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To meet the requirements of beyond 5G networks, the significant amount of unused spectrum in sub-TeraHertz frequencies is contemplated for high-rate wireless communications. Yet, the performance of sub-TeraHertz systems is severely degraded by strong oscillator phase noise. We investigate in this paper the design of digital communications robust to phase noise. This problem is addressed in three steps: the characterization of the phase noise channel, the design of the optimum receiver, and the optimization of the modulation scheme. This paper proposes a joint performance and implementation optimization. First, we address the design of the demodulation scheme for phase noise channels and propose the polar metric, a soft-decision rule for symbol detection. It is shown that performance gains are achieved for coded and uncoded systems with valuable complexity reductions of the receiver. Second, we investigate the optimization of the modulation scheme for phase noise. We demonstrate that using a constellation defined upon a lattice in the amplitude-phase domain leads to significant performance gains and a low-complexity implementation. Thereupon, we propose the Polar-QAM scheme with efficient binary labeling and demodulation. Numerical simulation results show that the proposed modulation and demodulation schemes offer valuable solutions to achieve high-rate communications on systems strongly impaired by phase noise.

Several speculative visions are conjecturing on what 6G services will be able to offer at the horizon of 2030. Nevertheless, the 6G design process is at its preliminary stages. The reality today is that hardware, technologies and new materials required to effectively meet the unprecedented performance targets required for future 6G services and network operation, have not been designed, tested or even do not exist yet. Today, a solid vision on the cost-benefit trade-offs of machine learning and artificial intelligence support for 6G network and services operation optimization is missing. This includes the possible support from hardware efficiency, operation effectiveness and, the immeasurable cost due to data acquisition-transfer-processing. The contribution of this paper is three-fold. This is the first paper deriving crucial 6G key performance indicators on hardware and technology design. Second, we present a new hardware technologies design methodology conceived to enable the effective software-hardware components integration required to meet the challenging performance envisioned for future 6G networks. Third, we suggest a paradigm shift towards goal-oriented and semantic communications, in which a totally new opportunity of joint design of hardware, artificial intelligence and effective communication is offered. The proposed vision is consolidated by our recent results on hardware, technology and machine learning performance., Comment: ESSCIRC

This paper describes a Field Programmable Gate Array (FPGA) implementation of a multi-Gb/s Block Filtered (BF) OFDM transceiver, fully 5G NR compatible. The main obstacles for such a work are (i) the support of multiple configurations and parameters, (ii) the high bandwidth w.r.t the board clock frequency and (iii) the intrinsic complexity of BF-OFDM. We prove that despite these barriers an hardware implementation of this waveform is possible, even with a bandwidth up to 400 MHz. We based our developments on the following pillars: smart layout of the basic modules, parallelization of dedicated functions design and ad hoc architecture. Measurements and complexity analysis demonstrate the high flexibility of BF-OFDM.

On the eve of 5G network deployment worldwide, a new boom in the mass digitization of our personal and professional lifestyles is looming. 5G marks a strong shift in the way in which connectivity will impact our societies and industries. This shift is taking place through a combination of technologies that have progressed business-as-usual with technical improvements. The future of 5G, already called 6G, currently belongs to the world of research, which must imagine the future development of mobile digital services in 10 years. In this ever more connected world, ownership of data and protection, control of ecological impact, both energetic and electromagnetic, in addition to guarantee an available, flexible network will be essential factors in the success of 6G. This new generation of networks brings along great challenges in terms of modularity, cost effectiveness and power efficiency. We present here a novel disruptive deployment strategy using cost-efficient modules along with aggregated connectivity meeting these requirements.

The significant amount of unused spectrum in sub-TeraHertz frequencies is contemplated to realize high rate wireless communications for beyond 5G networks. 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-input multiple-output (MIMO) systems with energy detection receivers to achieve high rate communications robust to phase noise. First, the design of the receiver detection algorithm is addressed. We derive the joint maximum likelihood detector corresponding to the studied nonlinear MIMO channel. Second, the system performance is assessed through numerical simulations. We consider a realistic scenario modeling an indoor wireless link with directive antennas and strongly correlated line-of-sight channels. Our results demonstrate that high rate sub-TeraHertz systems can be implemented on low-complexity and low-power architectures using MIMO systems and energy detection receivers.

International audience; Wireless 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.

Various measurements and studies have shown that some licensed frequency bands are underutilized at certain times and in certain locations. In particular, TV bands have been shown to have unused spectrum. Such observations have triggered strong interest in white space dynamic spectrum access among researchers, wireless equipment manufacturers, and standards development organizations. The IEEE Standards Committee on Dynamic Spectrum Access Networks has created the White Space Radio Working Group in June 2011 to develop the IEEE 1900.7 standard for white space dynamic spectrum access radio systems. The draft of this standard is now finalized and ready for review by a broad audience during the sponsor ballot procedure. This paper gives an overview of key concepts and technologies of the draft standard P1900.7, including its use cases and requirements, its physical layer and MAC sub-layer.

International audience; To 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.

Satellite networks using Low-Earth-Orbit (LEO) are considered to supplement the terrestrial network infrastructure in the context of the 5th generation of wireless systems and particularly for IoT applications. An evolution of Narrow-Band IoT based on Turbo-Frequency Shift Keying (FSK) is considered and evaluated. An efficient channel synchronization frame structure based on modified Zadoff-Chu sequences and associated channel estimation algorithms are proposed. Performance evaluation demonstrates the benefits of the proposed approach. This makes Turbo-FSK a serious contender for these application scenarios.

This paper proposes a thorough comparison of post-OFDM waveforms with both time and frequency selective channels. The waveforms which are considered are CP-OFDM, f-OFDM, WOLA, WOLA-COQAM, FBMC-OQAM, UF-OFDM, Wavelet-OFDM, FFT-FBMC and BF-OFDM. All these waveforms are potential candidates to support critical machine type communications (C-MTC) typically between devices. Based on real propagation channels, it first appears that UF -OFDM is more sensitive to delay spread compared to the others waveforms which have all similar performance. For large velocities, WOLA-COQAM, FFT-FBMC and BF-OFDM experience error floors much larger than the other waveforms.

International audience; —The radio spectrum above 90GHz offers opportunities for huge signal bandwidths, and thus unprecedented increase in the wireless network capacity, beyond the performance defined for the 5G technology. This spectrum is essentially exploited for scientific services, but attracts nowadays many interest within the wireless telecommunications research community, following the same trend as in previous network generations. The BRAVE project that was launched at early 2018, aims at the elaboration of new waveforms able to efficiently operate in the 90–200 GHz spectrum. The researches rely on three complementary works: the definition of relevant communications scenarios (spectrum usage, application, environment, etc); the development of realistic models for the physical layer (propagation channel and RF equipments); and the elaboration of a single-carrier modulation compliant with the propagation channel properties, and allowing improvement on the spectral and energy efficiency. The motivation for this work, and the preliminary results on the waveform definition, are exposed in the present paper. Index Terms—Tbit/s, beyond-5G, above-90GHz, single-carrier. I. INTRODUCTION The activities of research and industrialization concerning the fifth generation (5G) of wireless communication systems are well-under way. Several solutions are proposed for standardization starting with 5G-NR (New Radio) [1]. There are three main objectives driving the development of 5G: the support to extreme wireless broadband services for applications such as the virtual and augmented realities, the 3D 4K video, cloud services, etc.; the connectivity for massive Internet of Thing (IoT) applications as: smart cities and factories, wireless health care; and the support of mission-critical services such as for autonomous vehicle, or security, with strong requirements on latency, guaranteed throughput, etc. All these target applications have highly different needs, but make 5G required to offer: throughputs in the order of Gbps with sub-millisecond latency along with 1000x capacity increase, and 100x connected devices per cell compared to nowadays existing mobile networks. Dense small-cell deployments , centralized RAN (Radio Access Network), advanced MIMO schemes and new millimeter-Wave (mmW) bands are key enablers to achieve the expected increase in spectral efficiency and capacity [2]. Frequency bands 26 or 28 GHz and 39 or 42 GHz will be likely selected for early 5G deployments. Alongside these 5G initiatives, the scientific community has also launched many investigations on the beyond 5G

Spectrum crunch is a severe issue for below 6GHz wireless communications. Cognitive radio and Dynamic Spectrum access (DSA) based on geographic database are promising techniques to cope with this spectrum shortage. TV White Space (TVWS) usage relies on unlicensed secondary DSA under the principle on a non-harmful interference with incumbent users, allowing to use UHF channels whose availability is changing over time and space. In order to do so, a well-designed physical layer is required in order to reach accurate frequency localization while being highly flexible. We describe field-test experiments done with an implementation of the BF-OFDM (Block-Filtered OFDM) physical layer on versatile and portable hardware prototyping boards. Field-trials results confirm the potential of BF-OFDM for fragmented spectrum access and spectrum sharing usage.

One of the main issues, in the specification of the 5G radio access network (RAN) technology, is the design of a new waveform, overcoming the limitations of the CP-OFDM in terms of frequency localization, spectral efficiency and robustness to users asynchronism, while keeping low latency and reduced transceiver implementation complexity. In the last decade, many waveforms have been proposed in order to achieve the best compromise between the aforementioned constraints. This paper aims at comparing, as fair as possible, the performances of promising schemes namely WOLA-OFDM and BF-OFDM in terms of spectrum confinement, transmitter complexity and robustness in a typical multi-user asynchronous scenario.

International audience; A flexible and efficient use of the frequency resource is a key challenge for future wireless technologies. The new requirements are not satisfied by the CP-OFDM which has motivated the research on alternative waveforms. Recently, Block-Filtered OFDM modulation scheme has been proposed. This waveform addresses most of the CP-OFDM's drawbacks at the price of a slight complexity increase of the transmitter. The scheme is based on a filter-bank, a precoding stage that ensures the Near Perfect Reconstruction property and a pre-compensation stage which avoids filtering at the receiver. In this paper, the filter specifications for BF-OFDM are derived and an optimization method based on self-interference rejection is proposed. Optimized filter shape can provide up to 70 dB of Signal-to-Interference Ratio which justifies the Near Perfect Reconstruction property with an enhanced spectral confinement and no channel performance degradation.

5G will have to cope with a high degree of heterogeneity in terms of services and requirements. Among these latter, flexible and efficient use of all available non-contiguous spectrums for different network deployment scenarios is one challenge for the future 5G. To maximize spectrum efficiency, the 5G air interface technology will also need to be flexible and capable of mapping various services to the best suitable combinations of frequency and radio resources. Such requirements are not satisfied by legacy CP-OFDM and alternative multicarrier waveforms such as UFMC and FBMC partially meet them. In this article, we introduce a new quasi-orthogonal waveform called Block-Filtered OFDM (BF-OFDM) that combines most of the advantages of the aforementioned waveforms at the price of slight complexity increase. Spectral localization and performance in multi-user scenario will be enhanced w.r.t OFDM and simple equalization as well as all classical MIMO schemes can be straightforwardly considered. The proposed waveform offers the same performance in presence of multipath channel as CP-OFDM and is also scalable which paves the way for future multi-service scenarios.

International audience; The forthcoming fifth generation of mobile technology (5G) will be designed to satisfy the demands of 2020 and beyond. 5G does not just promise a huge increase in terms of data rates and capacity but it also targets new kind of use cases like Internet of Things or vehicular communications. The currently deployed 4G technology does not provide enough network capabilities to support this wide diversity of applications which has motivated the research on alternative waveforms. In this article, a new promising modulation scheme is introduced: Block-Filtered OFDM (BF-OFDM). The proposed waveform demonstrates an excellent frequency localization and can straightforwardly be integrated with the OFDM know-how and LTE principles. Besides, the proposed waveform relies on a receiver similar to the one used in CP-OFDM. BF-OFDM systems are also scalable, which is an interesting feature in order to steer the network capabilities on demand.

In this chapter, we discuss the implementation of an FBMC PHY for TVWS application. The baseline for this implementation is the recent IEEE 1900.7-2015 standard introduced in Chapter 2. To our knowledge, this is the first worldwide standard based on an FBMC air interface or, more generally speaking, on a nonorthogonal waveform. After a brief introduction, which highlights the benefits of FBMC in the context of TVWS, we describe the implementation using a frequency domain approach (namely Frequency Sampling FBMC, FS-FBMC). We show that this technique is very well suited for uncoordinated multiuser scenarios. We discuss the complexity of FS-FBMC implementation. Then, we analyze a flexible architecture that can manage FS-FBMC and OFDM modes with a discussion of the impact on the waveform on hardware constraints.

In order to reduce constant exchange of control signalling, relaxed synchronisation is considered for the fifth generation of wireless cellular networks. This requirement combined with dynamic spectrum access has led to reconsider conventional orthogonal frequency division multiple access. Frequency division multiple access for filter bank multicarrier FBMC modulation has emerged as a serious contender for these asynchronous fragmented spectrum access scenarios. In this paper, it is demonstrated that the frequency-spreading FBMC receiver architecture is particularly adapted to deal with these scenarios and is robust to severe channel conditions. Channel estimation has however so far only been partially addressed in this context. The challenges of this essential signal processing block are presented in this paper. Interference approximation methods have been applied to the so-called frequency-spreading FBMC receiver to propose and evaluate preamble structures and channel estimation schemes. A flexible preamble structure is finally described and analysed. Copyright © 2014 John Wiley & Sons, Ltd.

In this paper a flexible radio approach for opportunistic access to the television white space (TVWS) is presented. Requirement stems from the coexistence scheme used in this band between opportunistic transmission and TV broadcast signals (or wireless microphones). To ensure nonharmful interference of the TVWS signal on the incumbent services, a high adjacent leakage power ratio (ACLR) is expected. Also, flexibility is required to address the vacant channels in the UHF spectrum. Flexibility and low ACLR specifications are difficult to obtain simultaneously. The approach proposed in this paper is based on filter bank multi-carrier modulation (FBMC) scheme and a flexible hardware platform to combine the digital filtering capability of FBMC with RF agility. A FBMC hardware architecture implementation is presented and its associated complexity is studied for this platform. Then the hardware implementation validates that both flexibility and ACLR performance of the system are preserved even when off-the-shelf component impairments are considered. An experimental setup validates the coexistence with a TV broadcast signal and a comparison with a classical approach shows the gain in performance.

The 5G CHAMPION Consortium will provide the first fully integrated and operational 5G prototype in 2018 - this effort is a major leap ahead compared to existing punctual technology trials, such as, e.g., Proof-of-Concept platforms focusing on mmWave communication in specific bands, etc. This paper describes the overall set-up including a synergetic combination of technologies such as beamforming based mmWave a Satellite service provisioning, virtualized infrastructure, software reconfiguration across the entire stack, accurate positioning and high-speed solutions. The key enablers are described in detail and related efforts in standards and regulation organizations are discussed.

This chapter provides fundamental indications about wireless communications beyond LTE/LTE‐A (5G). We start by identifying the drivers for making the transition to 5G networks, and we make clear that the strict paradigm of synchronism and orthogonality as applied in LTE prevents efficiency and scalability. We challenge this paradigm and propose new key PHY‐layer technology components, the core being a unified frame structure concept, which supports an integrated 5G air interface, capable of dealing both with broadband data services and small packet services within the same band. It is essential for this concept to introduce waveforms that are more robust than OFDM, for example with respect to time‐frequency misalignment. Encouraging candidate waveform technologies are presented and discussed with their respective results. This goes along with the corresponding multiple access technologies, using multi‐layered signals and advanced multi‐user receivers. In addition, we introduce new strategies to enable “one shot transmission”, with greatly reduced control signaling, particularly for sporadic traffic. These components enable an efficient and scalable air interface supporting the highly varying set of requirements originating from the 5G drivers.

Low Power Wide Area networks aim at connecting low cost devices with high constraints on the link budget. Focusing on the physical layer, the combination of orthogonal modulation and coding in the same process has been shown efficient when associated with a turbo receiver. This work shows how this scheme, based on frequency shift keying modulation, can be efficiently implemented on today low-end platform based on a flexible radio frequency semiconductor component combined with a low power microcontroller. A link budget improvement of 4.6dB is demonstrated with a low-end receiver, enabling a coverage extension by a factor of 1.78 or a reduction of the transmit power by a factor 3, while keeping the same quality of service.

White space communications have attracted a particular interest after some national regulators have authorized TVWS unlicensed secondary usage. The IEEE 1900.7 working group has defined a specific air interface tailored to these applications. The standard, is based on an Filter Bank Multi Carrier (FBMC) physical layer and a CSMA-CA MAC sublayer. In this paper, the Modulation and Coding Schemes (MCS) of the IEEE 1900.7-2015 are considered to assess simulated expectations on throughput and coverage under various typical TVWS deployment scenarios: Fixed Long Range Access, campus WLAN (in Fixed Urban/Suburban environments), Indoor Femtocells (a TVWS low power transceiver for WLAN-like applications). Expected rate and coverage maps are provided for these scenarios.

The demand for faster transmission rates in radio frequency identification has led to the adoption of phase-shiftkeying (PSK) modulations for the communication between the proximity coupled device (PCD) and the proximity integrated circuit card (PICC). This paper derives a transmission model to analyze the intersymbol interference generated by the PCD-to-PICC coupled antennas. An equalizer structure is then introduced and performance compared against previous generations of very-high bit rate systems using amplitude shift keying. It concludes that PSK modulations proposed for VHBR can be robust even when the resonance of the antenna circuits is relatively high.

International audience; —The number of Machine to Machine (M2M) applications is increasing rapidly especially in cellular communication systems. These applications should support a very high number of stations (STAs) and facilitate communication without any human intervention. To fulfill these requirements random access protocols are a possible choice. Carrier sense multiple access collision avoidance (CSMA/CA) protocol with request to send and clear to send (RTS/CTS) mechanism presents high degradation of the throughput and packet drop probability performance especially when the packets size are small. The medium access control (MAC) overhead caused by the RTS and CTS messages is high comparing to the total duration of successful transmission. In order to reduce the MAC overhead we propose in this work a new strategy to serve many users successively. This strategy consists on sending many RTS in parallel by different stations on different frequency sub-bands. Once the RTS messages do not collide with each other, there will be no need to resend the RTS and wait for a CTS to gain the channel access. In this paper, this proposed strategy is investigated and we demonstrate that it reaches better saturation throughput and packet drop probability especially in loaded networks. Index Terms—Multiband Carrier sense multiple access/collision avoidance (M-CSMA/CA), throughput, MAC protocol, scheduling, M2M, overhead reduction, finite retransmission, packet drop probability.

International audience; —Machine to machine communication (M2M) or machine type communication (MTC) facilitates communication without any human intervention. These applications will support an enormous number of stations (STAs). To mitigate degradation of the throughput and delay performance in wireless local area networks (WLAN) that employ carrier sense multiple access collision avoidance (CSMA/CA) protocol with request to send and clear to send (RTS/CTS) mechanism, we propose to reduce the overhead introduced by the hand shake mechanism. The medium access control (MAC) overhead caused by the RTS and CTS messages is high comparing to the total duration of successful transmission. In order to reduce the MAC overhead we propose in this work a new strategy to serve many users successively. This strategy consists on sending many RTS in parallel by different stations on different frequency sub-bands. Once the RTS messages do not collide with each other, there will be no need to resend the RTS and wait for a CTS to gain the channel access. In this paper, this proposed strategy is investigated and we demonstrate that it reaches better saturation throughput and delay especially in loaded networks. Index Terms—Carrier sense multiple access/collision avoidance (CSMA/

International audience; We present in this paper a new medium access control (MAC) scheme devoted to orthogonal frequency division multiple access (OFDMA) systems which aims at reducing collision probabilities during the channel request period. The proposed MAC relies on the classical carrier sense multiple access/collision avoidance (CSMA/CA) protocol with RTS / CTS ("Request To Send" / "Clear To Send") mechanism. The proposed method focus on the collision probability of RTS messages exploiting a multi-channel configuration for these messages while using the whole band for data transmissions. The protocol may be interpreted as an asynchronous frequency multiplexing of RTS messages. This method achieves strong performance gains in terms of throughput and latency especially in crowded networks. Index Terms—Carrier sense multiple access/collision avoidance (CSMA/CA), multiband, throughput, MAC protocol.

International audience; Filter Bank MultiCarrier modulation (FBMC) is a promising waveform technology envisaged for future mobile communication networks. For many transmission scenarios, the combination of multiple non-contiguous spectrum bands is foreseen. Because of coexistence issues, very low Adjacent Channel Leakage is required making FBMC waveforms of particular interest. However the fair frequency localization of FBMC results in a time spreading of the waveform: the filter impulse response introduces transitions which increase the duration of the burst with respect to classical multicarrier schemes such as Orthogonal Frequency Division Multiplexing and may reduce the overall spectral efficiency. In this work, we propose to study the performance of a FBMC waveform considering Carrier Sense Multiple Access with Collision Avoidance. Two mechanisms are employed for packet transmission: a basic access and a reservation scheme (based on RTS/CTS). We study how effective the RTS/CTS handshake is under ideal channel conditions by taking into account the specificities of the FBMC physical layer. Furthermore, we discuss about the RTS threshold value on packet size that maximizes throughput performance by employing one of both possible schemes and the impact of subchannel aggregation strategies on throughput and latency.

Relaxed synchronization and access to fragmented spectrum are considered essential for future generations of wireless networks in order to reduce physical channel signaling. Frequency Division Multiple Access for Filter Bank Multicarrier (FBMC) modulation provides promising performance without strict synchronization requirements contrary to conventional Orthogonal Frequency Division Multiplexing (OFDM). In this paper, the architecture of a FBMC receiver suitable for this scenario is considered and its performance is compared against OFDM. The maximum achievable capacity of an asynchronous uplink transmission is analyzed when limited amount of feedback information on timing misalignment and power control is available. The proposed receiver architecture based on frequency domain processing combined with the fair frequency localization of the FBMC prototype filter provides an architecture that allows for more efficient multiuser asynchronous reception compared to OFDM.

International audience; —In this work we study the collision probability, saturation throughput and statistical delay for the carrier sense multiple access collision avoidance (CSMA/CA) protocol with request to send and clear to send (RTS/CTS) mechanism in the case of frequency channel division. We propose in this paper a modified version of CSMA/CA-RTS/CTS to be compatible with the channel repartition technique and we prove that an important gain is introduced in terms of system performance especially for loaded networks. Simulations highlight that dividing the channel into independent sub-channels reduces drastically the RTS collision probability. Moreover, a gain in terms of saturation throughput and delay is shown especially in dense networks. Index Terms—Carrier senses multiple access/collision avoid-ance (CSMA/CA), Frequency channel division, RTS/CTS, MAC protocol.

International audience; Many modern wireless networks integrate carrier sense mul-tiple access/collision avoidance (CSMA/CA) with exponential backoff as medium access control (MAC) technique. In order to decrease the MAC overhead and the collision probability, we propose in this paper a new backoff strategy leading to better saturation throughput and access de-lay performance comparing to the classical protocol. We investigate the CSMA/CA with RTS/CTS technique, and we show that our strategy reaches better saturation throughput and access delay especially in dense networks. This proposed strategy distributes users over all the backoff stages to solve the bottleneck problem present in the first backoff stage. Finally, we analyze our strategy and we compare it to the classical one modeled by Markov chain. Analytical and simulation results show the improvment in term of saturation throughput. Cumulative density func-tion (CDF) of the access delay illustrates the important gain obtained by the proposed strategy.

In this paper a flexible radio approach for opportunistic access to the television white space (TVWS) is presented. Requirement stems from the coexistence scheme used in this band between opportunistic transmission and TV broadcast signals (or wireless microphones). To ensure non harmful interference of the TVWS signal on the incumbent services, a high adjacent leakage power ratio (ACLR) is expected. Also, flexibility is required to address the vacant channels in the UHF spectrum. Flexibility and low ACLR specifications are difficult to obtain simultaneously. The approach proposed in this paper is based on filter bank multi-carrier modulation (FBMC) scheme and a flexible hardware platform that combines RF agility and the digital filtering capability of FBMC. The hardware implementation validates that both flexibility and ACLR performance of the system are preserved even when off-the-shelf components impairments are considered. An experimental setup validates the coexistence with a TV broadcast signal and a comparison with a classical approach shows the gain in performance.

We investigate the problem of sequence detection in a non linear channel for a contactless air interface. The work presented in this study is based on the the VHBR (Very High Bit-Rate) amendments of the ISO 14443 international standard. We focused more particularly on the part of the standard extension that defines the phase modulation (PSK) from the Proximity Coupling Device (PCD) to the Passive Inductive Coupled Card (PICC). We propose an efficient detector to overcome both Inter Symbol Interference (ISI) due to the high data rates, and system non linearities introduced by the differential detection at the receiver side. The proposed detector is an adaptation of the Viterbi algorithm for constraint-ternary alphabet. Our numerical results show that a rate of 13.56 Mbps can be achieved using a 15-states sequence detector.

A flexible data frame structure adapted to 5G operations and designed to support high bandwidth pipes or sporadic traffic is described. The frame structure imposes to consider receiver architectures that are adapted to orthogonal frequency division mutliplexing (OFDM) for structured synchronous traffic and alternative flexible asynchronous waveforms such as filterbank multicarrier (FBMC) for sporadic traffic. OFDM and FBMC receivers are reviewed and a new flexible receiver architecture is then proposed and described. The design of the new architecture is centered on a memory unit complemented with co-processor units improving the flexibility of the digital signal processing operations of the receiver. The architecture is particularly adapted to application specific integrated circuit. The throughput imposed on the memory and the associated data receiver bus has been evaluated. The evaluation concluded that the throughput is suitable for very large scale integration implementations.