Shift Keying Amplitude Modulation Research Articles

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.

Capacitive Power Transfer System With Integrated Wide Bandwidth Communication

This letter proposed a novel method for compensation network design used in capacitive power transfer (CPT) systems to achieve simultaneous power and data delivery. The proposed method combines both ladder filter and resonant circuit designs, allowing the existing double-sided CL compensation topology to exhibit different characteristics under the power channel and the communication channel. The proposed system significantly reduces the design complexity and increases the bandwidth for data transfer while maintaining the circuit resonance at the wireless power transfer frequency. The system is compatible with both amplitude shift keying (ASK) and frequency shift keying (FSK) modulation methods, passing the high-frequency data carrier with an approximately unity gain. Detailed circuit parameter design and system performance analysis are presented, and a new metric power to signal is introduced to analyze the effect of the data communication on the power transfer. A prototype CPT system rated at 10 W is built, which demonstrates a 81.2% dc–ac efficiency and a data transfer rate of 10 kbps by using either ASK or FSK modulation techniques.

A 220-GHz Energy-Efficient High-Data-Rate Wireless ASK Transmitter Array

In this work, we present a wireless energy-efficient fully integrated amplitude shift keying (ASK) transmitter (TX) array at 220 GHz. Each TX cell consists of an oscillator, a modulation switch, an on-chip antenna, and baseband amplifiers. The oscillator uses a harmonic generation technique that is optimized for maximum output power and efficiency. The ASK scheme is used for data modulation and is implemented with a fast switch that does not consume any dc power. Three of these TX cells are coherently coupled together to increase the signal-to-noise ratio (SNR) and, hence, the data rate. This also enables the possibility of having a four-level spatial ASK modulation. Fabricated in a 55-nm SiGe bipolar complementary metal oxide semiconductor (BiCMOS) process, the array dissipates 165.2 mW of dc power and generates 4.2-dBm effective isotropic radiated power (EIRP). The chip demonstrates a 20-Gb/s data transmission rate with on-off keying (OOK) modulation at a 28-cm distance using low-cost Teflon lenses. The measured energy efficiency of the array is 8.26 pJ/bit. To the best of our knowledge, this work demonstrates the best energy efficiency among TX arrays at this frequency range.

A low‐power amplitude shift keying modulator based on adaptive body‐biased injection‐locked current‐reuse voltage controlled oscillator for high data rate radio frequency identification applications

AbstractA low‐power consuming amplitude‐shift keying (ASK) modulator designed in 130 nm CMOS technology and operating at 10.5 GHz frequency is presented in this work. The modulator is based on current‐reuse voltage‐controlled oscillator (VCO) which uses the effects of adaptive body‐biasing and injection locking (IL) to achieve low‐phase noise and low‐power operation. The VCO has a phase noise of −106 dBc/Hz at 1 MHz offset. The ASK modulator consumes 790 μW with a 1.1 V voltage supply and draws an average current of 719 μA. For applying the bulk‐biasing signal, a deep n‐well NMOS is used in the PMOS‐NMOS oscillator pair which isolates the substrate and avoids the current path through it. The post‐layout simulation results of the 0.5 × 0.5 mm2 modulator IC verify its low‐power, low‐phase noise operation. It is intended for use in self‐powered active high data rate radio‐frequency identification (RFID) tags.

Design and implementation of reconfigurable ASK and FSK modulation and demodulation algorithm on FPGA (Field Programmable Gate Array)

Our modern world is completely driven by our ability to communicate all over the world with great precision, accuracy, and the least amount of time possible. Communication systems are used vastly in our worlds such as radar, aerospace, naval/maritime communication, underwater communication, mobile communication, or even in outer space such as satellite communication or space missions. Different communication system needs different types of modulation techniques. Design and implementation of reconfigurable modulators on cyclone-II FPGA (Field-programmable gate array) are proposed in this paper, wherein the type of modulations and demodulation can be dynamically reconfigured on the fly based on the requirement at any particular instance. The demodulator is intelligent enough to demodulate any modulated signal. FPGA or Field Programmable Gate Array is a computing device that can be programmed like CPU (Central Processing Unit) but fasted than CPU in parallel processing and DSP (Digital Signal Processing) related tasks. Consisting method of FPGA-based modulation does not support multiple modulation techniques at the same time and is not fast as they used Simulink-based simulation. This study has proposed FPGA based alternative to that, which can embody all the modulation techniques at once, making it way more versatile, cost-effective, and easy to use and test. The process begins with designing an algorithm. Then this algorithm has to be simulated. The algorithm is designed for both modulation and demodulation. In the modulation part, it is just simple logic to create different phrases and different frequencies of sinusoidal waves. But in demodulation, based on the frequency it can detect ASK (Amplitude Shift Keying) or FSK (Frequency Shift Keying) signal all by itself. Depending on the period of the signal, the algorithm can decide whether it is an ASK or FSK signal. After deciding it is an ASK of FSK signal, it starts to demodulate the signal. The outcome is, this FPGA-based modulator and demodulator are cheap, easy to configure, and can demodulate any type of demodulated signal. As it is reconfigurable, it's easy to deploy in any situation.

Low power ASK modulator based on direct injection‐locked current reuse VCO in 130‐nm CMOS technology for high data rate RFID applications

AbstractA low power consumption Amplitude Shift Keying (ASK) modulator employing current reuse cross‐coupled (CRC) LC‐VCO topology and direct injection locking (IL) technique at 10.5‐GHz frequency is presented in this paper. The modulator consumes 864 μW with a DC supply of 1.2 V drawing an average current of 720 μA. The differential VCO is composed of a PMOS‐NMOS pair in stacked series cross‐coupled connection enabling current reuse which results in reduction of the average current drawn from the power source. For comparison, the ASK modulator is also realized with conventional cross‐coupled (CC) topology using NMOS pair. Both circuit approaches are carried out in GF 130‐nm CMOS technology and the post‐layout simulation results of 0.5 × 0.5 mm2 integrated circuits (ICs) show that the CRC topology consumes less power and half of the average current compared to CC topology. Owing to low power requirements, the CRC ASK modulator can be used in self‐powered active Radio Frequency Identification (RFID) tag transmitters for higher data rates.

Free space optics communication channel with amplitude/frequency shift keying modulation technique based raised cosine line coding

Abstract The objective of the study is to simulate frequency shift keying (FSK)/amplitude shift keying (ASK) modulation schemes with raised cosine line coding based free space optics channel in clear weather conditions. The max. Q and optical signal/noise ratio (OSNR) with FSO channel length variations are simulated for the previous and proposed models at DRs of 10 Gbps, and also the max. Q factor with data rate (DR) variations is demonstrated for the previous and proposed models at 10 km FSO channel length. Max. Q, min. BER, signal power (SP), noise power, and total optical power (TOP) based FSK and ASK modulation schemes are illustrated through APD receiver with FSO channel length of 10 km.

An internally-controlled memristor-based amplitude shift keying modulator

Purpose The purpose of this paper is to design and construct an amplitude shift keying (ASK) modulator, which, using the digital binary modulating signal, controls a floating memristor emulator (MR) internally without the need for additional control circuits to achieve the ASK modulated wave. Design/methodology/approach A binary digital unipolar signal to be modulated is converted by a pre-processor circuit into a suitable bipolar modulating direct current (DC) signal for the control of the MR state, using current conveyors the carrier signal’s amplitude is varied with the change in the memristance of the floating MR. A high pass filter is then used to remove the DC control signal (modulating signal) leaving only the modulated carrier signal. Findings The results from the experiment and simulation are in agreement showed that the MR can be switched between two states and that a change in the carrier signals amplitude can be achieved by using an MR. Thus, showing that the circuit behavior is in line with the proposed theory and validating the said theory. Originality/value In this paper, the binary signal to be modulated is modified into a suitable control signal for the MR, thus the MR relies on the internal operation of the modulator circuit for the control of its memristance. An ASK modulation can then be achieved using a floating memristor without the need for additional circuits or signals to control its memristance.

Voltage mode ASK/BPSK modulator, its extended applications in precision rectifier and data communication using DXCCII

In this paper, two new modulator circuits are presented to realize two types of digital modulations, namely amplitude shift keying (ASK) and Binary phase shift keying (BPSK). The modulator circuits use one dual-X second-generation current conveyor (DXCCII), three MOS transistors, and one or two resistors. Since in data communication, there is a need for a demodulator and a modulator, a basic demodulator as an application of ASK modulator is presented using a rectifier, envelope detector, and comparator. Moreover, in an integrated circuit (IC), the modularity of sub-circuit is preferred, especially for the ease of fabrication. In maintaining the modularity, an attempt is made to design a precision rectifier, needed for demodulator, as an extension of the proposed modulator with little modifications. The proposed modulators possess the following important features: use all grounded passive components, ASK and BPSK obtain simultaneously, no need for matching passive components, circuits are fully cascadable and easily extendable to a precision rectifier. A non-ideal analysis is carried out. The proposed circuits are verified by PSPICE simulation with a supply voltage of ±0.9 V in 0.13 µm CMOS TSMC technology. Simulation results corroborate the theoretical proposition. Furthermore, the proposed ASK and BPSK modulator circuit is experimentally verified.

Mark ratio modulation over pulse position modulation

• Mark ratio modulation over inverse PPM modulation is proposed for optical label switching. • Two signals are transmitted by one ASK modulation. • The mark ratio difference of PPM and inverse PPM is utilized to deliver an overlay signal. • The mark ratio modulation doesn’t degrade the PPM signal. Orthogonal modulation superimposes non-amplitude-modulated signals on Manchester coded or pulse position modulated amplitude shift keying (ASK) signals, allowing two traffic flows with different bit rates to be modulated on the same wavelength channel, and hence improving spectrum efficiency. Inspired by the orthogonal modulation, this paper proposes a novel modulation format, i.e., mark ratio modulation over pulse position modulation (PPM), which utilizes the mark ratio difference between the PPM symbols and the inverse PPM symbols to deliver an overlaid signal. Better than traditional orthogonal modulation, in the mark ratio modulation over PPM, both low-speed and high-speed traffic flows are modulated by ASK with no need to sacrifice the extinction ratio, while keeping the reception simple and easy. According to theoretical analysis and test, we found 4PPM is a good option, which can balance the trade-off between the PPM signal’s effective bit rate and the mark ratio modulated signal’s quality.

Spectrum Sensing for Smart Embedded Devices in Cognitive Networks using Machine Learning Algorithms

Abstract Spectrum sensing is an essential step in cognitive radio-based dynamic spectrum management. Spectrum sensing to detect the presence of the licensed signals in a particular frequency band is one of the most important research topics in cognitive radio. To identify primary user (PU) presence, we propose a low cost and low power consumption implementation of spectrum sensing operation based on real signals. These signals are generated by smart embedded devices at 433 MHz wireless transmitter using ASK (Amplitude-Shift Keying) and FSK (Frequency-Shift Keying) modulation type. The reception interface is constructed using an RTL-SDR dongle connected to MATLAB software. The signal detection is done by using four techniques: the artificial neural network (ANN), support vector machine (SVM), Decision Trees (TREE), and k-nearest neighbors (KNN). This article comparatively analyzed the performance of the classifiers to identify the best method for spectrum sensing between the three techniques. The performance evaluation of our proposed model is the probability of detection (Pd) and the false alarm probability (Pfa). Results show also that the sensing is susceptible to signal to noise ratio value. This comparative study has been demonstrated that the spectrum sensing operation by ANN and SVM can be more accurate than KNN, TREE, and some other classical detectors.

Wireless Power and Data Transmission System of Submarine Cable-Inspecting Robot Fish and Its Time-Sharing Multiplexing Method

In this paper, a hybrid system topology with one-way wireless charging function and the function of the bi-directional data communication is proposed for the problem of electric energy replenishment and data transmission faced by robot fish in the implementation of autonomous submarine cable inspection. Three working modes of the system and the time-sharing multiplexing method are studied. In the power transmission mode, high-efficiency wireless charging is realized by utilizing the transmission characteristics of a series–series (SS)-type resonant network which involves series resonant networks in both the primary side and the secondary side. In the alignment detection and handshake communication mode, the charging platform distance recognition and the handshake signal transmission are implemented through a series–parallel (SP)-type resonant network based on the ASK (amplitude shift keying) modulation method. In the high-speed data transmission mode, the reverse (secondary to primary) high-speed transmission of the inspection data is achieved through a SP-type resonant network based on the OFDM (orthogonal frequency division multiplexing) modulation method. The three modes share the same coupled coils via a reconfigurable resonant network. The working principle of the system is expounded, the system characteristics under each working mode are analyzed, and the time-division multiplexing control strategy is given. The rationality and effectiveness of the scheme are verified by experiments.

A MEMS BPSK to ASK converter

PurposeThe purpose of this paper is to investigate the feasibility of using micro electromechanical systems (MEMS) to convert a binary phase shift keying (BPSK) signal to a simpler amplitude shift keying (ASK) scheme.Design/methodology/approachThe prototype is designed within the SOIMUMPs® fabrication process constraints. The fabrication constraints imposed geometric limitations on what could be tested. These constraints were used to build a mathematical model, which in turn was used to optimize the response using MATLAB®. The optimized design was tested using finite element analysis with CoventorWare®, and finally lab tests on the fabricated device were performed to confirm theoretical predictions.FindingsTheoretical predictions compared well with lab measurements on a prototype device measuring 2.9 mm2. The prototype was tested with a carrier frequency of 174 kHz at a BPSK data rate of 3 kHz and carrier amplitude of 6 V. With these parameters, ASK modulation indices of 0.96 and 0.94 were measured at the two output sensors.Originality/valueThis study provides a MEMS solution for BPSK to ASK conversion. The study also identifies what limits betterment of the modulation index and data rate. Such a device has potential application in wireless sensor network (WSN) nodes that have energy harvesters and sensors that are also built in MEMS. Being a MEMS device, it can facilitate integration in such WSN nodes and, hence, potentially reduce size and costs.

Design of Efficient Hybrid E/F Power Amplifier for Biomedical Purposes

This paper introduces a new hybrid E/F power amplifier for subcutaneous applications. The proposed design is based on Amplitude Shift Keying (ASK) modulation technique with Industrial Scientific Medical (ISM) band operating at 135 kHz to avoid the tissue damage. The Hybrid E/F power amplifier combines the tuning network circuits and uses a control unit to control a selectable switch to choose the desired amplifier. The Amplitude Shift Keying modulator is proposed to supply the proposed hybrid amplifier with approximately constant DC voltage. The proposed power amplifier aims to provide an appropriate power to power the implantable devices and reduce the hardware of the subcutaneous devices depending on the specific applications

Enhanced Biased ASK Modulation Performance for SWIPT With AWGN Channel and Dual-Purpose Hardware

A lot of small sensors are deployed in Internet of Things applications. Simultaneous wireless information and power transfer (SWIPT) is a solution to avoid a large amount of batteries, while exchanging information with the sensors. Combining both energy harvesting and information receiving in dual-purpose hardware lowers power consumption while also decreasing sensor size. Biased amplitude shift keying (ASK) is introduced as a solution for the SWIPT modulation technique. In particular, the design of enhanced biased ASK modulation in case of an additive white Gaussian noise channel is analyzed in this paper. Novel formulas for symbol error rate are derived, while improvements of the modulation scheme are proposed based on measurements, taking rectifier nonlinearity into account and resulting in reducing the transmitted power by 14 dB for fixed error rate.

A CMOS Medium Power Amplifier With Built-In Power Detector for Multistandard Dedicated Short-Range Communication Applications

This letter presents a 5.8-GHz medium power amplifier (PA) using 0.18- $\mu \text{m}$ CMOS technology with a built-in power detector for triple-mode operations, including amplitude-shift keying (ASK), frequency-shift keying (FSK), $\pi $ /4-quadrature-phase shift keying, and multilevel complex modulations, for multistandard dedicated short-range communication applications. For ASK/FSK operations, the PA can work in nonlinear regions owing to the constant envelope feature of input signals that improve the power added efficiency, by which ASK modulation is achieved by modulating the bias of the PA output stage. The measured results show more than 10-dBm output power for all mode operations, with a chip area of $0.92 \times 0.75$ mm2.

Proposal of Inverse Pulse Position Modulation for Downstream Signal in Remodulation PON With PolSK-Modulated Multicast Overlay

Inverse pulse position modulation (PPM) is proposed for downstream data modulation in an optical network unit-source-free wavelength-division-multiplexed passive optical network, while optical amplitude shift keying (ASK) modulation is used for upstream data remodulation. In such a PON, polarization shift keying (PolSK) modulation overlay can be supported on the downstream signals for multicasting services. Our experimental results show that the inverse PPM optical ASK modulation for downstream data has small channel crosstalk with PolSK multicast data and ASK-remodulated upstream data. Compared with the approaches based on the Manchester code or inverse return-to-zero code, the proposed scheme based on inverse PPM has a better power margin, indicating a longer transmission distance and a higher tolerance to link loss.

Analysis of Noncoherent ASK Modulation-Based RF-Interconnect for Memory Interface

A noncoherent amplitude shift keying (ASK)-based RF-interconnect (RF-I) system design for off-chip communication is analyzed. The proposed RF-I system exploits the simple architecture and characteristics of noncoherent ASK modulation. This provides an efficient way of increasing interconnect bandwidth by transmitting an RF-modulated data stream simultaneously with a conventional baseband counterpart over a shared off-chip transmission line. Both analysis and tested results prove that the performance of the proposed dual-band (RF+baseband) interconnect system is not limited by thermal noise interference. Therefore, a more sophisticated modulation scheme and/or coherent receiving scheme becomes unnecessary within the scope of system requirements. In addition, it confirms that the proposed inductive coupling network is able to support simultaneous bidirectional communications without using complicated replica circuits or additional filters to isolate simultaneous baseband and RF-band data streams.

Quadrature Amplitude Modulated Backscatter in Passive and Semipassive UHF RFID Systems

Passive and semipassive UHF RF identification (RFID) systems have traditionally been designed using scalar-valued differential radar cross section (DRCS) methods to model the backscattered signal from the tag. This paper argues that scalar-valued DRCS analysis is unnecessarily limiting because of the inherent coherence of the backscatter link and the complex-valued nature of load-dependent antenna-mode scattering from an RFID tag. Considering modulated backscatter in terms of complex-valued scattered fields opens the possibility of quadrature modulation of the backscatter channel. When compared with binary amplitude shift keying (ASK) or phase shift keying (PSK) based RFID systems, which transmit 1 bit of data per symbol period, and thus 1 bit per on-chip clock oscillator period, tags employing vector backscatter modulation can transmit more than 1 bit per symbol period. This increases the data rate for a given on-chip symbol clock rate leading to reduced on-chip power consumption and extended read range. Alternatively, tags employing an M-ary modulator can achieve log2 M higher data throughput at essentially the same dc power consumption as a tag employing binary ASK or PSK. In contrast to the binary ASK or PSK backscatter modulation employed by passive and semipassive UHF RFID tags, such as tags compliant with the widely used ISO18000-6c standard, this paper explores a novel CMOS-compatible method for generating M-ary quadrature amplitude modulated (QAM) backscatter modulation. A new method is presented for designing an inductorless M-ary QAM backscatter modulator using only an array of switched resistances and capacitances. Device-level simulation and measurements of a four-state phase shift keying (4-PSK)/four-state quadrature amplitude modulated (4-QAM) modulator are provided for a semipassive (battery-assisted) tag operating in the 850-950-MHz band. This first prototype modulator transmits 4-PSK/4-QAM at a symbol rate of 200 kHz and a bit rate of 400 kb/s at a static power dissipation of only 115 nW.

Investigation of efficient ASK demodulation for wirelessly powered biodevices

A new hardware architecture of amplitude shift keying (ASK) demodulation for portable wirelessly data-combined power transfer, especially those biomedical applications requiring permanently harvested power through radio frequency, is proposed. The architecture along with its circuit details provides dramatically enhanced energy efficiency in the system while at the same time achieving cost-effective data demodulation under a real challenging condition at the ASK modulation index. Experimental results in a 0.18 µm technology demonstrate the advantages of the proposed design.