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Compressed Sensing is a novel sampling technique that can be used to faithfully recover sparse signals from fewer measurements than those proposed by the Nyquist theorem. A simple and intuitive measure of sparsity in a signal is ℓ0-norm. However, the ℓ0-norm function does not satisfy all the axiomatic properties of a true mathematical norm. The discrete and discontinuous nature of ℓ0-norm poses many...
Intravascular ultrasonic (IVUS) imaging catheters currently use ceramic piezoelectric transducers to form radial images of blood vessel walls. Further improvements in image quality may be enabled through Capacitive and Piezoelectric Micromachined Ultrasonic Transducers (CMUTs and PMUTs). Polymer PMUTs offer many benefits in imaging quality, however, the low acoustic sensitivity and high electrical...
The energy efficiency (EE) maximization problem in amplify-and-forward (AF) relay-assisted downlink channels with orthogonal frequency-division multiple access (OFDMA) is studied. The power allocation is optimized together with subcarrier allocation and pairing at the relay. As the base station and the relay have individual power constraints, an alternating optimization approach is adopted to solve...
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...
This paper proposes a detailed evaluation of the impact of digital filters when applied to the Neutrinos Angra Experiment. The signals coming out from its front-end electronics are digitized and then sent to an FPGA where further processing might be carried out. In this context, this work proposes a set of peak amplitude estimators optimized to have minimum variance. Constrained optimization technique...
In view of dynamic multi-criteria decision-making problems, in which the criteria value of alternatives are three-parameters interval numbers and criteria exists different natural states, a dynamic grey stochastic multi-criteria decision-making method is proposed. According to the stationary distribution thought of Markov chain, the final state of natural possibility is obtained. The time information...
In this work, we present a novel robust distributed beam-forming (RDB) approach to mitigate the effects of channel errors on wireless networks equipped with relays based on the exploitation of the cross-correlation between the received data from the relays at the destination and the system output. The proposed RDB method, denoted cross-correlation and subspace projection (CCSP) RDB, considers a total...
Signal processing on graphs becomes popular nowadays due to its great potential in processing the large amount of high dimensional data which exhibit irregular structures. As a signal propagates on a graph, the signal at a later time slot can be thought of as the graph-filtered version of the previous one. Therefore, estimation of the graph filter is important and serves as the building block for...
Personal audio reproduction systems deal with the creation of personal sound zones within a room without the necessity of using headphones. These systems use an array of loudspeakers and design the required filters at each loudspeaker in order to render the desired audio signal to each person in the room as free of interferences as possible. There are very interesting proposals in the literature that...
Cognitive radio (CR) has been proposed as a promising solution to enhance the spectrum usage efficiency by exploiting underutilized spectral resources in an opportunistic manner [1]. However, a crucial factor in CRs' implementation lies in the spectrum sensing (SS) procedure [2]. During the SS, a CR typically needs to rapidly monitor multiple frequency bands, which demenads very high sampling rate...
This paper considers a multiuser system with one full-duplex (FD) base station (BS) serving a set of half duplex (HD) mobile users. Due to the self-interference and co-channel interference from the uplink users to the downlink users, the transmissions of the BS and uplink users have to jointly designed. In this paper, we consider such a joint design problem for maximizing the max-min-fairness (MMF)...
To fully exploit the increasingly dense deployments of mobile base station (BS) infrastructure, this paper proposes a novel caching paradigm called explicit caching, which stores selective contents at BSs and exposes such contents to users for volunteer browsing and download. We formulate the explicit caching problem as a joint content recommendation and delivery problem, which aims to maximize the...
User fairness and spectrum efficiency are conflicting objectives in cellular system optimization given that users share limited spectrum resources. Users at the cell edge are more likely to be unfairly treated due to their disadvantageous locations, where they experience high path losses and strong interferences if co-channel transmission exists. In this paper, a cell edge boundary is obtained and...
The present study deals with optimization of machining characteristics using Multi characteristic Optimization in collaboration with utility concept. Surface roughness & Tool wear rate are the selected response characteristics for investigation. The study makes use of Taguchi's robust design experiments with Utility concept. Each experiment was conducted using different combinations of input parameters...
Optimal waveform design is an important technology for cognitive radar. Much effort has been focused on designing algorithms without target impulse response prediction and constant modulus constraint. In this paper, a new waveform design method is proposed, the next transmitted waveform could match the next target signature well. Since the radar systems commonly require constant modulus waveforms...
In this paper, we propose a joint analog-digital (AD) beamforming scheme that exploits the mutual coupling effect to further improve the performance of multi-user multiple-input single-output (MU-MISO) systems. We firstly propose a joint AD scheme by iteratively optimizing the beamforming vectors in the digital domain and the load impedances of each antenna element in the analog domain. We further...
Terahertz (THz) band communication has abundant spectral resources to accommodate multiple broadband carriers. However, the strong path loss attenuation and the limited transmission power affect the maximum number of carriers that can be activated. A simple way to address this limitation consists in transmitting the same message from multiple transmission points, using Joint-Transmission (JT) Coordinated...
In this paper, we focus the attention on the superresolution of multispectral (MS) multiresolution images (e.g., Sentinel 2, Aster, MODIS). By taking advantage of the high spatial resolution bands, we minimize an objective function containing a quadratic data fitting term, an edge preserving regularizer, and a patch-based plug-and play prior promoting self-similar images. To cope with the ill-posedness...
Sparse unmixing of hyperspectral data is an important technique which aims at estimating the fractional abundances of endmembers (pure spectral components). It is well known that enforcing sparseness becomes a necessary process in sparse unmixing methods. To better exploit the sparsity in hyperspectral imagery, a double reweighted sparse unmixing algorithm has been proposed. However, it focusses on...
The individual applications of network coded opportunistic routing and successive interference cancellation have been proven with significant improvement on throughput performance of wireless multi-hop networks, but there lacks practical optimization on their combination application. Based on a TDMA system, this paper models the throughput maximization as network utility function maximization problem...
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