Design and Evaluation of a Wideband Full-Duplex OFDM System Based on AASIC

International audienceExisting methods of self-interference cancellation have greatly reduced the strong self-interference signal for the practical design of Full-Duplex (FuDu) wireless systems. However, current FuDu wireless is hard to be put into practice due to the reason that residual self-interference after interference cancellation is still much stronger than the thermal noise. In this paper, a wideband FuDu OFDM system with a single path self-interference channel is developed based on active analog self-interference cancellation (AASIC) at the RF component. Furthermore, a mathematical model of the wideband FuDu OFDM wireless system and the AASIC at the RF component are presented and elaborated. The performance of this FuDu system is evaluated by ADS-Matlab co-simulation based on the IEEE 802.11g system parameters. The comparison of the spectrum power of signals before and after the AASIC and the bite error rate (BER) performance of the FuDu OFDM wireless system show that the strong self-interference can be significantly reduced to almost noise level

Full Duplex Spatial Modulation System Performance Depending on Self-interference Cancellation Accuracy

International audienceSpatial modulation (SM) as a new Multiple-Input Multiple-Output (MIMO) technique is based on transmitting part of the information by activating different emitting antennas. SM increases spectral efficiency and uses only one radio frequency chain. For full-duplex (FD) communication systems, self-interference (SI) is always a central problem. Therefore, combining FD and SM can drastically reduce the difficulty of Self-interference Cancellation (SIC) because of the single SI chain. A Full Duplex Spatial Modulation (FDSM) system is proposed and an active analog SIC is highlighted in this paper. Moreover, the impact of SIC accuracy on the system performance is studied. The results demonstrate that the accuracy requirement will increase as the INR (Self-interference-to-noise Ratio) increases. The FDSM system is less sensitive than the FD system in presence of high estimated error value. Furthermore, an SI detector is presented to resolve the influence of the number of detect symbols

Analysis and Reduction of the Impact of Thermal Noise on the Full-Duplex OFDM Radio

International audienceSelf-Interference has been significantly reduced by current cancelation methods for the practical design of Full- Duplex wireless. However, the residual self-interference is still much stronger than the thermal noise due to many factors, e.g. phase noise in local oscillator, I/Q imbalance, thermal noise and so on, limiting the self-interference cancelation. In this paper, the influence of the thermal noise on the active self-interference cancelation (ASIC) for wideband Full-Duplex OFDM wireless system is analytically studied and demonstrated. We propose a little modification to the structure of data packet of IEEE 802.11g to reduce the impact of the thermal noise on the active selfinterference cancelation (ASIC) for Full-Duplex OFDM wireless. The ADS-Matlab co-simulation results show that we can reduce the residual self-interference to only 1.5dB higher than the receiver thermal noise

Enjeux et propositions sur les architectures RF pour l'homme connecté à la société numérique

International audienceThis article presents an overview of the challenges of increasing development of wireless links to enable a more consistent and transparent interconnection between people and the digital world. These issues are in the domain of high performance architectures for conventional applications of wireless Internet, but also in the field of sensor networks and connected objects. Beyond the constraints of the various applications push to develop architectures with high digital capabilities like software defined radio. In each of these categories, examples of approaches proposed by INRIA Socrate team are presented.Cet article présente une vue générale des enjeux du développement croissant de liaisons sans fil visant à permettre une interconnexion de plus en plus constante et transparente entre l'homme et le monde numérique. Ces enjeux se situent au niveau des architectures de terminaux hautes performances pour les applications classiques de l'Internet sans fil, mais également dans le domaine des réseaux de capteurs et des objets connectés. Au-delà, les contraintes de ces diverses applications poussent à développer des architectures à forte composante numérique de type radio logicielle. Dans chacune de ces catégories, des exemples d'approches proposées par l'équipe Inria Socrate sont présentées

Full Duplex Spatial Modulation System Performance Depending on Self-interference Cancellation Accuracy

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Combination of Digital Self-Interference Cancellation and AARFSIC for Full-Duplex OFDM Wireless

International audienceFull-Duplex radio provides many benefits beyond improving spectral efficiency. However, canceling the self-interference completely is a big challenge behind Full-Duplex wireless. Although many intelligent efforts devote to active analog radio frequency self-interference cancellation (AARFSIC), the power of the residual self-interference (SI) after the AARFSIC is still much stronger than that of the receiver thermal noise. In this paper, we first study deeply the AARFSIC and "dig" the core problem that causing the residual SI, and then propose a digital self-interference cancellation in time domain (DSICT) to complement AARFSIC for the Full-Duplex OFDM wireless. The ADS-Matlab co-simulation results demonstrate the actual performance and show that the residual SI after the AARFSIC can be canceled completely by employing the proposed DSICT

Full-Duplex Dual-Band Radio Dedicated to Flexible Radio Communications

This report presents the design of Full-Duplex Dual-Band radio which allows simultaneous transmission and reception in two separate spectrum fragments by combining the Full-Duplex radios and Dual-Band RF front-end. Our design employs two antennas, each one being used for simultaneous transmitting and receiving. To overcome the self-interference (SI) induced by the Full-Duplex radios, simple band pass lters (BPF) are utilized to suppress the inner SI and active analog self-interference cancellation (AASIC) method is used to cancel the inter SI. The two radio frequency (RF) signals corrupted individually by the residual SI are down-converted by the double I/Q structure. Then, the two output baseband signals are processed by the corresponding base-band receivers. We theoretically analyze and evaluate by simulation this Full-Duplex Dual-Band radio operating on the standard WiFi OFDM PHY in two separate spectrum fragments.Ce rapport presente le design d'un systeme radio Full-Duplex dual-band qui permet la transmission et la reception en simultanees de deux fragments de spectre separes en combinant l'approche Full-Duplex a un frontal RF dual-bande. Notre structure requiere deux antennes, chacune etant utilisee pour l'emission et la reception simultanement. Pour resoudre le probleme d'auto-interference (SI) induit par le Full-Duplex, de simples filtres passe-bande (BPF) sont utilises pour supprimer l'auto-interference interne et une suppression active de l'auto-interference au niveau analogique (AASIC) est ajoutee pour supprimer l'auto-interference croisee. Les deux signaux RF brouilles par l'auto-interference residuelle sont transposes en bande de base pour une structure a double IQ. Alors, chaque signal obtenu en bande de base est demodule par le recepteur approprie. Nous presentons ici une analyse theorique et une evaluation en simulation de cette architecture Full-Duplex Dula-Band fonctionnant sur le standard WiFi OFDM dans deux bandes separees

Digital I/Q Imbalance Correction for Full-Duplex Dual-Band OFDM Radio Transceivers I Introduction

International audienceThis paper presents a Full-Duplex Dual-Band (FDDB) OFDM radio architecture that enables the radio transceiver to be more flexible and provides a viable radio link capacity gain. A simple but practical I/Q imbalance estimation and compensation method, based on the frequency-flat-fading behavior of the self-interference channel, is proposed. The performance of the proposed I/Q imbalance compensation method is evaluated by system level simulations conducted with ADS and Matlab. The co-simulation results show that the proposed radio transceiver could potentially increase the physical layer transmission rate by four times compared to the conventional radio link at the cost of tolerable loss of BER performance. The I/Q imbalance compensation method can effectively compensate both high and low I/Q imbalance without the problem of algorithm convergence