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In the part of geophysics researches, the method Double Beam Forming (DBF) was found for separating the surface waves from the seismic waves. According to one of the kernels of DBF : extraction of group velocity and phase velocity, this paper benefit from this idea and concentrate on the time delay estimation (TDE) which is one of the key techniques in the array signal processing. The sound velocity...
While many companies have launched various wireless chargers in mobile industries, conventional wireless power transfer (WPT) technologies are available only for a very short distance due to large attenuation of the magnetic fields. A magnetic beamforming WPT system achieves an enhanced power transfer efficiency (PTE) with a longer wireless charging distance than conventional WPT technologies by adjusting...
A joint radar-communication (JRC) system can provide cost-effective and spectrum-efficient platform solution with simultaneous operation, while accomplishing important tasks, sensing via radar processing and allocation of communication links. Existing modulation techniques where information embedding is achieved using sidelobe Amplitude-Shift Keying (ASK) for the JRC system are not investigated so...
MU-MIMO beamforming offers great potential for the AP with multiple antennas to serve multiple receivers concurrently. A key factor to implement the MU-MIMO system is the CSI feedback mechanism. However, it might be exploited by malicious attackers to threaten the transmission security of benign clients. To better explore the attacks through false CSI feedback in MU-MIMO systems, this paper proposes...
In this paper, we investigate multiple-input single-output (MISO) simultaneous wireless information and power transfer (SWIPT) broadcast channels with confidential messages (BCC) scenario, in which a multiple-antenna transmitter simultaneously transmits confidential messages and power to multiple single-antenna receivers. Considering the imperfect channel state information (CSI), we study the joint...
From the perspective of national security, legitimate government agencies have long been committed to enforcing powerful surveillance measures on suspicious individuals or communications. This paper investigates a wireless legitimate surveillance system, where a full-duplex multi-antenna legitimate monitor aims to eavesdrop on a dubious communication link between a suspicious pair via proactive jamming...
In this paper, we investigate the secrecy rate maximization problem for a multi user multiple-input single-output (MISO) broadcast interference communication system with simultaneous wireless information and power transfer (SWIPT), in the presence of external eavesdroppers. Assuming that the channel state information is perfectly known at the transmitter, the main aim is to maximize the secrecy rate...
The non-invasive cortical bone quality assessments using ultrasound axial transmission technique have attracted strong attention. The estimation of phase velocity and attenuation of absorbing plate should help the assessment. To get the high-resolution estimation, we employ an adaptive beamforming technique that uses an eigenvalue decomposition. The technique can estimate not only the phase velocities...
The industrial demands for accurate localization systems have been rapidly increasing after the introduction of the Internet of Things (IoT) concept. Self localization and tracking transmitting sources are considered essential parts of IoT applications. In this paper we studied the possibility of applying angle of arrival (AoA) estimations to localize an IoT transceiver device in an indoor environment...
A novel multi-dimensional noise-shaping method is proposed to extend Δ-Σ modulation to the two-dimensional (2-D) (space, time) case. It uses spatial oversampling to provide another degree of freedom for ADC designers to shape quantization noise when temporal oversampling is limited. The method uses lossless discrete integrators (LDIs) to implement spatial integrators and is suitable for use in microwave...
Digital MIMO receivers featuring digitization at each element are critical for (massive) MIMO applications since they support complex space-time signal processing. However, the lack of spatial selectivity in the analog/RF domain necessitates high-dynamic-range analog-to-digital converters (A/Ds) to accommodate the uneven spatial power distribution, limiting the scale of such MIMO systems. This paper...
The initial phase of the Square Kilometre Array (SKA) [1] is represented by a −10% instrument and construction should start in 2018. SKA 1-Low, a sparse Aperture Array (AA) covering the frequency range 50 to 350 MHz, will be part of this. This instrument will consist of 512 stations, each hosting 256 antennas creating a total of 131,072 antennas. A first verification system towards SKA 1-Low, Aperture...
This paper investigates scheduling and precoding techniques via hybrid analog-digital transmitters in mm-wave frequency bands. As in spectrum sharing sub-6GHz scenarios, the presence of non-intended receivers limits the overall achievable rates. In order to circumvent this problem, we propose a scheduling and precoding algorithm able to maximize the sum-rate while keeping the interference to the external...
In this paper, we propose a low-complexity equalizer for multiple-input multiple-output systems with large receive antenna arrays. The computational complexity reduction is achieved by exploiting array separability on a geometric channel model. This property suggests a two-stage receive processing, consisting of (i) sub-array beamforming and (ii) low-dimension minimum mean square error (MMSE) equalization...
In this paper, we consider a heterogeneous cellular network with a macrocell and several femtocells. In each femtocell, the femto base station (FBS) serves one femto user (FU), which is capable of simultaneous wireless information and power transfer (SWIPT) energy harvesting (EH) in a power splitting manner. All FBSs suppress their interference to macro users (MUs) via a interference power constraint...
In this work, coordinated beamforming and power allocation schemes are proposed for multicell downlink non-orthogonal multiple access (NOMA) systems. Beamforming is adopted at the base-station to mitigate both intercell and intracell interference whereas power-domain multiplexing between a pair of users is considered in each spatial dimension. Given the beamforming vectors, intra-pair power allocation...
This paper studies energy-efficient joint transmit and receive beamforming in multi-cell multi-user multiple-input multiple-output systems. We consider conventional network energy efficiency metric where the users can receive unicasting streams in addition to the group-specific common multicasting streams which have certain rate constraints. The goal is to use the transmission resources more efficiently...
In this paper, we consider the balance between the energy efficiency (EE) and the short-term fairness among individual users in a muiticell MISO downlink. Firstly, the power consumption and sum proportional rate are utilized jointly to construct an objective function. Then a transmit beamformer optimization problem for the objective maximization subject to transmit power constraints is formulated...
In this paper, we study a wireless-powered two-way relay system, in which both wireless-powered sources exchange information through a multi-antenna relay. Both sources are assumed to have no embedded energy supply and thus first need to harvest energy from the radio frequency signals broadcasted by the relay before exchanging their information via the relay. We aim to maximize the sum throughput...
This paper considers an energy-efficient transmit design in a multiple-input single-output (MISO) wiretap channel. In particular, a transmitter sends one confidential message to a legitimate receiver, which must be kept perfectly secure from multiple external single-antenna eavesdroppers. Assuming statistical eavesdroppers' channel state information (ECSI) at the transmitter, we aim to design the...
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