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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%. [ABSTRACT FROM AUTHOR]

This article proposes an amalgam of phase-shift keying and asymmetrically clipped frequency-shift keying (i.e., AC-FPSK) for low-energy/low-data rate optical wireless communications. We design a near-optimal, low-complexity harmonic receiver by analyzing the AC-FPSK time-domain (TD) and frequency-domain (FD) waveforms. The Euclidean distance analysis between AC-FPSK waveform pairs yields lower and upper bounds for theoretical bit error probability. Using numerical simulations, we present an exhaustive evaluation of the optimal cardinality of PSK, which illustrates the superiority of AC-FPSK. We show that AC-FPSK provides better energy efficiency versus spectral efficiency trade-off than state-of-the-art AC-FSK, direct current-FPSK, pulse amplitude modulation, and asymmetrically clipped optical orthogonal frequency division multiplexing. We also demonstrate that by making a suitable choice for the cardinality of PSK, the proposed 2-tap harmonic receiver for AC-FPSK can reach a similar complexity as the AC-FSK harmonic receiver. [ABSTRACT FROM AUTHOR]

Nanocomposite coatings are made by atmospheric‐pressure plasma‐enhanced chemical vapor deposition from ethyl lactate (EL) and silica nanoparticles (NPs) in a dielectric barrier discharge (DBD) using frequency‐shift keying (FSK) to alternate between 1‐ and 15‐kHz voltages. In situ plasma Fourier‐transform infrared spectroscopy (FTIR) and thin film FTIR, scanning electron microscopy, atomic force microscopy, and profilometry show that (i) 1 kHz DBD mainly deposits NPs, 15 kHz only polymerizes EL; (ii) the EL polymerization rate is the same in FSK and continuous modes; (iii) despite the 50/50 contribution of both frequencies, the NP deposit is three times faster in FSK mode than in 1 kHz DBD and compared with 1 and 15 kHz coatings, in the nanocomposite, NP Si–O–Si and EL C═O bonds per unit length are equal to 68% and 34%, respectively. In situ FTIR detects SiO2 NPs, their functionalization, and the formation of CO2. [ABSTRACT FROM AUTHOR]

In this letter, we develop an acoustic spot data communication system using multiple parametric array loudspeakers, which are directional loudspeakers and can send audio in a specific direction. In our system, data are modulated and transmitted through multiple parametric array loudspeakers, and complete data reception is possible only at a specific spot. We implemented our system using low‐cost commercially available products and a self‐developed Java program, and we used frequency‐shift keying to modulate the acoustic data communication between the sender and receiver modules. Through comparative experimental evaluations, we show that data reception at a specific spot is possible using our system. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

A noncoherent two-way relaying system is developed using physical-layer network coding for improved throughput over conventional relaying in a fading channel. Energy-efficient noncoherent operation is achieved using multitone frequency shift keying (FSK). A novel soft-output demodulator is developed for the relay, and corresponding achievable exchange rates are found for Rayleigh fading and AWGN channels. Bit-error rate performance approaching the achievable rate is realized using a capacity-approaching channel code and a receiver architecture, which iterates between demodulation and channel decoding. Iterative decoding is performed feeding information back from the channel decoder to the demodulator. In addition, the error-rate performance is made to approach the achievable rate more closely by optimizing LDPC codes for this system. The energy efficiency improvement obtained by increasing the modulation order is more dramatic for the proposed physical-layer network coding scheme than it is for a conventional point-to-point system. Using optimized LDPC codes, the bit-error rate performance is improved by as much as 1.1 dB over a widely known standardized LDPC code, and comes to within 0.7 dB of the limit corresponding to the achievable rate. Throughout this paper, the performance for physical-layer network coding is compared with conventional network coding. When noncoherent FSK is used, physical-layer network coding enables higher achievable rates, and conventional network coding exhibits better energy efficiency at low rates. [ABSTRACT FROM AUTHOR]

Scatter radio, i.e., communication by means of reflection, has been recently proposed as a promising technology for low-power wireless sensor networks (WSNs). Specifically, this paper offers noncoherent receivers in scatter radio frequency-shift keying, for either channel-coded or uncoded scatter radio reception, in order to eliminate the need for training bits of coherent schemes (for channel estimation) at the packet preamble. Noncoherent symbol-by-symbol and sequence detectors based on hybrid composite hypothesis test (HCHT) and generalized likelihood-ratio test, for the uncoded case and noncoherent decoders based on HCHT, for small block-length channel codes, are derived. Performance comparison under Rician, Rayleigh, or no fading, taking into account fixed energy budget per packet is presented. It is shown that the performance gap between coherent and noncoherent reception depends on whether channel codes are employed, the fading conditions (e.g., Rayleigh versus Rician versus no fading), as well as the utilized coding interleaving depth; the choice of one coding scheme over the other depends on the wireless fading parameters and the design choice for extra diversity versus extra power gain. Finally, experimental outdoor results at 13-dBm transmission power corroborate the practicality of the proposed noncoherent detection and decoding techniques for scatter radio WSNs. [ABSTRACT FROM PUBLISHER]

We experimentally demonstrate an all-optical approach for generating frequency-shift keying (FSK) radio-frequency (RF) signal based on nonlinear polarization rotation (NPR) in a highly nonlinear fiber (HNLF). A continuous wave probe beam is polarization-rotated by an optical amplitude-shift keying control beam via NPR in the HNLF. After removing the undesired control beam by a tunable optical filter, the polarization-rotated probe beam is converted to an intensity-modulated optical signal using a polarizer. By carefully adjusting the polarization controller before the polarizer and the optical power of the control beam, FSK RF signals are generated after photodetection. [ABSTRACT FROM AUTHOR]

Orthogonal modulation, for example, frequency-shift keying (FSK) or pulse-position modulation (PPM), is primarily used in relatively-low-rate communication systems that operate in the power-limited regime. Optimal noncoherent detection of orthogonally modulated signals takes the form of sequence detection and has exponential (in the sequence length) complexity when implemented through an exhaustive search among all possible sequences. In this work, for the first time in the literature, we present an algorithm that performs generalized-likelihood-ratio-test (GLRT) optimal noncoherent sequence detection of orthogonally modulated signals in flat fading with log-linear (in the sequence length) complexity. Moreover, for Rayleigh fading channels, the proposed algorithm is equivalent to the maximum-likelihood (ML) noncoherent sequence detector. Simulation studies indicate that the optimal noncoherent FSK detector attains coherent-detection performance when the sequence length is on the order of 100, offering a 3–5 dB gain over the typical energy (single-symbol) detector. While the conventional exhaustive-search approach becomes infeasible for such sequence lengths, the proposed implementation requires a log-linear only number of operations, opening new avenues for practical deployments. Finally, we show that our algorithm also solves efficiently the optimal noncoherent sequence detection problem in contemporary radio frequency identification (RFID) systems. [ABSTRACT FROM AUTHOR]

We propose an orthogonal modulation scheme with 40 Gb/s Manchester-coded (MC) payload and 2.5 Gb/s frequency-shift keying (FSK) label. The high-speed FSK label is generated by an FSK modulator, which consists of two modulators, while MC payload is generated by an intensity modulator. Simulation results show that the available extinction ratio of FSK and amplitude-shift keying with MC payload can improve from 5.1 to 11.2 dB, compared with the traditional not-return-to-zero payload. The receiver sensitivities of both MC payload and FSK label show a remarkable improvement. [ABSTRACT FROM AUTHOR]

In this letter, we have analyzed the Internet protocol transmission and routing over frequency-shift keying optical code division multiple access based on a novel optical code.This code enhances the system bit error rate, packet error rate, number of simultaneous subscribers, and security, as compared to the other prime codes. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2852-2856, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27213 [ABSTRACT FROM AUTHOR]

In this paper, the performance of signaling strategies with high peak-to-average power ratio is analyzed in both coherent and noncoherent fading channels. Two modulation schemes, namely on-off phase-shift keying (OOPSK) and on-off frequency-shift keying (OOFSK), are considered. The optimal detector structures are identified and analytical expressions for the error probabilities are obtained for arbitrary constellation sizes. Numerical techniques are employed to compute the error rates. It is concluded that increasing the peakedness of the signals results in reduced error rates for a given power level and hence equivalently improves the energy efficiency for fixed error probabilities. [ABSTRACT FROM AUTHOR]

Abstract: A series of short-time stochastic resonance (SR) phenomena, realized in a bistable receiver, can be utilized to detect a train of information represented by signals that adopt frequency-shift keying (FSK). It is demonstrated that the values of noise intensity at resonance regions are close for adjacent periodic signals with an appropriate frequency separation. This establishes the possibility of decoding subthreshold or slightly suprathreshold M-ary FSK signals in bistable receivers. Furthermore, the mechanism of FSK signal detection via short-time SR effects is elucidated in terms of the receiver response speed. This phenomenon provides a possible mechanism for information processing in a bistable device operating in nonstationary noisy environments, where even the inputs appear over a short timescale or have a frequency shift. [Copyright &y& Elsevier]

Three algorithms to estimate instantaneous frequency of a frequency-modulated signal is discussed. These algorithms are based on Hilbert transform, Haar wavelet, and generalized pencil of function (GPOF) methods. While GPOF-based frequency detection method appears to be least sensitive to noise, wavelet-based method is easiest to implement. The latter method is also computationally more efficient and can be implemented in real-time. Results for both synthetic and experimental data are shown. [Copyright &y& Elsevier]

Power line communication (PLC) is a communications method where signals are carried across already existing power lines, rather than through other mediums such as optical fibers or radio waves. PLC has been a very important interdiscipline topic for power, communications, industrial, and automation engineers and researchers since the 1980s. Designing and planning optimized or standard PLC systems require information and data regarding signal attenuations, load variations, and communication performance for various locations of the world which have different power networks. In this study, PLC system is modeled by ABCD matrix and simulated via electronics workbench. In order to obtain data from Turkey's power lines, signal measurements at the frequencies of 50-200 kHz are carried out. The effects of load, frequency, line length, and the distribution transformers are examined. The properties of home appliances used in an average Turkish household are experimentally determined. System performance in terms of the bit error probability are calculated for FSK modulation. [ABSTRACT FROM AUTHOR]

A new large deviation FSK baseband receiver is presented. It is based on an eight port optical multiport that provides phase-quadrature detection so as to avoid aliasing when the input signal is baseband translated. The multiport device also provides insensititvity to laser intensity noise and suppresses channel intermodulation in FDM systems. [ABSTRACT FROM AUTHOR]

A channel-coded physical-layer network coding strategy is refined for practical operation. The system uses frequency-shift keying (FSK) modulation and operates noncoherently, providing advantages over coherent operation: there are no requirements for perfect power control, phase synchronism, or estimates of carrier-phase offset. In contrast with analog network coding, which relays received analog signals plus noise, the system relays digital network codewords, obtained by digital demodulation and channel decoding at the relay. The emphasis of this paper is on the relay receiver formulation. Closed-form expressions are derived that provide bitwise log-likelihood ratios, which may be passed through a standard error-correction decoder. The role of fading-amplitude estimates is investigated, and an effective fading-amplitude estimator is developed. Simulation results are presented for a Rayleigh block-fading channel, and the influence of block length is explored. An example realization of the proposed system demonstrates a 32.4% throughput improvement compared to a similar system that performs network coding at the link layer. By properly selecting the rates of the channel codes, this benefit may be achieved without requiring an increase in transmit power. [ABSTRACT FROM AUTHOR]

A very simple design rule for parallel concatenated Turbo codes over GF(q) with q-ary orthogonal modulation is proposed. Unlike previously proposed exhaustive search methods, the proposed design rule allows straightforward and systematic code designs for any value of q ≥ 2 and any constraint length greater than 2. [ABSTRACT FROM PUBLISHER]