CentraleSupélec

About: CentraleSupélec is a based out in . It is known for research contribution in the topics: MIMO & Wireless network. The organization has 1330 authors who have published 2344 publications receiving 30533 citations. The organization is also known as: CentraleSupelec & CentraleSupelec of the Paris-Saclay University.

Sub-Terahertz Wireless System Using Dual-Polarized Generalized Spatial Modulation With RF Impairments

Abstract: In this paper, we address a multiple-input multiple-output (MIMO) communication system based on generalized spatial modulation (GSM) and dual-polarized (DP) antennas in sub-TeraHertz (sub-THz) bands to improve the Spectral Efficiency (SE) while reducing the spatial correlation effect and the space occupancy. Moreover, the joint Maximum Likelihood (ML) detector and a Modified Ordered Block Minimum Mean-Squared Error (MOB-MMSE) detector algorithm are proposed to detect jointly the complex symbols and the virtual bits conveyed by the activated polarization and the transmit antenna combination index. MOB-MMSE can achieve near-ML performance with low complexity. The performance of DP-GSM system over correlated Rayleigh/Rician fading and indoor sub-THz channels is studied. Provided results show that DP-GSM system is robust to the spatial correlation effects under Rician fading channel. In addition, an average bit-error probability (ABEP) upper bounding is derived and analyzed for the DP-GSM system over correlated Rayleigh/Rician fading channels. Since the sub-THz band suffers from many technological limitations and severe RF-impairments such as low transmit output power and important phase noise (PN), the DP-GSM system is studied by considering the sub-THz impairments. Moreover, the Dual Polarized Spatial Multiplexing (DP-SMX) and the Uni-Polarized GSM (UP-GSM) are compared with the DP-GSM system. The results reveal that DP-GSM with low order modulation schemes as QPSK outperforms the UP-GSM. Besides, DP-GSM and DP-SMX provide a good performance up to medium PN, which is interesting for sub-THz bands, but DP-GSM can reduce the transceiver cost by using a lower number of RF chains when the used transmitter architecture is based on RF-switching.

Full-Duplex or Half-Duplex D2D Mode? Closed Form Expression of the Optimal Power Allocation

Abstract: In this paper, we investigate and derive a closed-form expression for the power allocation scheme of full duplex (FD) device to device (D2D) communications underlaying wireless cellular network. In this scenario, we consider the FD-D2D pair sharing the uplink resources of cellular users. We first derive a closed-form expression for the ergodic rate of the D2D link. Then we formulate the optimization problem which aims to maximize the D2D link rate while fulfilling the minimum QoS requirement of the cellular user. We further derive a closed-form expression for the optimal power allocation strategy for both D2D and cellular users. The simulation results show the accuracy of the derived power allocation scheme and provide important insights on the separation distance between the D2D users and the interfering cellular user. In addition, the results provide important conditions to switch between FD and half duplex (HD) D2D modes.

Unsupervised Adaptation of a Person-Specific Manifold of Facial Expressions

Abstract: In order to analyze expressions that are different from the prototypic expressions defined by Ekman, manifold learning has been proposed to build person-specific continuous representations of facial expressions. Yet, it is still a challenging problem to build such a manifold with no prior knowledge on the morphology of the subject. Here, we propose a method to build a person-specific manifold of facial expressions able to adapt to the morphology of the subject in an unsupervised manner. The manifold is initialized with the facial landmarks of the neutral face and 5 synthesized basic expressions. Our first contribution is to detect automatically the neutral face of the subject so that we can build the manifold in an unsupervised manner. Our second and main contribution is to adapt in an unsupervised manner the initialized manifold to the morphology of the subject by detecting the real basic expressions of the subject while maintaining constraints in the manifold. Our third contribution is to perform the adaptation on spontaneous expressions with typical head pose variation for human-computer interaction. The experiments show that the adaptation works well on posed expressions and that the constraints for the adaptation on spontaneous expressions is efficient when head pose variation is considered.

Solving minimum dynamic residual expansion and using results for error localization

Abstract: Minimum Dynamic Residual Expansion (MDRE) seeks to estimate the response of test modeshapes at all degrees of freedom of a model by minimizing the weighted sum of a test error defined at sensors and a modeling error takento be the strain energy of the dynamic residual associated with the estimated modeshape. Theoretically the computation of the dynamic residual gives a simple mechanism to localize modeling errors. While various forms of MDRE have been often considered in the literature, few systematic analyses of the exact resolution have been attempted on industrial models in good part because of excessive computational costs. The present paper introduces an iterative method allowing the exact solution of MDRE for large problems. Exact solutions, either direct or iterative, are compared with reduced basis versions that were proposed in earlier papers. The ability to localize errors is then evaluated for simulated tests with known modifications. The evaluations are shown for a small 1032 DOF model of the GARTEUR SM-AG-19 testbed and a more industrial 16840 DOF model of an engine cover.

Over- and Under-Voltage Containment Reserves for Droop-Based Primary Voltage Control of MTDC Grids

Abstract: This paper proposes a comprehensive methodology for determining the converter droop settings to ensure the voltage security in multi-terminal direct current (MTDC) grid. The novelty lies in the introduction of the concept of over- and under-voltage containment reserves in analogy to the frequency containment reserves in AC systems. This not only gives a distinction of the contribution between the converters in rectifying and inverting modes, but also significantly facilitates the sizing of necessary amount of reserves within their available headroom capacity of power. In particular, the constraints of converters outages, converter rating, and DC voltage deviations are all taken into account in the design of reserves. The effectiveness of the proposed approach is demonstrated by a contingency power flow analysis algorithm and EMT simulations of a four-terminal MTDC grid.