Emanuel Dogaru | Blabla - Academia.edu (original) (raw)

Papers by Emanuel Dogaru

Proceedings of the 8th International Conference on Informatics in Control, Automation and Robotics, 2011

This paper presents the application of several advanced control techniques to a nonlinear strongl... more This paper presents the application of several advanced control techniques to a nonlinear strongly coupled multivariable robot. The main difficulties come from the flexibility of the mechanical chain, but also from the lack of joints sensors. In a first stage, a state-feedback linear quadratic (LQG) technique and a model predictive control (MPC) are designed using optimal observers. Considering additional sensors that provide measurements of accelerations increases the robustness of the controlled system. The second stage consists into adding a supplementary robustness layer (i.e. explicitly considering the robust stability under unstructured uncertainties) on the stabilizing MPC developed at the previous stage. Comparative results are proposed highlighting the trade-off between robust stability and nominal performance for disturbances rejection.

The advent of increasingly powerful Integrated Circuits (IC) has led to the emergence of the Soft... more The advent of increasingly powerful Integrated Circuits (IC) has led to the emergence of the Software Defined Radio (SDR) concept, which brought the sector of secured mobile communications into a new era. The outstanding performance of these systems results from optimal trade-offs among advanced analog/Radio Frequency (RF) circuitry, high-speed reconfigurable digital hardware and sophisticated real-time software. The inherent sophistication of such platforms poses a challenging problem for product testing. Currently deployed industrial test strategies face rising obstacles due to the costlier RF test equipment, longer test time and lack of flexibility. Moreover, an SDR platform is field-upgradeable, which means it will support standards and scenarii not considered during the design phase. Therefore, an in-field test strategy is not anymore 'a nice to have' feature but a mandatory requirement. In this context, our research aims to invent and develop a new test methodology abl...

2013 Military Communications and Information Systems Conference, 2013

Software defined radios (SDR) platforms are increasingly complex systems which combine great flex... more Software defined radios (SDR) platforms are increasingly complex systems which combine great flexibility and high performance. These two characteristics, together with highly integrated architectures make production test a challenging task. In this paper, we introduce an Radio Frequency (RF) Built-in Self-Test (BIST) strategy based on Periodically Nonuniform Sampling of the signal at the output stages of multistandard radios. We leverage the I/Q ADC channels and the DSP resources to extract the bandpass waveform at the output of the power amplifier (PA). Analytical expressions and simulations show that our time-interleaved conversion scheme is sensitive to time-skew. We show a time-skew estimation technique that allows us to surmount this obstacle. Simulation results show that we can effectively reconstruct the bandpass signal of the output stage using this architecture, opening the way for a complete RF BIST strategy for multistandard radios. Future developments will be focused on ...

2018 IEEE International Symposium on Circuits and Systems (ISCAS), 2018

Software defined radios are a key enabling technology for Cognitive Radio Systems. However, produ... more Software defined radios are a key enabling technology for Cognitive Radio Systems. However, production testing of software defined radios remains a difficult and costly endeavor. This paper introduces a new implementation of a loopback Built-in Self-Test (BIST) strategy using periodically non-uniform sampling of second order for RF loopback test of flexible transceivers, by means of charge-domain sampling. The novel architecture is compared to voltage-based sampling architectures, and simulation results demonstrate that our charge-based sampling approach performs better and is more tolerant of clock jitter. Our proposal can also be advantageously applied in transmitter architectures that use pre-distortion compensation to improve power amplifier linearity, provided that the main receiver baseband channel is available (idle).

2013 IEEE International Symposium on Defect and Fault Tolerance in VLSI and Nanotechnology Systems (DFTS), 2013

Software defined radios (SDR) platforms are increasingly complex systems which combine great flex... more Software defined radios (SDR) platforms are increasingly complex systems which combine great flexibility and high performance. These two characteristics, together with highly integrated architectures make production test a challenging task. In this paper, we introduce a Radio Frequency (RF) Builtin Self-Test (BIST) strategy based on Periodically Nonuniform Sampling of the signal at the output stages of multistandard radios. We leverage the I/Q ADC channels and the DSP resources to extract the bandpass waveform at the output of the power amplifier (PA). Analytical expressions and simulations show that our time-interleaved conversion scheme is sensitive to time-skew. We propose a time-skew estimation technique based on a Least Mean Squares (LMS) algorithm to solve this problem. Simulation results show that we can effectively reconstruct the bandpass signal of the output stage using this architecture, opening the way for a complete RF BIST strategy for multistandard radios.

Design, Automation & Test in Europe Conference & Exhibition (DATE), 2014, 2014

Software defined radios (SDR) platforms are increasingly complex systems which combine great flex... more Software defined radios (SDR) platforms are increasingly complex systems which combine great flexibility and high performance. These two characteristics, together with highly integrated architectures make production test a challenging task. In this paper, we introduce a Radio Frequency (RF) Builtin Self-Test (BIST) strategy based on Periodically Nonuniform Sampling of the signal at the output stages of multistandard radios. We leverage the I/Q ADC channels and the DSP resources to extract the bandpass waveform at the output of the power amplifier (PA). Analytical expressions and simulations show that our time-interleaved conversion scheme is sensitive to time-skew. We propose a time-skew estimation technique based on a Least Mean Squares (LMS) algorithm to solve this problem. Simulation results show that we can effectively reconstruct the bandpass signal of the output stage using this architecture, opening the way for a complete RF BIST strategy for multistandard radios.

Proceedings of the 8th International Conference on Informatics in Control, Automation and Robotics, 2011

2013 Military Communications and Information Systems Conference, 2013

2018 IEEE International Symposium on Circuits and Systems (ISCAS), 2018

2013 IEEE International Symposium on Defect and Fault Tolerance in VLSI and Nanotechnology Systems (DFTS), 2013

Software defined radios (SDR) platforms are increasingly complex systems which combine great flex... more Software defined radios (SDR) platforms are increasingly complex systems which combine great flexibility and high performance. These two characteristics, together with highly integrated architectures make production test a challenging task. In this paper, we introduce a Radio Frequency (RF) Builtin Self-Test (BIST) strategy based on Periodically Nonuniform Sampling of the signal at the output stages of multistandard radios. We leverage the I/Q ADC channels and the DSP resources to extract the bandpass waveform at the output of the power amplifier (PA). Analytical expressions and simulations show that our time-interleaved conversion scheme is sensitive to time-skew. We propose a time-skew estimation technique based on a Least Mean Squares (LMS) algorithm to solve this problem. Simulation results show that we can effectively reconstruct the bandpass signal of the output stage using this architecture, opening the way for a complete RF BIST strategy for multistandard radios.

Design, Automation & Test in Europe Conference & Exhibition (DATE), 2014, 2014

Software defined radios (SDR) platforms are increasingly complex systems which combine great flex... more Software defined radios (SDR) platforms are increasingly complex systems which combine great flexibility and high performance. These two characteristics, together with highly integrated architectures make production test a challenging task. In this paper, we introduce a Radio Frequency (RF) Builtin Self-Test (BIST) strategy based on Periodically Nonuniform Sampling of the signal at the output stages of multistandard radios. We leverage the I/Q ADC channels and the DSP resources to extract the bandpass waveform at the output of the power amplifier (PA). Analytical expressions and simulations show that our time-interleaved conversion scheme is sensitive to time-skew. We propose a time-skew estimation technique based on a Least Mean Squares (LMS) algorithm to solve this problem. Simulation results show that we can effectively reconstruct the bandpass signal of the output stage using this architecture, opening the way for a complete RF BIST strategy for multistandard radios.