Modulation Communication Research Articles

Array Phase Center Dynamics Using Spatial Amplitude Modulation for High-Efficiency Secure Wireless Communication

Array Phase Center Dynamics Using Spatial Amplitude Modulation for High-Efficiency Secure Wireless Communication

Grant Free MIMO-NOMA With Differential Modulation for Machine Type Communications

Grant Free MIMO-NOMA With Differential Modulation for Machine Type Communications

Phase Offset Aided Index Modulation for UCA-Based OAM Communication

Phase Offset Aided Index Modulation for UCA-Based OAM Communication

OCDM with Index Modulation for Autonomous Underwater Vehicles Communication

OCDM with Index Modulation for Autonomous Underwater Vehicles Communication

OFDM with generalized cascade index modulation for secure communications

OFDM with generalized cascade index modulation for secure communications

Astrocyte ryanodine receptors facilitate gliotransmission and astroglial modulation of synaptic plasticity.

Intracellular Ca2+-signaling in astrocytes is instrumental for their brain "housekeeping" role and astroglial control of synaptic plasticity. An important source for elevating the cytosolic Ca2+ level in astrocytes is a release from endoplasmic reticulum which can be triggered via two fundamental pathways: IP3 receptors and calcium-induced calcium release (CICR) mediated by Ca2+-sensitive ryanodine receptors (RyRs). While the physiological role for glial IP3 became a focus of intensive research and debate, ryanodine receptors received much less attention. We explored the role for ryanodine receptors in the modulation of cytosolic Ca2+-signaling in the cortical and hippocampal astrocytes, astrocyte-neuron communication and astroglia modulation of synaptic plasticity. Our data show that RyR-mediated Ca2+-induced Ca2+-release from ER brings substantial contribution into signaling in the functional microdomains hippocampal and neocortical astrocytes. Furthermore, RyR-mediated CICR activated the release of ATP and glutamate from hippocampal and neocortical astrocytes which, in turn, elicited transient purinergic and tonic glutamatergic currents in the neighboring pyramidal neurons. The CICR-facilitated release of ATP and glutamate was inhibited after intracellular perfusion of astrocytes with ryanodine and BAPTA and in the transgenic dnSNARE mice with impaired astroglial exocytosis. We also found out that RyR-mediated amplification of astrocytic Ca2+-signaling enhanced the long-term synaptic potentiation in the hippocampus and neocortex of aged mice. Combined, our data demonstrate that ryanodine receptors are essential for astrocytic Ca2+-signaling and efficient astrocyte-neuron communications. The RyR-mediated CICR contributes to astrocytic control of synaptic plasticity and can underlie, at least partially, neuroprotective and cognitive effects of caffein.

Estimation of the Noise Immunity Characteristics of Telecommunication Network

The harmful impacts of various interference sources in the communication channel of data transmission systems and an increasing noise immunity in linear distortion conditions are important problems in the development of information transmission systems. To improve reliability and the data receiving accuracy, a mathematical model is developed, which allows to assessment of the survivability of telecommunication systems to interference at incoherent receiving. In this case is assumed that system impact the unintentional sources. The mathematical model considers the communication quality, spectral efficiency, coding method, and modulation principle used during the multimedia services. Presently, the development of the corporate multiservice communication networks is in conditions where the size of user and service traffic packets is rapidly increase. To ensure transmission reliability is promising of an implementation of the coherent modem. It will allow a decrease in the failures of such systems. To increase the transmission rate used coherent modem with noise-resistant characteristics. However, the communication quality in this case is decreased, due to more influence of the inter-symbol interference to the data quality receiving. The synthesis of optimal signals based on rectangular pulses with different shapes by the coherent modem for the data transmission system aims is solved by using of matching filter that has a pulse transient response. To obtain this the frequency limiter is used at the output of the channel digital demodulator. One of the ways to properly solve the problem noted above is by applying in the development of telecommunication multiservice networks the mathematical model with correction ability. This one can be developed based on the optimal signal-receiving theory.

Narracja filmowa – funkcja terapeutyczna. Kilka słów o Amatorze (1979) Krzysztofa Kieślowskiego

The strategy of the (auto)therapist in film art is a process of dynamic interaction between the transmitting and receiving roles, i.e. the director – the protagonist of his work and the projected viewers. The film is a space enabling the creator to analyze the problems of a modern man in order to increase the skills of self-understanding, self-distancing from emotions and developing reflection. The latter is conducive to the coherence of narratives about oneself and the construction of one’s identity. Results and conclusions: Projection and identification, which is part of the emotional and cognitive responses available to the creator and recipient of the work, are processes of therapeutic importance. Creation (and contact with its effect – a finished work) is then a tool helping to regulate: modulation of attention, emotions (modulation of emotion), fosters cognition (modulation of cognition), understanding behavior (modulation of behavior) and communication (modulation of communication).

CD133-containing microvesicles promote cancer progression by inducing M2-like tumor-associated macrophage polarization in the tumor microenvironment of colorectal cancer.

Tumor-associated macrophages (TAMs) are among the most abundant cell types in the tumor microenvironment (TME). The immunosuppressive TME formed by TAMs is an essential prerequisite for cancer progression. Tumor-derived microvesicles (MVs), a subtype of extracellular vesicle shed directly from the plasma membrane, are important regulators of intercellular communication and TME modulation during tumorigenesis. However, the exact mechanism by which tumor-derived MVs induce the generation of the immunosuppressive TME and polarization of TAMs remains unclear. Here, we investigated the role of CD133-containing MVs derived from colorectal cancer (CRC) cells in macrophage polarization and cancer progression. CD133-containing MVs from CRC cells were incorporated into macrophages, and M0 macrophages were morphologically transformed into M2-like TAMs. CD133-containing MVs were found to increase the mRNA expression of M2 macrophage markers. Additionally, cytokine array analysis revealed that M2-like TAMs induced by CD133-containing MVs increased the secretion of interleukin 6, which activated the STAT3 pathway in CRC cells. Furthermore, the conditioned medium of M2-like TAMs promoted cell motility, epithelial-mesenchymal transition, and cell proliferation. However, MVs from CD133-knockdown cells had little effect on TAM polarization and CRC progression. These results demonstrate that CD133-containing MVs induce M2-like TAM polarization and contribute to cancer progression by mediating crosstalk between tumor cells and TAMs in the TME of CRC.

Polarized OFDM-Based Pulse Position Modulation for High-Speed Wireless Optical Underwater Communications

Polarized OFDM-Based Pulse Position Modulation for High-Speed Wireless Optical Underwater Communications

FPGA-based microsystematic design of Gaussian modulation for continuous-variable quantum communication

FPGA-based microsystematic design of Gaussian modulation for continuous-variable quantum communication

Analysis on the Effect of Phase Noise on the Performance of Satellite Communication and Measurement System

An oscillator is a key component of a satellite communication measurement and control system, performing symmetry precisely as a time frequency reference. At the same time, the phase noise index has a close coupling relationship with the overall performance of the entire system, while persistently breaking the symmetry property of the oscillator during work. It is very important to study and reasonably allocate the phase noise index. According to the theoretical formula of phase noise, this paper analyzes the power law spectral model in the frequency domain and the noise jitter characteristics in the time domain. Using the carrier tracking loop in the measurement system, the frequency domain transfer model of phase noise is established, and typical analysis results are given. A discrete fractional integration algorithm is proposed, which can generate the phase noise time domain sequence under the given power law spectral model coefficients. The proposed algorithm is more realistic compared with the previous numerical calculation method, and has sufficient accuracy compared with the results of the instrument. After frequency domain conversion, the RMS deviation between the simulated noise sequence in the frequency domain and the measured single sideband power spectral density is less than 2.5 dB, indicating that the phase noise sequence can reflect the frequency domain characteristics more completely. A communication measurement simulation system is built, and a discrete sequence simulation analysis method combining frequency domain and time domain is provided, and the coupling relationship of key indicators such as phase noise, thermal noise, communication data rate, modulation method and bit error rate is synthesized. The results show that the BER of the QPSK/BPSK communication system will not be significantly reduced if the phase jitter RMS caused by the phase noise is less than 5 degrees, so 5 degrees can be used as a reference for the decomposition of the carrier SSB phase noise index. The simulation results have been successfully applied to a satellite inter-satellite link system, which has universal practical application value.

FPGA-based pulsed laser with high modulation depth from Mach-Zehnder electro-optic modulator and its application

Mach-Zehnder electro-optic modulator as the essential component of high-speed modulation in the optical fiber communication and sensing system, its stability control of operating bias-point plays a key role in determining the transmission signal quality. Based on the output characteristic principle of Mach-Zehnder electro-optic modulator, researches on its bias-point drifting for causing the reduction mechanism of modulation depth and extinction ratio are analyzed. Switching its internal state machine from FPGA is proposed to automatically adjust the bias voltage in real time realizing the operating bias-point control of Mach-Zehnder electro-optic modulator, which is studied through the theoretical investigation. A pulsed laser with the temperature sensing system of fiber Bragg grating ring-down cavity based on FPGA is established experimentally to demonstrate its effectiveness. The experimental results show the modulation depth and the extinction ratio of pulsed laser are improved by 40.45% and 32.85 dB, respectively. Output characteristic curve of the sensing system is optimized, which includes the phenomenon of initial curve rise of ring-down signals and the distortion of ring-down waveform are eliminated. The good linearity, repeatability, stability and accuracy of sensing system are investigated at the continuous variation temperature from −30℃ to 30℃.

Orthogonal time-frequency space (OTFS) modulation for underwater mobile acoustic communications

This paper investigates the Orthogonal Time-Frequency Space (OTFS) Modulation for Underwater Mobile Acoustic Communications where the communication channel suffers from severe multipath and Doppler effects simultaneously. Practical OTFS modulation schemes with different parameters are designed for acoustic transmission at a center frequency of 115 kHz and a bandwidth of 11.5 kHz. The schemes are tested in lake experiments where the transmitter was anchored and the receiver was towed by a boat at a speed of approximately 1 m/s or 3.6 km/h. The receiver utilizes low-complexity channel estimation and equalization algorithms, such as NLMS (Normalized Least Mean Squares) and IPNLMS (improved proportionate NLMS) algorithms. The results show some insights of the OTFS scheme for acoustic communications. First, the mobile acoustic channel characteristics are different in the 2D delay-Doppler domain than those in the 1D time and frequency domains for the Single-Carrier Coherent Modulation (SCCM) and the Orthogonal frequency division modulation (OFDM), respectively. Second, in mobile scenarios, the OTFS scheme receiver effectively and significantly reduces the accuracy requirements of the Doppler compensation algorithm and provides better frequency-selective fading suppression and Doppler effect robustness compared to SCCM and OFDM schemes. Third, the OTFS scheme has better anti-multipath performance and reduces multipath interference by effectively differentiating signals on different paths in the 2D delay-Doppler domain.

Block-Wise Index Modulation and Receiver Design for High-Mobility OTFS Communications

As a promising technique for high-mobility wireless communications, orthogonal time frequency space (OTFS) has been proved to enjoy excellent advantages with respect to traditional orthogonal frequency division multiplexing (OFDM). Although multiple studies have considered index modulation (IM) based OTFS (IM-OTFS) schemes to further improve system performance, a challenging and open problem is the development of effective IM schemes and efficient receivers for practical OTFS systems that must operate in the presence of channel delays and Doppler shifts. In this paper, we propose two novel block-wise IM schemes for OTFS systems, named delay-IM with OTFS (DeIM-OTFS) and Doppler-IM with OTFS (DoIM-OTFS), where a block of delay/Doppler resource bins are activated simultaneously. Based on a maximum likelihood (ML) detector, we analyze upper bounds on the average bit error rates for the proposed DeIM-OTFS and DoIM-OTFS schemes, and verify their performance advantages over the existing IM-OTFS systems. We also develop a multi-layer joint symbol and activation pattern detection (MLJSAPD) algorithm and a customized message passing detection (CMPD) algorithm for our proposed DeIM-OTFS and DoIM-OTFS systems with low complexity. Simulation results demonstrate that our proposed MLJSAPD and CMPD algorithms can achieve desired performance with robustness to the imperfect channel state information (CSI).

Time and phase features network model for automatic modulation classification

Automatic Modulation Classification (AMC) constitutes a fundamental technology for enabling automatic demodulation in Cognitive Communication Systems (CCS). Due to the size, weight, and power (SWaP) constraints of embedded computers employed in CCS, there are limited computational and memory resources. While deep neural networks possess strong feature representation and high accuracy recognition capabilities, they usually come with a high number of network parameters and high computational complexity, thereby reducing the real-time processing ability of CCS. Therefore, neural network structures intended for CCS must be lightweight and computationally efficient. In this paper, we propose a high-performance and resource-friendly network model based on an analysis of the modulation mechanism of communication signals. The network extracts phase features and short-time features sequentially using directional convolutional filters. Long short-term memory (LSTM) units are then used to extract long-term features, and only one fully connected layer is used for classification. Experiments with a standard dataset consisting of 11 communication modulation types demonstrate that our proposed model achieves an accuracy greater than 84.5%, even when the signal-to-noise ratio (SNR) is 0 dB, and the model has only 29187 parameters. On a Jetson Nano embedded platform, the model achieves a processing speed of up to 375366 in-phase and quadrature samples/s. Overall, the results suggest that our proposed approach is both lightweight and highly efficient, making it more suitable for CCS applications.

Characterizing the Transport and Surface Affinity of Extracellular Vesicles Isolated from Yeast and Bacteria in Well-Characterized Porous Media.

Extracellular vesicles (EVs) are membrane-bounded, nanosized particles, produced and secreted by all biological cell types. EVs are ubiquitous in the environment, operating in various roles including intercellular communication and plant immune modulation. Despite their ubiquity, the role of EV surface chemistry in determining transport has been minimally investigated. Using the zeta (ζ)-potential as a surrogate for surface charge, this work considers the deposition of EVs from the yeast, Saccharomyces cerevisiae, and two bacterial species, Staphylococcus aureus and Pseudomonas fluorescens, in well-characterized porous medium under various background conditions shown to influence the transport of other environmental colloidal particles: ionic strength and humic acid concentration. The affinity of S. cerevisiae EVs for the porous medium (glass beads) appeared to be sensitive to changes in ionic strength, as predicted by colloid stability (Derjaguin, Landau, Verwey, and Overbeek or DLVO) theory, and humic acid concentration, while P. fluorescens EVs deviated from DLVO predictions, suggesting that mechanisms other than charge stabilization may control the deposition of P. fluorescens. Calculations of attachment efficiency from these deposition studies were used to estimate EV transport using a clean-bed filtration model. Based on these calculations, EVs could be transported through such homogeneous porous media up to 15 m.

Public Speaking Training Plan for Mitigating Oral Communication Apprehension

This paper presents a public speaking training plan adapted from Toastmasters International’s Handbook of Competent Communication to reduce students’ communication apprehension. The training plan draws on Kolb’s (1984) experiential learning theory, which links experience, perception, cognition and behaviour, making it particularly well suited for developing practical skills such as public speaking. The programme engages participants in a cycle of concrete experience, reflective observation, abstract conceptualisation and active experimentation consistent with successful public speaking training principles. The training addresses aspects of public speaking that often contribute to communication apprehension, such as language structure, language use, non-verbal communication and voice modulation. The programme also emphasises active experimentation through visual aids and the delivery of persuasive and inspiring speeches so that participants have ample opportunity to practise and hone their public speaking skills. This approach effectively reduces communication apprehension and gives students the skills and confidence to deliver impressive oral presentations. However, the effectiveness of this training plan can be influenced by various factors, such as cultural background, language proficiency, and individual personality traits. Therefore, successful training should be flexible and adaptable to meet learners’ different needs and contexts.

Public Speaking Training Plan for Mitigating Oral Communication Apprehension

This paper presents a public speaking training plan adapted from Toastmasters International’s Handbook of Competent Communication to reduce students’ communication apprehension. The training plan draws on Kolb’s (1984) experiential learning theory, which links experience, perception, cognition and behaviour, making it particularly well suited for developing practical skills such as public speaking. The programme engages participants in a cycle of concrete experience, reflective observation, abstract conceptualisation and active experimentation consistent with successful public speaking training principles. The training addresses aspects of public speaking that often contribute to communication apprehension, such as language structure, language use, non-verbal communication and voice modulation. The programme also emphasises active experimentation through visual aids and the delivery of persuasive and inspiring speeches so that participants have ample opportunity to practise and hone their public speaking skills. This approach effectively reduces communication apprehension and gives students the skills and confidence to deliver impressive oral presentations. However, the effectiveness of this training plan can be influenced by various factors, such as cultural background, language proficiency, and individual personality traits. Therefore, successful training should be flexible and adaptable to meet learners’ different needs and contexts.

Spectrum analysis of multi-pulse position modulation in optical communication

In this paper, the authors aim to compare the performance of space optical communication and wireless optical communication by analyzing the transmission mechanism, transmission method, and transmission rate of MPPM (Multi-Pulse Pulse Position Modulation). MPPM is a widely used modulation technique in optical communication systems, which has the advantage of reducing the effect of noise and improving the system's error rate. To achieve the objective, the authors will employ mathematical models to compare the performance of space optical communication and wireless optical communication. They will analyze the transmission mechanism, transmission method, and transmission rate of MPPM in both communication systems and draw conclusions based on their findings. The authors hope that the results of this study will positively promote the development of MPPM in the future. By comparing the performance of space optical communication and wireless optical communication, this study will provide insights into the strengths and weaknesses of both systems, which can help in the development of more efficient and reliable optical communication systems.