Information Transmission Rate Research Articles

Channel Estimation Techniques over MIMO-OFDM System

The multiple input multiple output-orthogonal frequency division multiplexing or MIMO-OFDM frameworks are utilized to satisfy the necessities of high information transmission rates, as a result of their exceptional properties, for example, high otherworldly proficiency, high information rate and obstruction towards multipath proliferation. MIMO-OFDM frameworks are finding their applications in the advanced remote correspondence frameworks like IEEE 802.11n, 4G. In this paper, we consider the plan of LTE system and diagram the channel estimation. To achieve high data rate correspondence with flexibility, Long term evolution (LTE) has been displayed. LTE Downlink systems get Symmetrical Recurrence Division Different and MIMO to give upto 100 Mbps (expecting a 2x2 MIMO structure with 20MHz transmission limit). The execution get of MIMO overwhelmingly depends upon the correct estimation of Channel State information (CSI), which is crucial for every trade structure. In this paper, we show assorted channel estimation computations for LTE Downlink structures. This joins channel estimation using Pilot Images and Visually impaired Channel estimation counts. The estimation procedures incorporated the Slightest Square Mistake (LSE) and the Minimum mean square error (MMSE) is being inspected in conclusion broke down.

METHOD OF CODING INFORMATION DISTRIBUTED BY WIRELESS COMMUNICATION LINES UNDER CONDITIONS OF INTERFERENCE

The subject matter of the paper is the processes of analysis and evaluation of the effectiveness of information coding methods in wireless systems. The aim is to improve noise immunity of information messages under conditions of powerful electromagnetic interference, with the help of complex signal-code constructions. The objective is to develop a method for noise-immune encoding in a wireless information transmission system, providing increase in information transmission rate. The methods used: Simulation and digital signal coding. The following results have been obtained: A method for encoding information transmitted via wireless communication lines in presence of interference. For signal coding, it is proposed to use Gaussian monocycle with time-dependent position-pulse modulation (PPM). It is shown that for organization of independent channels within a single frequency band, it is practical to use a system of orthogonal codes. Pulses of the useful information signal accumulated in a receiver correlator provide significantly increase in signal-to-noise ratio, allowing transmission of information over a wide frequency range well below the noise level. As a result of encoding information in wireless information transmission systems with the help of ultra-short pulse signals, the effectiveness of the proposed method is a quantitatively and qualitatively evaluated. Conclusion. Using Pulse Position Modulation coding in wireless information transmission systems allows transmitting large volumes of information with high transmission rate and high noise immunity of the communication channel as well as protecting the channel from message interception. Ability to work with low radiating power and high signal capacity to penetrate various obstacles ensure fulfilment of electromagnetic compatibility requirements as well as stable communication in conditions of multipath radio wave propagation. A possibility that powerful electromagnetic disturbances accompanying a lightning discharge may have catastrophic impact on the information transmission channel is also eliminated.

Designing Prediction Markets to Achieve Convergence Speed

The aim of this paper is twofold: to propose the model of artificial prediction markets that capture the characteristics of real prediction markets and to study the impact of key parameters on the performance of the proposed markets. In the experiments, the artificial markets are implemented and the market performance in terms of convergence speed is measured. Our experimental results show that the number of traders and the mean value of initial belief have no significant impact on the convergence speed. However, the trader’s memory size impacts negatively on the convergence because of its delay in adjusting to the true value. Finally, the external information transmission rate and the ratio of smart traders have positive impacts on the convergence of the prediction markets. The insights can assist a market maker in designing and constructing more efficient prediction markets.

SSVEP Transient Feature Extraction and Rapid Recognition Method Based on Bistable Stochastic Resonance.

Steady-state Visual Evoked Potential, SSVEP), as the most commonly used communication paradigm for non-implantable Brain-Computer Interface (BCI), boasts the advantages of unnecessity of training, noise immunity and periodicity. The traditional SSVEP extraction methods can effectively identify the target frequency contained in original EEG, however, the required data length usually lasts a few seconds. In this paper, bistable stochastic resonance (BSR) is applied to SSVEP extraction. BSR is very sensitive to amplitude mutation and frequency fluctuation of the input signal, making the output difference can be used for the detection of the target frequency. The processing results illustrate that the proposed method not only has a high recognition accuracy, but also effectively shortens the recognition time, thus improving the calculating speed. Therefore, SSVEP extraction based on BSR has a higher information transmission rate (ITR), which is more suitable for the real-time BCI system.

A Covert Queueing Channel in FCFS Schedulers

We study covert queueing channels (CQCs), which are a kind of covert timing channel that may be exploited in shared queues across supposedly isolated users. In our system model, a user sends messages to another user via his pattern of access to the shared resource, which serves the users according to a first come first served (FCFS) policy. One example of such a channel is the cross-virtual network covert channel in data center networks, resulting from the queueing effects of the shared resource. First, we study a system comprising a transmitter and a receiver that share a deterministic and work-conserving FCFS scheduler, and we compute the capacity of this channel. We also consider the effect of the presence of other users on the information transmission rate of this channel. The achievable information transmission rates obtained in this study demonstrate the possibility of significant information leakage and great privacy threats brought by CQCs in FCFS schedulers.

Efficient Coding and Energy Efficiency Are Promoted by Balanced Excitatory and Inhibitory Synaptic Currents in Neuronal Network.

Selective pressure may drive neural systems to process as much information as possible with the lowest energy cost. Recent experiment evidence revealed that the ratio between synaptic excitation and inhibition (E/I) in local cortex is generally maintained at a certain value which may influence the efficiency of energy consumption and information transmission of neural networks. To understand this issue deeply, we constructed a typical recurrent Hodgkin-Huxley network model and studied the general principles that governs the relationship among the E/I synaptic current ratio, the energy cost and total amount of information transmission. We observed in such a network that there exists an optimal E/I synaptic current ratio in the network by which the information transmission achieves the maximum with relatively low energy cost. The coding energy efficiency which is defined as the mutual information divided by the energy cost, achieved the maximum with the balanced synaptic current. Although background noise degrades information transmission and imposes an additional energy cost, we find an optimal noise intensity that yields the largest information transmission and energy efficiency at this optimal E/I synaptic transmission ratio. The maximization of energy efficiency also requires a certain part of energy cost associated with spontaneous spiking and synaptic activities. We further proved this finding with analytical solution based on the response function of bistable neurons, and demonstrated that optimal net synaptic currents are capable of maximizing both the mutual information and energy efficiency. These results revealed that the development of E/I synaptic current balance could lead a cortical network to operate at a highly efficient information transmission rate at a relatively low energy cost. The generality of neuronal models and the recurrent network configuration used here suggest that the existence of an optimal E/I cell ratio for highly efficient energy costs and information maximization is a potential principle for cortical circuit networks.SummaryWe conducted numerical simulations and mathematical analysis to examine the energy efficiency of neural information transmission in a recurrent network as a function of the ratio of excitatory and inhibitory synaptic connections. We obtained a general solution showing that there exists an optimal E/I synaptic ratio in a recurrent network at which the information transmission as well as the energy efficiency of this network achieves a global maximum. These results reflect general mechanisms for sensory coding processes, which may give insight into the energy efficiency of neural communication and coding.

Optimizing the Energy and Throughput of a Water-Quality Monitoring System.

This work presents a new approach to the maximization of energy and throughput in a wireless sensor network (WSN), with the intention of applying the approach to water-quality monitoring. Water-quality monitoring using WSN technology has become an interesting research area. Energy scarcity is a critical issue that plagues the widespread deployment of WSN systems. Different power supplies, harvesting energy from sustainable sources, have been explored. However, when energy-efficient models are not put in place, energy harvesting based WSN systems may experience an unstable energy supply, resulting in an interruption in communication, and low system throughput. To alleviate these problems, this paper presents the joint maximization of the energy harvested by sensor nodes and their information-transmission rate using a sum-throughput technique. A wireless information and power transfer (WIPT) method is considered by harvesting energy from dedicated radio frequency sources. Due to the doubly near–far condition that confronts WIPT systems, a new WIPT system is proposed to improve the fairness of resource utilization in the network. Numerical simulation results are presented to validate the mathematical formulations for the optimization problem, which maximize the energy harvested and the overall throughput rate. Defining the performance metrics of achievable throughput and fairness in resource sharing, the proposed WIPT system outperforms an existing state-of-the-art WIPT system, with the comparison based on numerical simulations of both systems. The improved energy efficiency of the proposed WIPT system contributes to addressing the problem of energy scarcity.

Dual-polarization nonlinear Fourier transform-based optical communication system

New services and applications are causing an exponential increase in internet traffic. In a few years, current fiber optic communication system infrastructure will not be able to meet this demand because fiber nonlinearity dramatically limits the information transmission rate. Eigenvalue communication could potentially overcome these limitations. It relies on a mathematical technique called "nonlinear Fourier transform (NFT)" to exploit the "hidden" linearity of the nonlinear Schr\"odinger equation as the master model for signal propagation in an optical fiber. We present here the theoretical tools describing the NFT for the Manakov system and report on experimental transmission results for dual polarization in fiber optic eigenvalue communications. A transmission of up to 373.5 km with bit error rate less than the hard-decision forward error correction threshold has been achieved. Our results demonstrate that dual-polarization NFT can work in practice and enable an increased spectral efficiency in NFT-based communication systems, which are currently based on single polarization channels.

High Speed Wireless Internet Using LiFi

The internet has become a basic necessity, so with the advancement in technology, people are demanding something faster than WI-FI. Since light is the only medium that can travel fastest than any other source of data transmission else so if we use this medium for internet, it will be the best utilization of medium with a higher data transmission rate. This technology was implemented over and came out with concept of LI-FI Technology. Li-Fi in known for Light-Fidelity, Li-Fi uses an idea of visible light communication (VLC) technology that uses light as a medium to convey fast high-speed communication in a manner like Wi-Fi. Since visible light is present everywhere, the main idea of our review paper is how LI-FI technology can help in security, speed and reliability of internet and even can change our life style. This innovation is actualized utilizing white LED bulbs matched with the Downlink transmitter that can give a higher information transmission rate up to 10Gbps. The main prospective of this paper demonstrates the forthcoming routine of Li-Fi technology innovation and its highlights to expand the execution of information transmission and different applications where Li-Fi has been put to utilize.

Performance Analysis of Wireless Powered Communications With Multiple Antennas

This paper analytically investigates the performance of a wireless powered communication system, where a source powered by multiple dedicated power beacons communicates with a destination. Specifically, we consider a harvest-then-transmit multiple-input multiple-output communication system, where the source uses all harvested energy for information transmission in each time block. The random placement of terminals is characterized by stochastic geometry tools. Taking into account the effects of imperfect channel state information in wireless energy transfer and wireless information transmission, the ergodic achievable rate of information transmission is derived analytically by considering co-channel interference (CCI) and the noise. In addition, assuming the CCI can be accurately approximated by a Gamma distributed variable, the outage probability of information transmission is investigated. Numerical results validate the analytical results and show the impacts of the antenna number, distribution density, estimation error, and the transmit power of terminals on the system performance.

Предыскажающая компенсация продуктов интермодуляции в усилителях мощности сверхвысокочастотных сигналов

The article presents an analysis of various technical solutions focused on correction of amplitude and amplitude-phase distortions of modulated signals that occur in vacuum and solid-state microwave power amplifiers as a result of nonlinear changes of instantaneous current values in active amplifying devices. It is shown that intermodulation distortions of odd orders in the vicinity of the input signal main frequency band degrade the amplifier’s power efficiency and give rise to additional side spectrum components, which violate strict requirements for electromagnetic compatibility for radio electronic devices and lead to the necessity to operate the amplifier well below its power rating for reducing the distortion levels. It is noted that there is a tendency toward increasing the information transmission rate in microwave bands along with growing requirements for the mass, dimensions, and reliability of automatic on-board satellite equipment. In view of these circumstances, after the period during which structural digital-and-analog and fully digital solutions were elaborated, some developers turn back to analog solutions that do not require introduction of complicated digital-and-analog components into the microwave signal flow path and open the possibility to widen the information frequency band of transmitted signals. The article presents the results from studying a microstrip linearizer on its simulation model. The linearizer model contains nonlinear elements made using domestically produced high-speed Schottky diodes with decoupling circuits on the basis of two hybrid microstrip bridges. The model of a standard traveling-wave tube (TWT) with an 11 GHz central frequency that takes into account the AM/AM and AM/PM distortions occurring in this TWT is used as the active component. The measurement results have shown that in case of using the optimal combination of linearizer parameters, the modulated signal input power in its main band can be increased by 2 dB in comparison with the TWT without the linearizer, with concurrently decreasing the level of side spectrum distortion by 12 and 21 dB for third- and fifth-order components, respectively. The microstip predistortion diode linearizer development results can be used in constructing a satellite on-board radio transmitting equipment with improved characteristics.

Asymptotic Outage Analysis of HARQ-IR Over Time-Correlated Nakagami- $m$ Fading Channels

In this paper, outage performance of hybrid automatic repeat request with incremental redundancy (HARQ-IR) is analyzed. Unlike prior analyses, time-correlated Nakagami- $m$ fading channel is considered. The outage analysis thus involves the probability distribution analysis of a product of multiple correlated shifted Gamma random variables and is more challenging than prior analyses. Based on the findings of the conditional independence of the received signal-to-noise ratios, the outage probability is exactly derived by using conditional Mellin transform. Specifically, the outage probability of HARQ-IR under time-correlated Nakagami- $m$ fading channels can be written as a weighted sum of outage probabilities of HARQ-IR over independent Nakagami fading channels, where the weightings are determined by a negative multinomial distribution. This result enables not only an efficient truncation approximation of the outage probability with uniform convergence but also asymptotic outage analysis to further extract clear insights, which have never been discovered for HARQ-IR even under fast fading channels. The asymptotic outage probability is then derived in a simple form, which clearly quantifies the impacts of transmit powers, channel time correlation, and information transmission rate. It is proved that the asymptotic outage probability is an inverse power function of the product of transmission powers in all HARQ rounds, an increasing function of the channel time correlation coefficients, and a monotonically increasing and convex function of information transmission rate. The simple expression of the asymptotic result enables optimal power allocation and optimal rate selection of HARQ-IR with low complexity. Finally, numerical results are provided to verify our analytical results and justify the application of the asymptotic result for optimal system design.

Feedback Enhances Simultaneous Wireless Information and Energy Transmission in Multiple Access Channels

In this paper, the fundamental limits of simultaneous information and energy transmission in the two-user Gaussian multiple access channel with feedback (G-MAC-F) and without feedback (G-MAC) are fully characterized. More specifically, all the achievable information and energy transmission rates (in bits per channel use and energy-units per channel use, respectively) are identified. Furthermore, the fundamental limits on the individual and sum- rates given a minimum-energy rate ensured at an energy harvester are also characterized. In the case without feedback, an achievability scheme based on power-splitting and successive interference cancellation is shown to be optimal. Alternatively, in the G-MAC-F case, a simple yet optimal achievability scheme based on power-splitting and Ozarow’s capacity achieving scheme is presented. Finally, the energy transmission enhancement induced by the use of feedback is quantified. Feedback can at most double the energy transmission rate at high SNRs when the information transmission sum-rate is kept fixed at the sum-capacity of the G-MAC, but it has no effect at very low SNRs.

Capacity of coherent-state adaptive decoders with interferometry and single-mode detectors

A class of Adaptive Decoders (AD's) for coherent-state sequences is studied, including in particular the most common technology for optical-signal processing, e.g., interferometers, coherent displacements and photon-counting detectors. More generally we consider AD's comprising adaptive procedures based on passive multi-mode Gaussian unitaries and arbitrary single-mode destructive measurements. For classical communication on quantum phase-insensitive Gaussian channels with a coherent-state encoding, we show that the AD's optimal information transmission rate is not greater than that of a single-mode decoder. Our result also implies that the ultimate classical capacity of quantum phase-insensitive Gaussian channels is unlikely to be achieved with the considered class of AD's.

Individual and ecological determinants of social information transmission in the wild

Social information, acquired through the observation of others, has been documented in a variety of adaptive contexts. The transmission of social information relies on social connections and therefore it is important to consider that individuals may vary in their access to, and use of, such information. Social network analysis allows for the consideration of individual variation in social connections, which until recently has been ignored in the study of social processes. Furthermore, few previous studies of social information use have considered the potential effects of traits such as dominance and personality, which have been found to influence group social structure. We used network-based diffusion analysis, which incorporates information on individual social associations, to examine whether wild flocks of black-capped chickadees, Poecile atricapillus , utilize social information when locating novel foraging patches. Additionally, we incorporated individual traits (age, sex, dominance and exploratory personality) while examining flocks from rural and urban environments, to assess the influence of individual and habitat level characteristics on the rate of information transmission. Social information transmission was found to occur in all flocks, as individual time of discovery of the novel foraging patches was explained by network connections as predicted. However, the only individual level variable found to influence social transmission was dominance rank: dominant individuals had higher rates of information transmission than subordinates. We also found that the rate of social information transmission was higher in rural than urban environments. Our results highlight the importance of considering social associations when examining social information use. Additionally, our results suggest that dominant individuals have greater access to social information than more subordinate individuals, which may demonstrate a previously undocumented additional benefit provided by social dominance.

A Synchronous Motor Imagery Based Neural Physiological Paradigm for Brain Computer Interface Speller.

Brain Computer Interface (BCI) speller is a typical BCI-based application to help paralyzed patients express their thoughts. This paper proposed a novel motor imagery based BCI speller with Oct-o-spell paradigm for word input. Furthermore, an intelligent input method was used for improving the performance of the BCI speller. For the English word spelling experiment, we compared synchronous control with previous asynchronous control under the same experimental condition. There were no significant differences between these two control methods in the classification accuracy, information transmission rate (ITR) or letters per minute (LPM). And the accuracy rates of over 70% validated the feasibility for these two control strategies. It was indicated that MI-based synchronous control protocol was feasible for BCI speller. And the efficiency of the predictive text entry (PTE) mode was superior to that of the Non-PTE mode.

Social contagions on time-varying community networks

Time-varying community structures exist widely in real-world networks. However, previous studies on the dynamics of spreading seldom took this characteristic into account, especially those on social contagions. To study the effects of time-varying community structures on social contagions, we propose a non-Markovian social contagion model on time-varying community networks based on the activity-driven network model. A mean-field theory is developed to analyze the proposed model. Through theoretical analyses and numerical simulations, two hierarchical features of the behavior adoption processes are found. That is, when community strength is relatively large, the behavior can easily spread in one of the communities, while in the other community the spreading only occurs at higher behavioral information transmission rates. Meanwhile, in spatial-temporal evolution processes, hierarchical orders are observed for the behavior adoption. Moreover, under different information transmission rates, three distinctive patterns are demonstrated in the change of the whole network's final adoption proportion along with the growing community strength. Within a suitable range of transmission rate, an optimal community strength can be found that can maximize the final adoption proportion. Finally, compared with the average activity potential, the promoting or inhibiting of social contagions is much more influenced by the number of edges generated by active nodes.

A real signal and its states

The paper describes the general physical theory of signals, carriers of information, which supplements Shannon’s abstract classical theory and is applicable in much broader fields, including nuclear physics. It is shown that in the absence of classical noise its place should be taken by the physical threshold of signal perception for objects of both macrocosm and microcosm. The signal perception threshold allows the presence of subthreshold (virtual) signal states. For these states, Boolean algebra of logic (A = 0/1) is transformed into the “algebraic logic” of probabilities (0 ≤ a ≤ 1). The similarity and difference of virtual states of macroand microsignals are elucidated. “Real” and “quantum” information for computers is considered briefly. The maximum information transmission rate is estimated based on physical constants.

Information Rate Analysis of a Synaptic Release Site Using a Two-State Model of Short-Term Depression.

Synapses are the communication channels for information transfer between neurons; these are the points at which pulse-like signals are converted into the stochastic release of quantized amounts of chemical neurotransmitter. At many synapses, prior neuronal activity depletes synaptic resources, depressing subsequent responses of both spontaneous and spike-evoked releases. We analytically compute the information transmission rate of a synaptic release site, which we model as a binary asymmetric channel. Short-term depression is incorporated by assigning the channel a memory of depth one. A successful release, whether spike evoked or spontaneous, decreases the probability of a subsequent release; if no release occurs on the following time step, the release probabilities recover back to their default values. We prove that synaptic depression can increase the release site's information rate if spontaneous release is more strongly depressed than spike-evoked release. When depression affects spontaneous and evoked release equally, the information rate must invariably decrease, even when the rate is normalized by the resources used for synaptic transmission. For identical depression levels, we analytically disprove the hypothesis, at least in this simplified model, that synaptic depression serves energy- and information-efficient encoding.

Classical correlation and quantum entanglement in the mixed-spin Ising-XY model with Dzyaloshinskii–Moriya interaction

In the present work, initially, a mixed-three-spin (1/2,1,1/2) cell of a mixed-[Formula: see text]-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 [Formula: see text] is considered for the system in thermal equilibrium. Integer-spins have a single-ion anisotropy property with coefficient [Formula: see text]. 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.