scholarly journals Two-way covert quantum communication in the microwave regime

2020 ◽  
Author(s):  
Roberto Di Candia ◽  
Hüseyin Yiğitler ◽  
Gheorghe Paraoanu ◽  
Riku Jäntti
Keyword(s):  
Quantum Communication ◽  
Signal To Noise Ratio ◽  
Quantum Correlations ◽  
Quantum Metrology ◽  
New Paradigm ◽  
Circuit Qed ◽  
Information Theoretic ◽  
Discrete Phase ◽  
Receiver Performance ◽  
Microwave Regime

Abstract Quantum communication addresses the problem of exchanging information across macroscopic distances by employing encryption techniques based on quantum mechanical laws. Here, we advance a new paradigm for secure quantum communication by combining backscattering concepts with covert communication in the microwave regime. Our protocol allows communication between Alice, who uses only discrete phase modulations, and Bob, who has access to cryogenic microwave technology. Using notions of quantum channel discrimination and quantum metrology, we find the ultimate bounds for the receiver performance, proving that quantum correlations can enhance the signal-to-noise ratio by up to 6 dB. We show that security can be reached by covering the carrier signal through the presence of the thermal noise in the environment. We complement our information-theoretic results with a feasible experimental proposal in a circuit QED platform. This work makes a decisive step toward implementing secure quantum communication concepts in the previously uncharted 1 − 10 GHz frequency range, in the relevant scenario when the available power is severely constrained.

scholarly journals Symmetrized persistency of Bell correlations for Dicke states and GHZ-based mixtures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcin Wieśniak
Keyword(s):  
Communication Complexity ◽  
Quantum Communication ◽  
Bell Inequality ◽  
Bell Inequalities ◽  
Quantum Correlations ◽  
Complexity Reduction ◽  
Main Difficulty ◽  
Quantum Communication Complexity ◽  
Number Of Particles ◽  
Dicke States

AbstractQuantum correlations, in particular those, which enable to violate a Bell inequality, open a way to advantage in certain communication tasks. However, the main difficulty in harnessing quantumness is its fragility to, e.g, noise or loss of particles. We study the persistency of Bell correlations of GHZ based mixtures and Dicke states. For the former, we consider quantum communication complexity reduction (QCCR) scheme, and propose new Bell inequalities (BIs), which can be used in that scheme for higher persistency in the limit of large number of particles N. In case of Dicke states, we show that persistency can reach 0.482N, significantly more than reported in previous studies.

scholarly journals Through-Wall Image Enhancement Based on Singular Value Decomposition

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Muhammad Mohsin Riaz ◽  
Abdul Ghafoor
Keyword(s):  
Singular Value Decomposition ◽  
Image Enhancement ◽  
Visual Inspection ◽  
Signal To Noise Ratio ◽  
Singular Values ◽  
Singular Value ◽  
Information Theoretic ◽  
Value Decomposition ◽  
Suppress Noise ◽  
Wall Imaging

Singular value decomposition and information theoretic criterion-based image enhancement is proposed for through-wall imaging. The scheme is capable of discriminating target, clutter, and noise subspaces. Information theoretic criterion is used with conventional singular value decomposition to find number of target singular values. Furthermore, wavelet transform-based denoising is performed (to further suppress noise signals) by estimating noise variance. Proposed scheme works also for extracting multiple targets in heavy cluttered through-wall images. Simulation results are compared on the basis of mean square error, peak signal to noise ratio, and visual inspection.

scholarly journals Cooperative GPS and Neighbors Awareness Based Device Discovery for D2D Communication in in-Band Cellular Networks

2018 ◽  
Vol 7 (2.29) ◽  
pp. 700 ◽  
Author(s):  
O Hayat ◽  
R Ngah ◽  
Yasser Zahedi
Keyword(s):  
Cellular Networks ◽  
Channel Capacity ◽  
Signal To Noise Ratio ◽  
Threshold Value ◽  
D2d Communication ◽  
Core Network ◽  
New Paradigm ◽  
Signal To Noise ◽  
Device Discovery ◽  
Noise Ratio

Device to Device (D2D) communication is a new paradigm for next-generation wireless systems to offload data traffic. A device needs to discover neighbor devices on the certain channel to initiate the D2D communication within the minimum period. A device discovery technique based on Global Positioning System (GPS) and neighbor awareness base are proposed for in-band cellular networks. This method is called network-centric approach, and it improves the device discovery efficiency, accuracy, and channel capacity. The differential code is applied to measure the signal to noise ratio of each discovered device. In the case that the signal to noise ratio (SNR) of two devices is above a specified threshold value, then these two devices are qualified for D2D communication. Two procedures are explored for device discovery; discovery by CN (core network) and eNB (evolved node B) cooperation with the help of GPS and neighbor awareness. Using ‘Haversine’ formula, SNR base distance is calculated. Results show an increment in the channel capacity relative to SNR obtained for each device.  

scholarly journals Using Virtual Reality to Test for Telepathy: A Proof-of-Concept Study

2020 ◽  
Vol 34 (4) ◽  
pp. 683-702
Author(s):  
David Vernon ◽  
Thomas Sandford ◽  
Eric Moyo
Keyword(s):  
Virtual Reality ◽  
Signal To Noise Ratio ◽  
Proof Of Concept ◽  
Hit Rate ◽  
Receiver Performance ◽  
Valence And Arousal ◽  
Post Hoc ◽  
The Relationship ◽  
Correct Target ◽  
Sensory Isolation

Telepathy is one of the most commonly reported psi-type experiences and represents the idea that one person can acquire information relating to the thoughts/feelings/intentions of another from a distance via a non-usual route. Typically the procedure involves a Sender and a Receiver who are physically separated whilst the former attempts to relay target information to the latter. Refinements to this paradigm have included placing the Receiver in sensory isolation in an effort to enhance the signal to noise ratio of the signal, as seen in the ganzfeld research. Here the aim was to immerse the Sender in a virtual reality (VR) environment in an effort to boost the transmission of the target whilst keeping the Receiver in partial sensory isolation. Using such a paradigm we tested eleven pairs of participants, each acting as Sender and Receiver across five trials. In each trial the Sender was immersed in a VR environment depicting a positive arousing experience (e.g., skiing downhill, driving a racing car). The Receiver’s task was to identify the correct target image from a set of 5 (i.e., 20% chance) matched for mean valence and arousal. Initial analysis of Receiver performance showed hit rates that did not differ significantly from chance. However, a post-hoc analysis comparing participants top two choices to chance showed a mean hit rate of 52% which was significantly greater than chance (at 40%). Examination of possible associations between hit rate and belief in psi as well as the subjectively rated strength of the relationship between Sender-Receiver pairings only showed a correlation with the psi sub-scale of the RPB. Hence, we argue that participant hit rate is more suggestive than conclusive of a telepathic effect. In addition, we outline a number of methodological refinements which we think could help to improve the viability and effectiveness of using VR.

scholarly journals Remote State Design for Efficient Quantum Metrology with Separable and Non-Teleporting States

2021 ◽  
Vol 3 (1) ◽  
pp. 228-241
Author(s):  
Rahul Raj ◽  
Shreya Banerjee ◽  
Prasanta K. Panigrahi
Keyword(s):  
Parameter Estimation ◽  
Quantum Information ◽  
Fisher Information ◽  
Quantum Information Processing ◽  
Quantum Fisher Information ◽  
Quantum Correlations ◽  
Quantum States ◽  
Quantum Metrology ◽  
High Quantum ◽  
Non Local

Measurements leading to the collapse of states and the non-local quantum correlations are the key to all applications of quantum mechanics as well as in the studies of quantum foundation. The former is crucial for quantum parameter estimation, which is greatly affected by the physical environment and the measurement scheme itself. Its quantification is necessary to find efficient measurement schemes and circumvent the non-desirable environmental effects. This has led to the intense investigation of quantum metrology, extending the Cramér–Rao bound to the quantum domain through quantum Fisher information. Among all quantum states, the separable ones have the least quantumness; being devoid of the fragile non-local correlations, the component states remain unaffected in local operations performed by any of the parties. Therefore, using these states for the remote design of quantum states with high quantum Fisher information can have diverse applications in quantum information processing; accurate parameter estimation being a prominent example, as the quantum information extraction solely depends on it. Here, we demonstrate that these separable states with the least quantumness can be made extremely useful in parameter estimation tasks, and further show even in the case of the shared channel inflicted with the amplitude damping noise and phase flip noise, there is a gain in Quantum Fisher information (QFI). We subsequently pointed out that the symmetric W states, incapable of perfectly teleporting an unknown quantum state, are highly effective for remotely designing quantum states with high quantum Fisher information.

Quantum non-gaussianity from an indefnite causal order of Gaussian operations

2021 ◽  
Author(s):  
Seid Koudia ◽  
Abdelhakim Gharbi
Keyword(s):  
Quantum Information ◽  
Quantum Key Distribution ◽  
Degrees Of Freedom ◽  
Quantum Communication ◽  
Quantum Information Processing ◽  
Quantum Metrology ◽  
Causal Order ◽  
Gaussian States ◽  
Control Qubit ◽  
Non Gaussian

Quantum non-Gaussian states are considered a useful resource for many tasks in quantum information processing, from quantum metrology and quantum sensing to quantum communication and quantum key distribution. Another useful tool that is gaining attention is the newly constructed quantum switch. Its applications in many tasks in quantum information have been proved to outperform many existing schemes in quantum communication and quantum thermometry. In this contribution, we demonstrate this to be very useful for engineering highly non-Gaussian states from Gaussian operations whose order is controlled by degrees of freedom of a control qubit. The nonconvexity of the set of Gaussian states and the set of Gaussian operations guarantees the emergence of non-Gaussianity after post-selection on the control qubit deterministically, in contrast to existing protocols in the literature. The nonclassicality of the resulting states is discussed accordingly.

A Complex Cell-Like Receptive Field Obtained by Information Maximization

2001 ◽  
Vol 13 (3) ◽  
pp. 547-562 ◽  
Author(s):  
Kenji Okajima ◽  
Hitoshi Imaoka
Keyword(s):  
Signal To Noise Ratio ◽  
Energy Model ◽  
Linear Operators ◽  
Maximization Problem ◽  
Complex Cell ◽  
Signal To Noise ◽  
Information Theoretic ◽  
Complex Cells ◽  
Information Maximization ◽  
Ratio Limit

The energy model (Pollen & Ronner, 1983; Adelson & Bergen, 1985) for a complex cell in the visual cortex is investigated theoretically. The energy model describes the output of a complex cell as the squared sum of outputs of two linear operators. An information-maximization problem to determine the two linear operators is investigated assuming the low signal-to-noise ratio limit and a localization term in the objective function. As a result, two linear operators characterized by a quadrature pair of Gabor functions are obtained as solutions. The result agrees with the energy model, which well describes the shift-invariant and orientation-selective responses of actual complex cells, and thus suggests that complex cells are optimally designed from an information-theoretic viewpoint.

scholarly journals Intrinsic quantum correlations of weak coherent states for quantum communication

2011 ◽  
Vol 83 (3) ◽  
Author(s):  
Yong Meng Sua ◽  
Erin Scanlon ◽  
Travis Beaulieu ◽  
Viktor Bollen ◽  
Kim Fook Lee
Keyword(s):  
Coherent States ◽  
Quantum Communication ◽  
Quantum Correlations

scholarly journals Joint Detection and DOA Tracking with a Bernoulli Filter Based on Information Theoretic Criteria

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3473 ◽  
Author(s):  
Guangpu Zhang ◽  
Ce Zheng ◽  
Sibo Sun ◽  
Guolong Liang ◽  
Yifeng Zhang
Keyword(s):  
Likelihood Function ◽  
Signal To Noise Ratio ◽  
Joint Detection ◽  
Information Theoretic ◽  
Practical Applications ◽  
Stochastic Signal ◽  
State Process ◽  
Finite Set ◽  
Bernoulli Filter ◽  
Information Theoretic Criteria

In this paper, we study the problem of the joint detection and direction-of-arrival (DOA) tracking of a single moving source which can randomly appear or disappear from the surveillance volume. Firstly, the Bernoulli random finite set (RFS) is employed to characterize the randomness of the state process, i.e., the dynamics of the source motion and the source appearance. To increase the performance of the detection and DOA tracking in low signal-to-noise ratio (SNR) scenarios, the measurements are obtained directly from an array of sensors and allow multiple snapshots. A track-before-detect (TBD) Bernoulli filter is proposed for tracking a randomly on/off switching single dynamic system. Secondly, since the variances of the stochastic signal and measurement noise are unknown in practical applications, these nuisance parameters are marginalized by defining an uninformative prior, and the likelihood function is compensated by using the information theoretic criteria. The simulation results demonstrate the performance of the filter.

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