Formation of service information in telemetry systems with data compression

In telemetry systems, using irreversible data compression, several message generation methods can be used. In the channel output packet, there may be several code words defining its composition. They can be combined and arranged in a strictly defined sequence. Such a data packet is a constant or variable length code combination, wherein the constant length of the packet is generated in the case of a predetermined and unchanged amount of information at the data output interval, and the variable is otherwise generated. The channel data packet can then be treated as a single whole: provide it with address information about the source of the message, information about the time interval at which the packet was formed, to bind significant samples to time, additional check symbols and codes to increase interference immunity of transmission, or to form a packet structure in the same way. Address, time and synchronization information in the literature is called overhead. The need to transmit overhead information reduces the efficiency of the transceiver systems. Therefore, the problem of reducing the volume of service information is extremely urgent.

The interference immunity of decameter circuit with spatial interference compensation

В статье представлена оценка помехоустойчивости декаметрового канала связи, использующего пространственный метод компенсации естественных помех. Метод компенсации базируется на результаты экспериментальных исследований пространственно-корреляционных свойств сигналов и естественных помех декаметрового диапазона. Для реализации метода используется цифровая антенная решетка с пространственно-корреляционным методом обработки сигналов. Также в канале использована гауссовая амплитудная модуляция, формирующая шумоподобный сигнал с расширенной базой. Оценка помехоустойчивости построена на модели ионосферного канала с релеевскими замираниями с учетом пространственно-корреляционных свойств сигналов и естественных помех. Анализ проведенных исследований показал возможность компенсации помех за счет роста антенных элементов в антенной решетке, которая, как следствие, позволит повысить помехоустойчивость ионосферного декаметрового канала связи при низких отношениях уровней сигнал/шум на входе приемного тракта. Возможность обеспечения высокой помехоустойчивости в ионосферных декаметровых каналах позволит использовать новые виды связи для обмена данными в судами и кораблями ВМФ в пределах акваторий Мирового океана. The interference immunity assessment of the decameter circuit using a spatial method of natural interference compensation is presented. The compensation method is based on experimental studies results of spatial and correlation properties of decameter range signals and natural interference. For the method realization the digital array with a spatially-correlation signals processing method is used. Also in the channel the Gaussian amplitude modulation forming a noise-shaped signal with extended base is used. The interference immunity assessment is based on the ionospheric channel model with the Rayleigh fadings taking into account signals and natural interference spatially-correlation properties. The simulation findings showed the interference compensation possibility due to increase in antenna array elements which, as a result, will allow to increase the interference immunity of ionospheric decameter circuit at the low levels of signal/noise ratio in the reception path entrance. The possibility of ensuring high interference immunity in ionospheric decameter circuits will allow to use new communication types for data exchange with NAVY battleships and vessels within the World Ocean water areas.

A Performance–Consumption Balanced Scheme of Multi-Hop Quantum Networks for Teleportation

Teleportation is an important protocol in quantum communication. Realizing teleportation between arbitrary nodes in multi-hop quantum networks is of great value. Most of the existing multi-hop quantum networks are based on Bell states or Greeberger–Horne–Zeilinger (GHZ) states. Bell state is more susceptible to noise than GHZ states after purification, but generating a GHZ state consumes more basic states. In this paper, a new quantum multi-hop network scheme is proposed to improve the interference immunity of the network and avoid large consumption at the same time. Teleportation is realized in a network based on entanglement swapping, fusion, and purification. To ensure the robustness of the system, we also design the purification algorithm. The simulation results show the successful establishment of entanglement with high fidelity. Cirq is used to verify the network on the Noisy Intermediate-Scale Quantum (NISQ) platform. The robustness of the fusion scheme is better than the Bell states scheme, especially with the increasing number of nodes. This paper provides a solution to balance the performance and consumption in a multi-hop quantum network.

Application of Broadband Signals to Increase Interference Immunity in Channels with Inter-Symbol Interference

Proposals for improving the noise immunity of receiving phase-shift keying signals in the conditions of inter-symbol interference caused by fading in the channel are presented. The use of Barker sequences for the expansion of modulating information pulses has been substantiated. The results of evaluating the noise immunity of Rice fading channels at various ratios of the effective voltages of the regular and diffuse signal components are presented. Proposals for the practical application of the results obtained are formulated.

Design and Analysis of Different Optical Attocells Deployment Models for Indoor Visible Light Communication System

Visible light communication (VLC) is a promising candidate that is expected to revolutionize indoor environment communications performance and fulfill fifth generation and beyond (5GB) technologies requirements. It offers high and free bandwidth, electromagnetic interference immunity, low-cost front end and low power consumption. Also, VLC has dual functions that could be utilized in both illumination and communication concurrently. The number of optical attocells (OAs) and their deployment in the room represent the main issue that should be taken into consideration in designing an optimal VLC system. In this paper, we have introduced a new model of five OAs in the typical room. In addition to an investigation of various optical attocells (OAs) deployment models, in which a multi-variable evaluation was performed in terms of received power, illumination, SNR and RMS delay spread in order to determine the optimal OAs model. Also, various modulation schemes performances were investigated which included NRZ-OOK, BPSK, and QPSK in order to improve the BER performance. Results indicated that BPSK modulation had superior BER performance when compared with all OAs models. Further, a comprehensive results analysis and comparison of all proposed models was conducted over various parameters, in which our new proposed OAs model achieved an optimal performance in comparison with the other models.

Development of a fiber optic torque sensor and a single channel, high precision optical strain measurement platform

Fiber optic sensors based on Fiber Bragg Grating (FBG) technology have been successfully adopted for sensor measurements for almost two decades. The advantages offered by FBG sensors, such as Electro-Magnetic Interference immunity and inherent intrinsic safety, provide motivation for the development of a commercial measurement platform. With the development of an FBG Fabry-Perot cavity, a sensor with sub-picometer spectral width allows for a factor of 1000 times improvement in strain measurement. This thesis presents the development of a highly-accurate optical measurement platform based on the FBG Fabry-Perot cavity and Pound-Drever-Hall (PDH) laser locking technique that is demonstrated through the development of an optical torque sensor. With the fiber optic sensor designed as per the PDH requirements, the platform achieved a measurement accuracy of +/-0.015% of the full-scale torque value of 188N∙m. With the platform at ~$2,000, a successful demonstration of the platform and a fiber optic torque sensor is presented.

Development of a fiber optic torque sensor and a single channel, high precision optical strain measurement platform

Fiber optic sensors based on Fiber Bragg Grating (FBG) technology have been successfully adopted for sensor measurements for almost two decades. The advantages offered by FBG sensors, such as Electro-Magnetic Interference immunity and inherent intrinsic safety, provide motivation for the development of a commercial measurement platform. With the development of an FBG Fabry-Perot cavity, a sensor with sub-picometer spectral width allows for a factor of 1000 times improvement in strain measurement. This thesis presents the development of a highly-accurate optical measurement platform based on the FBG Fabry-Perot cavity and Pound-Drever-Hall (PDH) laser locking technique that is demonstrated through the development of an optical torque sensor. With the fiber optic sensor designed as per the PDH requirements, the platform achieved a measurement accuracy of +/-0.015% of the full-scale torque value of 188N∙m. With the platform at ~$2,000, a successful demonstration of the platform and a fiber optic torque sensor is presented.

Potential interference immunity of coherent reception of quadruple phase-manipulated radio signal in the presence of coherent harmonic interference

Introduction: The known methods for calculating the interference immunity of radio signal reception in the presence of, for example, harmonic interference, often lead to significantly different numerical values. Each calculation technique of this type has its own algorithm for the resulting formula output, and these conclusions are based on a different level of “engineering rigor”. Purpose: To develop, оn the basis of linear transformation of coordinates, a correct method for calculating the error probability in the correlating reception of a four-fold phase-manipulated radio signal in the presence of coherent harmonic interference. Methods: Four-dimensional probability density of a vector of output voltages of the demodulator correlators in a four-fold integral was represented by a product of one-dimensional probability densities in the space of eigenvectors of the covariance matrix, in which two probability densities are Dirac delta functions. The quadruple integral is brought to double, with new integration limits defined from the plane equations bounding the integration region in this space. Results: Formulas were derived for accurate calculation of average probabilities of symbol and bit errors in coherent reception of a four-fold phase-manipulated radio signal in the presence of coherent harmonic interference. The derived exact formulas were used to plot the dependencies of the average probabilities of symbol and bit errors on the signal-to-noise ratio for the given interference-to-noise ratio and the given interference phase shift relative to the signal phase. It has been studied how the energy ratios of the signal and interference, as well as the interference phase shift, affect the probabilities of symbol and bit errors. It was found that the influence of a non-energy parameter equivalently leads to a change in the energy ratios. Practical relevance: The results of the research can be used in assessing the communication efficiency under interference. The developed technique will allow you to accurately determine the energy characteristics of a radio channel providing the required quality for the reception of transmitted messages in presence of harmonic interference.

VLC-based Data Transfer and Energy Harvesting Mobile System

This paper explores a low-cost portable visible light communication (VLC) system to support the increasing needs of lightweight mobile applications. VLC grows rapidly in the past decade for many applications (e.g., indoor data transmission, human sensing, and visual MIMO) due to its RF interference immunity and inherent high security. However, most existing VLC systems heavily rely on fixed infrastructures with less adaptability to emerging lightweight mobile applications. This work proposes Light Storage, a portable VLC system takes the advantage of commercial smartphone flashlights as the transmitter and a solar panel equipped with both data reception and energy harvesting modules as the receiver. Light Storage can achieve concurrent data transmission and energy harvesting from the visible light signals. It develops multi-level light intensity data modulation to increase data throughput and integrates the noise reduction functionality to allow portability under various lighting conditions. The system supports synchronization together with adaptive error correction to overcome both the linear and non-linear signal offsets caused by the low time-control ability from the commercial smartphones. Finally, the energy harvesting capability in Light Storage provides sufficient energy support for efficient short range communication. Light Storage is validated in both indoor and outdoor environments and can achieve over 98% data decoding accuracy, demonstrating the potential as an important alternative to support low-cost and portable short range communication.