This paper presents a single-antenna receiver passive radar system in the context of moving target detection such as trains, car, planes and UAVs, leveraging the long-term evolution (LTE) network as an illumination source. The proposed system uses signal reconstruction enabled by the telecom structure of the opportune signal in order to forego the use of a reference antenna. This presents the advantage of not relying on a physical signal for reference and its possible defect, potentially yielding better performances. The techniques introduced are validated through simulation and experiments. Moreover, a simplified passive radar system emphasises one of the key advantage of passive radar over other competing technologies for moving target detection: stealthiness and cost-effectiveness.

Considering the increasing demands of wireless data transfer fuelled by the introduction of 4G and 5G, the maritime transport industry is looking for new wireless technologies able to provide a sufficient quality of service on board based on extended terrestrial wireless coverage. However due to the nature of the propagation channel and the large cell size, the design of a maritime wireless network with terrestrial base station is challenging. We present in this paper the deployment of a maritime network in the 3.5 GHz TDD band complementary to a satellite network to deliver high-speed data rate with low latency at low cost. The network architecture is first described and performance of the proposed 5G NR-like system are assessed under field trials. We demonstrate that the coverage the Channel from the French and UK coasts is possible with appropriate base station location and dedicated antenna strategies to deliver 80+ Mbps.

Several techniques are used to mitigate the Self-Interference (SI) in In-Band Full-Duplex (IBFD) applications. Antenna isolation and especially dual polarized antenna is an efficient way to reach such objective in restricted footprint. Moreover antenna isolation does not generate noise and it does not create non-linear distortion. A test bench, including dual port antenna, analog and digital cancellation techniques is proposed, and the SI cancellation is evaluated in a controlled environment. A specific design of antenna is presented. An isolation of 47.5 dB is experimentally obtained between the two cross-polarized ports of a particular patch antenna. Matching of the antenna's reflection parameters to -20 dB and broadside gains of 8 dBi are obtained. The additional analog and digital cancellers bring 48.9 dB more cancellation to reach 103 dB Self Interference mitigation.

In-band Full Duplex (IBFD) is a promising wireless transmission technology allowing to increase data rates by up to a factor of two, via simultaneous transmission and reception, but with a potential to increase system throughput even much more in cognitive radio and random access systems thanks to simultaneous transmission and sensing. The main ingredient allowing FD is Self Interference Cancellation (SIC). To reach the required high level of SIC, normally several SIC techniques need to be combined, such as antenna isolation or circulator attenuation, analog and digital SIC. Some of these techniques, esp. analog SIC, do not scale well with the number of antennas as required for Massive MIMO. In this paper we consider two promising directions, namely Hybrid SIC (HSIC), and MIMO SI Nulling (SIN), which is based on separate transmit and receive antenna arrays. HSIC can be realized with a number of SIC branches that scale linearly with the number of antennas. On the other hand, the MIMO SI channel can be designed to be of reduced rank, leading to reduced zero-forcing requirements for MIMO SIN. Both HSIC and MIMO SIN can be combined with digital SIC which does not introduce additional hardware. In this paper we present simulation and measurement results to capture some of the characteristics of both approaches.

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.

In-Band Full-Duplex transmissions are promising solutions for wireless 5G small cell communication scenarios. It allows to increase the overall capacity under certain conditions. In this paper we evaluate two combined techniques to mitigate the analog self-interference. Instead of using high performance components with high linearity and high bandwidth for a frequency band, a single SDR chip has been chosen. Based on its characteristics and its simple architecture, a compact and low complexity test bench is proposed to reduce the undesired self-interference. The analog self-interference cancellation reaches 71 dB over 40 MHz bandwidth with a transmitted power of 12 dBm.

Multi-service transmissions are expected in the upcoming fifth-generation (5G) of cellular networks. These heterogeneous applications lead to many constraints that need to be addressed in a flexible way. We investigate the division of the bandwidth into several subbands, each one having a given physical layer numerology to support a given type of 5G services. This work highlights and demonstrates the possible coexistence of Broadband, Ultra-Reliable Low-Latency and Internet of Things services within the same channel using a flexible waveform. We describe field-test experiments carried out with an implementation of the BF-OFDM (Block-Filtered OFDM) physical layer on custom hardware prototyping boards. Field- trials results confirm the potential of BF-OFDM and the feasibility of the use of mixed numerologies for the next generation of cellular network.

For future wireless communication systems, full duplex is seen as a possible solution to the ever present spectrum shortage. The key aspect to enable In-Band Full Duplex (IBFD) is sufficient cancellation of the unavoidable Self-Interference (SI). In this work we evaluate the performance of a low complexity IBFD transceiver, including the required analog and digital interference cancellation techniques. The Radio Frequency Self-Interference Canceler (RFSIC) is based on the isolation of a circulator in combination with a vector modulator regenerating the interference signal, to destructively combine it with the received signal. On the digital side, a Digital Self-Interference Cancellation (DSIC) algorithm based on non-linear adaptive filtering is used. With the simplified analog front-end of a Software Defined Radio (SDR) platform, SI cancellation of 90 dB is achieved with the presence of a received signal.

In-band full-duplex transceivers are considered for future generations of cellular network systems. This paper proposes to evaluate the performance of in-band full-duplex transceivers using a modified architecture based on hardware available for multiple-input multiple-output transceivers. A hybrid self-interference cancellation technique using an auxiliary transmitter is therefore introduced. Performance is evaluated using simulation models and is confirmed by hardware experimentation. The main limiting factors of the proposed architecture are analyzed and improvements to the architecture are then suggested.

Power amplifier nonlinearity compensation based on nonlinearity estimation at the receiver is a potential solution to decrease both the cost and the complexity of the transmitter in femtocell or relay. In this paper, we performed an end-to-end test with realistic multipath propagation effects emulated in an anechoic chamber.

In this study a novel scheme of predistortion of power amplifier non-linearities is developed and demonstrated. The originality of the proposed system architecture is that the estimation of non-linearities is carried out at the receiver, thanks to a training sequence, and sent back to the transmitter for predistortion. The proposed architecture achieves efficient compensation of power amplifier non-linearities on WiMAX and long-term evolution (LTE) standards without extra hardware. An evaluation of power consumption savings is carried out, considering digital consumption of the estimation algorithm at the receiver side and predistortion look up table refreshment at the transmitter side. The results show that the suggested architecture can be applied for high data rate systems at base stations, relay stations and mobile stations as well.

In this paper, a digital algorithm is proposed for the compensation of base station power amplifier nonlinearity for 802.16j very high data rate systems. The compensation takes place into the relay station receiver, which reduce the overall network power consumption. Simulation results show good performance enhancement, while an experimental test bed achieves the proof of concept on WIMAX signal.

This paper analyses the impact of RF impairments in a new wireless environment where relays are introduced to improve performances. Thanks to a simulation chain supporting theoretical RF impairments models, different techniques are evaluated. The transmission chain can simulate amplify-and-forward or decode-and-forward protocols in either simple relaying or cooperative scenarios. The results of these simulations show BER degradations versus several realistic sets of RF impairments.

Motivated by the theoretical results on multi-antenna signal processing techniques promising substantial performance gains, a feasible reconfigurable hardware architecture for OFDM-based Wireless LANs is presented in this paper. The ultimate objective of the platform is to support single-antenna links, as well as antenna arrays at the receiver and/or at the transmitter, taking into account the limitations caused by a real-time implementation. After a brief overview of the implemented multi-antenna algorithms, we present the hardware platform that has been built based on both fixed point and floating point DSPs from Texas Instruments, together with the evaluation of the complexity associated to the operations, and their scheduling. The performance indicates that a multi-antenna architecture supporting up to four antennas at the receiver side might accomplish the real-time requirements.

In the last five years, transmissions using multiple sensors at both ends of the link have been a major research topic. Many transmission schemes are studied such as point to point links using diversity coding, point to point links using multiplexing, tradeoffs between both and at last multi-point to point links. This last scheme was already covered by Space Division Multiple Access (SDMA) processing but a step forward was made with multiple subscriber detection. This paper asses the multi-point to point links for uplink and point to multi-point for the downlink based on OFDM waveform in the frame of the Wireless Metropolitan Area Network (WMAN) IEEE Std 802.16-2004 or HIPERMAN standard. It describes a realistic implementation of transceivers for Physical (PHY) layer to Medium Access Control (MAC) layer allowing a system capacity increase with minor modifications of the standard and with a low impact on the complexity of the subscriber equipment. In this context, this paper proposes to focus on based-band techniques: The Obèle algorithm based on the channel knowledge in the downlink and multiple-user detection in the uplink. The algorithm complexity and the tradeoffs for implementation are extensively discussed.

This paper deals with the translation into a practical hardware design of antenna array algorithms developed especially for the European Wireless LAN standard Hiperlan/2 (HL2). The ultimate goal is to demonstrate the feasibility of Multi Element Antenna (MEA) systems with current available hardware. Whereas optimality is the key point in the theoretical analysis of techniques, practical details play the main roles in hardware integration. Here, we describe both the optimum techniques based on theoretical studies and related practical concerns about those algorithms. We show that optimum performances are not always attainable in realistic hardware design.

One of the major challenges of the telecommunication community for the coming years will be to make multimedia services available to everyone, even to those who are in remote places. Broadband fixed wireless access (BFWA) is one of the best positioned radio access technologies to provide broadband access with performances that surpass current 3G mobile data rates and are similar to wired xDSL systems. The paper addresses the solutions which are proposed and demonstrated in the frame of the IST-STRIKE project to enhance spectral efficiency for BFWA and to guarantee end-to-end quality of service (QoS) through a dual mode HiperMAN/HiperLAN system. The first aspect is covered by the use of multi-transmit multi-receive (MTMR) techniques. Indeed, as it is foreseen that the data rates available with the studied standards will be sufficient for the majority of single user needs, the best way to increase the capacity and lower the deployment cost is to multiply the number of simultaneous transmissions. Besides, it is shown that to ensure QoS for high data rate and time constrained services (such as video streaming), interworking is provided at the data link control (DLC) level.

Motivated by the theoretical studies concerning multiple antennas at the receiver side in OFDM systems, we develop in this paper a feasible hardware structure for this kind of architectures, which has nowadays some inherent limitations if real-time operation is sought. First, we review briefly the theoretical background, and then present our reconfigurable hardware structure, for which we finally analyze the performance and complexity of the proposed multi-antenna strategies.

This document intends to present a definition of scenarios, and a first approach to the definition of STRIKE project requirements, to be used by the different technical activities within the STRIKE project (WP3, WP4, WP5 and WP6). Aspects such as definition of services, traffic models, scenarios, channel models, and simulation and demonstrator common methodology are presented. A detailed specification of HIPERMAN and HIPERLAN/2 PHY, DLC and CL layers is provided. Also, the options of HIPERMAN–HIPERLAN/2 interworking, and the relevant multiple antennas techniques are introduced.