a near maximum likelihood detector based on QRD-M algorithm shows a better performance in terms of complexity without degradation in terms of Bit Error Rate with respect to [11] for DSTTD space-time code. Therefore, we conclude that this scheme is an attractive candidate for hardware implementation.
Joaquin Cortez; Ramon Palacio; Julio Ramírez; Erica Ruiz-Ibarra. A very low complexity near ML detector based on QRD-M algorithm for STBC-VBLAST architecture. 2015 7th IEEE Latin-American Conference on Communications (LATINCOM) 2015, 1 -5.
AMA StyleJoaquin Cortez, Ramon Palacio, Julio Ramírez, Erica Ruiz-Ibarra. A very low complexity near ML detector based on QRD-M algorithm for STBC-VBLAST architecture. 2015 7th IEEE Latin-American Conference on Communications (LATINCOM). 2015; ():1-5.
Chicago/Turabian StyleJoaquin Cortez; Ramon Palacio; Julio Ramírez; Erica Ruiz-Ibarra. 2015. "A very low complexity near ML detector based on QRD-M algorithm for STBC-VBLAST architecture." 2015 7th IEEE Latin-American Conference on Communications (LATINCOM) , no. : 1-5.
The purpose of this study was to evaluate the usability perception of seniors on video game use with different control devices. Twenty-four seniors participated in the study (12 women, 12 men, 69 years old in average) and eight children (8 years old in average). The setting included the use of two Kinect motion sensors, three computers, three projectors, three video cameras, two audio devices, the Angry Birds and Happy Sky videogames, one Xbox 360 console, a Nintendo Wii device and a Touchscreen configured so that participants could play the games in senior–child pairs. Data were collected according to user friendliness, experience and social interaction. This study suggests that video game control devices for seniors should be adapted to compensate for their function, sensor and cognitive limitations.
Ramón R. Palacio; Christian O. Acosta; Joaquin Cortez; Alberto Morán. Usability perception of different video game devices in elderly users. Universal Access in the Information Society 2015, 16, 103 -113.
AMA StyleRamón R. Palacio, Christian O. Acosta, Joaquin Cortez, Alberto Morán. Usability perception of different video game devices in elderly users. Universal Access in the Information Society. 2015; 16 (1):103-113.
Chicago/Turabian StyleRamón R. Palacio; Christian O. Acosta; Joaquin Cortez; Alberto Morán. 2015. "Usability perception of different video game devices in elderly users." Universal Access in the Information Society 16, no. 1: 103-113.
This paper defines the generalized wavelet Fisher information of parameterq. This information measure is obtained by generalizing the time-domain definition of Fisher’s information of Furuichi to the wavelet domain and allows to quantify smoothness and correlation, among other signals characteristics. Closed-form expressions of generalized wavelet Fisher information for1/fαsignals are determined and a detailed discussion of their properties, characteristics and their relationship with waveletq-Fisher information are given. Information planes of1/fsignals Fisher information are obtained and, based on these, potential applications are highlighted. Finally, generalized wavelet Fisher information is applied to the problem of detecting and locating weak structural breaks in stationary1/fsignals, particularly for fractional Gaussian noise series. It is shown that by using a joint Fisher/F-Statistic procedure, significant improvements in time and accuracy are achieved in comparison with the sole application of theF-statistic.
Julio Ramírez-Pacheco; Homero Toral-Cruz; Luis Rizo-Domínguez; Joaquin Cortez; Ramí Julio Rez-Pacheco; Rizo- Domí Luis Nguez. Generalized Wavelet Fisher’s Information of1/fαSignals. Advances in Mathematical Physics 2015, 2015, 1 -9.
AMA StyleJulio Ramírez-Pacheco, Homero Toral-Cruz, Luis Rizo-Domínguez, Joaquin Cortez, Ramí, Julio Rez-Pacheco, Rizo- Domí, Luis Nguez. Generalized Wavelet Fisher’s Information of1/fαSignals. Advances in Mathematical Physics. 2015; 2015 ():1-9.
Chicago/Turabian StyleJulio Ramírez-Pacheco; Homero Toral-Cruz; Luis Rizo-Domínguez; Joaquin Cortez; Ramí Julio Rez-Pacheco; Rizo- Domí Luis Nguez. 2015. "Generalized Wavelet Fisher’s Information of1/fαSignals." Advances in Mathematical Physics 2015, no. : 1-9.
Division is an operation extensively used in architectures for digital signal processing algorithms, which in portable devices require an implementation using fixed-point format. In this paper, a novel fixed-point divider is proposed. The divider architecture is based on a division algorithm that uses the reciprocal operation and a post-multiplication. In turn, reciprocal operation is based on the Newton-Raphson algorithm, where the seed is provided through piecewise polynomial approximation. Reciprocal operation is performed with only two clocks cycles and division operation requires only three clock cycles. A comparison between the proposed architecture and dividers based on coordinate rotation digital computer, shows that the proposed architecture achieves approximately 5-fold gain in execution time for applications in 50-100 MHz frequency range and higher signal-to-quantization-noise ratio.
A. Rodríguez-García; L. Pizano-Escalante; R. Parra-Michel; O. Longoria-Gandara; Joaquin Cortez. Fast fixed-point divider based on Newton-Raphson method and piecewise polynomial approximation. 2013 International Conference on Reconfigurable Computing and FPGAs (ReConFig) 2013, 1 -6.
AMA StyleA. Rodríguez-García, L. Pizano-Escalante, R. Parra-Michel, O. Longoria-Gandara, Joaquin Cortez. Fast fixed-point divider based on Newton-Raphson method and piecewise polynomial approximation. 2013 International Conference on Reconfigurable Computing and FPGAs (ReConFig). 2013; ():1-6.
Chicago/Turabian StyleA. Rodríguez-García; L. Pizano-Escalante; R. Parra-Michel; O. Longoria-Gandara; Joaquin Cortez. 2013. "Fast fixed-point divider based on Newton-Raphson method and piecewise polynomial approximation." 2013 International Conference on Reconfigurable Computing and FPGAs (ReConFig) , no. : 1-6.
Hybrid MIMO systems are defined as a combination of architectures designed to achieve both multiplexing gain (such as VBLAST), and diversity gain, (such as STBC). In these systems the detection can be performed with an ordered successive interference cancellation (OSIC) based on SQRD algorithm, in which the layers with diversity are decoded first. In this paper we introduce a new way to represent hybrid systems, in which the detection process is carried out in a unified manner for both spatial and diversity transmitted symbols, using an OSIC algorithm, but symbol by symbol, just as single VBLAST systems performs. We show that within this approach, linear dispersion (LD) coding has been actually generated, that allows the use of LD theory to determine the performance achieved by the hybrid system. Therefore a bridge between hybrid systems and LD codes has been established.
O. Longoria-Gandara; A. Sanchez-Hernandez; Joaquin Cortez; Miguel Bazdresch; R. Parra-Michel. Linear Dispersion Codes Generation from Hybrid STBC-VBLAST Architectures. 2007 4th International Conference on Electrical and Electronics Engineering 2007, 142 -145.
AMA StyleO. Longoria-Gandara, A. Sanchez-Hernandez, Joaquin Cortez, Miguel Bazdresch, R. Parra-Michel. Linear Dispersion Codes Generation from Hybrid STBC-VBLAST Architectures. 2007 4th International Conference on Electrical and Electronics Engineering. 2007; ():142-145.
Chicago/Turabian StyleO. Longoria-Gandara; A. Sanchez-Hernandez; Joaquin Cortez; Miguel Bazdresch; R. Parra-Michel. 2007. "Linear Dispersion Codes Generation from Hybrid STBC-VBLAST Architectures." 2007 4th International Conference on Electrical and Electronics Engineering , no. : 142-145.