Technology Roadmap for Beyond 5G Wireless Connectivity in D-band

International audienceWireless communication in millimeter wave bands, namely above 20 GHz and up to 300 GHz is foreseen as a key enabler technology for the next generation of wireless systems. The huge available bandwidth is contemplated to achieve high data rate wireless communications, and hence, to fulfill the requirements of future wireless networks. Several Beyond 5G applications are considered for these systems: high capacity back-haul, enhanced hot-spot kiosk as well as short-range Device-to-Device communications. In this paper we propose to discuss the trade-offs between scenario requirements and current silicon technologies limits to draw a technology roadmap for the next generation of wireless connectivity in D-band

Mitigation of Carrier Frequency Offset in a Sub-THz Channel Bonding Scenario

International audienceWireless communications in the sub-THz bands are contemplated to achieve the soon required Tbit/s data rate. To fulfill this requirement, sub-THz transceivers aggregate several carriers, or in other words, implement channel bonding. In this paper we investigate the mitigation of the carrier frequency offset impact on channel bonding systems. In contrast to the literature, we consider that each of the carriers is corrupted by an independent random carrier frequency offset. Moreover, we do not address the carrier frequency offset estimation to compensate it but instead the optimization of the demodulation to mitigate the impact of this impairment. First, a system model is presented to describe channel bonding transceivers corrupted by carrier frequency offsets and the analytical expression of the resulting interference is outlined. Second, we pursue the analytical study for systems using waveforms with rectangular pulse-shaping. By evaluating the capacity, it is exhibited that a detection algorithm jointly demodulating the carriers could enhance the performance. Third, several detection algorithms are introduced and compared by means of numerical simulations. We show that a joint linear detection algorithm achieves a significant performance gain in comparison to a receiver demodulating independently the carriers

Modèles de Bruit de Phase pour les Communications Sub-TeraHertz

International audienceThis paper discusses the appropriate choice of phase noise model for sub-THz communications. Two phase noise models are introduced and compared: one correlated, accurate but complex, and another uncorrelated, analytically simpler. The expression of the likelihood ratio enables us to propose an analytical condition to select the best of the two models for a measured oscillator characteristic. It is shown that an uncorrelated Gaussian process is appropriate to model the impact of phase noise in sub-THz systems.Cet article aborde la question de la modélisation de bruit de phase pour les communications sub-THz. Deux modèles de bruit de phase sont introduits et comparés : un corrélé, précis mais complexe, et un non-corrélé, analytiquement plus simple. L'expression du rapport de vraisemblance nous permet de proposer une condition analytique afin de sélectionner le meilleur des deux modèles pour un spectre d'oscillateur donné. Il est montré, à partir des oscillateurs de la littérature, qu'un processus gaussien non-corrélé est adéquat pour modéliser le bruit de phase dans les systèmes sub-THz

Espaces de Hilbert pour les Modulations Numériques d'Enveloppe

International audienceThis paper proposes an algebraic framework for digital envelope modulation. We represent waveforms with non-negative real values on a Hilbert space defined by transport of structure of the usual signal-space L 2 . Therefore, existing schemes developed for real-valued signals can be exploited upon envelope modulation. To illustrate the relevance of the proposed framework, we show that constraints on embedded analog-to-digital converters in sub-THz communications can be relaxed with the use of non-negative orthogonal waveforms.Cet article propose un cadre algébrique pour les modulations numériques d'enveloppe. Les formes d'ondes à valeurs non-négatives sont représentées dans un espace de Hilbert défini par transport de structure de l'espace usuel L 2. Ainsi, les méthodes classiques de traitement du signal pour les formes d'ondes réelles peuvent être exploitées pour les modulations d'enveloppe. Afin d'illustrer la pertinence du cadre proposé, nous montrons que les contraintes liées aux convertisseurs analogique-numérique dans le cadre de communications sub-THz peuvent être assouplies par l'utilisation de forme d'ondes non-négatives orthogonale

Phase Noise Model Selection for Sub-THz Communications

International audienceTo face the exponential data traffic growth, the sub-THz spectrum (100-300 GHz) is envisioned for wireless communications. However, sub-THz systems are critically im-pacted by the strong phase noise of high frequency oscillators. This paper discusses the appropriate choice of phase noise model for sub-THz communications. Two phase noise models are introduced and compared: one correlated, accurate but complex, and another uncorrelated, analytically simpler. The expression of the likelihood ratio enables us to propose an analytical condition to select the best of the two models for a measured oscillator spectral characteristic. Numerical simulations are performed with realistic phase noise generated according to a state-of-the-art sub-THz oscillator and show that an uncorrelated Gaussian process is appropriate to model the impact of phase noise in sub-THz systems. Eventually, the proposed results are applied to link adaptation in the presence of phase noise in order to choose the most robust scheme between a coherent and a differential modulation

Design of MIMO Systems with Energy Detection Receivers for Future Sub-TeraHertz Applications

Virtual ConferenceInternational audienceTo meet the requirements of beyond 5G networks, the significant amount of unused spectrum in sub-TeraHertz frequencies is contemplated to realize high data-rate wireless communications. Yet, the performance of sub-TeraHertz systems is severely degraded by strong oscillator phase noise. Therefore, we investigate in this paper the use of multiple-inputs multipleoutputs (MIMO) systems with non-coherent detection receivers to achieve high spectral efficiency communications robust to phase noise. Based on energy detection receivers, we derive the maximum likelihood symbol detection decision rule and compare it to the standard Euclidean receiver. The performance of the detectors is assessed through numerical simulations on a realistic scenario modeling an indoor wireless link. Results demonstrate that sub-TeraHertz systems with high spectral efficiency can be implemented on low complexity and low power architectures using MIMO systems and energy detection receivers

Adaptive PSK Modulation Scheme in the Presence of Phase Noise

International audience—Phase noise is one of the major impairments affecting severely performance of millimeter-wave systems. This paper addresses the problem of link adaption for coherent and non-coherent phase modulated signals subject to Gaussian and Wiener phase noise. We first derive closed-form approximations of the bit error rate. Then, in contrast to usual link adaptation techniques, we propose a simple scheme exploiting estimations of not only the signal-to-noise ratio but also of the phase noise variance, which is essential to achieve reliable communications

Optimized Single Carrier Transceiver for Future Sub-TeraHertz Applications

International audienceThe performance of sub-THz communications, contemplated for the next generation of wireless networks, are significantly degraded by oscillator phase noise. In this paper, we address the design of a single carrier transceiver resilient to phase noise. This problem is treated in two steps: First, we derive for phase noise channels the optimum symbol detection criterion. Second, we propose a phase noise robust modulation scheme with a comprehensive and efficient structure. System level simulations modeling the sub-THz propagation channel of a rich outdoor environment through ray tracing are also presented. Results show that optimizing the modulation and demodulation schemes is necessary to achieve high spectral efficiency in the presence of phase noise

On the Optimum Demodulation in the Presence of Gaussian Phase Noise

International audience—Millimeter-wave systems appears to be one of the foremost solutions to face the exponential growth of the data traffic. Yet, their performance are severely degraded by oscilla-tors phase noise. This paper addresses the design of optimum receivers affected by phase noise. We first derive the optimum decision metric for symbol detection under the assumption of a Gaussian phase noise and a high signal-to-noise ratio. In contrast to state-of-the-art approaches, we propose to represent within a complete metric space the demodulation over the phase noise channel. The provided framework enables the use of efficient algorithms to perform the demodulation. Computable probabilistic demapper values are derived upon the optimum metric to implement soft channel decoding. This work shows that knowledge of the channel statistics can be capitalized to enhance performance of both coded and uncoded systems. Eventually, we propose the necessary channel estimation scheme and evaluate the performance degradation due to estimation errors