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In the present work, initially, a mixed-three-spin (1/2,1,1/2) cell of a mixed-$N$-spin chain with Ising-XY model is introduced, for which pair spins (1,1/2) have Ising-type interaction and pair spins (1/2,1/2) have both XY-type and Dzyaloshinskii–Moriya (DM) interactions together. An external homogeneous magnetic field $B$ is considered for the system in thermal equilibrium. Integer-spins have a single-ion anisotropy property with coefficient $\zeta$. Then, we investigate the quantum entanglement between half-spins (1/2,1/2), by means of the concurrence. Classical correlation (CC) for this pair of spins is investigated as well as the concurrence and some interesting temperature, the magnetic field and the DM interaction properties are expressed. Moreover, single-ion anisotropy effects on the correlation between half-spins is verified. According to the verifications based on the communication channels category by Rossini, Giovannetti and Fazio [D. Rossini, V. Giovannetti and R. Fazio, Int. J. Quantum Inf.5, 439 (2007)], we theoretically consider such tripartite spin model as an ideal quantum channel, then calculate its information transmission rate and express some differences in behavior between this suggested model and introduced simple models in the previous works (chains without spin integer and DM interaction) from information transferring protocol point of view.

In this paper, an accelerated two-qubit system initially prepared in maximum or partial entangled state, which interacts locally with white/color or white-color noises, is considered. Due to the acceleration process and the noise effect, the entanglement degraded. Therefore, the effect of noise strength, initial state settings and the acceleration on the survival entanglement are investigated by means of the concurrence. Moreover, the initial parameters that describe this system are estimated by using the quantum Fisher information, where two forms are considered, namely by using a single and two-qubit forms. It is shown that, by using the two-qubit form, the estimation degree of these parameters is larger than that displayed by using a single-qubit form.

In this paper, the performance of a two-dimensional (2D) Massive MIMO angle parameter system with a uniform circular array (UCA) topology at base station is studied based on the field measurements in indoor line-of-sight (LOS) scenario at a frequency of 4.45GHz. Many spatial parameters are extracted, including angle information and correlation characteristic. It is shown that correlation lies between antenna elements and users. It is illustrated in the envelope correlation coefficient which goes on a downward trend while the antenna spacing is increasing in the measurements.

This paper deals with the development of a realistic power line channel simulator wherein power line communication devices can be tested before implementation to meet the massive need of data transfer. The statistics of the noise follow the experimentally observed in different sites, namely the time-varying non-white power spectral densities (PSDs) of the background noise and a target non Gaussian amplitude distribution. The procedure based on the inverse cumulative distribution function method of generation of random numbers and iteratively updating a target spectrum necessitates knowledge of a maximum of 17 parameters for successful implementation and has been validated for three sites in the low-frequency ($<$500kHz) and high-frequency (1–30MHz) bands. The average percentage errors in prediction of the mean of the channel capacity (CC) are 12.68% and 10.66% in the two bands, respectively. The minimum correlations of the distribution of BER of OFDM in a channel corrupted by the simulated and observed noises are is 0.883 and 0.801 in the two bands which are high compared to 0.422 and 0.355, respectively, when the requirement of a target amplitude distribution is neglected. With low-frequency noise emulated by a data acquisition card, an average percentage error of 11.82% in the CC and a correlation of 0.867 (against 0.498) in BER are obtained. The noise thus generated can be used as a testbed for system testing, instead of the conventional static models (additive white Gaussian noise or with time-invariant colored PSD), leading to better optimization of the implemented devices.

We re-take the possibilistic (as opposed to probabilistic) approach to information coding put forward in ^1,2. To enhance the possibilistic approach also outside the realm of "subjective" uncertainties, in this paper we adopt an "objective" interpretation of possibilistic source coding based on utility functions and an "objective" interpretation of possibilistic channel coding based on distortion measures and similarity indices. We stress the relationship between possibilistic coding as based on distortions between sequences and algebraic coding as based on minimum distances between codewords. We compute the operational (coding-theoretic) entropy for a new class of possibilistic sources.

MIMO is a type of antenna technology which utilizes multiple antennas to separate signals traveling in various paths as a result of reflections, etc., to be separated and their ability utilized to enhance the throughput of data and the signal to noise ratio which in return enhances the performance of the system. For providing enhanced signal performance and enhanced data rates, MIMO is utilized within LTE. When the quantities of antennas are increased, there is increase in the probability that deep fading is experienced by at least some antennas, which affects the overall efficiency of the MIMO system. To handle these issues, a reliable technique has been presented that involves selection of antenna subset. The proposed technique incorporates combination of SBO and PSO for antenna selection. Antenna selection’s main concept is to utilize a bounded quantity of analog chains that are adaptively switched to subset of the available antennas capable of preserving the selection diversity gains and also can minimize the quantity of radio frequency chains needed. The maximum channel capacity of the channel has been considered as the objective function for selecting optimal antennas. The comparison of the proposed approach’s performance and the existing approaches’ performance is done. From the simulation result, it has been shown that the presented approach’s performance has been better than the performance of the existing approaches in terms of BER, energy efficiency, spectral efficiency and optimal transmit power.

Variance-based logic (VBL) uses the fluctuations or the variance in the state of a particle or a physical quantity to represent different logic levels. In this paper, we show that compared to the traditional bi-stable logic representation, the variance-based representation can theoretically achieve a superior performance trade-off (in terms of energy dissipation and information capacity) when operating at fundamental limits imposed by thermal noise. We show that, in addition to the universal KT ln(1/$ϵ$) energy dissipation required for a single bit flip, a bi-stable logic device needs to dissipate at least 4.35KT/bit of energy, whereas under similar operating conditions, a VBL device reduces the additional energy dissipation requirements down to sub-KT/bit. These theoretical results are generally enough to be applicable to different instantiations and variants of VBL ranging from digital processors based on energy-scavenging or to processors based on the emerging valleytronic devices.

The empowerment formalism offers a goal-independent utility function fully derived from an agent's embodiment. It produces intrinsic motivations which can be used to generate self-organizing behaviors in agents. One obstacle to the application of empowerment in more demanding (esp. continuous) domains is that previous ways of calculating empowerment have been very time consuming and only provided a proof-of-concept. In this paper we present a new approach to efficiently approximate empowerment as a parallel, linear, Gaussian channel capacity problem. We use pendulum balancing to demonstrate this new method, and compare it to earlier approximation methods.

In quantum communication, feedback may be defined in a number of distinct ways. An analysis of the effect feedback has on the rate information may be communicated is given, and a number of results and conjectures are stated.

In this paper, an improved approximation formula is proposed to calculate the symmetric capacity of the 2-dimentional constellations under additive white Gaussian noise (AWGN) channel with the algorithm complexity reduced significantly. The parameters of the formula are evaluated by using the Levenberg-Marquardt (LM) and the Universal Global Optimization (UGO) algorithms. The simulation results show that the analytical solution calculated by the improved formula corresponds with the complex symmetry capacity evaluated by the Gauss-Hermit integration.