Amplitude Shift Keying Research Articles

High‐Speed Laser‐to‐Microwave Wireless Transmissions through Dual‐Band Time‐Domain Optoelectronic Metasurface

Radio and optical signals are two different carriers with their own distinctive features, and their efficient conversion is pivotal to achieve better performance and wider applications in information transmission. Unlike the conventional radio‐over‐fiber system based on fiber and circuit technologies, herein a laser‐to‐microwave wireless transmission scheme is proposed by dual‐band time‐domain optoelectronic metasurface. By integrating the high‐speed positive‐intrinsic‐negative diodes and meticulously designed photoelectric circuit into the metasurface, the amplitude and phase of the reflected microwaves at different frequency bands can be modulated quickly by laser intensities. Therefore, the on–off keying (OOK) laser can be modulated directly onto the phase shift keying (PSK) and amplitude shift keying (ASK) microwaves on one platform, achieving seamless laser‐to‐microwave transmissions. As a demonstration, a metasurface‐based hybrid wireless communication system is constructed, in which the data can be transmitted through OOK laser signal and received through ASK and PSK microwave signals. Based on the basic signal modulation format, 2.5 Mbps communication rate can be achieved over the hybrid link. This work will be of great benefit to design novel spatial photoelectric devices and wireless communication systems.

Overcoming Printed Circuit Board Limitations in an Energy Harvester with Amplitude Shift Keying and Pulse Width Modulation Communication Decoder Using Practical Design Solutions

This paper presents PCB design solutions for implementing a radiative-field RF energy harvester with an ASK-PWM decoding communication scheme using available commercial components. The paper provides the design approach and tackles key challenges such as the impact of inductive parasitic effects at the output of the harvester, how to maintain the PCE at a constant value regardless of the time constant at the output of the communication path’s rectifier, and the difficulty of changing the aspect ratio of the discrete inverter used for PWM decoding. These challenges are addressed by using multiple capacitors connected in parallel at the output of the rectifier to reduce inductive parasitic effects, adding a series resistor in the communication path’s rectifier to isolate its loading from impacting the PCE, and utilizing a potentiometer in the inverter to realize PWM decoding on PCB. The system was manufactured using FR-4 substrate material with a size of 5 cm × 4 cm × 0.6 cm, harvesting energy at the ISM frequency of 924 MHz with a PCE of 42.12% at a bit rate of 15 Kbps. Moreover, the system consumes only 355 μW of power and maintains correct harvesting and decoding operation in the antenna separation range of 6–12 cm. This work aims to provide an alternative to IC realization by implementing the system entirely using commercial discrete components, reducing costs, adding flexibility, reducing development time, and allowing for simple debugging.

Construction of an Experimental Device for Military Communication Using Binary Amplitude Shift Keying

Aims: To address the core requirement for military communication systems—ensuring "timely, accurate, confidential, and secure" communication—this study aims to overcome the limitations of traditional amplitude modulation (AM) methods by developing a modern experimental device using Binary Amplitude Shift Keying (BASK) modulation. Study Design: Traditional military communication systems rely on AM modulation due to its simplicity and ease of implementation. However, AM is susceptible to noise, suitable only for long-wave transmissions (e.g., AM radio), and struggles to integrate with modern technologies like 4G and 5G. To address these challenges, this study explores the mathematical foundation and system design of BASK modulation and demodulation. Methodology: The research investigates the mathematical principles of BASK, designs the system architecture for BASK modulation and demodulation, and develops an experimental device to validate the performance of the BASK-based communication model. Results: The study successfully developed an experimental device that demonstrates the feasibility of using BASK modulation for military communication. The device provides a platform for practical testing and verification of the BASK model, laying the groundwork for further advancements. Conclusion: This research provides a foundation for modernizing military communication devices. By overcoming the limitations of traditional methods and facilitating the integration of advanced technologies, the proposed device meets the stringent requirements of military environments.

Generation of frequency-shift keying (FSK) and amplitude-shift keying (ASK) RF signals by diode-tuned Fourier domain mode-locked opto-electronic oscillator.

An approach to the generation of frequency-shift keying (FSK) and amplitude-shift keying (ASK) RF signals with a diode-tuned Fourier domain mode-locked opto-electronic oscillator (FDML OEO) is proposed and demonstrated. We use a low-cost varactor diode tuned phase shifter to form a high speed tunable bandpass filter (TBF) to implement the FDML-OEO. When a square wave modulation signal is used to drive the TBF, FSK RF signals are generated, with the flexibility to easily change the center frequency and tuning bandwidth of the FSK signals. For the ASK RF signal generation, a band-pass filter (BPF) with a bandwidth less than the TBF tuning range is added to the FDML OEO RF feedback loop. When the TBF center frequency hops in and out of the BPF bandwidth within a mode locking period, the FDML OEO generates ASK RF signals. The phase noises of the FSK and ASK RF signals generated by our FDML-OEO are both measured to be -123dBc/Hz at 10 kHz offset frequency. The key significance of this approach is that no microwave source is required to generate the ASK signal and reconfigurable FSK and signals, which may find wide applications in future radar and communications systems.

Pre-compensating digital-to-analog converter impairments with an LSTM neural network

The performance of high-speed coherent communication heavily depends on digital-to-analog converters (DACs) when they operate within bandlimited and nonlinear regimes. We examine neural network (NN) based digital pre-distortion (DPD) methods to compensate the memory effects that are intertwined with the nonlinear response of the DAC. Using a long short-term memory (LSTM) NN architecture, we examine 8-level amplitude shift keying (ASK-8) at 64 Gbaud. We demonstrate experimental improvements of 1.6 dB and 2 dB in signal-to-noise ratio (SNR) compared to the Volterra and linear solutions, respectively.

Digital Modulator using Digitally Programmable Complementary metal–oxide–semiconductor Differential Voltage Current Conveyor

This study aims to Developing a digital modulation system using a new technology and idea, which is the digitally programmable CMOS (Complementary metal–oxide–semiconductor), Integrate the CMOS DVCC circuit as a modulator in the communication systems, as will be explained in chapter 3, Finally, simulate this new idea in communication by using a simulation program, which is PSpice software, and analyzing the results. By focusing on How to use digital programmable CMOS (Complementary Metal–Oxide–Semiconductor) in a communication system as a digital modulator, Verifying the effectiveness of the study using simulation software such as PSpice and MATLAB, and Analyzing and verifying the effectiveness of the three modified modulation techniques. Digitally programmable Binary Amplitude shift keying (DP BASK), Digitally programmable Binary Phase shift keying (DP BPSK), And Digitally programmable Binary Frequency shift keying (DP BFSK). This study adopts an applied research approach. The study demonstrated that the CMOS DVCC circuit could be successfully integrated into communication systems as a digital modulator. The study recommended to conduct further research on the noise resistance capabilities of the DP modulation techniques, and explore additional modulation techniques that could benefit from digitally programmable CMOS technology, such as Quadrature Amplitude Modulation (QAM) or Orthogonal Frequency-Division Multiplexing (OFDM).

SWITCHING RIPPLE DATA TRANSFER TECHNIQUE USING STEP-DOWN DC-DC CONVERTER

This paper describes an electronic communication method based on the use of the DC-DC converter as a data transfer device. Output voltage of a DC-DC converter is modulated with Amplitude-Shift Keying (ASK) signal carrier. Modulation takes place in the feedback loop of the DC-DC converter. The output signal passes through the transition line to the band pass filter, where unexpected noise and DC components are removed. Transition line is represented as a long wire with a certain length that contains active and reactive parasitic parameters. These parameters affect Total Harmonic Distortion (THD) of the initial ASK signal waveform. Switching ripple communications are introduced to simplify electrical connection and reduce the wire count. This makes it particularly suitable for Internet of Things (IoT) applications in challenging environments where RF may be weak or unreliable. Nowadays wiring is an expensive part of electronic products. Industry leading companies usually spend sufficient resources on wiring production and installation work. Switching ripple communication modules can reduce a final product price and increase reliability. Also, these systems can be easily implemented to existing designs because power line communication devices do not require additional signal pass conductors or additional RF modules for data transfer. The proposed communication method can be used in such industries as: battery management systems, industrial lightning control, automotive or even in high performance power supplies for telecom solutions. The purpose of this paper is to create a signal transfer model and show a dependency between transition wire length and total harmonic distortion parameter, which affects output signal. Low THD parameter is important for carrier signal decode operations. After the filtering stage ASK signal usually passes to the Microcontroller unit through the Analog to Digital converter (ADC) block. By increasing carrier signal THD the ADC effective number of bits (ENOB) parameter will be affected. As a result, all further signal processing stages such as digital filtering and calculations will take more hardware resources.

Reinforcement learning-based automated modulation switching algorithm for an enhanced underwater acoustic communication

Acoustic communication is the preferred method for underwater communication due to its superior propagation characteristics, including longer range, lower attenuation, better penetration, and adaptability to water density. However, challenges like varying water depths, temperature gradients, noise, and multipath propagation require innovative solutions beyond fixed-data rate systems and single modulation schemes. To address these challenges, we propose a reinforcement learning (RL)-based automated modulation switching algorithm designed to enhance data transmission efficiency. This approach leverages the UNETStack software and the Frequency Hopping-Binary Frequency Shift Key (FH-BFSK) modulation, extending its capabilities by incorporating Amplitude Shift Keying (ASK), Phase Shift Keying (PSK), and Orthogonal Frequency Division Multiplexing (OFDM) modulation techniques. We designed a cost-effective, software-controlled acoustic modem using commercial off-the-shelf (COTS) components, enabling full-duplex underwater communication. The RL algorithm utilizes a Q-matrix guided by a greedy policy to assess network conditions, such as data volume and data rates. It continuously monitors underwater environments to select the most suitable modulation scheme dynamically. Experimental validation demonstrates a 3.648 % improvement in Received Signal Strength Indicator (RSSI), a 32 % reduction in bit error rate at a constant 7 dB Signal-to-Noise Ratio (SNR), and a 5 % increase in utility at 10 dB SNR when using OFDM selected by the reinforcement learning algorithm, compared to FH-BFSK.

A Power-Efficient Envelope-Detector-Less Amplitude-Shift-Keying Forward Telemetry for Wirelessly Powered Biomedical Devices.

This paper proposes an envelope-detector-less (EDL) amplitude-shift-keying (ASK) forward telemetry (FT) demodulator for wireless power/data transfer (WPDT) systems. The EDL ASK FT demodulator can substitute bulky and power-hungry components, which are an envelope detector and an analog comparator in the conventional ASK FT demodulator, with a digital controller, reducing both power dissipation and chip area. The proposed demodulator shares the gate control signals of pass transistors, which are used in an ac-dc regulator for wireless power reception, to maintain a constant load voltage while efficiently demodulating the forward telemetry data. Also, a proposed digital cleaner in the EDL demodulator refines this control signal into a wide pulse without suffering from resonant frequency noise, while a synchronizer can align its frequency with the data rate and resonant frequency. The 0.25-μm CMOS prototype chip of the proposed power-path-less EDL ASK FT demodulator, equipped with the ac-dc regulator, demonstrates a significant 38.2% reduction in power dissipation compared to the conventional ASK FT demodulator. Moreover, the EDL ASK FT demodulator occupies only 0.023-mm2 silicon area and achieves a low bit error rate (BER) less than 10-4 while maintaining a regulated voltage of 4.5 V on the load.

Measuring the amplitudes of the received symbols of the shift keyed radio signals

In high-speed discrete information transmission systems, multi-position signals with various types of phase and amplitude shift keying are widely used. There are multi-level amplitude shift keyed (ASK), amplitude and phase-shift keyed (APSK) and quadrature amplitude modulation (QAM) signals. When demodulating the amplitude code of such signals, the amplitude of the received symbol is determined, and its calibrated value is compared with the specified threshold levels. It is proposed to directly calculate the minimum and maximum amplitudes of the symbols at the output of the demodulator, with a subsequent definition of decision thresholds. It is noteworthy that there is no need to calibrate the amplitude characteristics of the reception path. The logarithmic ratio of the amplitudes of the received and previous symbols is further calculated. And if its value falls within the specified boundaries, independent of the signal and noise, then a decision is made about whether the amplitudes of these symbols belong to the maximum or minimum values. These obtained values are averaged after that and used to set thresholds for decision-making in the demodulator. The results of the statistical simulation confirm the high efficiency of the proposed technical solution.

IQ-channel multiplexed DP-4ASK signal using power loading for downlink coherent PON system with access-span length difference

This study explores the integration of dual-polarized (DP) four-level amplitude shift keying (4ASK) signals within an intensity and quadrature division multiplexing framework, mainly focusing on coherent passive optical network (PON) systems. The primary objective is to address the challenges associated with distance disparities in downstream transmissions, which are prevalent in coherent PON architectures. We introduce a novel approach that significantly reduces the power consumption of digital-to-analog converters by implementing power loading strategies tailored explicitly for IQ channel division multiplexing (IQDM)-DP-4ASK signals. Our simulations confirm that ASK standard frequency offset compensation is adaptable to these signals, providing a robust method for managing frequency offsets in a dynamic network environment. Moreover, we propose and empirically validate an energy-efficient adaptive downlink solution capable of supporting 128 Gb/s per optical network unit (ONU), utilizing IQ-imbalanced DP-4ASK signals. This solution is particularly advantageous for systems where the transmission conditions include a 10 km variance in access span lengths between ONUs. Results from our experimental setup demonstrate that reducing the digital-to-analog converter output current for the Q channel by 137 mA is feasible without compromising signal integrity or system performance. Additionally, the research verifies the effectiveness of the automatic bias controller on the transmitter side, ensuring stable operation across varying conditions. Equally, the receiver-side digital signal processing effectively handles polarization separation, illustrating the system's capability to maintain high data integrity and reliability under diverse operational scenarios. These findings highlight the technical feasibility and operational benefits of using IQDM-DP-4ASK signals in coherent PON systems and underscore the potential for significant power savings and enhanced system efficiency in optical networks. The study paves the way for future research into scalable, energy-efficient solutions suitable for high-capacity optical access networks striving for increased sustainability and reduced operational costs.

Crafting very low frequency magnetoelectric antenna via piezoelectric and electromechanical synergic optimization strategy

A boom in exploration for marine geology and ocean resources has resulted in a huge demand for radio navigation or special environment communications, in turn spurring the rapid development of portable underwater wireless communication technology. State of the art acoustic communication methods used today are plagued by substantial transmission delays, multipath effects, and doppler frequency shifts, among other challenges, thus impeding the advancement of underwater wireless communication technology. Low-frequency electromagnetic transmission has proven to be a prospective solution for underwater communication, but the conventional electrical antennas is too large for portable underwater wireless communication. Emergent magnetoelectric (ME) antennas driven by piezoelectric materials have become a promising solution for miniaturizing very low frequency (VLF) communication systems. Here, a theoretical model between the radiation performance and piezoelectric material properties of the ME antenna was conducted. Guide by the theory analysis, Pb(In1/2Nb1/2)O3Pb(Mn1/3Sb2/3)O3Pb(Zr0.49Ti0.51)O3 (PIN-PMS-PZT) piezoelectric ceramic simultaneous with high d33 and Qm (d33 ∼ 401, Qm ∼ 1510) has been designed to enhance the magnetoelectric radiation of the VLF ME antenna. The PIN-PMS-PZT based ME antenna achieves a large converse magnetoelectric response 1.78 Gs⋅cm/V in EMR, which is almost doubled to commercial PZT based ME antenna. More importantly, a VLF communication system was built based on the VLF antenna, which successfully transmitted digital signals using Amplitude-Shift-Keying (ASK) modulation. It is believed that the presented work could provide a theoretical basis and feasible technical path for the employment of ME antennas in the future.

Wirelessly Powered and Bi-Directional Data Communication System With Adaptive Conversion Chain for Multisite Biomedical Implants Over Single Inductive Link.

A wirelessly powered and data communication system is presented which is implemented as a full system, designed for multisite implanted biomedical applications. The system is capable of receiving wireless power and data communication for each implant separately, using inductive links with different resonance frequencies. To achieve this, dual-band coils are presented in the system. In addition, the system supports bi-directional half-duplex data communication, utilizing amplitude and load shift keying (ASK and LSK) modulation schemes over a single inductive link. The system employs a digitally assisted active rectifier and an automatic resonance tuning system, to improve the power transfer efficiency (PTE) through various coupling coefficients, while minimizing the reverse current and power dissipation. The power control unit enables closed-loop monitoring to prevent high or low power delivery, and it can detect inefficient or excessive wireless power transmission or prevent temperature elevation by limiting the voltage to a safe level. A new structure of self-sampling separated- Vb ASK demodulator is proposed in the paper which is utilized within the data conversion chain, serving both the external and implanted units. The whole system is fabricated using a standard 180-nm 1.8/3.3 V CMOS process with a core area of 0.82 mm[Formula: see text]. The system is tested with coupled multisite inductive links and offers the maximum overall PTE of 31.2%, from the Tx coil to the implant load.

Experimental Study of Fast Orthogonal Frequency Division Multiplexing Transmission over a Random Media Channel for Optical Wireless Communications

In this paper, a 4 amplitude shift keying (4-ASK) fast orthogonal frequency division multiplexing (FOFDM) scheme was experimentally investigated over a turbulent air–water channel for optical wireless communications. The experiment results showed that the 4-ASK-FOFDM modulated signals were not sensitive to weak atmospheric turbulence, and the bit-error rate (BER) was lower than the 7% forward error correction (FEC) limit of 3.8 × 10−3. Under the condition of the same spectra efficiency, the 4-ASK-FOFDM scheme just had a tiny performance penalty compared to the 16-QAM-OFDM scheme. Consequently, the 4-ASK-FOFDM scheme is a promising alternative to the conventional 16-QAM-OFDM scheme in optical wireless communications.

Scalable and Lightweight Approach to Toll Collection Management Using Amplitude Shift Keying (ASK) Modulation Technique

Scalable and Lightweight Approach to Toll Collection Management Using Amplitude Shift Keying (ASK) Modulation Technique

High-Performance Wireless Power and Data Transmission System for Medical Implant Devices Using ASK Modulation

Wireless power and data transmission (WPDT) solutions for medical implants are highly desired. However, achieving a high-power transmission efficiency and data rate simultaneously over an inductive link remains a significant challenge. This paper presents an innovative WPDT circuit that incorporates additional MOSFETs with an inductor in a Class-E power amplifier (PA), achieving amplitude-shift keying (ASK) modulation to address this issue. Firstly, the efficiency of the inductive power transmission link and Class-E PA was analyzed, providing design insights. Then, leveraging the insights, the proposed circuit was designed in such a way that it could effectively switch between two load networks to maintain high transfer efficiency for ASK modulation. Based on the load networks, the relationship between introducing the inductor’s value and the data modulation index (MI) was derived to help achieve the desired high-power transmission efficiency. Additionally, the design and calculation of the proposed circuit are also presented. Finally, the proposed circuit was validated through simulations and experiments, demonstrating a power delivery to a load of 84.1 mW with a power transmission efficiency of 70.8% at a data rate and carrier frequency of 3 Mbps and 16 MHz, respectively. Furthermore, the bit error rate (BER) is less than 10−6 with an MI of 10%.

Design of A Chaos-based Digital Radio over Fiber Transmission Link using ASK Modulation for Wireless Communication Systems

Secured broadband radio communications are becoming increasingly pivotal for high-speed connectivity in radio access networks, playing a crucial role in both mobile information systems and wireless IoT connections. This paper introduces a chaos-based two-channel digital radio communication system utilizing fiber optic radio transmission technology. The system comprises two radio channels operating at up to 1 Gbps using amplitude shift keying (ASK) modulation, followed by modulation with a chaotic sequence before conversion to the optical domain using the MZM modulator. To compensate for fiber loss, the system utilizes an Erbium Doped Fiber Amplifier (EDFA) and employs the optical links through standard ITU-G.655 optical fibers. Numerical simulation of the designed system is performed using the commercialized simulation software Optisystem V.15 to assess and characterize transmission performance. The results demonstrate the system’s effective operation on two channels with a fiber transmission distance of up to 110 km, maintaining a bit error ratio of less than 10−9. This feature ensures reliable performance for high-speed radio connections, particularly in applications such as fronthaul networks in cloud radio access and wireless sensor network connections.

Optimization of RFID Attack Detection using a Received Signal Strength Indication Comparison Method

The growing popularity of IoT (Internet of Things) devices and the ever-increasing multiplicity of their applications ranging from security issues of automated locking systems in homes or hotels to contactless payments. This poses more and more challenges for RFID (Radio-Frequency Identification) users to raise the level of security. Problems of RFID-based devices often involve limited access to computing resources or persistent memory, which is associated with the low cost of the devices and their wide range of applications.The subject of this research is the comparative analysis of the power of communication signals between reader and transponder and reader and attacker. Measurement results were quantified, and the signal was compared for two types of modulations: ASK (Amplitude-Shift Keying) and PSK (Phase-Shift Keying), presenting their readings in the form of contrast histograms based on Fourier transforms. Based on the readings obtained, a security method was proposed based on an algorithm that allows 100% detection of attempted attacks on RFID devices based on the signal power emitted by the transponder to the reader. The conditions under which the effectiveness of the method is possible were also determined based on experiments for IoT devices.

A 6-9 GHz 1.28 Gbps 76 mW Amplitude and Synchronized Time Shift Keying IR-UWB CMOS Transceiver for Brain Computer Interfaces.

This paper proposes a low-power, high-speed impulse radio-ultra-wideband (IR-UWB) transceiver for brain computer interfaces (BCIs) using amplitude and synchronized time shift keying technique (ASTSK). The proposed IR-UWB transmitter (Tx) generates two pulses (sync pulse and data pulse) per symbol rate. The time difference between two pulses is used for synchronized time shift keying and the amplitude of the two pulses is used for amplitude shift keying. The receiver (Rx) demodulates the time difference with a low power time-to-digital converter (TDC) and peak detector (PD) based amplitude demodulation is suggested to relax analog-to-digital converter (ADC) burden for low power receiver. Especially the Tx-based synchronized operation eliminates the need for complex clock circuitry such as phase-lock loop (PLL) and reference crystal oscillator. Therefore, it can achieve low power and high-speed operation. The prototype, fabricated in 65 nm CMOS, has a frequency range of 6-9 GHz, communication speed of 1.28 Gbps, and power consumption of 18 mW (Tx) and 58 mW (Rx). This work is a fully integrated RF transceiver adapted for high-order modulation and designed to include the receiver.

Energy-Efficient Deep Neural Networks for EEG Signal Noise Reduction in Next-Generation Green Wireless Networks and Industrial IoT Applications

Wireless electroencephalography (EEG) has emerged as a critical interface between human cognitive processes and machine learning technologies in the burgeoning field of sensor communications. This paper presents a comprehensive review of advancements in wireless EEG communication and analysis, with an emphasis on their role in next-generation green wireless networks and industrial IoT. The review explores the efficacy of modulation techniques, such as amplitude-shift keying (ASK) and frequency-shift keying (FSK) in EEG data transmission, and emphasizes the transformative role of deep learning in the joint transmission and restoration of EEG signals. In addition, we propose a novel, energy-efficient approach to deep learning-based EEG analytics, designed to enhance wireless information transfer for industrial IoT applications. By applying an autoencoder to sample the EEG data and incorporating a hidden layer to simulate a noisy communication channel, we assessed the energy efficiency and reliability of the transmission. Our results demonstrate that the chosen network topology and parameters significantly affect not only data fidelity but also energy consumption, thus providing valuable insights for the development of sustainable and efficient wireless EEG systems in industrial IoT environments. A key aspect of our study is related to symmetry. Our results demonstrate that the chosen network topology and parameters significantly impact not only data fidelity but also energy fidelity and energy consumption, thus providing valuable insights for the development of sustainable and efficient wireless EEG systems in industrial IoT environments. Furthermore, we realized that the EEG data showed mildly marked symmetry. Neural networks must also exhibit asymmetric behavior for better performance.