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Recent experimental results show that full-duplex (FD) communication is feasible provided that the residual self-interference after cancellation is close to the noise floor. In this paper, we present a low-complexity active self-interference cancellation technique for FD orthogonal frequency division multiplexing (OFDM) systems, which accounts for the inherent cyclostationarity of the OFDM signal in order to effectively cancel the self-interference. The method here proposed estimates the self-interference cancellation path by using a time-averaged mean-square error criterion, combined with a filtered least mean squares adaptive algorithm. Then, its performance is experimentally validated using a self-developed FD radio testbed implemented with off-the-shelf components. When combined with passive cancellation, applying the proposed technique provides enough self-interference suppression as to reach close (less than 2 dB) to the receiver noise floor.

As the transmission power increases for high-power full-duplex (FD) communications, the nonlinear effects of the transmit chain become more significant, resulting in severe nonlinear self-interference (SI) at the receiver of the FD transceiver and hence demodulation performance degradation for the desired signal from a remote user. In this paper, a blind nonlinear SI cancellation method, which consists of a cancellation stage and a recovery stage, is proposed to cancel the nonlinear SI along with the linear SI signal for an orthogonal frequency division multiplexed (OFDM)-modulated FD transceiver. By taking the advantage of two symbols on adjacent subcarriers received in one OFDM symbol, the cancellation stage cancels both the linear SI and its nonlinear SI components of the received signal without estimating the transmitter nonlinearity as well as the SI channel response. Subsequently, the recovery stage is performed on the resulting signal of the cancellation stage to eliminate any impacts on the desired signal. Simulations are performed on a nonlinear model extracted from a practical class AB power amplifier with transmission power ranging from 10 to 30 dBm to demonstrate different nonlinear distortions. The effectiveness of the proposed nonlinear cancellation method is verified in terms of the computation complexity, the cancellation capability for the SI signal, and the bit error rate of the desired signal.

This article presents a comprehensive survey of the literature on self-interference management schemes required to achieve a single frequency full duplex communication in wireless communication networks. A single frequency full duplex system often referred to as in-band full duplex (FD) system has emerged as an interesting solution for the next generation mobile networks where scarcity of available radio spectrum is an important issue. Although studies on the mitigation of self-interference have been documented in the literature, this is the first holistic attempt at presenting not just the various techniques available for handling self-interference that arises when a full duplex device is enabled, as a survey, but it also discusses other system impairments that significantly affect the self-interference management of the system, and not only in terrestrial systems, but also on satellite communication systems. The survey provides a taxonomy of self-interference management schemes and shows by means of comparisons the strengths and limitations of various self-interference management schemes. It also quantifies the amount of self-interference cancellation required for different access schemes from the 1 st generation to the candidate 5 th generation of mobile cellular systems. Importantly, the survey summarises the lessons learnt, identifies and presents open research questions and key research areas for the future. This paper is intended to be a guide and take off point for further work on self-interference management in order to achieve full duplex transmission in mobile networks including heterogeneous cellular networks which is undeniably the network of future wireless systems.

In this paper, the fundamental problem for the full-duplex communication systems, i.e., self-interference cancellation (SIC), is investigated, and a novel digital-domain SIC method based on blind source separation is proposed. This method achieves SIC by separation and has two prominent characteristics that are: 1) it is a blind method, and no training sequence or time is needed and 2) it is unaffected by the nonlinear components of the self-interference signal. Meanwhile, the critical factors for spectral efficiency (SE) are fully analyzed herein. In the simulations, the performances of the proposed method, including SIC capacity, signal-to-interference-plus-noise ratio, SE, and SE gain, are comprehensively evaluated and compared with least-square-based SIC algorithms. These results show that the proposed algorithm can obtain considerable performances, even the best performance in some cases.

With the growing demand for spectrum utilization, the concept of full duplex transceivers has become attractive. These simultaneous transmit and receive systems (STAR) are attractive as they double bandwidth utilization. To realize STAR, we must suppress self-interference (SI) between transmit and receive antennas. Doing this across a wide bandwidth presents an even greater challenge. Further, for antenna arrays, SI can be higher due to mutual coupling among neighboring elements. In this paper, we achieve 100 dB isolation for practical STAR, across a large 500 MHz bandwidth. Specifically, four stages of the self-interference cancellation are proposed. In addition to high isolation cross-polarized array elements, we employ multi-tap filters at the transceiver RF front-end for interference cancellation. These filters emulate direct SI coupling using frequency-domain optimization techniques. Measured results show an average of 25 dB filter cancellation is possible across 500 MHz.

Electrical balance duplexers (EBDs) present a potential alternative to the fixed-frequency duplexing filters used for frequency division duplexing in cellular handset radio frequency front ends. However, the transmit-to-receive (Tx–Rx) isolation can be affected by interaction between the antenna and the environment, and therefore, the EBDs balancing impedance must adaptively track time-domain antenna impedance variation. A rail scenario presents a potentially demanding use case for an EBD, as fast moving trains in the vicinity of the antenna may cause dynamically changing reflections, which can be received as self-interference. In this paper, measured dynamic antenna reflection coefficients at 745 and 1900 MHz from train mounted antennas are included in the EBD circuit simulations in order to investigate the resulting variation in Tx–Rx isolation, and determine requirements for balancing impedance adaptation. This paper also presents the results from rail-based field trials of a hardware prototype EBD, which implements real-time antenna impedance tracking. Results show that the rail scenario does result in variation in Tx–Rx isolation, but that rebalancing the EBD at the intervals of 5 ms was sufficient to maintain >50 dB isolation for ~95% of the time.

International audience; In this paper, we present a new Transmitting-Receiving-Sensing (TRS) mechanism for full-duplex cognitive radio. Our proposed mechanism permits Secondary Users (SUs) to establish a bidirectional communication over the same frequency band while keeping aware of the Primary User (PU) activity status. The activity period of SU in our proposed mechanism is composed of two stages: In the first stage SU communicates in bidirectional way with his peer SU. At the second stage, one of the SUs becomes silent in order to do not disturb his peer, which performs a spectrum sensing and remains active at the same time using self-interference cancellation technique. The probability of collision related to our mechanism is derived as well as the probability of waste and the average throughput. Our simulation results show that the proposed mechanism can significantly decrease the probability of collision at low SNRp (Signal to Noise Ratio of PU at SU).

National audience; Dans cet article, plusieurs topologies d’annulation d’auto-inférence au niveau RF/antennaire pour communications Full-Duplex (FD) sont comparées. L’importance du premier niveau de réduction de la Self-Interférence (couplage de l’émission TX vers la réception RX) au niveau antennaire/RF est mise en avant pour différentes applications. Ainsi, plusieurs configurations multi-antennaires sont comparées en mettant en évidence leurs avantages/inconvénients respectifs dans le but d’identifier les techniques les plus pertinentes pour la mise en oeuvre d’une liaison FD ISL (Inter-Satellite-Link) entre nano-satellites.

We develop adaptive self-interference cancellation algorithms for both filter-and-forward and decode-and-forward multiple-input multiple-output relays. The algorithms are blind in the sense that they only exploit the spectral properties of the transmitted signal to identify the self-interference channel, while dealing with frequency-selective channels and arbitrary signal spectra. Our approach is non-intrusive in the sense that the algorithms can successfully identify, track, and cancel the self-interference distortion while the relay is operating in its normal mode. We study the stationary points of the algorithms and analyze under which conditions they achieve perfect cancellation of the self-interference. Simulation results show that the algorithms provide residual self-interference levels below the noise floor by using the time samples of only a few OFDM symbols. HighlightsWe solve the problem of self-interference mitigation in full-duplex MIMO relays.Blind adaptive time-domain algorithms based on recursive least-squares are developed.Simulation results show residual self-interference levels below the noise floor.

This paper studies the performance of the analog multi-tap (MT) canceller, where the tap coefficients are calculated based on the estimated self-interference (SI) channel state information (CSI). In this paper, both the time-invariant and the time-varying SI channels scenarios are investigated, considering the dynamic range of the analog-to-digital converter (ADC) and the linearity of the receiver chain. Closed-form expressions are first developed to calculate the residual SI power after the MT cancellation, characterizing the joint effects of the imperfect SI CSI, reconstruction errors on the estimated SI CSI, and the variation of the SI channels. Then, the achievable rate of the full-duplex transceivers is derived as a function of the residual SI power after the MT cancellation, dynamic range of the ADC, and the linearity of the receiver chain. Theoretical and simulated results show that with imperfect SI CSI, deploying more taps may harm the amount of analog SI cancellation. The sensitivity of the canceller to the doppler frequency shift reduces the amount of analog SI cancellation, and thus brings rate gain loss even with a doppler negligible in conventional communications.

Many researchers expect to see the efficiency of wireless local area networks (WLANs) increased by in-band simultaneous transmit and receive (STR). While insufficient suppression of self-interference has been a major obstacle to implementing the STR capability, an even bigger obstacle is the fact that enabling STR involves significant modification to the current IEEE 802.11 medium access control (MAC) protocol. In this paper, we propose MASTaR , a novel MAC protocol that enables STR in 802.11 WLAN using standard-compliant methods. The feasibility and performance of MASTaR are extensively evaluated via 3-D ray-tracing-based simulation. The simulation results demonstrate that significant performance enhancement, e.g., up to $2.58\times $ higher throughput than the current 802.11 MAC protocol, can be achieved by an STR-capable access point.

In this paper, we develop a reliable bandwidth-efficient solution for coherent reception in networks prone to self-interference. Our primary focus is on orthogonal-frequency-division-multiplexing (OFDM)-based amplify-and-forward (AF) two-way relaying, where each source node suffers from reradiation of its own signal. An important issue is the superposition of the desired and interfering signals, which makes the channel estimation task difficult, particularly for varying channel coefficients. To address this challenging problem, we introduce a factor graph model of the estimation and detection problem at hand. Exploiting the conditional independence between unknown variables in the factor graph, an efficient message-passing algorithm, which performs joint Bayesian channel estimation, self-interference mitigation, and decoding, is derived. Simulation results show that the performance of the proposed method is close to that given by perfect knowledge of the channel for the target and interfering signals, even with limited training overhead.

International audience; This work introduces a new design approach of multilayer Electromagnetic Band Gaps (EBGs) for wideband antenna isolation in a Full-Duplex transceiver. The design methodology is applied to a conventional type of EBGs in order to improve its initial performance in terms of bandwidth and size. By stacking multiple dielectric layers with integrated vias, an enhancement of the relative bandwidth of the band gap and a strong miniaturization of the unit cell is achieved. The dispersion diagrams of the proposed EBGs are studied and full-wave electromagnetic simulations are realized to validate the isolation level and the proposed lumped model of the final structures.

Residual self-interference (SI) cancellation in the digital baseband is an important problem in full-duplex (FD) communication systems. In this paper, we propose a new technique for estimating the SI and communication channels in a FD communication system, which is inspired from superimposed signaling. In our proposed technique, we add a constant real number to each constellation point of a conventional modulation constellation to yield asymmetric shifted modulation constellations with respect to the origin. We show mathematically that such constellations can be used for bandwidth efficient channel estimation without ambiguity. We propose an expectation maximization (EM) estimator for use with the asymmetric shifted modulation constellations. We derive a closed-form lower bound for the mean square error (MSE) of the channel estimation error, which allows us to find the minimum shift energy needed for accurate channel estimation in a given FD communication system. The simulation results show that the proposed technique outperforms the data-aided channel estimation method, under the condition that the pilots use the same extra energy as the shift, both in terms of MSE of channel estimation error and bit error rate. The proposed technique is also robust to an increasing power of the SI signal.

ispartof: pages:1389-1394 ispartof: 2018 CONFERENCE RECORD OF 52ND ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS, AND COMPUTERS pages:1389-1394 ispartof: 52nd Asilomar Conference on Signals, Systems, and Computers location:CA, Pacific Grove date:28 Oct - 1 Nov 2018 status: published

Enabling ultra fast systems has been widely investigated during recent decades. Although polarization has been deployed from the beginning in satellite communications, nowadays it is being exploited to increase the throughput of satellite links. More precisely, the application of diversity techniques to the polarization domain may provide reliable, robust, and fast satellite communications. Better and more flexible spectrum use is also possible if transmission and reception can take place simultaneously in close or even overlapping frequency bands. In this paper we investigate novel signal processing techniques to increase the throughput of satellite communications in fixed and mobile scenarios. First, we investigate four-dimensional (4D) constellations for the forward link. Second, we focus on the mobile scenario and introduce an adaptive algorithm which selects the optimal tuple of modulation order, coding rate, and MIMO scheme that maximizes the throughput constraint to a maximum packet error rate. Finally, we describe the operation of radio transceivers which cancel actively the self-interference posed by the transmit signal when operating in full-duplex mode.

Full-duplex (FD) communication and spatial modulation (SM) are two promising techniques to achieve high spectral efficiency. Recent works in the literature have investigated the possibility of combining the FD mode with SM in the relay system to benefit their advantages. In this paper, we analyze the performance of the FD-SM decode-and-forward (DF) relay system and derive the closed-form expression for the symbol error probability (SEP). To tackle the residual self-interference (RSI) due to the FD mode at the relay, we propose a simple yet effective power allocation algorithm to compensate for the RSI impact and improve the system SEP performance. Both numerical and simulation results confirm the accuracy of the derived SEP expression and the efficacy of the proposed optimal power allocation.

Due to the increasing demand of wireless communication services and the limitation in the spectrum resources, Cognitive Radio (CR) has been initially proposed in order to solve the spectrum scarcity. CR divides the communication transceiver into two categories: the Primary (PU) or the Secondary (SU) Users. PU has the legal right to use the spectrum bandwidth, while SU is an opportunistic user that can transmit on that bandwidth whenever it is vacant in order to avoid any interference to the signal of PU. Hence the detection of PU becomes a main priority for CR systems. The Spectrum Sensing is the part of the CR system, which monitors the PU activities. Spectrum Sensing plays an essential role in the mechanism of the CR functioning. It provides CR with the available channel in order to access them, and on the other hand, it protects occupied channels from the interference of the SU transmission. In fact, Spectrum Sensing has gained a lot of attention in the last decade, and numerous algorithms are proposed to perform it. Concerning the reliability of the performance, several challenges have been addressed, such as the low Signal to Noise Ratio (SNR), the Noise Uncertainty (NU), the Spectrum Sensing duration, etc. This dissertation addresses the Spectrum Sensing challenges and some solutions are proposed. New detectors based on Cyclo-Stationary Features detection and the Power Spectral Density (PSD) of the PU are presented. CanonicalCorrelation Significance Test (CCST) algorithm is proposed to perform cyclo-stationary detection. CCST can detect the presence of the common cyclic features among the delayed versions of the received signal. This test can reveal the presence of a cyclo-stationary signal in the received mixture signal. Another detection method based on the cumulative PSD is proposed. By assuming the whiteness of the noise (its PSD is at), the cumulative PSD approaches a straight line. This shape becomes non-linear when a telecommunication signal is present in the received mixture. Distinguishing the Cumulative PSD shape may lead to diagnose the channel status.Full-Duplex Cognitive Radio (FD-CR) has been also studied in this manuscript, where several challenges are analyzed by proposing a new contribution. FD functioning permits CR to avoid the silence period during the Spectrum Sensing. In classical CR system, SU stops transmitting during the Spectrum Sensing in order to do not affect the detection reliability. In FD-CR, SU can eliminate the reflection of its transmitted signal and at the same time achieving the Spectrum Sensing. Due to some limitations, the residual of the Self Interference cannot be completely cancelled, then the Spectrum Sensing credibility is highly affected. In order to reduce the residual power, a new SU receiver architecture is worked out to mitigate the hardware imperfections (such as the Phase Noise and the Non-Linear Distortion of the receiver Low-Noise Amplifier). The new architecture shows its robustness by ensuring a reliable detection and enhancing the throughput of SU.; En raison de la demande croissante de services de communication sans fil et de la limitation des ressources de spectre, la radio cognitive (CR) a été initialement proposée pour résoudre la pénurie de spectre. CR divise les systèmes transmetteurs-récepteurs de communication en deux catégories : les Utilisateurs Principaux (PU) et les Utilisateurs Secondaires (SU). PU a le droit légal d'utiliser la bande spectrale, tandis que SU est un utilisateur opportuniste qui peut transmettre sur cette bande chaque fois qu'elle est vacante afin d'éviter toute interférence avec le signal de PU. De ce fait, la détection des activités de PU devient une priorité principale pour toute CR.Le Spectrum Sensing devient ainsi une partie importante d’un système CR, qui surveille les transmissions de PU. En effet, le Spectrum Sensing joue un rôle essentiel dans le mécanisme du fonctionnement du CR en localisant les canaux disponibles et, d'autre part, en protégeant les canaux occupés des interférences de la transmission SU. En fait, Spectrum Sensing a gagné beaucoup d'attention au cours de la dernière décennie, et de nombreux algorithmes sont proposés. Concernant la fiabilité de la performance, plusieurs défis comme le faible rapport signal sur bruit, l'incertitude de bruit (NU), la durée de détection du spectre, etc. Cette thèse aborde les défis de la détection du spectre et apporte quelques solutions. De nouveaux détecteurs basés sur la détection des caractéristiques cyclo-stationnaires et la densité spectrale de puissance (PSD) du signal de PU sont présentés. Un algorithme de test de signification de corrélation canonique (CCST) est proposé pour effectuer une détection cyclo-stationnaire. CCST peut détecter la présence des caractéristiques cycliques communes parmi les versions retardées du signal reçu. Ce test peut révéler la présence d'un signal cyclo-stationnaire dans le signal de mélange reçu. Une autre méthode de détection basée sur la PSD cumulative est proposée. En supposant que le bruit est blanc (sa PSD est plate), la PSD cumulative s'approche d'une droite. Cette forme devient non linéaire pour les signaux de télécommunication. Distinguer la forme cumulative PSD peut donc conduire à diagnostiquer l'état du canal.La radio cognitive Full-Duplex (FD-CR) a également été étudiée dans ce manuscrit, où plusieurs défis sont analysés en proposant de nouvelles contributions. Le fonctionnement FD permet au CR d'éviter la période de silence pendant la détection du spectre. Dans le système CR classique, le SU cesse de transmettre pendant la détection du spectre afin de ne pas affecter la fiabilité de détection. Dans FD-CR, SU peut éliminer la réflexion de son signal transmis et en même temps réaliser le Spectrum Sensing. En raison de certaines limitations, le résidu de l'auto-interférence ne peut pas être complètement annulé, alors la crédibilité de la détection du spectre est fortement affectée. Afin de réduire la puissance résiduelle, une nouvelle architecture de récepteur SU est élaborée pour atténuer les imperfections du circuit (comme le bruit de phase et la distorsion non linéaire de l'amplificateur à faible bruit du récepteur). La nouvelle architecture montre sa robustesse en assurant une détection fiable et en améliorant le débit de SU.

International audience; In Full-d uplex Cognitiv e Radios, the silen t period of the Secondary User (SU) during the Spectrum Sensing can be elimina ted by appl ying the Self -Interf erence Cancella tion (SIC). Due to the channel estima tion error and the hardw are imperf ections (the Phase Noise and the Non-Linear Distortion (NLD)) SIC is not perf ectl y perf ormed and resul ts in the Resid ual Self -Interf erence (RSI) which aects the Spectrum Sensing reliability . In this paper , the eect of RSI on Spectrum Sensing is anal yticall y deriv ed by expressing the detection (pd ) and false alarm (pf a) probabilities under FD in terms of the ones under Half -Duplex (HD) (where SU shoul d remain silen t during the Spectrum Sensing period). In addition, an algorithm is proposed to suppress the NLD and improv es the Spectrum Sensing perf ormance. Hereinafter , the SU throughput under FD is anal ysed comparing to HD by deriving the upper and lower bounds to be respected by pf a and pd respectiv ely in order to make FD beneficia rela tiv e to HD.

For efficient spectral utilization of satellite channels, a shared band transmission technique is introduced in this paper. A satellite transmits multiple received signals from a gateway and terminal in the common frequency band by superimposing the signals. To improve the power efficiency as well as the spectral efficiency, a travelling wave tube amplifier in the satellite should operate near the saturation level. This causes a nonlinear distortion of the superimposed transmit signal. Without mitigating this nonlinear effect, the self‐interference cannot be properly cancelled and the desired signal cannot be demodulated. Therefore, an adaptive compensation scheme for nonlinearity is herein proposed with the proper operation scenario. It is shown through simulations that the proposed shared band transmission approach with nonlinear compensation and self‐interference cancellation can achieve an acceptable system performance in nonlinear satellite channels.

In this paper, we study beamforming based full-duplex (FD) systems in millimeter-wave (mmWave) communications. A joint transmission and reception (Tx/Rx) beamforming problem is formulated to maximize the achievable rate by mitigating self-interference (SI). Since the optimal solution is difficult to find due to the non-convexity of the objective function, suboptimal schemes are proposed in this paper. A low-complexity algorithm, which iteratively maximizes signal power while suppressing SI, is proposed and its convergence is proven. Moreover, two closed-form solutions, which do not require iterations, are also derived under minimum-mean-square-error (MMSE), zero-forcing (ZF), and maximum-ratio transmission (MRT) criteria. Performance evaluations show that the proposed iterative scheme converges fast (within only two iterations on average) and approaches an upper-bound performance, while the two closed-form solutions also achieve appealing performances, although there are noticeable differences from the upper bound depending on channel conditions. Interestingly, these three schemes show different robustness against the geometry of Tx/Rx antenna arrays and channel estimation errors.

International audience; Full-Duplex (FD) transceiver has been proposed to be used in Cognitive Radio (CR) in order to enhance the Secondary User (SU) Data-Rate.In FD CR systems, in order to diagnose the Primary User activity, SU can perform the Spectrum Sensing while operating. Making an accurate decision about the PU state is related to the minimization of the Residual Self Interference (RSI). RSI represents the error of the Self Interference Cancellation (SIC) and the receiver impairments mitigation such as the Non-Linear Distortion (NLD) of the receiver Low-Noise Amplifier (LNA). In this manuscript, we deal with the RSI problem by deriving, at the first stage, the relation between the ROC curves under FD and Half-Duplex (HD) (when SU stops the transmission while sensing the channel). Such relation shows the RSI suppression to be achieved in FD in order to establishan efficient Spectrum Sensing relatively to HD. In the second stage, we deal with the receiver impairments by proposing a new technique to mitigatethe NLD of LNA. Our results show the efficiency of this method that can help the Spectrum Sensing to achieve a closed performance under FD to that under HD.

This paper considers the implementation and application possibilities of a compact full duplex multiple-input multiple-output (MIMO) architecture, where direct communication exists between users, e.g., device-to-device (D2D) and cellular link coexisting on the same spectrum. For the architecture of the compact full duplex radio, we combine an analog self-interference canceler-based dual polarization with high cross-polarization discrimination and long-term evolution (LTE)-based per-subcarrier digital self-interference canceler. While we consider the compactness and power efficiency of an analog solution, we focus on the digital canceler design with robustness to a frequency-selective channel and high compatibility with a conventional LTE system. For an over-the-air wireless experiment of full duplex testbed with a two-user-pair, we implement a full duplex MIMO physical layer, supporting 20-MHz bandwidth, on an Field-Programmable Gate Array-based software-defined radio platform. Furthermore, we propose a novel timing synchronization method to construct a more viable full duplex MIMO link. By having the full duplex link prototype fully operating in real time, we present the first characterization of the proposed compact full duplex MIMO performance depending on the transmit power of the full duplex node. We also show the link quality between nodes. One of the crucial insights of this paper is that the full duplex operation of a user is capable of acquiring the throughput gain if the user has self-interference capability with guaranteed performance.

Electrical balance duplexing enables simultaneous transmit and receive from a single antenna; however, the transmit-to-receive isolation depends on the ability of the balancing algorithm to determine the correct balancing impedance. A novel balancing algorithm based on in situ characterization of the duplexer self-interference channel is proposed. The algorithm requires no a priori knowledge of the antenna impedance or hybrid junction characteristics and automatically compensates for circuit imperfections. A novel balancing network implementation that uses active signal injection is also proposed. A hardware prototype implementing the proposed balancing algorithm and combining passive and active balancing techniques has achieved 81.5-dB isolation over an 80-MHz bandwidth.

This paper describes three RF self-interference reduction techniques for full-duplex wireless links, which specifically target integration in compact radios. Concretely, a self-interference cancelling front-end, a dual-polarized antenna, and an electrical balance duplexer are proposed. Each technique offers specific benefits in terms of implementation density, selfinterference rejection, bandwidth and flexibility. Depending on their characteristics, they can be adopted in different next generation full-duplex applications and standards. All concepts are prototyped, and achieve at least 45dB of self-interference reduction over more than 10MHz bandwidth. Index Terms—Full-duplex wireless, self-interference, polarized antenna, electrical balance duplexer, analog cancellation.

The wireless medium is a shared and limited resource. Current wireless standardsalways share the medium with Half-Duplex principle: the transmission and receptionof signals are done in two separate time slots or two different frequency bands.Besides, the transceiver can only transmit and receive one signal at a time.This dissertation takes an alternate approach: Instead of sharing the medium withHalf-Duplex principle, the entire licensed frequency band is shared for simultaneoustransmission and reception, which we call Full-Duplex. Besides, the design conceptfor a wideband flexible radio transceiver can process two different types of signals ata time.To reach this goal, we propose to use an active analog radio frequency (RF) selfinterferencecancellation (AARFSIC) method or a combination scheme of the AARFSICand active digital self-interference cancellation in time domain (ADSICT) to cancelthe strong self-interference (SI) induced by the Full-Duplex principle. Based on theFull-Duplex radio, we propose a flexible Full-Duplex Dual-Band (FDDB) OFDM radiotransceiver by combining the Dual-Band RF front-end.Building on these, we make three main contributions: We present an active selfinterferencecancellation (ASIC) scheme, which can cancel both the strong one-pathand multi-path SI completely, based on the combination of the AARFSIC and DSICT.Next, we introduce the design and evaluation of a Full-Duplex OFDM radio, includinganalysis and qualification of the impact of the thermal noise and phase noise onthe system performance. Finally, we develop an FDDB OFDM radio that can work ontwo separate spectrum fragments. In order to eliminate the impact of the I/Q imbalanceon the FDDB radio, a simple but practical digital I/Q imbalance estimation andcompensation method is presented. The system level simulation conducted with ADSand Matlab software shows that this method can efficiently compensate both high andlow I/Q imbalance., Le medium sans fil est une ressource partagée et limitée. Les normes sans filactuelles partagent toujours le principe de partage du medium Half-Duplex: la transmissionet la réception de signaux sont effectuées dans deux intervalles de temps distinctsou deux bandes de fréquences différentes. En outre, l’émetteur-récepteur nepeut émettre et recevoir qu’un signal à la fois.Cette thèse suit une autre approche: au lieu de partager le support avec le principede Half-Duplex, toute la bande de fréquence autorisée est partagé pour la transmissionet la réception simultanée, approche qui est appelée Full-Duplex. Dès lors, on peutconcevoir une architecture d’un émetteur-récepteur radio flexible à large bande pourtraiter deux types de signaux différents à la fois.Pour approcher cet objectif, nous utilisons une méthode de suppression activeanalogique de l’auto-interférence (AARFSIC) et l’annulation active numérique d’autointerférencedans le domaine temporel (ADSICT) pour annuler la forte auto-interférence(SI) induite par le principe Full-Duplex. Basé sur la radio Full-Duplex, nous proposonsun système flexible Dual-Band (FDDB) émetteur-récepteur radio OFDM Full-Duplexen la combinant avec un front-end RF double bande.S’appuyant sur ces principes, nous exposons trois contributions principales: Nousprésentons une technique d’annulation analogique de l’auto-interférence (ASIC), quipeut annuler complètement l’auto-interférence à trajet direct ou multi-trajets, baséesur la combinaison des méthodes AARFSIC et DSICT. Ensuite, nous présentons la conceptionet l’évaluation d’une radio OFDM Full-Duplex, y compris l’analyse et la qualificationde l’impact du bruit thermique et du bruit de phase sur les performances dusystème. Enfin, nous développons une radio dual-bande FDDB OFDM qui peut fonctionnersur deux fragments de spectre séparés. Afin d’éliminer l’impact du déséquilibreI/Q sur la radio FDDB, une méthode d’estimation des déséquilibres I/Q et decompensation, simple mais efficace, est présentée. La simulation au niveau systèmemenée avec ADS et Matlab montre que cette méthode peut effectivement compenserdes déséquilibres I/Q aussi bien élevés que faibles.