Signal Transmission Method Research Articles

An alternative method of biomedical signal transmission through the GSM voice channel

In this work, a new solution for online and accurate biomedical data transmission is presented. For this purpose, a global system for mobile (GSM) communication voice channel is, for the first time, used as a communication link between the patient and healthcare provider. Biomedical signals are converted into speech-like signals before being transferred over a GSM voice channel. On the receiver side, speech-like symbols are stored in a symbols bank, and constructed using random stochastic signals. On the receiver end, the index of the symbol with the most similarity to the received signal is selected as the identified sample. This method enables us to communicate with an accuracy of 99.8% at a transfer rate of 110 samples per second and signal-to-noise ratio (SNR) of 10. By utilizing a GSM voice channel, any voice channel, such as a cell phone, can be used for data transmission. The transmitted signal is encoded; therefore, the connection is secured. GSM technology has benefits such as availability, reliability, and robustness. Additionally, GSM can be used as a backup or service for transmitting vital physiological signals in emergency situations (e.g. in an ambulance). This technology can also be used to transmit other physiological signals as well as nonphysiological generic data.

On the Stability and Stabilization of Nonlinear Non-Stationary Discrete Systems

The study of many biological, economic and other processes leads to its modeling based on discrete equations. Currently, the need to develop a mathematical apparatus for the qualitative analysis of discrete equations is caused by the creation of digital control systems, processors and microprocessors as well as discrete methods of signal transmission in automatic control systems and other theoretical and technical problems. One of the important areas of the qualitative analysis of discrete equations is the stability problem. The main method for studying the stability of nonlinear differential, discrete, and other types of equations is the direct Lyapunov method. The aim of this paper is to develop the direct Lyapunov method in the study of the limiting behavior and asymptotic stability of nonlinear nonstationary discrete equations using the comparison principle. New theorems are proved that are applied in the stability problem of the well-known epidemiological model as well as in solving the stabilization problem of a nonlinear discrete controlled system. An example is shown illustrating a qualitative difference in the conditions of stabilization of non-stationary and stationary discrete systems.

Integrated micro tesla magnetic sensor for detecting photovoltaic cells failure

Recently more attention on the failure of PV systems has been paid and more reports have been found in PV related papers. Various methods to detect failure of PV module have been developed; They are visual method, I-V characteristic method, electroluminescence (EL) method, UV fluorescence method, signal transmission method, IR thermography method, photoluminescence (PL) method. However, each method has some limitations. Developing a new alternative diagnostic method of PV cells will be required for efficient operation of PV system. The proposed method uses μ-tesla magnetic sensor (MI-CB-1DM) to detect failure in a PV cell. The experimental design carried out in this study covered two stages. In the first stage, we developed a method for detecting faults in PV cells using the μ-tesla magnetic sensor method. In this second stage a calculation will be made to determine the current level due to the failure of the PV cell. The results show that Bx at the lower busbar in the degraded module has smaller magnetic density than the upper busbar. No obvious difference can be seen in the Bx and By profiles between the normal and degraded cells.

Research on High Frequency Signal Transmission Method of Transmission Line under Internet of Things Communication Environment

In order to better promote the safety and stability of transmission line signal transmission, a research on transmission line high frequency signal transmission method based on Internet of Things communication environment is proposed. Firstly, the noise interference in the transmission line signal transmission process is removed by combining the wavelet transform algorithm, and the original high-frequency signal is subjected to waveform constraint processing after denoising, so as to realize the safe transmission of the high-frequency signal of the electric line. Finally, the experiment proves that the transmission line high-frequency signal transmission method under the Internet of Things communication environment has higher safety and stability than the traditional method, which fully meets the research requirements.

A time difference of arrival/angle of arrival fusion algorithm with steepest descent algorithm for indoor non-line-of-sight locationing

In complex indoor propagation environment, the non-line-of-sight error caused by various obstacles brings great error to node positioning. Choosing the appropriate signal transmission methods is important to improve node indoor positioning accuracy. In this research, ultra-wideband technology, as baseband with high theoretical positioning accuracy and real-time performance, is implemented to transmit indoor signals. The proposed fusion algorithm with ultra-wideband baseband takes advantages from both time difference of arrival and angle of arrival algorithms, combined through the steepest descent algorithm. The non-line-of-sight signal estimation error is iteratively eliminated to achieve effective positioning accuracy. The experimental results indicate that the novel time difference of arrival/angle of arrival fusion algorithm with steepest descent algorithm can largely improve node positioning accuracy and stability.

Equivalent Circuit Model Viewed From Receiver Side in Human Body Communication.

Human body communication (HBC) is a signal transmission method that uses the human body as a part of the transmission path. The incoming signal through the receiver electrode can be modeled as a signal from a signal source, which consists of the equivalent signal source voltage and output impedance. These values are important parameters for analyzing the transmission characteristics of HBC as well as for designing the front-end circuit of the receiver. In this paper, an equivalent circuit model of signal transmission from a transmitter on the human body to an off-body receiver touched by a finger was constructed. The ground electrode of the transmitter was in contact with the human body. This is a different configuration compared to capacitive HBC configurations that leave the ground electrode floating. The relationship between the received signal voltage and the distance between the transmitter's electrodes, the size of the receiver ground, and the transmitter-receiver distance were evaluated. Results were analyzed by using the equivalent circuit model. The transmitter-receiver distance and the distance between the transmitter's electrodes were both independently related to the equivalent signal source voltage. The receiver ground size which was related to the capacitive coupling between the receiver ground and the human body was related to the equivalent output impedance.

CALIBRATION OF ULTRASONIC FLOWMETER FOR WI-FI NETWORK WITH THE HELP OF WEB BROWSER

Objectives. The purpose of the work was to change the method of signal transmission containing metrological information from industrial time-pulse ultrasonic gas flow meter to a compu-ting device (CD). It was planned to expand the range of devices serving as gas flow calculators. A hardware-software complex (HSC) for automatic calibration / verification of ultrasonic flowmeters was to be developed. This HSC should work equally well on different operating systems. The information exchange between the CD and the flowmeter was to be carried out wirelessly.Method. The Wi-Fi Pro-tocol was used as a wireless Protocol. The energy-efficient ESP8266 controller was chosen as micro-controller to provide the functionality of Wi-Fi. The ESP8266 board acted as a Wi-Fi access point on the network to which CD was connected for data exchange. The ESP8266 microcontroller also served as a HTTP server. Exchange of metrological and other information was carried out by GET-requests. Given the need for continuous flow measurements and simultaneous communication between the user and the flow meter, requests to the server were transmitted using AJAX technology. The software part of the APK consisted of 3 programs: a program that measured the flow and transmitted the information further to the ESP8266 microcontroller, a server program recorded in ESP8266, providing a response to the requests of CD users, and the client program installed on the CD. The article discusses the key points of the HSC.Result. As a result of this work, the HSC was processed for calibration/verification of ultrasonic gas flow meters. For the first time this process for industrial flow meters was implemented using the ESP8266Wi-Fi controller as an access point. As a WU, it became possible to use any desktop or laptop computer or mobile device with a modern browser.Conclusion. The method proposed in the paper significantly simplified the data exchange between the VU and the flowmeter, reduced the cost of software development due to the common approach for different operating systems.

A Distributed Jamming Signal Transmission Method Considering Node Density to Prevent Eavesdropping in Wireless Networks

In wireless networks, data frames transmitted from wireless node are broadcasted and they can be received in a specific communication area. If an eavesdropper is located in the communication area, not only the receiver node but also the eavesdropper can receive the data. In this letter, we propose a distributed method for reducing the communication area by cooperative jamming among neighbor nodes. In our method, a node becomes a jamming node stochastically based on the locally available information. Through simulation evaluations, we conformed that our method is more effective than the conventional method in the situation where the node density is high. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Multi-channel signal transmission method of non-contact slip ring based on capacitive coupling and quasi-time division multiplexing.

The single-axis rotary inertial navigation system can use the rotary joint to compensate the drift error of the inertial components. Therefore, whether the signal can be transmitted in the rotary joint freely, accurately, for a long time, and without maintenance determines the accuracy of inertial navigation. A noncontact slip ring based on capacitive coupling and quasitime division multiplexing is proposed in this paper. First, the theoretical calculation is carried out on the method of signal transmission using two pairs of capacitors, and the factors affecting signal quality are analyzed. Second, the principle of quasitime division multiplexing and Manchester encoding is used to solve the problems such as converting multiple signals into a single signal, capacitor cannot transmit DC signal, and signal synchronization. Finally, an improved differential transmission method is designed to enhance the anti-interference of the system and to solve the level mismatch of the primary and secondary circuits. In this paper, a prototype is designed to verify the method. When the transmission rate of the three navigation signals is 1 Mbps, the navigation signals can be transmitted without distortion. And the maximum transmission frequency is 17 MHz, which can be further improved. The experimental results show that the proposed method provides a new design for the signal transmission of noncontact power slip ring. It has the advantages of high reliability, fast transmission rate, and good versatility. It can be applied to aviation, aerospace, navigation, wind power generation, and other fields where the power and signal need to be transmitted simultaneously.

Performance evaluation of a small animal PET scanner a high level of multiplexing and charge-signal transmission

Small animal positron emission tomography (PET) is a noninvasive imaging modality that enables in vivo imaging and quantification of the biological processes of small experimental animals. We have developed a small animal PET that utilizes a high-resolution multiplexed readout and charge signal transmission (CST) method. The small animal PET was composed of six detector blocks consisting of SiPMs and LYSO arrays. Six detector blocks were mounted on a PET gantry having an inner diameter of 76 mm, outer diameter of 112 mm, and axial length of 40.8 mm. The charge signals of SiPM output were transmitted to the input of multiplexed readout using 4 m flexible flat cables. The multiplexed readout was composed of six main boards, each of which included 36 detector boards, to reduce the number of readout channels by a factor of 36, with a multiplexing ratio of 144:4. The performance of the small animal PET was evaluated using NEMA NU 4-2008 standards, and its imaging capability was demonstrated by in vivo mouse imaging studies. The average energy and time resolutions were 13.2% ± 0.3% and 3.8 ns, respectively. The spatial resolution at the center of the transaxial FOV was 1.1 mm, and the peak sensitivity at the center of the axial FOV was 1.5%. The peak noise equivalent count (NEC) rate and scatter fraction were 21.1 kcps at 18.2 MBq and 21%, respectively. The acquired images demonstrated high quality tracer uptake patterns of small experimental animals. The results of performance evaluation and animal imaging indicate that the small animal PET developed in this study can provide high-quality small animal imaging with cost-effectiveness and compactness.

Introduction to Photonics: Principles and the Most Recent Applications of Microstructures.

Light has found applications in data transmission, such as optical fibers and waveguides and in optoelectronics. It consists of a series of electromagnetic waves, with particle behavior. Photonics involves the proper use of light as a tool for the benefit of humans. It is derived from the root word “photon”, which connotes the tiniest entity of light analogous to an electron in electricity. Photonics have a broad range of scientific and technological applications that are practically limitless and include medical diagnostics, organic synthesis, communications, as well as fusion energy. This will enhance the quality of life in many areas such as communications and information technology, advanced manufacturing, defense, health, medicine, and energy. The signal transmission methods used in wireless photonic systems are digital baseband and RoF (Radio-over-Fiber) optical communication. Microwave photonics is considered to be one of the emerging research fields. The mid infrared (mid-IR) spectroscopy offers a principal means for biological structure analysis as well as nonintrusive measurements. There is a lower loss in the propagations involving waveguides. Waveguides have simple structures and are cost-efficient in comparison with optical fibers. These are important components due to their compactness, low profile, and many advantages over conventional metallic waveguides. Among the waveguides, optofluidic waveguides have been found to provide a very powerful foundation for building optofluidic sensors. These can be used to fabricate the biosensors based on fluorescence. In an optical fiber, the evanescent field excitation is employed to sense the environmental refractive index changes. Optical fibers as waveguides can be used as sensors to measure strain, temperature, pressure, displacements, vibrations, and other quantities by modifying a fiber. For some application areas, however, fiber-optic sensors are increasingly recognized as a technology with very interesting possibilities. In this review, we present the most common and recent applications of the optical fiber-based sensors. These kinds of sensors can be fabricated by a modification of the waveguide structures to enhance the evanescent field; therefore, direct interactions of the measurand with electromagnetic waves can be performed. In this research, the most recent applications of photonics components are studied and discussed.

능동 소나 시스템에서 고속 탐색을 위한 신호 송신 기법 분석

능동 소나 시스템에서 고속 탐색을 위한 신호 송신 기법 분석

Cooperative Transmission Scheme for Cell Interference Mitigation in Wireless Communication System

In a wireless communication system, the performance is decreased by various interference and disturbance elements. In order to decrease the influence by these elements, the various schemes have been studied. In this paper, the method mitigating inter-cell interference (ICI) is proposed when a mobile user is located in the cell edge. ICI is one reason among the reasons of the performance reduction. The proposed scheme constructs the cooperative communication system and suggests the signal transmission method using pre-coding vectors. The proposed scheme can provide improved performance when the mobile user is located in the cell edge.

Multi-level quantization and blind equalization based direct transmission method of digital baseband signal

The direct transmission of digital baseband signals has practical significance in the field of Ethernet terminal connection, high-speed digital communication, data transmission of various types of information peripherals. The signal amplitude gradually decays while the transmission distance increases. Also the attenuation is proportional to the signal frequency, resulting in signal distortion and receiving error. It is a common method for digital baseband signal transmission to use pre-emphasis chip and equalizer chip to improve the transmission quality with a wide range of mature applications. This paper describes a new type of digital signal transmission method, as the receiver using analog-to-digital converter, instead of equalizer chip, to achieve the multi-level quantization of receiving time-domain data waveform. The waveform of the transmitted digital high and low level signal is sampled into multi-bit values. Then, the paper realizes adaptive frequency domain equalization based on soft threshold and makes use of multi-level quantization soft information for error correction. Error correcting code is mainly used to correct the error caused by the channel bandwidth limit, external noise or interference in the process of data transmission, so as to improve the stability and reliability of the transmission. The paper uses the two-stage error correcting codec system based on both Turbo and BCH coding, to achieve the high performance of Turbo code, and good characters of respond time and complexity. The transmitter outputs 12.5 MHz pseudo-random sequence through a 199.93 meter unshielded balanced twisted pair transmission medium. And the receiver circuit using a 62.5MSPS analog-to-digital converter over-samples the waveform to 8-level quantity. The output error of a 65536 bit pseudo-random sequence is less than 8 bits, and the error correction can be further improved by 8b-10b codec. Compared with the traditional pre-emphasis and balanced interface ICs connection, the method described in this article has the advantages of longer transmission distance, better flexibility and wider scope of use.

REACH: An Efficient MAC Protocol for RF Energy Harvesting in Wireless Sensor Network

This paper proposes a MAC protocol for Radio Frequency (RF) energy harvesting in Wireless Sensor Networks (WSN). In the conventional RF energy harvesting methods, an Energy Transmitter (ET) operates in a passive manner. An ET transmits RF energy signals only when a sensor with depleted energy sends a Request-for-Energy (RFE) message. Unlike the conventional methods, an ET in the proposed scheme can actively send RF energy signals without RFE messages. An ET determines the active energy signal transmission according to the consequence of the passive energy harvesting procedures. To transmit RF energy signals without request from sensors, the ET participates in a contention-based channel access procedure. Once the ET successfully acquires the channel, it sends RF energy signals on the acquired channel during Short Charging Time (SCT). The proposed scheme determines the length of SCT to minimize the interruption of data communication. We compare the performance of the proposed protocol with RF-MAC protocol by simulation. The simulation results show that the proposed protocol can increase the energy harvesting rate by 150% with 8% loss of network throughput compared to RF-MAC. In addition, the proposed protocol can increase the lifetime of WSN because of the active energy signal transmission method.

Adaptive coupled synchronization among three coupled chaos systems and its application to secure communications

In this paper, the adaptive synchronization method of three coupled identical chaos systems is proposed. New generic criteria of global chaos synchronization and strict theoretical proofs are given. The unidirectional (bidirectional) coupled system will synchronize by adding three adaptive feedback gain equations. As an example, the three Rossler chaotic systems with unidirectional coupling are given to realize the adaptive coupled synchronization; at the same time, the three Lorenz chaotic systems donate the bidirectional coupling adaptive synchronization. This paper also extends the above adaptive synchronization method to secure chaos communications through the method of chaos masking. Based on the three coupled identical Lorenz chaotic systems, a novel method of chaos encryption is proposed, and the basic idea is that after encrypting two times in two transmitters and one receiver, information signal can be recovered exactly at the receiver end. In consideration of interfering random white noise, the results of encoding and decoding are simulated and analyzed for the multistage chaos synchronized system. By analyzing the characteristics of noise, this paper presents a de-noising method using wavelet transform. At last, a secure communications method for high amplitude information signal transmission based on chaotic masking is studied. With the MATLAB, the effects of signal de-noising could be demonstrated.

Performance evaluation of neuro-PET using silicon photomultipliers

Recently, we have developed the second prototype Silicon photomultiplier (SiPM) based positron emission tomography (PET) scanner for human brain imaging. The PET system was comprised of detector block which consisted of 4×4 SiPMs and 4×4 Lutetium Yttrium Orthosilicate arrays, charge signal transmission method, high density position decoder circuit and FPGA-embedded ADC boards. The purpose of this study was to evaluate the performance of the newly developed neuro-PET system. The energy resolution, timing resolution, spatial resolution, sensitivity, stability of the photo-peak position and count rate performance were measured. Tomographic image of 3D Hoffman brain phantom was also acquired to evaluate imaging capability of the neuro-PET. The average energy and timing resolutions measured for 511keV gamma rays were 17±0.1% and 3±0.3ns, respectively. Spatial resolution and sensitivity at the center of field of view (FOV) were 3.1mm and 0.8%, respectively. The average scatter fraction was 0.4 with an energy window of 350–650keV. The maximum true count rate and maximum NECR were measured as 43.3kcps and 6.5kcps at an activity concentration of 16.7kBq/ml and 5.5kBq/ml, respectively. Long-term stability results show that there was no significant change in the photo-peak position, energy resolution and count rate for 60 days. Phantom imaging studies were performed and they demonstrated the feasibility for high quality brain imaging. The performance tests and imaging results indicate that the newly developed PET is useful for brain imaging studies, if the axial FOV is extended to improve the system sensitivity.

THE WAYS OF LONG-TERM BLOOD PRESSURE CONTROL SYSTEMS DEVELOPMENT

The significance of arterial hypertension (AH) is discussed as the main predictor of cardiovascular catastrophes development — myocardial infarction and stroke, and technologies for the solution of blood pressure (BP) control. The most modern world developments are presented for the distant observation of cardiovascular system (CVS) condition, including BP level in high risk patients. The main specifications of abroad invasive BP systems are provided, and Russian developing system with a layout of BP sensor and the method of no wired signal transmission and electrical supply. It is presupposed that such invasive device can in real time mode send the data on BP and its values, that characterize CVS condition. In critical BP changes the signals of alarm are incorporated to send to the emergency care stations and to the physician for proper solutions on the care, including urgencies. Such system might increase the effectiveness of prophylactic and medical care for the patients with cardiovascular pathology, increase the duration of life, and decrease funding, and not need supplementary inclusion of higher qualified specialists for dispensary screening.

Signal Transmission With Long Cable for Design of PET Detector for Hybrid PET-MRI

Recently, we reported a hybrid positron emission tomography-magnetic resonance imaging (PET-MRI) approach involving the transmission of a photo-sensor charge signal to a preamplifier using a long cable. However, in this application, pulse distortions may degrade the performance of the PET detector. The purpose of this study is to further extend the charge signal transmission (CST) approach and to design a PET detector module capable of transmitting the photo-sensor charge signal to PET electronics remotely located outside the MRI room for the hybrid PET-MRI. To achieve this, we developed a pulse restoration circuit (PRC) compensating the performance degradations caused by using the long cable from Geiger-mode avalanche photodiode (GAPD) to PET electronics. The effect of the cable length on the PET detector performance was examined using different lengths of flexible flat cable ranging from 0 to 21 m. Rise time, fall time and amplitude of the GAPD output were measured as a function of the cable length. Photopeak position, energy resolution and time resolution were also measured using a 100 MS/s data acquisition unit. PRC based on the filtering and shaping networks consisted of amplitude, and rise and fall restorations. The amplitude restoration was designed using op-amp and resistors. The rise time-fall time restoration was designed using RC shaping filter. The measured pulse shapes passing through the long cable with PRC were similar to the output of GAPD with the cable length of 0 m (amplitude 169 mV, rise time 35 ns and fall time 210 ns), and the degrading PET detector performance caused by long cable were restored (energy resolution 16%, photopeak position 400 ch and time resolution 1.3 ns). There were no significant changes in the PET detector module performance using the CST approach with PRC as a function of the cable length, both outside and inside the MRI room. There were no obvious artifacts or changes in the MR phantom images. These results show that the proposed approach using extended charge signal transmission method with long cable and simple pulse restoration circuit is reliable and useful for the development of a hybrid PET-MRI system.

Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was maintained. The change of gain of the 256 GAPD/scintillator elements of a detector block was <3% for 60 min, and simultaneous PET and MR images of a brain phantom were successfully acquired. Experimental results indicate that a compact and lightweight PET insert for hybrid PET/MRI can be developed using GAPD arrays and charge signal transmission method proposed in this study without significant interference.