This page has only limited features, please log in for full access.
Methods to implement communication in natural and humanmade disasters have been widely discussed in the scientific community. Scientists believe that unmanned aerial vehicles (UAVs) relays will play a critical role in 5G public safety communications (PSC) due to their technical superiority. They have several significant advantages: a high degree of mobility, flexibility, exceptional line of sight, and real-time adaptative planning. For instance, cell edge coverage could be extended using relay UAVs. This paper summarizes the sidelink evolution in the 3GPP standardization associated with the usage of the device to device (D2D) techniques that use long term evolution (LTE) communication systems, potential extensions for 5G, and a study on the impact of circular mobility on relay UAVs using the software network simulator 3 (NS3). In this simulation, the transmitted packet percentage was evaluated where the speed of the UAV for users was changed. This paper also examines the multi-input multi-output (MIMO) communication applied to drones and proposes a new trajectory to assist users experiencing unfortunate circumstances. The overall communication is highly dependent on the drone speed and the use of MIMO and suitable antennas may influence overall transmission between users and the UAVs relay. When the UAVs relaying speed was configured at 108 km/h the total transmission rate was reduced to 55% in the group with 6 users allocated to each drone.
Joseanne Viana; Francisco Cercas; Américo Correia; Rui Dinis; Pedro Sebastião. MIMO Relaying UAVs Operating in Public Safety Scenarios. Drones 2021, 5, 32 .
AMA StyleJoseanne Viana, Francisco Cercas, Américo Correia, Rui Dinis, Pedro Sebastião. MIMO Relaying UAVs Operating in Public Safety Scenarios. Drones. 2021; 5 (2):32.
Chicago/Turabian StyleJoseanne Viana; Francisco Cercas; Américo Correia; Rui Dinis; Pedro Sebastião. 2021. "MIMO Relaying UAVs Operating in Public Safety Scenarios." Drones 5, no. 2: 32.
The demand for ubiquitous telecommunications services forces operators to have a special concern about signal quality and the coverage area they offer to their customers. This was usually checked by using suitable propagation models for Single Input Single Output (SISO) systems, which are no longer the case for new and future mobile generations, such as 5G and beyond. To guarantee good signal quality coverage, operators started to replace these models with Multiple Input Multiple Output (MIMO) ones. To achieve the best results, these models are usually calibrated with Drive Test (DT) measures; however, the DTs available for MIMO propagation models are sparse, in contrast to SISO ones. The main contribution presented in this paper is a methodology to extend the propagation models of SISO systems so they can be applied in MIMO sytems with Single-Carrier and Frequency-Domain Equalization (SC-FDE), while still using DTs acquired for SISO systems. This paper presents the impact on Bit Error Rate (BER) performance and its coverage area resulting from the application of our proposed method. We consider a MIMO SC-FDE system with an Iterative Block Decision Feedback Equalization (IB-DFE) receiver and we present the improvement expressions for the BER that we illustrate with some simulations.
Daniel Fernandes; Francisco Cercas; Rui Dinis; Pedro Sebastião. Estimating the Performance of MIMO SC-FDE Systems Using SISO Measurements. Applied Sciences 2020, 10, 7492 .
AMA StyleDaniel Fernandes, Francisco Cercas, Rui Dinis, Pedro Sebastião. Estimating the Performance of MIMO SC-FDE Systems Using SISO Measurements. Applied Sciences. 2020; 10 (21):7492.
Chicago/Turabian StyleDaniel Fernandes; Francisco Cercas; Rui Dinis; Pedro Sebastião. 2020. "Estimating the Performance of MIMO SC-FDE Systems Using SISO Measurements." Applied Sciences 10, no. 21: 7492.
To help telecommunication operators in their network planning, namely coverage estimation and optimisation tasks, this paper presents a comparison between a semi-empirical propagation model and a propagation model generated using Artificial Intelligence (AI). These two types of propagation models are quite different in their design. The semi-empiric Automatically Calibrated Standard Propagation Model (ACSPM) is specific for an operating antenna, being calibrated every time a use case application is used and the Artificial Intelligence Propagation Model (AIPM) can be applied in different scenarios, once trained, allowing to estimate coverage for a new antenna location, using information from neighboring antennas. These models have quite different features and applicability. The ACSPM should be applied in network optimisation, when using data from the current state of the antennas. The AIPM can be used in the deployment of new antennas, as it uses data from a certain geographical area. For a better comparison of the models studied, extensive Drive Tests (DT) collection campaigns conducted by operators are used, since coverage estimations are more realistic when DTs are considered. Both models are generated using very different methodologies, but their resulting performance is very similar. The AIPM achieves a Mean Absolute Error (MAE) up to 6:1 dB with a standard deviation of 4 dB. When compared to the ACSPM we have an improvement of 0:5 dB, since this only achieves a MAE up to 6:6 dB. AIPM achieves better results and is the characterised for being completely agnostic and definition-free, when compared with known propagation models.
Daniel F. S. Fernandes; Antonio Raimundo; Francisco Cercas; Pedro J. A. Sebastiao; Rui Dinis; Lucio S. Ferreira. Comparison of Artificial Intelligence and Semi-Empirical Methodologies for Estimation of Coverage in Mobile Networks. IEEE Access 2020, 8, 139803 -139812.
AMA StyleDaniel F. S. Fernandes, Antonio Raimundo, Francisco Cercas, Pedro J. A. Sebastiao, Rui Dinis, Lucio S. Ferreira. Comparison of Artificial Intelligence and Semi-Empirical Methodologies for Estimation of Coverage in Mobile Networks. IEEE Access. 2020; 8 (99):139803-139812.
Chicago/Turabian StyleDaniel F. S. Fernandes; Antonio Raimundo; Francisco Cercas; Pedro J. A. Sebastiao; Rui Dinis; Lucio S. Ferreira. 2020. "Comparison of Artificial Intelligence and Semi-Empirical Methodologies for Estimation of Coverage in Mobile Networks." IEEE Access 8, no. 99: 139803-139812.
The exposure to colored light with different wavelengths has proved to affect the physiological functions of the human body. To test such influence, this work was focused on heart rate variability (HRV) analysis associated with different colored light exposure of healthy volunteers. A Photoplethysmography (PPG) wireless sensor network node was employed to acquire information about the cardiac activity, as it proves to be a more convenient and less intrusive method as electrocardiography (ECG). A small group of healthy volunteers were exposed to 10 minutes of blue and red light, preceded and followed by 5 minutes of dark lighting conditions. HRV was acquired during the last 5 minutes of each colored illumination period. The HRV analysis was based on time-domain variables, frequency-domain variables and fractal (nonlinear) analysis. The experimental results from this study show that PPG can be considered as a reliable method to study HRV. The exposure to different colored light conducted to HRV variations that characterize the autonomous nervous system balance. Experimental results obtained for volunteers exposed to different illumination conditions are also included in the paper.
John Araujo; Mariana Jacob Rodrigues; Octavian Postolache; Francisco Cercas; Francisco Ferrero Martin; Alberto Lopez Martinez. Heart Rate Variability Analysis in Healthy Subjects Under Different Colored Lighting Conditions. 2020 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) 2020, 1 -5.
AMA StyleJohn Araujo, Mariana Jacob Rodrigues, Octavian Postolache, Francisco Cercas, Francisco Ferrero Martin, Alberto Lopez Martinez. Heart Rate Variability Analysis in Healthy Subjects Under Different Colored Lighting Conditions. 2020 IEEE International Instrumentation and Measurement Technology Conference (I2MTC). 2020; ():1-5.
Chicago/Turabian StyleJohn Araujo; Mariana Jacob Rodrigues; Octavian Postolache; Francisco Cercas; Francisco Ferrero Martin; Alberto Lopez Martinez. 2020. "Heart Rate Variability Analysis in Healthy Subjects Under Different Colored Lighting Conditions." 2020 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) , no. : 1-5.
Healthcare optimization has become increasingly important in the current era, where numerous challenges are posed by population ageing phenomena and the demand for higher quality of the healthcare services. The implementation of Internet of Things (IoT) in the healthcare ecosystem has been one of the best solutions to address these challenges and therefore to prevent and diagnose possible health impairments in people. The remote monitoring of environmental parameters and how they can cause or mediate any disease, and the monitoring of human daily activities and physiological parameters are among the vast applications of IoT in healthcare, which has brought extensive attention of academia and industry. Assisted and smart tailored environments are possible with the implementation of such technologies that bring personal healthcare to any individual, while living in their preferred environments. In this paper we address several requirements for the development of such environments, namely the deployment of physiological signs monitoring systems, daily activity recognition techniques, as well as indoor air quality monitoring solutions. The machine learning methods that are most used in the literature for activity recognition and body motion analysis are also referred. Furthermore, the importance of physical and cognitive training of the elderly population through the implementation of exergames and immersive environments is also addressed.
Mariana Jacob Rodrigues; Octavian Postolache; Francisco Cercas. Physiological and Behavior Monitoring Systems for Smart Healthcare Environments: A Review. Sensors 2020, 20, 2186 .
AMA StyleMariana Jacob Rodrigues, Octavian Postolache, Francisco Cercas. Physiological and Behavior Monitoring Systems for Smart Healthcare Environments: A Review. Sensors. 2020; 20 (8):2186.
Chicago/Turabian StyleMariana Jacob Rodrigues; Octavian Postolache; Francisco Cercas. 2020. "Physiological and Behavior Monitoring Systems for Smart Healthcare Environments: A Review." Sensors 20, no. 8: 2186.
One of the main concerns of telecommunications operators is related to network coverage. A weak coverage can lead to a performance decrease, not only in the user experience, when using the operators’ services, such as multimedia streaming, but also in the overall Quality of Service. This paper presents a novel cloud-based framework of a semi-empirical propagation model that estimates the coverage in a precise way. The novelty of this model is that it is automatically calibrated by using drive test measurements, terrain morphology, buildings in the area, configurations of the network itself and key performance indicators, automatically extracted from the operator’s network. Requirements and use cases are presented as motivations for this methodology. The results achieve an accuracy of about 5 dB, allowing operators to obtain accurate neighbour lists, optimise network planning and automate certain actions on the network by enabling the Self-Organising Network concept. The cloud implementation enables a fast and easy integration with other network management and monitoring tools, such as the METRIC platform, optimising operators’ resource usage recurring to elastic resources on-demand when needed. This implementation was integrated into the METRIC platform, which is currently available to be used by several operators.
Daniel Fernandes; Diogo Clemente; Gabriela Soares; Pedro Sebastiao; Francisco Cercas; Rui Dinis; Lucio S. Ferreira. Cloud-Based Implementation of an Automatic Coverage Estimation Methodology for Self-Organising Network. IEEE Access 2020, 8, 66456 -66474.
AMA StyleDaniel Fernandes, Diogo Clemente, Gabriela Soares, Pedro Sebastiao, Francisco Cercas, Rui Dinis, Lucio S. Ferreira. Cloud-Based Implementation of an Automatic Coverage Estimation Methodology for Self-Organising Network. IEEE Access. 2020; 8 (99):66456-66474.
Chicago/Turabian StyleDaniel Fernandes; Diogo Clemente; Gabriela Soares; Pedro Sebastiao; Francisco Cercas; Rui Dinis; Lucio S. Ferreira. 2020. "Cloud-Based Implementation of an Automatic Coverage Estimation Methodology for Self-Organising Network." IEEE Access 8, no. 99: 66456-66474.
In the Fifth Generation of telecommunications networks (5G), it is possible to use massive Multiple Input Multiple Output (MIMO) systems, which require efficient receivers capable of reaching good performance values. MIMO systems can also be extended to massive MIMO (mMIMO) systems, while maintaining their, sometimes exceptional, performance. However, we must be aware that this implies an increase in the receiver complexity. Therefore, the use of mMIMO in 5G and future generations of mobile receivers will only be feasible if they use very efficient algorithms, so as to maintain their excellent performance, while coping with increasing and critical user demands. Having this in mind, this paper presents and compares three types of receivers used in MIMO systems, for further use with mMIMO systems, which use Single-Carrier with Frequency-Domain Equalization (SC-FDE), Iterative Block Decision Feedback Equalization (IB-DFE) and Maximum Ratio Combining (MRC) techniques. This paper presents and compares the theoretical and simulated performance values for these receivers in terms of their Bit Error Rate (BER) and correlation factor. While one of the receivers studied in this paper achieves a BER performance nearly matching the Matched Filter Bound (MFB), the other receivers (IB-DFE and MRC) are more than 1 dB away from MFB. The results obtained in this paper can help the development of ongoing research involving hybrid analog/digital receivers for 5G and future generations of mobile communications.
Daniel Fernandes; Francisco Cercas; Rui Dinis. Analytical Performance Evaluation of Massive MIMO Techniques for SC-FDE Modulations. Electronics 2020, 9, 533 .
AMA StyleDaniel Fernandes, Francisco Cercas, Rui Dinis. Analytical Performance Evaluation of Massive MIMO Techniques for SC-FDE Modulations. Electronics. 2020; 9 (3):533.
Chicago/Turabian StyleDaniel Fernandes; Francisco Cercas; Rui Dinis. 2020. "Analytical Performance Evaluation of Massive MIMO Techniques for SC-FDE Modulations." Electronics 9, no. 3: 533.
The quality of service offered to customers is a concern of telecommunications providers. With this concern, the providers keep a constant monitorization on their networks so that they can immediately fix any network problems. This paper presents the cloud implementation of a propagation model calibrated with real data that allows telecommunications providers to properly plan and optimize the network. This implementation is to be added into a Self-Organizing Network tool called Metric.
Daniel Fernandes; Gabriela Soares; Diogo Clemente; Rodrigo Cortesao; Pedro Sebastiao; Francisco Cercas; Rui Dinis; Lucio Studer Ferreira. Integration of a Cloud-Based Realistic and Automatic Coverage Estimation Methodology in Metric SaaS. 2019 22nd International Symposium on Wireless Personal Multimedia Communications (WPMC) 2019, 1 -4.
AMA StyleDaniel Fernandes, Gabriela Soares, Diogo Clemente, Rodrigo Cortesao, Pedro Sebastiao, Francisco Cercas, Rui Dinis, Lucio Studer Ferreira. Integration of a Cloud-Based Realistic and Automatic Coverage Estimation Methodology in Metric SaaS. 2019 22nd International Symposium on Wireless Personal Multimedia Communications (WPMC). 2019; ():1-4.
Chicago/Turabian StyleDaniel Fernandes; Gabriela Soares; Diogo Clemente; Rodrigo Cortesao; Pedro Sebastiao; Francisco Cercas; Rui Dinis; Lucio Studer Ferreira. 2019. "Integration of a Cloud-Based Realistic and Automatic Coverage Estimation Methodology in Metric SaaS." 2019 22nd International Symposium on Wireless Personal Multimedia Communications (WPMC) , no. : 1-4.
This article presents a wireless sensor network capable to acquire and analyze indoor environmental quality (IEQ) parameters and improving such indoor conditions using actuator nodes. An additional WSN end node capable associated with user's physiological parameters monitoring in indoor conditions as part of ambient assisted living for elderly people is considered. The user's cardiac activity is sensed in an unobtrusive way and the acquired and primary processed data is displayed in real time by a developed web application. As a measurement channel associated with cardiac assessment, a Photoplethysmography (PPG) sensor is embedded in a daily used office chair. The proposed system also served to study the influence of indoor environment changes obtained through a set of distributed actuators on the user's cardiac activity. Preliminary experimental results are included in the paper.
Mariana Jacob Rodrigues; Octavian Postolache; Francisco Cercas. Wireless Sensor Network for Cardiac Activity Monitoring. 2019 E-Health and Bioengineering Conference (EHB) 2019, 1 -4.
AMA StyleMariana Jacob Rodrigues, Octavian Postolache, Francisco Cercas. Wireless Sensor Network for Cardiac Activity Monitoring. 2019 E-Health and Bioengineering Conference (EHB). 2019; ():1-4.
Chicago/Turabian StyleMariana Jacob Rodrigues; Octavian Postolache; Francisco Cercas. 2019. "Wireless Sensor Network for Cardiac Activity Monitoring." 2019 E-Health and Bioengineering Conference (EHB) , no. : 1-4.
In radio access network planning and optimisation, the estimation and evaluation of cell coverage is crucial. For it, operators use several methodologies, ranging from theoretical propagation models for planning cell coverage, to drive test measurements for evaluating the performance within a cell. A novel propagation model is proposed which combines drive test measurements, cell reach statistics, antenna radiation patterns, terrain morphologies, and classical theoretical propagation models. Considering a realistic scenario of an LTE cell, the use of a classical propagation model such as Walfish- Ikegami results in an average error of -27 dB of estimations with respect to measurements, evidencing a pessimistic estimation of signal. By opposition, the proposed model fits with DT measurements.
Daniel Fernandes; Gabriela Eleuterio Soares; Diogo Clemente; Rodrigo Cortesao; Pedro Sebastiao; Francisco Cercas; Rui Dinis; Lucio Studer Ferreira. Combining Measurements and Propagation Models for Estimation of Coverage in Wireless Networks. 2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall) 2019, 1 -5.
AMA StyleDaniel Fernandes, Gabriela Eleuterio Soares, Diogo Clemente, Rodrigo Cortesao, Pedro Sebastiao, Francisco Cercas, Rui Dinis, Lucio Studer Ferreira. Combining Measurements and Propagation Models for Estimation of Coverage in Wireless Networks. 2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall). 2019; ():1-5.
Chicago/Turabian StyleDaniel Fernandes; Gabriela Eleuterio Soares; Diogo Clemente; Rodrigo Cortesao; Pedro Sebastiao; Francisco Cercas; Rui Dinis; Lucio Studer Ferreira. 2019. "Combining Measurements and Propagation Models for Estimation of Coverage in Wireless Networks." 2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall) , no. : 1-5.
In this paper, an indoor air quality monitoring system based on a wireless sensor network (WSN) and compatible with the internet of things (IoT) is presented. By providing relevant information about indoor air conditions, the system may help to prevent the triggering of respiratory distresses, such as an asthma crisis, by highlighting critical air quality conditions. The sensor network contains several sensing nodes with temperature, humidity, gas and particulate matter sensors, and a set of actuators that will help improve indoor's thermal comfort and lighting quality. A Web-based application was developed to provide data analysis, system control and alert mechanisms for asthma attacks prevention. A smart lighting system was implemented to generate visual alert mechanisms and improve indoor's lighting comfort.
Mariana Jacob Rodrigues; Octavian Postolache; Francisco Cercas. Indoor Air Quality Monitoring System to Prevent the Triggering of Respiratory Distress. 2019 International Conference on Sensing and Instrumentation in IoT Era (ISSI) 2019, 1 -6.
AMA StyleMariana Jacob Rodrigues, Octavian Postolache, Francisco Cercas. Indoor Air Quality Monitoring System to Prevent the Triggering of Respiratory Distress. 2019 International Conference on Sensing and Instrumentation in IoT Era (ISSI). 2019; ():1-6.
Chicago/Turabian StyleMariana Jacob Rodrigues; Octavian Postolache; Francisco Cercas. 2019. "Indoor Air Quality Monitoring System to Prevent the Triggering of Respiratory Distress." 2019 International Conference on Sensing and Instrumentation in IoT Era (ISSI) , no. : 1-6.
Non-orthogonal multiple access (NOMA) schemes have been recognized as a promising multiple access method for the fifth generation (5G) communication systems. In NOMA, multiple users can share the same physical channel, which allows for a substantial increase in capacity gains when comparing to conventional orthogonal multiple access (OMA) techniques. This paper considers the downlink transmission of NOMA schemes combined with single-carrier (SC) signals. We present a multi-antenna transmission technique that is compatible with highly efficient power amplifiers without requiring any pre-processing. Furthermore, a multi-user detection scheme based on iterative frequency-domain equalization (FDE) is presented. We show that besides the high power-efficiency of the transmission scheme, the system’s performance can be close to the matched filter bound (MFB).
Filipe Casal Ribeiro; João Guerreiro; Rui Dinis; Francisco Cercas; Dushantha Nalin K. Jayakody. Multi-user detection for the downlink of NOMA systems with multi-antenna schemes and power-efficient amplifiers. Physical Communication 2019, 33, 199 -205.
AMA StyleFilipe Casal Ribeiro, João Guerreiro, Rui Dinis, Francisco Cercas, Dushantha Nalin K. Jayakody. Multi-user detection for the downlink of NOMA systems with multi-antenna schemes and power-efficient amplifiers. Physical Communication. 2019; 33 ():199-205.
Chicago/Turabian StyleFilipe Casal Ribeiro; João Guerreiro; Rui Dinis; Francisco Cercas; Dushantha Nalin K. Jayakody. 2019. "Multi-user detection for the downlink of NOMA systems with multi-antenna schemes and power-efficient amplifiers." Physical Communication 33, no. : 199-205.
Supporting spontaneous low-latency machine-type communications requires fast synchronization and channel estimation at the receiver. The problems of synchronizing the received frame and estimating the channel coefficients are often addressed separately with the later one relying on accurate timing acquisition. While these conventional approaches can be adequate in flat fading environments, time dispersive channels can have a negative impact on both tasks and severely degrade the performance of the receiver. To circumvent this large degradation, in this paper, we consider the use of a sparse-based reconstruction approach for joint timing synchronization and channel estimation by formulating the problem in a form that is closely related to compressive sensing framework. Using modified versions of well-known sparse reconstruction techniques, which can take into account the additional signal structure in addition to sparsity, it is shown through numerical simulations that, even with short training sequences, excellent timing synchronization and channel estimation performance can be achieved, both in single user and multiuser scenarios.
Bruno Lopes; Silvia Catarino; Nuno M. B. Souto; Rui Dinis; Francisco Cercas. Robust Joint Synchronization and Channel Estimation Approach for Frequency-Selective Environments. IEEE Access 2018, 6, 53180 -53190.
AMA StyleBruno Lopes, Silvia Catarino, Nuno M. B. Souto, Rui Dinis, Francisco Cercas. Robust Joint Synchronization and Channel Estimation Approach for Frequency-Selective Environments. IEEE Access. 2018; 6 ():53180-53190.
Chicago/Turabian StyleBruno Lopes; Silvia Catarino; Nuno M. B. Souto; Rui Dinis; Francisco Cercas. 2018. "Robust Joint Synchronization and Channel Estimation Approach for Frequency-Selective Environments." IEEE Access 6, no. : 53180-53190.
The constant need of operators to ensure a high quality of service requires an adequate estimation of signal level in the service area. Drive Tests (DTs) are used to monitor signal level. Still this is an expensive task, not being able to cover all areas. A methodology to build complete path loss grids for a given site is proposed. Starting from available DTs measurements for certain pixels, path loss is estimated for the remaining ones by tuning a propagation model and extrapolating the path loss for neighboring pixels. This allows to provide a complete path loss estimation for the desired area around the cell.
Daniel Fernandes; Lucio Studer Ferreira; Mohammad Nozari; Pedro Sebastiao; Francisco Cercas; Rui Dinis. Combining Drive Tests and Automatically Tuned Propagation Models in the Construction of Path Loss Grids. 2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) 2018, 1 -2.
AMA StyleDaniel Fernandes, Lucio Studer Ferreira, Mohammad Nozari, Pedro Sebastiao, Francisco Cercas, Rui Dinis. Combining Drive Tests and Automatically Tuned Propagation Models in the Construction of Path Loss Grids. 2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC). 2018; ():1-2.
Chicago/Turabian StyleDaniel Fernandes; Lucio Studer Ferreira; Mohammad Nozari; Pedro Sebastiao; Francisco Cercas; Rui Dinis. 2018. "Combining Drive Tests and Automatically Tuned Propagation Models in the Construction of Path Loss Grids." 2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) , no. : 1-2.
This paper considers a Multiple-Input Multiple-Output (MIMO) system with P transmitting and R receiving antennas and different overall noise characteristics on the different receiver antennas (e.g., due to nonlinear effects at the receiver side). Each communication link employs a Single-Carrier with Frequency-Domain Equalization (SC-FDE) modulation scheme, and the receiver is based on robust iterative frequency-domain multi-user detectors based on the Iterative Block Decision Feedback Equalization (IB-DFE) concept. We present low complexity efficient receivers that can employ low resolution Analog-to-Digital Converters (ADCs) and require the inversion of matrices with reduced dimension when the number of receive antennas is larger than the number of independent data streams. The advantages of the proposed techniques are particularly high for highly unbalanced MIMO systems, such as in the uplink of Base Station (BS) cooperation systems that aim for Single-Frequency Network (SFN) operation or massive MIMO systems with much more antennas at the receiver side.
Filipe Casal Ribeiro; João Guerreiro; Rui Dinis; Francisco Cercas; Adao Silva. Reduced Complexity Detection in MIMO Systems with SC-FDE Modulations and Iterative DFE Receivers. Journal of Sensor and Actuator Networks 2018, 7, 17 .
AMA StyleFilipe Casal Ribeiro, João Guerreiro, Rui Dinis, Francisco Cercas, Adao Silva. Reduced Complexity Detection in MIMO Systems with SC-FDE Modulations and Iterative DFE Receivers. Journal of Sensor and Actuator Networks. 2018; 7 (2):17.
Chicago/Turabian StyleFilipe Casal Ribeiro; João Guerreiro; Rui Dinis; Francisco Cercas; Adao Silva. 2018. "Reduced Complexity Detection in MIMO Systems with SC-FDE Modulations and Iterative DFE Receivers." Journal of Sensor and Actuator Networks 7, no. 2: 17.
In this paper we consider the uplink of Base Station (BS cooperation) systems, where each Mobile Terminal (MT) employs a Single-Carrier with Frequency-Domain Equalization (SC-FDE) modulation scheme. The combined signals at each BS are detected and/or separated by a Central Processing Unit (CPU) with Iterative Block Decision Feedback Equalization (IB-DFE) receivers. We consider a Radio-over-Fiber (RoF) link between the BS and the CPU, the electrical and optical conversions are performed by a Mach-Zehnder (MZ) modulator, which introduces nonlinear distortion. We design robust receivers that take advantage of the statistical characteristics of the nonlinear distortion.
F. Casal Ribeiro; J. Guerreiro; Rui Dinis; F. Cercas; A. Silva; Armando N. Pinto. Nonlinear Effects of Radio over Fiber Transmission in Base Station Cooperation Systems. 2017 IEEE Globecom Workshops (GC Wkshps) 2017, 1 -6.
AMA StyleF. Casal Ribeiro, J. Guerreiro, Rui Dinis, F. Cercas, A. Silva, Armando N. Pinto. Nonlinear Effects of Radio over Fiber Transmission in Base Station Cooperation Systems. 2017 IEEE Globecom Workshops (GC Wkshps). 2017; ():1-6.
Chicago/Turabian StyleF. Casal Ribeiro; J. Guerreiro; Rui Dinis; F. Cercas; A. Silva; Armando N. Pinto. 2017. "Nonlinear Effects of Radio over Fiber Transmission in Base Station Cooperation Systems." 2017 IEEE Globecom Workshops (GC Wkshps) , no. : 1-6.
In this paper, we consider the use of TCH codes to perform channel estimation in an OFDM system, using either data multiplexed pilots or superimposed pilots over the data. TCH codes possess several properties that allow us to use them efficiently in various applications which includes channel estimation, as we address in this paper. With this objective, several performance results were obtained through simulations which allowed the evaluation of the impact of different pilot power levels and modulations, as well as the comparison of TCH against other conventional pilots. In order to cope with the interference between pilots and data, an iterative receiver with interference suppression was employed for the superimposed pilots method.
Bruno Lopes; Silvia Catarino; Francisco Cercas; Nuno Souto; Rui Dinis. Efficient channel estimation using TCH codes. 2017 9th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT) 2017, 117 -122.
AMA StyleBruno Lopes, Silvia Catarino, Francisco Cercas, Nuno Souto, Rui Dinis. Efficient channel estimation using TCH codes. 2017 9th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT). 2017; ():117-122.
Chicago/Turabian StyleBruno Lopes; Silvia Catarino; Francisco Cercas; Nuno Souto; Rui Dinis. 2017. "Efficient channel estimation using TCH codes." 2017 9th International Congress on Ultra Modern Telecommunications and Control Systems and Workshops (ICUMT) , no. : 117-122.
Lorenzo Cabral; Daniel Fernandes; Francisco Cercas; Rui Dinis. Efficient frequency-domain detection for massive MIMO systems. 2017 South Eastern European Design Automation, Computer Engineering, Computer Networks and Social Media Conference (SEEDA-CECNSM) 2017, 1 -5.
AMA StyleLorenzo Cabral, Daniel Fernandes, Francisco Cercas, Rui Dinis. Efficient frequency-domain detection for massive MIMO systems. 2017 South Eastern European Design Automation, Computer Engineering, Computer Networks and Social Media Conference (SEEDA-CECNSM). 2017; ():1-5.
Chicago/Turabian StyleLorenzo Cabral; Daniel Fernandes; Francisco Cercas; Rui Dinis. 2017. "Efficient frequency-domain detection for massive MIMO systems." 2017 South Eastern European Design Automation, Computer Engineering, Computer Networks and Social Media Conference (SEEDA-CECNSM) , no. : 1-5.
Andre Gloria; Francisco Cercas; Nuno Souto. Comparison of communication protocols for low cost Internet of Things devices. 2017 South Eastern European Design Automation, Computer Engineering, Computer Networks and Social Media Conference (SEEDA-CECNSM) 2017, 1 .
AMA StyleAndre Gloria, Francisco Cercas, Nuno Souto. Comparison of communication protocols for low cost Internet of Things devices. 2017 South Eastern European Design Automation, Computer Engineering, Computer Networks and Social Media Conference (SEEDA-CECNSM). 2017; ():1.
Chicago/Turabian StyleAndre Gloria; Francisco Cercas; Nuno Souto. 2017. "Comparison of communication protocols for low cost Internet of Things devices." 2017 South Eastern European Design Automation, Computer Engineering, Computer Networks and Social Media Conference (SEEDA-CECNSM) , no. : 1.
Filipe Casal Ribeiro; R. Dinis; F. Cercas; Adao Silva. Multiuser detection for the uplink of clustered 5G systems with universal frequency reuse. Physical Communication 2017, 23, 29 -36.
AMA StyleFilipe Casal Ribeiro, R. Dinis, F. Cercas, Adao Silva. Multiuser detection for the uplink of clustered 5G systems with universal frequency reuse. Physical Communication. 2017; 23 ():29-36.
Chicago/Turabian StyleFilipe Casal Ribeiro; R. Dinis; F. Cercas; Adao Silva. 2017. "Multiuser detection for the uplink of clustered 5G systems with universal frequency reuse." Physical Communication 23, no. : 29-36.