The use of multiple antennas for wireless communication systems has gained overwhelming interest during the last decade - both in academia and industry. Multiple can be utilized order to accomplish a multiplexing gain, diversity or an antenna thus enhancing bit rate, error performance, signal-to-noise-plus-interference ratio systems, respectively. With enormous amount yearly publications, field multiple-antenna often called multiple-input multiple-output (MIMO) evolved rapidly. To date,...

In this paper, we consider a relay-assisted wideband cognitive-radio (CR) system under the assumption that frequency band chosen by CR relay network for unlicensed spectrum usage overlaps with one or more bands dedicated to primary (e.g., licensed) narrowband links. Our objective is optimize performance of while limiting interference in direction receivers, without requiring any adaptation transmitted signal spectra at cognitive nodes. To end, study appropriate transmit power allocation...

This paper presents an anti-drone system which consists of a 3D Frequency Modulated Continuous Wave (FMCW) Multiple Input Output (MIMO) radar and directional jammer working at 2.4 GHz. The is continuously scanning certain area waits until target enters the to secure. A tracking algorithm evaluates movement target. If potential threat identified, antenna, mounted on two-axis gimbal, steered With use control signal drone can be superimposed by strong jamming makes controlling impossible. Even...

Multiple-input multiple-output (MIMO) radars have been shown to improve target detection for surveillance applications thanks their proven high-performance properties. In this paper, the design, implementation, and results of a complete 3-D imaging frequency-modulated continuous-wave MIMO radar demonstrator are presented. The sensor working frequency range spans between 16 17 GHz, proposed solution is based on 24-transmitter 24-receiver architecture, implemented by time-division multiplexing...

The pod integrated variant of the airborne SmartRadar by AIRBUS Defence and Space, mounted under wing a Learjet 35 aircraft, is used as testbed to develop advanced radar modes. In particular, it offers capabilities multiphase-center active electronically steered array (AESA) antenna flexible, wide-bandwidth core. During last 2 years, already-operated synthetic aperture (SAR) ground moving target indication (GMTI) modes have been supplemented newly developed maritime This overview paper...

The generalized κ-fading model, characterized by two parameters, κ and m, is a very versatile model was recently shown to accurately capture the effects of composite shadowing multipath fading in wireless communication systems. Furthermore, it can be used cascade fading, which relevant in, e.g., mobile-to-mobile scenarios. In this paper, we derive closed-form expressions for bit error probability non-coherent transmission schemes over L diversity branches being subject κ-fading....

Responsive communications jamming is an emerging technology for electronic-warfare applications. In contrast to state-of-the-art barrage jammers, which continuously jam entire frequency bands irrespective of current signal activities, responsive jammers regularly perform wideband scans the radio spectrum and are thus able react observed signals. By this means, available transmit energy can be focused on currently relevant spectral areas, potentially leads significantly improved efficiencies....

Ever since the era of autonomous systems started, multisensor platforms have become a key topic in aerospace, automotive, and robotics industries. Multifunctional integrate more than one sensor and/or actuator device are capable creating synergies between them. As consequence, their performance is superior compared to single-sensor systems, for different reasons [1]-[3].

Multiple-antenna systems, denoted multiple-input multiple-output promise huge performance gains over conventional single-antenna systems. Many MIMO transmission schemes proposed in the literature are, however, based on idealized assumptions. Several effects that may occur a practical system, such as intersymbol interference, nonperfect channel knowledge, fast fading, and correlation between individual paths, significantly influence system performance. On basis of two particularly simple but...

The probabilistic data association (PDA) decoder is investigated for use in coded multiple-input multiple-output (MIMO) systems and its strengths weaknesses are determined. conventional PDA includes two approximations. received symbols assumed to be statistically independent a Gaussian approximation applied the interference noise term. We provide an analytical formula exact probability density function (PDF) of term, which used discuss impact presence soft-input soft-output channel decoder....

In this paper, typical uplink scenarios in a cellular system are considered, where two cooperating mobile stations (serving, for example, as relays) transmitting the some information to base station by using distributed space-time coding scheme. Due nature of system, transmitted signals typically subject different average path losses. For fixed distances between and station, error performance scheme is determined analytically. Then, based on considerations concerning spatial distribution...

We address the issue of optimal transmit power allocation in relay-assisted cognitive-radio (CR) systems. In particular, we assume that frequency band chosen for unlicensed spectrum usage is not completely unoccupied, but contains one or more licensed narrowband users. For such a setting, develop distributed schemes, which optimize performance CR system, while at same time interference experienced by users limited. Numerical results illustrate notable improvements compared to non-cooperative...

We address the problem of direction-of-arrival (DoA) estimation for air targets using a compact, multi-functional radar sensor. In order to enhance angular resolution such sensors while exploiting sparseness typical scenarios, we consider combination multiple-input multiple-output (MIMO) approach with suitable compressive-sensing (CS) techniques. particular, investigate MIMO processing two-dimensional (2D) antenna arrays CS-based three-dimensional (3D) target localization and 2D DoA in...

We analyze the performance of a fully decentralized (FD) transmit power allocation (TPA) scheme for relay-assisted cognitive-radio (CR) systems. In particular, we assume that frequency band chosen by CR relay network unlicensed spectrum usage overlaps with an active primary narrowband link. The considered FD-TPA maximizes signal-to-noise-plus-interference ratio at destination node according to best-effort strategy, while limiting interference experienced receiver. Numerical results show...

In this paper, we propose two novel pre-equalization schemes for multiple-input single-output (MISO) direct-sequence ultra-wideband (DS-UWB) systems with pre-Rake combining and symbol-by-symbol detection. The first scheme employs one filter (PEF) per transmit antenna, whereas in the second scheme, simplified PEF (S-PEF) all antennas share same PEF. For both optimum finite impulse response (FIR) infinite (IIR) PEFs are calculated based on minimum mean squared error (MMSE) criterion. Our...

In this paper, we propose a novel optimization-based pre-equalization filter (PEF) design framework for direct-sequence ultra-wideband (DS-UWB) systems with pre-Rake combining. The key feature in our is that explicitly take into account the spectral mask constraints are usually imposed practice by telecommunications regulation and standardization bodies. This avoids need an inefficient power back-off, which necessary existing pre-Rake-based transmitter structures designed solely based on...

In this paper, we propose a novel multi-hop relaying scheme to improve the performance and coverage of impulse-radio-based ultra-wideband (IR-UWB) systems. With regard simple practical realization, focus on non-coherent system setup in conjunction with amplify-and-forward (A&F) relaying. particular, employ multiple-differential encoding at source node single differential decoding each relay destination node, respectively, so as efficiently limit intersymbol-interference effects node. For...

We present a compact multiple-input multiple-output (MIMO) radar sensor for near-to medium-range three-dimensional (3D) imaging and target object detection. The MIMO contains 16 transmit (Tx) receive (Rx) antenna elements employs frequency modulated continuous wave (FMCW) modulation scheme. Orthogonality between the transmitted signals is ensured by means of time-division multiplexing (TDM) First, brief description overall system architecture given. Then, two distinctive array designs are...

We consider error-rate prediction for dual-use lighting systems with visible light communication (VLC) functionality. Since <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">light planning</i> rather than communications engineering is usually the driving discipline practical settings, we extract VLC channel parameters as a by-product from advanced 3-dimensional (3D) light-planning models. By this means, attain realistic signal-to-noise ratios...

To enable a safe and reliable operation in future urban air mobility scenarios with large number of autonomous aerial vehicles, automatic sensing systems will be required during the starting landing phase, as well through comparatively narrow spaces typical for areas. This letter shows an implementation compressive (CS)-based obstacle-detection direction-of-arrival (DoA) estimation approach. this end, multiple-input multiple-output (MIMO) frequency-modulated continuous wave radar system two...

Abstract Two‐dimensional direction‐of‐arrival (DoA) estimation in azimuth and elevation via radar systems equipped with uniform rectangular arrays (URAs) will play an important role various application areas—most distinctively future urban air mobility settings unmanned aerial vehicles. A key factor is the fast reliable provision of target detections terms range DoA for safe autonomous operation vehicle using on‐board antenna compact installation size. The authors present a technique...

Current research focuses on radio frequency (RF) systems for autonomous driving and urban air mobility, sharing demands utmost reliable communication radar installed in confined spaces. As a result, co-existence considerations are becoming increasingly important. By dividing antenna groups into sub-groups increasing their spacing, mutual interference can be reduced. In our research, we seek to reduce RF effects medium-size aerial vehicles (AAVs). To this end, distributed MIMO arrays employed...

The application of distributed space-time coding schemes in a simulcast network is considered and key challenge addressed which arises the downlink: since local oscillators employed at individual transmitting nodes may independently differ from nominal carrier frequency, frequency offsets will occur between transmission signals. influence these on performance specific scheme investigated both simulative analytical results are presented. Appropriate receiver-sided counter measures...