FSK Modulation Research Articles

Transmission model and analysis of characteristics of downhole wireless RFID signal based on FSK modulation

Transmission model and analysis of characteristics of downhole wireless RFID signal based on FSK modulation

A Design of Analog PLL-Based Self-Calibrated Open-Loop FSK Modulator for BLE Advertising Transmitter

A Design of Analog PLL-Based Self-Calibrated Open-Loop FSK Modulator for BLE Advertising Transmitter

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.

Investigation of Characteristics of Ultraviolet Light Pulse Weak Signal Communication System Based on Fourth-Order Frequency-Shift Keying Modulation

In ultraviolet (UV) communication, On–Off Keying (OOK) is the primary modulation technique. Compared to OOK, frequency modulation offers stronger resistance to path attenuation. Currently, research on frequency modulation demodulation schemes for UV communication is limited, mainly employing waveform detection and laser pulse response methods, which require high detection sensitivity to light. This study presents a novel frequency modulation communication scheme using discrete Poisson channel distribution and optical pulse signal processing algorithms, enhancing the signal processing sensitivity of the existing frequency modulation scheme to the level of photons. The proposed system model is rigorously evaluated through theoretical derivations and simulations. Additionally, a hardware system integrating optical pulse counting, frequency detection, and clock data recovery algorithms is developed. Experimental results show the system achieving a 5 kbps transmission rate under frequency modulation. In non-line-of-sight (NLOS) scenarios, communication reaches up to 65 m, with the receiver elevation angle ranging from 10° to 25° and the bit error rate (BER) stabilized at 10−4, while in line-of-sight (LOS) situations, the BER remains at 10−5 up to 400 m and 10−4 up to 700 m, achieving the farthest distance and fastest communication rate achievable in the current FSK modulation scheme of ultraviolet communication systems. The integrated components enhance its applicability in communication systems. This study offers a valuable addition to UV communication technology.

Multichannel signal transmission and reception using compact multichannel underwater communication devices: A unified theory and experimental results from different underwater media

Simultaneous transmission of multiple signals over the same bandwidth allows for optimal utilization of the limited bandwidth in underwater systems and networks. To avoid using multiple spatially separated single-channel projectors, one compact multichannel device can be used instead [E. Zhang, R. Rashid, A. Abdi, “Particle velocity underwater data communication: Physics, channels, system and experiments,” IEEE J. Oceanic Eng. (2023); E. Zhang, R. Rashid, A. Abdi, “Underwater communication experiments for transmitting multiple data streams using a vector acoustic MIMO system: OFDM and FSK modulations,” Proc. Oceans (2023)]. Simultaneous reception of multiple signals using one compact multichannel device is also feasible and improves the communication performance, without using several spatially separated single-channel hydrophones [R. Rashid, E. Zhang, A. Abdi, “On the performance of a new wireless communication compact multichannel underwater receiver using a sphere vector sensor,” IEEE Transactions on Vehicular Technology (2023); R. Rashid, E. Zhang, A. Abdi, “Underwater acoustic signal acquisition and sensing using a ring vector sensor communication receiver: Theory and experiments,” Sensors (2023)]. In this paper, we present various experimental results using a number of compact multichannel underwater devices in different setups, and demonstrate their usefulness for underwater communication. [Work supported in part by NSF, Grant IIP-1500123].

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.

Dy-MAC: Implementation of dynamic MAC stack for IEEE 802.15.4e-TSCH

This paper presents the lessons learnt in the implementation of IEEE 802.15.4e-Time Slotted Channel Hopping (TSCH) Medium Access Control (MAC) protocol on commercially available hardware. Our MAC Application programming Interface (API) called the Dy-MAC is agnostic to the PHY layer and is coded on a ARM cortex M4. MAC functions such as TDMA, FDMA, frame counter, channel access, synchronization and PAN formation are abstracted as part of this API. Dy-MAC is demonstrated for 2.4GHz with O-QPSK modulation and 868MHz with SUN FSK modulation. Furthermore, the API supports star, mesh and tree network to provide flexible topologies in factory environment. Our experiments show that for a 76 byte payload, the TSCH Dy-MAC provides ∼99% packet delivery ratio (PDR) for 26ms timeslot with SUN FSK PHY and ∼97% PDR for 10ms timeslot with O-QPSK PHY. To maintain synchronization over the entire network, we implemented algorithms to successfully communicate between fast and slow nodes. Resilience to interference and range with packet delivery ratio is evaluated. We consolidate our implementation in terms of 10 lessons that were learnt in building the Dy-MAC protocol.

Hybrid FSK–FDM Scheme for Data Rate Enhancement in Dual-Function Radar and Communication

In this paper, we present a hybrid frequency shift keying and frequency division multiplexing (i.e., FSK–FDM) approach for information embedding in dual-function radar and communication (DFRC) design to achieve an improved communication data rate. Since most of the existing works focus on merely two-bit transmission in each pulse repetition interval (PRI) using different amplitude modulation (AM)- and phased modulation (PM)-based techniques, this paper proposes a new technique that doubles the data rate by using a hybrid FSK–FDM technique. Note that the AM-based techniques are used when the communication receiver resides in the side lobe region of the radar. In contrast, the PM-based techniques perform better if the communication receiver is in the main lobe region. However, the proposed design facilitates the delivery of information bits to the communication receivers with an improved bit rate (BR) and bit error rate (BER) regardless of their locations in the radar’s main lobe or side lobe regions. That is, the proposed scheme enables information encoding according to the transmitted waveforms and frequencies using FSK modulation. Next, the modulated symbols are added together to achieve a double data rate using the FDM technique. Finally, each transmitted composite symbol contains multiple FSK-modulated symbols, resulting in an increased data rate for the communication receiver. Numerous simulation results are presented to validate the effectiveness of the proposed technique.

Simultaneous wireless power and data transfer based on 4FSK modulation using the four splitting frequencies of series–parallel combined resonant circuit-based system

Simultaneous wireless power and data transfer based on 4FSK modulation using the four splitting frequencies of series–parallel combined resonant circuit-based system

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.

Study of data and power transmission based on frequency-shift modulation in wireless charging

To ensure the reliability of the Wireless Power Transfer (WPT), the simultaneous wireless power and data transmission technology has gained more attention to realize real-time information exchange between the transmitter and receiver sides. In this paper, the shared channel technology and 2FSK modulation method are proposed to accomplish data and power transmission simultaneously. The theoretical analysis of the series-series compensation network is established, and the data modulation method through frequency-shifted modulation is analyzed. In order to reduce the bit error rate of transmitted data, a communication data format containing start and stop bits is proposed in this proposed system. Finally, an experimental prototype is constructed to validate the correctness and effectiveness of the proposed design and approach.

Analysis and design of wireless power and data synchronous transfer system based on 2FSK modulation using dual‐resonant frequency

In this paper, a reconfigurable double-sided inductor-capacitor-capacitor (LCC)-based data transfer method for wireless power transfer (WPT) system is proposed. The power and the data are, respectively, transferred through the orthogonal decoupled inductive links, and thus, the interference between the power transfer link and the data transfer link can be eliminated. Dual-resonant frequency is used to exchange data in the binary frequency-shift keying (2FSK) modulation. The performance of the reconfigurable LCC compensation topology is explored, and the design method is presented to improve the data transfer rate and to guarantee the similar data transfer characteristics under the two different frequencies. Thus, a stable data transfer can be guaranteed irrespective of the data type. The power transfer link and data transfer link are, separately, analyzed. Together with the well-designed parameters, 512 W power with 115.2 kbps transfer rate half-duplex communication is obtained, and the direct current–direct current (DC–DC) efficiency reaches 80.44%.

LoRa Based Framework for Smart Greenhouse Monitoring Systems

Abstract: Agriculture being the largest profession in India depends on various factors like temperature, humidity, soil moisture, and others. LoRa is a long-range, low-power wireless platform framework developed for smart greenhouse monitoring to gain accurate values for dependent factors like temperature, humidity, soil moisture. LoRa is based on chirp spread spectrum modulation, which has low power characteristics like FSK modulation but can be used for long-range communications. LoRa can be used to connect sensors, gateways, machines, devices, animals, people, etc. wirelessly to the cloud. The purpose involves eliminating the traditional methods of the agriculture system and enhancing the crop yield and quality. Automated tools utilization is also being implemented, thereby improving the agricultural conditions, and reducing the human intervention.

Research on Ultra-Low-Frequency Communication Based on the Rotating Shutter Antenna

This paper proposes a rotating shutter antenna that can directly generate 2FSK signals in the ULF band and it is expected to be used as the transmitter for magnetic induction (MI) underground communication systems. The antenna was modeled using ANSYS Maxwell and the magnetic field distribution was simulated. The results show that the interaction between the high-permeability shutter and the mutual cancellation of magnets decreased the transmitting magnetic moment of the antenna. A prototype antenna was manufactured and the time and frequency properties of the measured Bz field were the same as the simulated results, while the magnitude of the measured signal was larger. The propagation characteristics of the antenna in air–soil–rock were simulated using FEKO and the results show that the signal strength was greater than 1 fT at a depth of 450 m from the antenna whose magnetic moment as 1 Am2. The relationship between different magnetic components and azimuth could be used to enhance the signal strength. The formula of the Bz field was derived using the measured magnitude versus distance and the path loss was also analyzed. Finally, the 2FSK modulation property of the antenna was verified by indoor communication experiments with a code rate of 12.5 bps in the ULF band.

PORTABLE AVIATION NAVIGATION CALIBRATION SYSTEM BASED ON RASPBERRY PI, HACK RF ONE, AND SOFTWARE DEFINED RADIO COMMUNICATION SYSTEM

Calibration procedures for the aviation navigation system which involve full size aircraft and its crew may be considered risky and high cost . This paper introduces the state of the art communication system to provide lower cost and flexible solutions based on Raspberry Pi, and SDR device Hack RF One, equipped with proper and aviation-related sensors, which later may be treated as unmanned aerial vehicle payload to replace flying aircraft aviation instruments. Design principles which mainly consist of both flexible communication and operating feasibility are explained in early of this paper. As a preliminary method, simple FSK modulation coupled with data integrity mechanisms are implemented to realize reliable but fast sensor data transmission. Data communication rate under a single board computer environment may achieve 40 kbps. Proposed system achieved a data transmission success rate as high as 88% in reasonable condition. In addition, the discussion of further system development is presented.

Joint Design of Physical-layer Network Coding and LDPC Code Modulated by 2FSK

In order to improve the transmission efficiency in wireless communication and reduce the bit error rate in the transmission process, a physical-layer network coding(PNC) system with 2FSK modulation and low-density parity check(LDPC) codes as the channel coding is established, and a relay detection scheme for the system is designed. This scheme first obtains the waveform diagram of the signal in the network encoding process. According to the characteristics of 2FSK modulation, and then we can extracts the prior probability soft information by the waveform characteristics, and finally we can combine the log likelihood ratio belief propagation(LLR-BP) algorithm to complete the decoding and relay mapping process. The simulation results show that the system adopts 2FSK modulation and has superior bit error rate performance compared with BPSK modulation. After introducing low-density parity check(LDPC) codes, the system can ensure high-speed transmission of information while effectively improving system Bit error ratio performance.

An Ultra-Low Power 2.4 GHz Transmitter for Energy Harvested Wireless Sensor Nodes and Biomedical Devices

We present a 2.4GHz ultra-low power energy-harvested narrowband transmitter (TX) for wireless sensing and biomedical devices. We used a 434 MHz RF energy for resonant cavity based wireless power transfer (WPT). An efficiency tracking loop maximizes the power transfer efficiency of WPT and achieves an efficiency of 11.5%. The TX comprises a voltage-controlled power oscillator (VCPO) and a loop antenna which is patterned over a flexible Parylene C substrate to achieve biocompatibility. The loop antenna acts as a radiator as well as an inductive element for the VCPO, eliminating a power amplifier stage and bulky off-chip matching network. The TX is designed for low active and sleep mode power consumption to support both continuous-data mode or deeply duty cycled burst-data mode of transmission. Implemented in 0.18 μm CMOS, the TX supports OOK and FSK modulations with the sleep mode power dissipation of 128 pW. Our active RF TX consumes an active-mode power of 70 μW at 10 Mbps while radiating -33 dBm of power, resulting in an energy efficiency of 7 pJ/bit, which is the best reported till date.

Simulation of FSK Modulation for Signal Transmission

Simulation of FSK Modulation for Signal Transmission

Implementation of digital and analog modulation systems using FPGA

<p><span>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 & 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.</span></p>

A Power-Efficient Configurable FSK–OOK Transmitter with Scalable Data Rate for Wireless Medical Applications

This paper presents a 922 MHz power-efficient configurable frequency-shift keying–on–off keying (FSK–OOK) phase-locked loop (PLL)-based transmitter. The proposed transmitter works as a multimode structure with configurable data rate and output power. In OOK modulation, by duty cycle adjustment of input data and producing return-to-zero data (RZ-data) by a simple circuit, the data rate can be scaled with power consumption. This implies that any desired level of output power can be transmitted with different power consumption according to the power budget. The transmitter benefits from a new phase frequency detector, an improved charge pump and a low-power voltage-controlled oscillator. The proposed structure represents data rate of 0.24–2.4 Mb/s in OOK mode and 1.8 Mb/s in FSK mode, and it can deliver output power level from − 19.71 to 0.53 dBm. The efficiency of the transmitter at RZ–OOK modulation with data rate of 2.4 Mb/s and output power of 0.53 dBm is 57.25%. Also, the efficiency of transmitter in FSK modulation is 22.1%. The post-layout simulation results in 0.18 µm RF CMOS process are obtained and verify the effectiveness of the proposed circuit.