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A novel method for distance estimation is introduced, based on an OFDM signal combined with the Zadoff-Chu Sequences. By exploiting the properties of these sequences it is possible to evaluate the distance between a transmitter and a receiver with a very good precision and accuracy. The technique effectiveness is demonstrated in a real operating environment by measuring the distance between two active...
Recent years have witnessed a new content delivery paradigm named crowdsourced CDN, in which devices deployed at edge network can prefetch contents and provide content delivery service. Crowdsourced CDN offers high-quality experience to end-users by reducing their content access latency and alleviates the load of network backbone by making use of network and storage resources at millions of edge devices...
The strain imposed by the bandwidth demands of multimedia applications on wired and wireless networks calls for efficient novel solutions to the problem of network resource allocation, to avoid significant packet losses. In this letter, we focus on a large variety of MPEG-4, H.264 and H.265-encoded video traces. We use the metaheuristic technique of Simulated Annealing to predict the size of B-frames,...
This paper presents outdoor wideband small-scale spatial fading and autocorrelation measurements and results in the 73 GHz millimeter-wave (mmWave) band conducted in downtown Brooklyn, New York. Both directional and omnidirectional receiver (RX) antennas are studied. Two pairs of transmitter (TX) and RX locations were tested with one line-of-sight (LOS) and one non-line-of-sight (NLOS) environment,...
In this paper we consider the necessary condition for the recoverability with probability close to one (3 sigma criterion) of a band-limited band-passed signal from event-based samples. Specifically, we consider sampling events derived from non-zero level crossings of a stochastic differentiable signal on a finite time interval. Using a Fourier approach we write the system in matrix form allowing...
Deep convolutional neural networks (CNNs) trained for object classification have a number of striking similarities with the primate ventral visual stream. In particular, activity in early, intermediate, and late layers is closely related to activity in V1, V4, and the inferotemporal cortex (IT). This study further compares activity in late layers of object-classification CNNs to activity patterns...
In a cloud distributed system, machine failure or region failure is a very common scenario. Data replication is a key technique for ensuring data availability. However, Objects are usually assumed independently by distributed systems, despite, a user-level task typically requests multiple data objects. This paper studies the effect of data placement on the availability of user-level tasks from a theoretical...
Chirp spread spectrum (CSS) technique is capable of providing high processing gain, low power, robustness to multipath interference and immunity to Doppler frequency offset. The paper presents a new phase-coded modulation technique for CSS multiuser communication. The construction of a nth power chirp signal is explained and the design of the phase-coded linear chirp signal is presented in detail...
Cognitive Radio requires both efficient and reliable spectrum sensing of wideband signals. In order to cope with the sampling rate bottleneck when dealing with such signals, sub-Nyquist methods have been proposed. However, these techniques decrease the signal to noise ratio (SNR) due to aliasing effects. Cyclostationary detection, which exploits the periodic property of communication signal statistics,...
We present ABC-MRT16—a new algorithm for objective estimation of speech intelligibility following the Modified Rhyme Test (MRT) paradigm. ABC-MRT16 is simple, effective and robust. When compared to subjective MRT data from 367 diverse conditions that include coding, noise, frame erasures, and much more, ABC-MRT16 (containing just one optimized parameter) yields a very high Pearson correlation (above...
There is considerable interest in determining differences between radio channel characteristics in the currently allocated mobile radio frequency bands and bands that might be allocated for this purpose in the future. This paper is therefore devoted to a determination and comparison of channel characteristics caused by multipath (time) dispersion on microcellular mobile radio channels at frequencies...
The waveform of the electric field radiated by an antenna in a UWB system is usually a distorted form of the input pulse applied at the terminals. This distortion can be expressed in terms of the antenna impulse response in the time domain or directional transfer function in the frequency domain. Even for a simplest antenna like a linear dipole, the impulse response can be direction dependent. However,...
Cooperative regenerating codes are a class of codes that enable a data collector to reconstruct the original data by connecting to a subset of storage nodes, and also can repair multiple failed nodes by downloading data from the surviving nodes and exchanging data among the new nodes. In cooperative regenerating codes, there exists a tradeoff between the storage size of each node and repair-bandwidth...
As we move to higher data rates, the performance of clock and data recovery (CDR) circuits becomes increasingly important in maintaining low bit error rates (BER) in wireline links. Digital CDRs are popular in part for their robustness, but their use of bang-bang phase detectors (BB-PD) makes their performance sensitive to changes in jitter caused by PVT variations, crosstalk or power supply noise...
This paper presents a simple compact square patch dual band Multiple Input Multiple Output (MIMO) antenna for wireless terminal devices. The antenna designed to operate in the frequency bands of 1.78–2.74 GHz and 3.33–6.06 GHz that covers LTE, Bluetooth, WiMAX and WLAN applications. The antenna consists of two concentric square ring slots etched on the corner truncated square patch monopole radiator...
BPSK-signals reception quality depends on the quality of the signal processing. BPSK-modulated codes reception quality depends on the quality of the correlation functions. RF frontend distortions leads to efficiency of the signal processing degrading. RF frontend non-optimal filtering, noise and dynamic range limiting has significant impact on the signal processing quality. In this research simulation...
Methods of modern GNNS organization, their frequency bandwidth and signals generation were described. Nowadays bandwidth for every field of concern is strongly limited. Popularity of radionavigation leads to overlapping spectrum. Modern GNSS are using signals with CDMA to minimize interference. The signals non-orthogonality interference are named multiple-access interference. The multiple-access interference...
Analog circuits of radar systems can strongly distort spectrum of transmitted and received signal. Radar characteristics such as resolution, signal to noise ratio, sidelobe level depend on spectral characteristics of a signal. This work considers basic types of signal distortions: spectrum limitation by low-pass filtering and near-zero frequency band suppression. Each case of distortion is studied...
With the development of the technology, life is filled with increasing information equipment. When they work, a great deal of information will be radiated. For the leaked information, an interception system is built with USRP (Universal Software Radio Peripheral), and the line synchronization signal was extracted with a method called cepstrum. Compared with the method of autocorrelation, the new method...
We propose a digital modulation scheme, based on the generalization of the chirp signal, that allows to improve the performance of Global Navigation Satellite System receivers in scenarios affected by channel additive white Gaussian noise, narrowband interference and multipath. Different signaling schemes, characterized by autocorrelation functions with small secondary peaks, can be obtained by adjusting...
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