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In this paper is described a set of constraints applied to a wireless power-supply system (emitter and receiver) for operating in optimal conditions. These constraints regard both geometrical aspects and operational conditions of the system. There is also presented the performance optimization in the power wireless transfer. Starting from the equivalent scheme of a wireless power transfer system sinusoidal...
This paper considers a wireless power transfer system with multiple antennas by using the multicarrier signal waveforms. A prior art optimizes the waveform with the channel state information at the transmitter (CSIT) to improve the energy harvesting efficiency of the receiver with the non-linear model. The impact of the imperfect CSIT on the energy harvesting capability is studied as a function of...
Energy efficient cognitive radio networks can simultaneously improve spectrum efficiency (SE) and energy efficiency (EE) of wireless communication networks. This paper studies energy efficient spectrum sensing interval, spectrum sensing energy and transmit power allocation scheme of the secondary user (SU) in CR networks. The EE maximization problem subject to the transmit power constraint and average...
Due to the low out-of-band emission and robustness against asynchronous transmissions, generalized frequency division multiplexing (GFDM) has potential to be a new modulation scheme for the foreseeable applications. In this paper, a novel precoding scheme with tunable band sizes is proposed for GFDM systems. The precoder and equalizer are jointly designed aiming at minimizing the system total mean...
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...
Increased demand for wireless services has spurred research into spectrum co-existence between radar and communication systems. The effect of an unaltered radar interference on an uncoded communication receiver has been investigated for constellations used in commercial systems. However, the constellation design — possible for a cognitive transmitter-receiver pair — that maximizes the transmission...
This paper studies a backscatter assisted wireless powered communication network (BAWPCN) with two users, which can work in the backscatter communication (BackCom) and harvest-then-transmit (HTT) modes, respectively. The user with the HTT mode is also equipped with initial energy stored in its battery with a finite capacity. The proposed model is studied based on a time block, which is divided into...
Wireless Power Transfer (WPT) technologies aim at getting rid of cables used by consumer devices for energy provision. As long distance WPT is becoming mature, the health impact of WPT becomes increasingly important to consider. In this paper we look at how to maximize the wireless power transfer to remote devices, while maintaining a safe level of electromagnetic radiation (EMR) for humans that are...
The paper investigates a problem of allocating three types of flows (unicast, anycast, multicast) in elastic optical network (EON) with dedicated path protection (DPP). We model the problem using integer linear programming (ILP) and propose solution methods: two greedy algorithms and column generation (CG)-based approach. The main paper focus is put on proposal and comparison of several CG versions...
Indoor localisation is a currently a key issue, from robotics to the Internet of Things. With hardware advancements making Ultra-Wideband devices more accurate and low powered (potentially even passive), this unlocks the potential of having such devices in common place around factories and homes, enabling an alternative method of navigation. Therefore, anchor calibration indoors becomes a key problem...
Abstractive multi-document summarization aims at generating new sentences whose elements originate from different source sentence. It can be achieved via phrase selection and merging approach which aims at constructing new sentences by exploring syntactic units such as fine-grained noun and verb phrase. It can be also achieved by extracting semantic information from source sentence which uses the...
A limiting factor of GaAs Schottky diodes used as mixers in heterodyne receivers is their high intrinsic noise when compared to SIS or HEB devices. This work presents results on the numerical optimization of fundamental Schottky diode mixers, results which predict a significant improvement in the noise performance of current Schottky mixer technology in the THz band. The optimization of the Schottky...
Device-to-device (D2D) will be the future of wireless technology with low power, high data rate and low latency for information exchange between wireless devices. However it may not be always feasible because of mobility and influence of surroundings on the devices. This paper presents an approach to model and investigate D2D network at two millimeter wave (mmW) frequencies of 28 and 60 GHz, by calculating...
In this work, the optimization of the analog transmit waveform for joint delay-Doppler estimation under sub-Nyquist conditions is considered. Based on the Bayesian Cramer-Rao lower bound (BCRLB), we derive an estimation theoretic design rule for the Fourier coefficients of the analog transmit signal when violating the sampling theorem at the receiver through a wide analog pre-filtering bandwidth....
Acoustic channels are typically described by their Acoustic Impulse Response (AIR) as a Moving Average (MA) process. Such AIRs are often considered in terms of their early and late parts, describing discrete reflections and the diffuse reverberation tail respectively. We propose an approach for constructing a sparse parametric model for the early part. The model aims at reducing the number of parameters...
The joint optimization of partial response continuous phase modulation (CPM) parameters is addressed. For fixed modulation order and memory length, the modulation index, the symbol rate and the phase pulse shape are considered as degrees of freedom. In particular, we drop the restriction of “classical” phase pulses and we allow for custom shapes, which are parametrized through Bezier curves. In order...
This paper reviews our most recent results on mode-division multiplexing systems based on few-mode fibres with low differential mode delay, spanning from the fibre design optimization to the receiver memory dimensioning. First, the fibre refractive-index profile is optimized for low differential mode delay and low macro-bend losses. Afterwards, we present a semi-analytical model of the linear mode...
Ultra-dense cellular networks are emerging as one key characteristic of 5G wireless networks. In this context, frequency reuse is a fundamental technology enabler for efficient utilization of limited spectrum resources. In this paper, we investigate the in-band Full-Duplex (FD) self-backhauling architecture, in which Base Stations (BSs) operate on the same spectrum used by the users to access the...
In this paper, we study new schemes to maximize network and users' minimum EE energy efficiency through transmission power control. The problem is formulated as fractional optimization programming and solved with a successive convex approximation. The EE metrics are analysed via extensive numerical simulations under different clustering algorithms, namely a variant of nearest neighbor clustering and...
In this paper, we study the waveform design problem for a single-input single-output (SISO) radio-frequency (RF) wireless power transfer (WPT) system in frequency-selective channels. First, based on the actual non-linear current-voltage model of the diode at the energy receiver, we derive a semi-closed-form expression for the deliverable DC voltage in terms of the incident RF signal and hence obtain...
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