ASK Modulation Research Articles

Class-E, active electrically small antenna with enhanced bandwidth-efficiency product and high radiated power at the high-frequency (HF) band

Antennas operating at the high-frequency (HF) band (3–30 MHz) are frequently electrically small due to the large wavelength of electromagnetic waves (10–100 m). However, the bandwidth-efficiency products of passively matched electrically small antennas (ESAs) are fundamentally limited. Wideband HF waveforms using bandwidths of 24 kHz or more have recently received significant attention in military communications applications. Efficiently radiating such signals from conventional passive ESAs is very challenging due to fundamental physical limits on bandwidth-efficiency products of ESAs. However, active antennas are not subject to the same constraints. In this work, we present the design and experimental characterization of a high-power, class-E active ESA with enhanced bandwidth-efficiency product compared to that of passively matched ESAs. Specifically, the proposed class-E active ESA can radiate wideband HF signals with bandwidths of 24 kHz or more at 3 MHz (fractional bandwidths of ≈1%–4%), with total efficiencies ranging from 40% up to 80% depending on the modulation type and radiated power levels approaching 100 W. Our approach uses a highly efficient, integrated class-E switching circuit specifically designed to drive an electrically small, high-Q HF antenna over a bandwidth exceeding 24 kHz at 3 MHz. Using a high-Q RLC antenna model, we have successfully demonstrated wideband binary ASK, PSK, and FSK modulations with the proposed class-E active ESA. Experimental results indicate that the bandwidth-efficiency product of this class-E active ESA is 5.4–9.8 dB higher than that of an equivalent passive design with the same data rate and bit-error-rate.

Performance comparison of implementing ASK and PPM modulations for free space optics system integrated with FBG device

Performance comparison of implementing ASK and PPM modulations for free space optics system integrated with FBG device

FSK/ASK Orthogonal Modulation System Based on Novel Noncoherent Detection and Electronic Dispersion Compensation for Short-Reach Optical Communications

We propose an FSK/ASK orthogonal modulation system based on a novel noncoherent detection (NCD) scheme, aimed at expanding the system capacity for short-reach optical communications cost-effectively. In the transmitter, the FSK optical signal is generated by simple frequency modulation through a directly modulated distributed feedback laser. Subsequently, by utilizing a Mach–Zehnder modulator for ASK modulation, the FSK/ASK optical signal is obtained. The novel and low-complexity NCD receiver consists of an intensity detection branch and a frequency detection branch. The frequency detection branch is composed of an optical differentiator, a photodetector, and frequency extraction circuits. Notably, the proposed NCD scheme overcomes the limitation of the traditional FSK/ASK-NCD receiver stemming from the trade-off between the detected signal quality of the amplitude and frequency. Furthermore, electronic dispersion compensation (EDC) is available. Through numerical simulations, our findings demonstrate that the proposed FSK/ASK-NCD system, assisted by EDC, achieves a remarkable 100 km transmission span for both 40 Gbps 2FSK/2ASK and 60 Gbps 2FSK/4ASK modulation formats, which surpasses the 2ASK-DD and the 4ASK-DD systems, where the maximum achievable spans are limited to less than 20 km. These results underscore the potential of the proposed system as a robust candidate for future passive optical access networks.

Performances Study of PSK and ASK Modulation Technique under Atmospheric Turbulence in FSO Communication System

Performances Study of PSK and ASK Modulation Technique under Atmospheric Turbulence in FSO Communication System

Convolutional neural network-based modulation recognition technique for communication signals

The last decade has seen breakthroughs in communication technology. The increasingly complex signal transmission environment has placed higher demands on signal modulation recognition. Traditional modulation recognition approaches cannot guarantee satisfactory recognition accuracy. Fortunately, with the continuous advancement of deep learning algorithms, convolutional neural network-based communication signal modulation recognition techniques have become the mainstream of current research. Therefore, this paper first reviews the development history of signal modulation recognition techniques and introduces the concepts of signal modulation theory. It includes ASK, PSK and FSK modulation methods, which are common today. Subsequently, I analyze the principles of signal modulation recognition and the implementation method of CNN in modulation recognition. To further explore the shortcomings of CNNs, I propose two optimized models, the residual network model and the CLDNN model. After comparing the performance, the former has higher performance, but its computational complexity is higher while the latter takes into account the high recognition accuracy while still reducing the network parameters as much as possible to keep the complexity at a low level.

A Novel Reconfigurable Nonlinear Cascaded MZM Mixer, Amplitude Shift Key Modulator (ASK), Frequency Hopping and Phase Shifter

A novel reconfigurable Microwave Photonics (MWP) mixer is presented in this paper, which can be configured to work as a frequency hopper, ASK modulator and phase shifter. This mixer is based on a cascaded Mach–Zehnder Modulator (MZM) structure. A general nonlinear analytical model for the structure is presented. This model is platform free, which means it can be applied to several MWP and integrated MWP platforms. Based on the analytical model, the performance of the structure and output results, such as the optical and electrical spectrum of the structure, are derived in mathematical closed-form expressions. The results of the presented analytical model are compared and evaluated with the results obtained from the simulation to prove the correctness of the analytical model. The presented structure has a simple form, which can be fabricated at a low cost. In addition, according to the obtained results from the analytical model, there is no need to change the arrangement of the structure to operate in any of the mentioned configurations, and the desired function is achievable only by changing the bias voltage of the modulators at the desired frequency.

An Implantable Wireless System for Remote Hemodynamic Monitoring of Heart Failure Patients.

This article presents an implantable wireless system for remote hemodynamic monitoring, which enables direct, continuous (24/7), and simultaneous measurement of pulmonary arterial pressure (PAP) and cross-sectional area (CSA) of the artery. The implantable device, which measures 3.2 mm × 2 mm × 10 mm, comprises a piezoresistive pressure sensor, an ASIC implemented in 180-nm CMOS, a piezoelectric ultrasound (US) transducer, and a nitinol anchoring loop. An energy-efficient pressure monitoring system, which employs duty-cycling and spinning excitation technique, achieves 0.44 mmHg resolution in a pressure range from -135 mmHg to +135 mmHg and consumes 1.1 nJ conversion energy. The artery diameter monitoring system utilizes the inductive characteristic of the implant's anchoring loop and achieves 0.24 mm resolution within a diameter range of 20 mm to 30 mm, four times higher than echocardiography lateral resolution. The wireless US power and data platform enables simultaneous power and data transfer employing a single piezoelectric transducer in the implant. The system is characterized with an 8.5 cm tissue phantom and achieves a US link efficiency of 1.8%. The uplink data is transmitted by using an ASK modulation scheme parallel to the power transfer and achieves a modulation index of 26%. The implantable system is tested in an in-vitro experimental setup, which emulates the arterial blood flow, and accurately detects fast pressure peaks for systolic and diastolic pressure changes at both 1.28 MHz and 1.6 MHz US powering frequencies, with corresponding uplink data rates of 40 kbps and 50 kbps.

Low-Frequency Dual-Driven Magnetoelectric Antennas With Enhanced Transmission Efficiency and Broad Bandwidth

Low frequency (LF) dual-driven magnetoelectric (i.e., DDME) antennas are proposed, which include a pair of self-biased magnetoelectric (ME) heterostructures (i.e., Ni/Metglas/ [Pb(Zr,Ti)O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ] <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> /Metglas/Ni) wrapped with small coils. For the DDME transmitter, the [Pb(Zr,Ti)O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ] <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> layers are designed as a piezoelectric transformer. This enhances the transmitted magnetic field significantly due to the dual-driven mode: the generated magnetic field of transmitting coils driven by the transformer at the magneto-mechanical resonance (MMR) and magnetization oscillation of magnetostrictive layer driven by the mechanical stress of inverse piezoelectric effect. Meanwhile, the DDME receiver consists of a self-biased ME heterostructure wrapped with search coils, whose signal-to-noise ratio (SNR) is improved due to the synergistically induced voltage of Faraday law's induction and ME effects. The nonmonotonic inductance of search coils near MMR broadens the bandwidth (1904 kHz) due to the LC resonances at multiple frequencies. The letter indicates that the DDME antenna achieves a communication distance of 11 m with power consumption of 212.7 mW, whose operation distance and channel capacity (12.54 kbit/s) are 1.69 times and 10.62 times larger than that of ME antenna (i.e., Ni/Metglas/[Pb(Zr,Ti)O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ] <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> /Metglas/Ni). The communication distance can be further increased to 170 m with a larger DDME antenna. Furthermore, the DDME antenna can realize more robust ASK modulation compared to ME antenna.

A Power-Line Communication System Governed by Loop Resonance for Photovoltaic Plant Monitoring

Within this paper, a PLC system that takes advantage of the loop resonance of an entire DC-PV string configured as a circular signal path is developed and implemented. Low cost and extremely simple transceivers intended to be installed within each PV module of a string have been designed and successfully tested. In addition, an anti-saturation coil has been conceived to avoid saturation of the core when the entire DC current of the string flows through it. Bi-directional half-duplex communication was successfully executed with up to a 1 MHz carrier frequency (150 kbps bitrate), using a simple ASK modulation scheme. The transmission and reception performance are presented, along with the overall system cost in comparison to the previous literature.

Digital Keying Enabled by Reconfigurable 2D Modulators.

Energy, area, and bandwidth efficient communication primitives are essential to sustain the rapid increase in connectivity among internet-of-things (IoT) edge devices. While IoT edge-sensing, edge-computing, and edge-storage have witnessed innovation in materials and devices, IoT edge communication is yet to experience such transformation. The aging silicon (Si)-based complementary metal-oxide-semiconductor (CMOS) technology continues to remain the mainstay of communication devices where they are used to implement amplitude, frequency, and phase shift keying (amplitude-shift keying [ASK]/frequency-shift keying [FSK]/phase-shift keying [PSK]). Keying allows digital information to be communicated over a radio channel. While CMOS-based keying devices have evolved over the years, their hardware footprint and energy consumption are major concerns for resource constrained IoT communication. Furthermore, separate circuit designs and hardware elements are needed for each keying scheme and achieving multibit modulation to improve bandwidth efficiency remains a challenge. Here, a reconfigurable modulator is introduced that exploits unique ambipolar transport and programmable Dirac voltage in ultrathin MoTe2 field-effect transistors to achieve ASK, FSK, and PSK modulation. Furthermore, by integrating two programmed MoTe2 field-effect transistors, multibit data modulation is demonstrated, which improves the bandwidth efficiency by 200%. Finally, a frequency quadrupler is also realized exploiting the unique "double-well" transfer characteristic.

Optimized Linear and Non-Linear Precoding for Biased ASK Modulation in Multiuser SWIPT With Integrated Receiver

Simultaneous wireless information and power transfer can be achieved using an <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">integrated</i> receiver, where the incoming signal is rectified, and both the energy harvesting (EH) and the information detection (ID) operate on this rectified signal. Because phase information is lost at the input of the ID, commonly-used modulation techniques cannot be straightforwardly applied and biased <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$M$ </tex-math></inline-formula> -ASK is used instead. We consider downstream communication over a Rician block-fading channel, from a multi–antenna basestation to a number of single-antenna users. Multi-user interference is eliminated by applying zero-forcing precoding. Using a realistic rectifier model, we compare EH and ID performances of linear precoding (LP) and modified Tomlinson-Harashima precoding (THP). We add low-complexity algorithms to these precoders that optimize the user ordering and the constellation rotations. Moreover, we investigate the effect of the amplitude ratio <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\rho _{\mathrm {ASK}}$ </tex-math></inline-formula> of the constellation on the energy-rate trade-off. Compared to the same precoders without optimization, optimizing the user ordering, rotations and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\rho _{\mathrm {ASK}}$ </tex-math></inline-formula> considerably reduces the transmit power required to achieve a harvested power of −30 dBm or an average mutual information of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$(\log _{2}M)/2$ </tex-math></inline-formula> . Both with and without optimizations, THP outperforms LP in terms of EH and ID, but THP exhibits much larger gains when optimizations are applied.

Research and practice of three-phase signal source design based on DDS technology

This paper analyzes the working principle and basic structure of DDS, combined with the design points of three-phase signal source based on DDS technology, including software development platform, hardware description language, sinusoidal signal, AM module, FM module, ASK modulation and demodulation, system assistant, system top, etc. The purpose is to improve the application value of DDS technology and the application effect of three-phase signal source.

Design and Implementation of a Low Power Consumption of ASK, FSK PSK, and QSK Modulators Based on FPAA Technology

Wireless communication techniques have become more popular due to their characteristics. These systems adopt the digital modification application, which provides more information for transmission and compatibility with digital data services as well as high information security and quality improvement. Digital wave signal-based communication techniques such as PSK, FSK, ASK, and QPSK considered among the most significant digital modulation techniques. These technologies are a crucial part of digital communication systems. Digital communication devices designed by FPAAs can provide multiple communication without arranging new devices and can support new within seconds. FPAA is extremely easy to reconfigure and program concerning FPGA or DSP-based applications. This article offers real-time implementation of ASK, FSK PSK, and QPSK modulator techniques with low power consumption ”Žbased on the ”Žcapability for dynamic reprogramming of the FPAA AN231E04 device ”ŽAnadigm. FPAA techniques provide growing application and high pliability in the implementation of analog circuits. The measurements achieved from the proposed modulated circuits show that the form and properties of the theoretical outcomes agree perfectly with the practical outcomes. FPAA techniques provide growing application and high pliability in the implementation of analog circuits for minimizing the time of design and testing. Another feature is the minimum power exhaustion (165 mw) due to the switched capacitor method used by the FPAA Chip, which gives a high accuracy process.

Optical label switching based on Manchester code + NRZ modulation

Optical label switching (OLS) is regarded as one promising solution for the packet-based optical switching. In this paper, a novel modulation, i.e., Manchester code + NRZ modulation is proposed for OLS. The Manchester coded payload signal the NRZ label signal are combined and then modulated onto an optical carrier by only one ASK modulator. The Manchester coded payload signal and the NRZ label signal are recovered by half-bit-delayed differential and a low-speed ASK receiver, respectively. Better than traditional orthogonal modulation, the proposed Manchester code + NRZ modulation requires no non-amplitude modulation and only one ASK modulator, reducing the equipment cost, modulation loss and operation complexity. The coding is simple and decoding is not required. According to theoretical analysis and simulation test, the induced crosstalk decreases with the bit rate ratio. The tested results verify the feasibility of the OLS based on the proposed Manchester code + NRZ modulation.

Simple and Efficient Transcutaneous Inductive Micro-System Device Based on ASK Modulation at 6.78 MHz ISM Band

Simple and Efficient Transcutaneous Inductive Micro-System Device Based on ASK Modulation at 6.78 MHz ISM Band

Galvanically Isolated DC-DC Converter Using a Single Isolation Transformer for Multi-Channel Communication

This paper presents a galvanically isolated dc-dc converter with multi-channel communication exploiting a single isolation transformer. The proposed architecture makes compliant both regulated output power and data transmission on the same isolation physical link by using ASK modulation of the power signal and data/control signal multiplexing. The dc-dc converter consists of two integrated chips fabricated in 0.18- $\mu \text{m}$ BCD and 0.13- $\mu \text{m}$ CMOS technologies, respectively, along with a thick polyimide transformer chip able to comply with reinforced isolation requirements. The dc-dc converter delivers an isolated output power up to 50 mW at 3.3-V output voltage, while providing three data channels with a data rate up to 10 Mb/s.

Design of efficient optimized wireless power transfer system

To balance the output stability and maximum efficiency of a system, an efficiency optimization method based on adaptive frequency control is proposed. In this paper, load transmission is carried out using a DC–DC converter at the receiving end. When the load changes, controlling the rectified output voltage is carried out to realize the maximum efficiency point tracking. Meanwhile, the duty cycle of the rear stage DC–DC converter is changed to keep the output voltage constant. The sampled rectified voltage is compared with the estimated value and the resulting error data are sent to the system transmitter through ASK modulation wireless communication. Then the transmitter demodulation communication information through PID algorithm control is used to achieve the frequency of the adaptive adjustment. The feasibility of the proposed method has been verified by the simulation and experimental results. When the output voltage is 5 V, the constant voltage accuracy is within ± 1%, the maximum efficiency is up to 79.2%, and the dynamic response time is only 160 ms.

Implementation of digital and analog modulation systems using FPGA

&lt;p&gt;&lt;span&gt;FPGA (Field Programmable Gate Array) based implementations of digital and analog modulation techniques play a vital rule in the design of signal processing system. The performance and flexibility provided by reconfigurable computing speeds up the development process in signal processing implementations using FPGA. Different methods for digital and analog modulation are designed in this paper by usinSg System Generator tools &amp;amp; Vivado. Then all designed systems are implemented successfully in an FPGA hardware via the NEXYS 4 DDR with ARTIX 7 XC7A100T. A comparison between five types of digital modulation techniques is discussed in terms of resources utilization in FPGA hardware. And also, the implementation of analog modulations in FPGA is contributed in this work. The hardware implementation shows that the number of slice LUTs in ASK modulation is 0.07% while in FSK modulation is 0.13% of the total number of slice LUTs. And also, the number of bounded IO that used for PSK modulation is 4.8% while in PM modulation is 61.4% of the total number bounded IO.&lt;/span&gt;&lt;/p&gt;

Analysis of Influence of Impedance Matching on Signal Transmission Through Long Wires of XCTD Profiler

Although expendable conductivity–temperature–depth (XCTD) profiler has been extensively studied, there are relatively few studies on the transmission performance of XCTD channel, which makes it unclear that the signal is affected by the channel in the long-distance transmission process. First, the structure of the XCTD is analyzed. Then, according to the working mode and channel structure characteristics of XCTD, the circuit model of the transmission channel is established. In order to better study the channel compensation method, a laboratory transmission system of XCTD is built. By analyzing the influence of channel impedance parameters on the transmission signal, the channel model of XCTD is optimized, and the compensation channel is determined to be series inductance. Finally, the bit error rate (BER) of unoptimized and optimized channels is compared based on ASK and differential phase-shift keying (DPSK) modulation. It is verified that the optimized channel model of XCTD has a certain significance in reducing the BER of the transmission signal. This article has important theoretical significance and practical application value for the research of transmission signal transmission performance of expendable profiler.

Methods to Improve the Long Distance Time-Varying Channel Transmission Performance of Expendable Profiler

To improve the transmission performance of XCTD channel, this paper proposes a method to measure directly and fit the channel transmission characteristics by using frequency sweeping method. Sinusoidal signals with a frequency range of 100 Hz to 10 kHz and an interval of 100 Hz are used to measure transmission characteristics of channels with lengths of 300 m, 800 m, 1300 m, and 1800 m. The correctness of the fitted channel characteristics by transmitting square wave, composite waves of different frequencies, and ASK modulation are verified. The results show that when the frequency of the signal is below 1500 Hz, the channel has very little effect on the signal. The signal compensated for amplitude and phase at the receiver is not as good as the uncompensated signal. Alternatively, when the signal frequency is above 1500 Hz, the channel distorts the signal. The quality of signal compensated for amplitude and phase at receiver is better than that of the uncompensated signal. Thus, we can select the appropriate frequency for XCTD system and the appropriate way to process the received signals. Signals below 1500 Hz can be directly used at the receiving end. Signals above 1500 Hz are used after amplitude and phase compensation at the receiving end.