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Oxide-based thin-film transistors (TFTs) with a lateral in-plane electrode are self-assembled on paper substrates, and the electrical modulation effect of the in-plane electrode is investigated. A \SiO2-based solid-electrolyte film with high specific capacitance is used as the gate dielectric, and the operation voltage is reduced to less than 2.0 V. The threshold voltage (Vth) of such paper TFTs is tuned from -0.98 to 0.94 V by different voltage biases on the in-plane electrode. The threshold voltage shift (\Delta Vth) can be described by \Delta Vth = -(CG2/CG1)VG2, where CG2 and CG1 are the in-plane electrode and bottom-gate specific capacitance values. High electrical performance with a current on/off ratio of \6 \times \10^5 \sim \10^6, a subthreshold swing of 0.14 \sim 0.19 V/dec, and a mobility of \8.64 \sim \9.45\ \cm^2/\V\cdot \s is obtained at different in-plane electrode voltage biases. Such low-voltage paper TFTs are promising for low-cost and portable electronics. [ABSTRACT FROM PUBLISHER]

A simple scheme that achieves the capacity and the reliability function of the wideband Costa dirty-paper channel is proposed. The scheme can be interpreted as an opportunistic version of pulse position modulation (PPM). This interpretation suggests a natural generalization of the scheme which we show to achieve the capacity per unit cost of Gel'fand-Pinsker channels with a zero-cost input letter. [ABSTRACT FROM AUTHOR]

An extensive revision of the IEEE C37.011 ‘Application Guide for TRV for AC High-Voltage circuit Breakers’ has been in process for the last four years. The main aim was to introduce the two- and the four- parameter description of the transient recovery voltage (TRV) as used in IEC Switchgear standards that have been introduced in the revisions of Standards C37.04 and C37.06. These two standards are being concurrently revised, but IEEE C37.011 provides the necessary explanations on TRV characteristic in advance. Non-specialist engineer users of the guide will better understand these standards. [ABSTRACT FROM AUTHOR]

A high-harmonic traveling-wave tube (HHTWT) is designed, developed, and tested in this paper. This device is configured as a multiplier–amplifier with Q-band input signals and its third harmonic, i.e., D-band output power. The tested result demonstrates that 280 mW at 133.5 GHz is obtained as a result of 200 mW at 44.5-GHz input signal. The simulation and experiment validate that the high-harmonic radiation can be generated and amplified in the HHTWT. The approach described in this paper could find application in exploring high power, wideband tunable terahertz source. This paper is expanded from a conference paper on IVEC 2017. The detail design produce and tested result are added in this paper. The explanation of the simulation and tested results is also presented. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new adaptive modulation based on the wavelet packet transform, which targets a good resistance against frequency selective channels while avoiding a large PAPR. Classical multi-carrier modulation schemes divide the channel bandwidth into narrowband sub-channels to improve its robustness against frequency selective fading. However, they suffer from the peak-to-average power ratio (PAPR) problem, which occurs due to a random constructive addition of sub-carriers. By contrast, single carrier modulation schemes, where each transmitted symbol fully occupies the bandwidth, are more sensitive to frequency selective environments and less affected by the PAPR problem. In this paper, we show how the bandwidth division can be reconfigurable and adapted to the channel properties, and we provide several examples to prove that the proposed adaptive modulation represents an alternative modulation which is adjustable between two extreme cases: single carrier modulation and classical multi-carrier modulation. [ABSTRACT FROM AUTHOR]

In this paper, we study the capacity and symbol error probability (SEP) of generalized spatial modulation (GSM) multiple-input multiple-output (MIMO) using measured channels that are obtained by channel sounding in an indoor office environment at 60GHz. Spatial modulation (SM) and GSM are emerging low-complexity MIMO schemes that have been extensively researched for low-GHz (below 6GHz) communications. Recently, they have been considered and shown to be promising also for (mmWave) communications. In the simplest possible case, they require only one RF chain both at the transmitter (TX) and receiver (RX), and thus, are especially attractive for mmWave communications, in which the number of RF chains needs to be as low as possible. Despite of some early works on the theoretical analysis of SM/GSM for mmWave communications, there have been no investigations using real-world channel data. We focus on the office line-of-sight (LOS) scenario and investigate three problems: 1) the performance of GSM using the extracted LOS component of measured channels; 2) the impact of non-LOS NLOS components on the performance of GSM; and 3) possible simple modulation and reception algorithms for GSM that rely only on the LOS component of the channel. The results being reported in this paper not only validate the main claims of previous studies based on ideal pure LOS channels, but also lead to novel findings. One major conclusion is that NLOS components are harmful to the SEP of GSM and should be avoided. As another important outcome, our results strongly motivate the use of precoding in GSM systems to simultaneously improve the channel capacity and reduce the physical size of MIMO arrays (thus eliminating one major issue of LOS GSM). [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented in which the editor discusses an article on the real-time optimization of a step multilevel modulation, the use of zero state in the minimization of distortion, and the analysis of selective harmonic control based on the utilization of resonant filters.

The rank modulation scheme has been proposed for efficient writing and storing data in nonvolatile memory storage. Error correction in the rank modulation scheme is done by considering permutation codes. In this paper, we consider codes in the set of all permutations on n elements, S_{n} , using the Kendall \tau -metric. The main goal of this paper is to derive new bounds on the size of such codes. For this purpose, we also consider perfect codes, diameter perfect codes, and the size of optimal anticodes in the Kendall \tau -metric, structures which have their own considerable interest. We prove that there are no perfect single-error-correcting codes in S_{n} , where n>4 is a prime or 4\leq n\leq 10 . We present lower bounds on the size of optimal anticodes with odd diameter. As a consequence, we obtain a new upper bound on the size of codes in S_{n} with even minimum Kendall \tau -distance. We present larger single-error-correcting codes than the known ones in S5 and S7 . [ABSTRACT FROM AUTHOR]

This paper investigates the impact of backgate biasing ( VBS ) on the drain current ( ID ) of ultrathin-body III-V heterojunction tunnel FET (HTFET). Compared with homojunction TFET and III-V/Ge MOSFET, this paper indicates that HTFET exhibits significantly higher I\mathrm{{\scriptstyle OFF}} ( ID at VGS = 0 V and VDS=0.5 V) modulation efficiency and the influence of VBS rapidly decreases with increasing VGS . In addition, it is observed that the change of source available states with VBS determines the ID modulation efficiency of p-type HTFET (pHTFET). Depending on the source doping concentration and operating VGS , the ID of HTFET under forward VBS can be anomalously smaller than that at VBS=0 V. Furthermore, the impacts of source/drain doping concentrations and junction properties are discussed and shown to be critical in determining the ID modulation efficiency of HTFET. We find that, under controlled ambipolar current, reverse backgate biasing can be utilized to suppress the I\mathrm{{\scriptstyle OFF}} of HTFET, and the modulation efficiency increases with decreasing source doping concentration. Our study may provide insights for device/circuit designs with advanced TFET technologies. [ABSTRACT FROM PUBLISHER]

This paper presents a new asymmetric Class-F−1/F Doherty power amplifier (DPA) consisting of a Class-F−1 carrier amplifier and a Class-F peaking amplifier. The asymmetric current waveform due to different harmonic loading conditions offers an asymmetric fundamental current in load modulation region, ensuring an improvement in the performance at the peak output power. In this paper, improvements in the large signal performances, such as the output power and efficiency, are analyzed using the derived fundamental current models. For verification, a 2.4-GHz GaN Class-F−1/F DPA was designed and fabricated. The designed Class-F−1/F DPA achieves a peak output power of 44 dBm with a peak drain efficiency (DE) of 86.7%. Using a local thermal equilibrium 10-MHz signal with a 6.6-dB peak-to-average power ratio, the Class-F−1/F DPA achieves an average output power of 37.3 dBm with a DE of 68% at a supply voltage of 28 V. The measured adjacent channel leakage power ratio with a digital predistortion is below −50 dBc. [ABSTRACT FROM AUTHOR]

This paper presents a novel flux-modulated type dual-axis motor that has two mechanical inputs/outputs, since it consists of a stator, a permanent magnet rotor, and a modulating rotor. Furthermore, since the dual-axis motor has a function the same as a planetary type magnetic gear, it can transmit torque with arbitrary gear ratio and divide mechanical input/output into two rotors without any mechanical contact. In this paper, first, conventional and proposed flux-modulated type dual-axis motors are optimized and compared using finite-element analysis. Next, the proposed dual-axis motor is prototyped and demonstrates the validity and availability by experiment. [ABSTRACT FROM AUTHOR]

This paper discusses interference precancellation in digital hierarchical broadcasting (HB). In particular, we present the principles and implementation of structured dirty paper coding (SDPC) that approaches the capacity limit of dirty paper coding in multilayer broadcasting. As an alternative to Tomlinson-Harashima precoding (THP), SDPC eliminates the significant performance loss suffered by THP in the low signal-to-noise ratio (SNR) regime due to :he modulo operation. The key idea behind the SDPC scheme is the exploitation of the modulation structure of interference, thereby simplifying the demodulation process in hierarchical reception. We exemplify the SDPC technique by implementing an SDPC-based HB system on a real-time test bed. The experimental results show that SDPC delivers the performance of "superposition coding with successive interference cancellation" without extra computation or memory requirements at the receiver side. [ABSTRACT FROM AUTHOR]

This paper applies multiple-input multiple-output (MIMO) transmission methods to multiwire communication systems. Using channel matrices generated from a binder MIMO channel model, a performance assessment of digital subscriber line (DSL) technology based on MIMO transmission methods finds that symmetric data rates of more than 1 Gbps are achievable over four twisted pairs (category 3) for a 300 m range. Similar results are also obtained for a ‘quad’ cable. To achieve this data rate, this paper proposes that the source and load be excited using common mode. [ABSTRACT FROM AUTHOR]

In this paper, two major multiple-input-multiple-output (MIMO) transmission techniques such as spatial modulation (SM) and spatial multiplexing (SMX) are considered. In particular, the focus is on an interference scenario, where an SM MIMO system interferes with a conventional SMX MIMO system. The interference caused by SM has a peculiar behavior. In SMX MIMO networks, the interference subspace is fixed in a given coherence time interval. It can be estimated accurately, and interference suppression techniques can be applied accordingly. However, the interference caused by an SM system has no fixed interference subspace, and it changes in every single channel use. Therefore, SM interference could pose some unique challenges to SMX MIMO systems in some scenarios. In this paper, the effect of SM interference on SMX MIMO systems and methods to overcome/reduce the adverse effects caused by SM interference are studied. Furthermore, the effect of SMX interference on SM MIMO systems is also studied. [ABSTRACT FROM AUTHOR]

The neutral-point voltage-balancing control is a critical issue of a neutral-point-clamped converter. The conventional control strategy is to inject the specific zero-sequence voltage to regulate the redundant vector, but it is unacceptable to the three-phase four-wire system. This paper provides a neutral-point voltage-balancing control by the dipolar modulation, and the control freedom of the zero-sequence voltage is flexible. Therefore, the proposed method is suitable for both three-phase three-wire and three-phase four-wire systems. Besides, the proposed method improves the control dynamic in a reactive power system. The proposed neutral-point voltage-balancing control is verified by the mathematical analysis and experimental results. The control dynamic, power loss estimation, and the output current performance are analyzed in this paper. [ABSTRACT FROM PUBLISHER]

Two-dimensional magnetic recording (TDMR) is a promising technology for boosting areal densities (ADs) using sophisticated signal processing algorithms within a systems framework. The read/write channel architectures have to effectively tackle 2-D inter-symbol interference (ISI), 2-D synchronization errors, media and electronic noise sources, as well as thermal asperities resulting in burst erasures. The 1-D low-density parity check (LDPC) codes are well studied to correct large 1-D burst errors/erasures. However, such 1-D LDPC codes are not suitable for correcting 2-D burst errors/erasures due to the 2-D span of errors. In this paper, we propose construction of a native 2-D LDPC code to effectively correct 2-D burst erasures. We also propose a joint detection and decoding engine based on the generalized belief propagation algorithm to simultaneously handle 2-D ISI, as well as correct bit/burst errors for TDMR channels. This paper is novel in two aspects: 1) we propose the construction of native 2-D LDPC codes to correct large 2-D burst erasures and 2) we develop a 2-D joint signal detection-decoder engine that incorporates 2-D ISI constraints, and modulation code constrains along with LDPC decoding. The native 2-D LDPC code can correct >20% more burst erasures compared with the 1-D LDPC code over a 128 $\times $ 256 2-D page of detected bits. Also, the proposed algorithm is observed to achieve a signal-to-noise ratio gain of >0.5 dB in bit error rate performance (translating to 10% increase in ADs around the 1.8 Tb/in2 regime with grain sizes of 9 nm) as compared with a decoupled detector-decoder system configuration over a small 2-D LDPC code of size 16 $\times $ 16. The efficacy of our proposed algorithm and system architecture is evaluated by assessing AD gains via simulations for a TDMR configuration comprising of a 2-D generalized partial response over the Voronoi media model assuming perfect 2-D synchronization. [ABSTRACT FROM PUBLISHER]

This paper proposes a new fast algorithm to estimate the fundamental phasor of fault current signals, based on discrete Fourier transform (DFT). Since fault currents include decaying dc component (ddc), DFT-based algorithms have inaccuracy in phasor estimation. The proposed algorithm consists of four steps. First, a new auxiliary signal is introduced based on a simple high-frequency modulation of the fault current. Then, DFT of the fault current and sample-summation of both fault current and auxiliary signal are calculated, for each one-cycle-length data stream. Next, DFT estimation error due to the ddc is calculated. Finally, by removing this error, accurate fundamental phasor is obtained. This paper uses an innovative and accurate formulation based on notations of signal processing literature. To validate the proposed algorithm, several computer-simulated signals and an electromagnetic transient program-generated signal are employed. The proposed algorithm is compared with recent phasor estimation methods, using wide variety of test signals. Standard indices of rise time, settling time, and percentage overshoot are used for comparison. These comparisons show that the proposed algorithm has robust performance in off-nominal frequency condition, and presence of harmonics, noise and multiple ddc components. Moreover, it provides faster convergence speed and lower computation burden. [ABSTRACT FROM AUTHOR]

This paper presents data on wafer-fused 1550-nm vertical-cavity surface-emitting lasers (VCSELs) based on the active region and distributed Bragg reflectors (DBRs) grown by molecular beam epitaxy. VCSELs with a tunnel junction aperture diameter of 8 μm show lasing at a threshold current density jth <; 3 kA/cm2, an output optical power of ~4 mW, and a -3 dB bandwidth of approximately 7 GHz at a 10-mA bias current. The devices demonstrate single-mode continuous wave operation with the transverse side-mode suppression ratio (SMSR) varying in the range of 40-45 dB up to roll-over currents. The increase in mirror losses due to the etching of the top DBR makes the output optical power increase to 6 mW and causes the wallplug efficiency value to reach 20%, but SMSR remains in the range of 40-45 dB. This also makes it possible to reduce both the photon lifetime and, as a result, the effect of damping and increase the modulation bandwidth to 9 GHz. The observed open and clear eye diagrams indicate that non-return-to-zero operation is possible at bit rates of up to 30 Gbps without equalization or forward error correction. The high-output optical power and modulation performance pave the way for the dense wavelength division multiplexing application of wafer-fused 1550-nm VCSELs. [ABSTRACT FROM AUTHOR]

It is widely recognized that traditional single radio frequency (RF)-chain-aided spatial modulation (SM) does not offer any transmit diversity gain. As a remedy, constellation randomization (CR), relying on transmit prescaling (TPS), has been shown to provide transmit diversity for single-RF-chain-aided SM. In this paper, we propose a low-complexity approach to SM with the aid of constellation randomization (SM-CR) that considerably improves the transmit diversity gain of SM at a reduced computational burden compared with conventional SM-CR. While conventional SM-CR performs a full search among a set of candidate TPS factors to achieve the maximum minimum Euclidean distance (MED) in the received SM constellation, here, we propose a thresholding approach, where, instead of the maximum MED, the TPS aims to satisfy a specific MED threshold. This technique offers a significant complexity reduction with respect to the full maximization of SM-CR, since the search for TPS is terminated once a TPS set is found that satisfies the MED threshold. Our analysis and results demonstrate that a scalable tradeoff can be achieved between transmit diversity and complexity by appropriately selecting the MED threshold, where a significant complexity reduction is attained, while achieving a beneficial transmit diversity gain for the single-RF SM. [ABSTRACT FROM PUBLISHER]

In this paper, an extremely low-power and low-complexity CMOS sourceless millimeter-wave (mmW) receiver for the next-generation wireless communication and sensing systems including fifth-generation (5G) is proposed and demonstrated. It makes the use of injection-locked self-oscillating mixers (SOMs) in order to enable a direct conversion to baseband without resorting to any external local oscillator (LO) nor an IF processing block, therefore, greatly reducing power consumption, as well as the receiver’s complexity. This architecture is created through multi-input and multi-output (MIMO) arrays in connection with slicing frequency spectrum or frequency band of interest. In this way, the proposed receiver supports a high data transmission throughput based on the frequency-diversified MIMO, which presents a unique feature in the architectural implementation of a low-power and high bit-rate communication and sensing systems. Transmission and demodulation of a digital modulated signal M-quadratic-amplitude modulation (M-QAM) at 40 GHz, is successfully demonstrated with simulated and measured results. [ABSTRACT FROM AUTHOR]

Wireless power transfer (WPT) to the implantable medical devices (IMDs) often suffers from antenna radiation direction and polarization misalignments, which degrades the wireless power link efficiency. Although increasing the incident power density is able to solve the power hunger of IMDs, it poses safety issues to the human tissue. In this paper, an antenna alignment method using intermodulation is proposed to address WPT antenna misalignment in a safe way. Two-tone (2T) waveform excitation is employed to enhance the rectification as well as to generate intermodulation. The intermodulation power is fed back via a magnetic resonant coupling link. Due to the monotonic relation between the intermodulation power and the degree of antenna misalignments, the receiving antenna (in body) can be aligned with the transmitting one (out body). Such a scheme has the advantages of less harm to human tissue and less interference between the 2T waveform excitation and the magnetic resonant coupling link. The whole system is theoretically analyzed and experimentally validated. [ABSTRACT FROM AUTHOR]

This paper presents a simple but effective overmodulation scheme for direct torque controlled reluctance synchronous motor (RSM) incorporating field-weakening (FW) operation. To overcome the problems of high torque ripples and variable switching frequency experienced by conventional direct torque control (DTC), constant-switching-frequency-based torque regulator is employed. By combining the proposed overmodulation scheme with this torque regulator, the dynamic torque response and constant power speed range of RSM drives are improved. Simultaneously, low torque ripples are obtained. Furthermore, an adaptive activation algorithm is proposed to activate overmodulation only when high torque output is demanded. This algorithm also contributes to ensure the stability of drives with overmodulation through effective flux regulation, which is essential for FW operations. The validity of the proposed method is verified by experimental results supplemented in this paper. [ABSTRACT FROM AUTHOR]

Analog-transmission-based soft video delivery suffers from the leveling-off effect when the allocated channel bandwidth is severely insufficient. Fortunately, with superimposed modulation, it is possible for analog traffic to share bandwidth with digital traffic. In this paper, we design and analyze such a hybrid digital-analog superimposed modulation (HDA-SIM) scheme for soft video delivery. Unlike previous work, we treat the bandwidth of competing digital traffic as hidden resources for the video delivery system. The key problem in this scheme is how to allocate the bandwidth and power resources among various modulation symbols so that we can improve the performance of video delivery without sacrificing the throughput of existing digital traffic. The resource allocation problem is formulated and the optimal solution under any given channel signal-to-noise ratio is derived. Based on the results, the sufficient and necessary condition for the video delivery system to achieve performance gain is given. In addition, we implement the proposed scheme for two state-of-the-art soft video delivery systems known as SoftCast and SharpCast. Both simulations and testbed evaluations show that the HDA-SIM version can achieve significant gains in the received video quality over their original designs. [ABSTRACT FROM AUTHOR]

In this paper, metrics for assessing the performance of directional modulation (DM) physical-layer secure wireless systems are discussed. In the paper DM systems are shown to be categorized as static or dynamic. The behavior of each type of system is discussed for QPSK modulation. Besides EVM-like and bit error rate (BER) metrics, secrecy rate as used in information theory community is also derived for the purpose of this QPSK DM system evaluation. [ABSTRACT FROM PUBLISHER]

In this paper, we analyze the performance of convolutionally coded space-shift keying (SSK) modulation on block-fading channels. We derive the transfer function bound for the conditional error performance of coded SSK modulation. Existing works on SSK error performance focus mostly either on uncoded systems or on coded systems with independent fading between successive symbols. Code performance analysis is complicated by the fact that SSK modulation does not yield a uniform symbol, i.e., the error probability of a bit in a symbol is not independent of the position of the bit in the label. Furthermore, there are no nearest neighbors in the SSK constellation. The code and modulation must be jointly analyzed. We show techniques that can be employed to derive the error transfer function of the convolutional code. The degrees of separation in SSK modulation are accurately represented. The diversity order achieved by the system can be predicted. We also show a technique that can simplify analysis of the coded system. We present simulation results that demonstrate the asymptotic accuracy of the derived transfer function bound. [ABSTRACT FROM AUTHOR]

This paper extends the previous virtual synchronous generator (VSG) control for voltage-source converters to modular multilevel converters (MMCs). Compared with the ac synchronous generator (SG), the VSG-based MMC is embedded with a power-angle characteristic. Starting from this feature and with reference to the existing ac system coherency-based equivalence methods, this paper proposes a novel coherency equivalence method for MMC used in large-scale renewable energy systems connected to the ac grid. This novel method mainly focuses on the coherency criterion and parameter aggregation methods which have significant differences compared with the ac system methods. The proposed equivalence method is validated on PSCAD/EMTDC and the study results indicate that: 1) the VSG-based MMC model does show the power-angle characteristic similar to the SG model; 2) the proposed coherency criterion can accurately and efficiently classify the paralleled MMC into coherent groups; and 3) the dynamic behaviors of the external systems are preserved after the aggregations of all previous coherency MMC groups. [ABSTRACT FROM AUTHOR]

In this paper, distributed spatial modulation (DSM) is introduced. DSM is a cooperative diversity protocol for multirelay wireless networks, which is based on the concept of spatial modulation (SM). The distinguishable feature of DSM lies in improving the reliability of the source via distributed diversity and by increasing the aggregate throughput of the network since new data is transmitted during each transmission phase. This is achieved by encoding the data transmitted from the source into the spatial positions of the available relays and by exploiting the signal domain to transmit the data of the relays. At the destination, a diversity combiner that is robust to demodulation errors at the relays is proposed, and its end-to-end error probability and achievable diversity are studied. It is mathematically proved that DSM allows the source to achieve second-order diversity. With the aid of Monte Carlo simulations, DSM is compared against state-of-the-art cooperative protocols, and it is shown to provide a better error probability. [ABSTRACT FROM AUTHOR]

This paper presents the modular multilevel cascade converter based on double-star chopper-cells, which is intended for grid connection to medium-voltage power systems without using line-frequency transformers. The converter is characterized by a modular arm structure consisting of cascade connection of multiple bidirectional pulsewidth modulation chopper-cells with floating dc capacitors. This arm structure requires voltage-balancing control of all the dc capacitors. However, the voltage control combining an averaging control with an individual-balancing control imposes certain limitations on operating conditions. This paper proposes an arm-balancing control to achieve voltage balancing under all the operating conditions. The validity of the arm-balancing control as well as the theory developed in this paper is confirmed by computer simulation and experiment. [ABSTRACT FROM AUTHOR]

To design various electronic papers, the panel designers may adopt different types of electrophoretic materials and active matrix backplanes for resolution, speed, and contrast ratio considerations. The electrical and optical characteristics are quite different under different design requirements so that a good display timing controller should provide an easy way to modify waveforms accordingly. In this paper, we present a configurable timing controller for active matrix electrophoretic displays (EPD). The design principle of driving waveforms is first discussed and the controller can support all variations of driving waveforms with pulse width modulation. The performance of the controller has been verified by several practical EPD system. [ABSTRACT FROM AUTHOR]

In this paper, a new control system to regulate the reactive power supplied by a variable-speed wind energy conversion system (WECS), based on an induction generator fed by a matrix converter (MC), is presented. The control system discussed in this paper is based on an input current observer, implemented using an estimation of the modulation matrix, and a nonlinear control loop that regulates the displacement angle at the MC input. The reactive power capability of the proposed system is also investigated. The work presented in this paper demonstrates that, for the proposed WECS, the maximum reactive power supplied to the grid is about 40% of the nominal value. Experimental results obtained from an experimental prototype are presented in this paper. The performance of the system using a wind turbine emulator and typical wind profiles is discussed in this paper. [ABSTRACT FROM AUTHOR]

In this paper, a novel relaying strategy that uses multiple-input multiple-output (MIMO) fixed relays with linear processing to support multiuser transmission in cellular networks is proposed. The fixed relay processes the received signal with linear operations and forwards the processed signal to multiple users creating a multiuser MIMO relay. This paper proposes upper and lower bounds on the achievable sum rate for this architecture assuming zero-forcing dirty paper coding at the base station, neglecting the direct links from the base station to the users, and with certain structure in the relay. These bounds are used to motivate an implementable multiuser precoding strategy that combines Tomlinson-Harashima precoding at the base station and linear signal processing at the relay, adaptive stream selection, and QAM modulation. Reduced complexity algorithms based on the sum rate lower bounds are used to select a subset of users. We compare the sum rates achieved by the proposed system architecture and algorithms with the sum rate upper bound and the sum rate achieved, by the decode-and-forward relaying. [ABSTRACT FROM AUTHOR]

To support the development of high-frequency ac microgrids in terms of compact design, high-voltage gain and low total harmonic distortion (THD), a buck–boost dual-leg-integrated step-up inverter is proposed in this paper. The inverter is formed by integrating a buck–boost converter into a conventional single-phase full-bridge inverter by sharing the upper switch and the body diode of the lower switch in both bridge-legs. Consequently, the component count is significantly reduced over the step-up inverter counterparts. In addition, to address the drawbacks of hybrid modulation methods adopted by existing dual-leg-integrated inverters, such as double-variable control, and high THD of output voltage/current at high input voltage and heavy load conditions, unipolar frequency doubling sinusoidal pulse width modulation scheme is adopted in this inverter. As a result, the modulation ratio M becomes the only control variable to regulate the output voltage/current and the control is simplified. The THD of the proposed inverter output can remain low throughout the entire input voltage range and load power range. This paper presents the topology derivation procedure, operation principle, and steady-state characteristics of the proposed inverter. To validate the effectiveness of theory, experimental results of a 400 W hardware prototype, where the output voltage frequency is at 500 Hz, are reported. [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM AUTHOR]

A new modulated carrier control (MCC) method is proposed in this paper for a power factor correction (PFC) boost converter, which provides high power factor (PF) and low total harmonic distortion (THD) in wide input voltage and load range. The proposed MCC method employs a zero current duration (ZCD) demodulator that detects ZCD in each switching cycle to estimate current conduction duration of the boost inductor. Using the estimated signal of the ZCD demodulator, the proposed controller generates a compensated duty signal with a PFC converter to properly operate in continuous conduction mode (CCM) or discontinuous conduction mode (DCM). Unlike the conventional MCC PFC converter where the line current is distorted in DCM resulting in poor PF and high THD, the proposed MCC method can provide higher PFC performance regardless of CCM and DCM while maintaining the simple control loop of conventional MCC control method that does not require inner current loop and using relatively small inductance. In this paper, the operational principle of the proposed method has been discussed. To verify the proposed method, it has been tested on a 400-W PFC boost converter. [ABSTRACT FROM AUTHOR]

An analytical steady-state model of the modular multilevel converter (MMC) can be used for component sizing and assessment of the impact of different parameters on the MMC performance. Thus, this paper proposes an enhanced steady-state model for the MMC, which enables one to calculate the amplitudes of the harmonic components of MMC arm currents, submodule capacitor voltages, and arm voltages. In addition, the proposed model allows for the calculation of the amplitude and phase angle of the modulating signal, and it also presents a criterion for resonance of the arm currents. This is achieved by means of a polynomial function of the modulation index, and through checking the stability criteria established by the proposed model. The capability of formulating the modulating signal enables a more accurate calculation of the steady-state amplitudes of the variables, as compared to the previously published models. This paper also presents an accurate method of submodule capacitor sizing, based on the proposed steady-state model. The proposed method gives the exact value of the submodule capacitance (i.e., the capacitance that results in dc voltage fluctuations within a desired range) for a prespecified submodule capacitor voltage variation and a given circulating current amplitude. The stability criterion given by the proposed steady-state model, used for sizing the arm inductance, and the submodule capacitor voltage variation given by the proposed capacitor sizing method, used for sizing the submodule capacitor, allows for the determining of the operating limits of the MMC in terms of its parameters. Extensive simulation results are presented to demonstrate the efficacy of the proposed steady-state model and the capacitor sizing method. Further, the results obtained from the proposed capacitor sizing method are compared with experimental results from the literature. [ABSTRACT FROM AUTHOR]

An optimal dual-phase-shift control strategy of an isolated buck–boost converter is proposed in this paper. The theoretical analysis of dual-phase-shift control strategy is complemented, and the three-dimensional graphs of the output current versus two control variables are given. The optimal operating point is determined by the peak current of a clamped inductor and is shown as control trajectories in the three-dimensional graphs. Moreover, with the optimal dual-phase-shift control strategy, low current value, soft-switching operation, wide input voltage range regulation, whole load range regulation, and high-efficiency performance can be achieved. Furthermore, parameter design method deriving from the minimum peak current of the clamped inductor is given. At the end of this paper, a 1000 W-output prototype is fabricated to verify the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]

A new theory about terminal technology is proposed for superjunction lateral double-diffused metal–oxide–semiconductor field effect transistors with multiple floating buried layers (MFBL SJ-LDMOS) based on the bulk electric field (E-field) modulation in this paper for the first time. A concise and efficient analytical theory is presented to predict the vertical voltage and bulk E-field distributions of MFBL SJ-LDMOS. The analytical formulas for the breakdown voltage (BV) and the vertical peak E-field of MFBL SJ-LDMOS are derived in the closed-form equations, which starts from a single floating buried layer for the vertical E-field modulation, extending this theory to predict the vertical E-field peaks and vertical voltage distributions between the MFBLs. Quantitative analytical description has been given to explain the bulk E-field modulation for the MFBL. Moreover, the optimal spacing and the maximum BV are procedurally predicted. All analytical results are well verified by the 3-D numerical simulations, proving the applicability of the method presented in other power devices with MFBL including MFBL LDMOS, MFBL lateral insulated gate bipolar transistor, and MFBL diode. [ABSTRACT FROM AUTHOR]

This paper presents a detailed numerical analysis of work-function modulated cylindrical gate metal–oxide–semiconductor field-effect transistor (MOSFET)-based CMOS inverter. Introduction of work-function modulation in the control gate of dual-material cylindrical gate MOSFET exhibits significant reduction in short-channel effects (SCEs) and threshold voltage. The analytic potential-based model of this device is developed by considering 2-D Poisson’s equation in the cylindrical coordinate system. Development of the numerical model is based on certain boundary conditions to study the electrostatic behavior effectively. The results thus obtained from the analytical model are in good agreement with the model developed in the TCAD simulator. Improved drain current, reduced threshold voltage, immunity against SCEs, lower circuit delay, and high-speed switching have made this device a leader in CMOS logic family. [ABSTRACT FROM AUTHOR]

Using the wireless signals to extend the sensors’ battery life in a network or make them battery-free becomes prominent with the high number of sensors and circuits that are desired in the Internet of Things. Decreasing the power consumption of the sensors is also a valid point. Colocating information signals and power signals at the same frequency further decreases the size of the sensor and the used bandwidth. To fulfill all the mentioned requirements, we used an integrated rectifier–receiver (IRR) to decrease the power consumption and fully utilize all the received signals without splitting signals. We propose a novel magnitude ratio modulation, utilizing two-tone signals. We extend this paper by introducing the ratio phase modulation (PM) and, finally, merging the ratio amplitude–PM. The main advantage of the proposed modulations is the degree of freedom that it is possible to deliver a constant dc power to the sensor even with symbol variations, that is not possible by using M-ASK or ON–OFF keying modulations. If the channel is narrowband, the demodulation of our proposed modulation is possible even by not knowing the channel’s attenuation. Since the IRR is highly nonlinear and this feature is used to fulfill our goals to receive power and information, we characterize the IRR’s to show the symbol diagram considering the influence of nonlinearity of the circuit and its limitation on modulation. We report the power conversion efficiency to prove that the IRR is harvesting RF energy well with the proposed modulation. [ABSTRACT FROM PUBLISHER]

When a photonic crystal fiber has more than one core, the switching capacity loss among the cores as of a given power, called critical power, becomes a relevant effect for switching applications. In this paper, we study the critical power obtained when ultrashort pulses are propagated in a nonlinear directional coupler. Here, we consider the specific example of a three-core photonic crystal fiber in two possible arrangements: one-dimensional and triangular array. In each core, the pulses propagate in the anomalous dispersion regime, in which an input pulse in the form of a hyperbolic secant is injected into one of the cores, considering different input peak powers. By relating the group velocity dispersion and the coupling coefficient with the temporal width of the input pulse, we can observe some relations between the fiber parameters and the critical power. In addition, we show that when self-phase modulation is combined with other effects, the critical power can be increased or decreased depending on the combination of these effects. [ABSTRACT FROM AUTHOR]

Differential amplitude phase shift keying (DAPSK) is a promising modulation technique for use in high-mobility environments, as it does not require channel estimation. In this paper, a novel reduced complexity soft demodulator for high-order DAPSK constellations is proposed. The main idea relies on a two-step approximation of the sum-log demapper. In the first step, a parallel factor analysis (PARAFAC) decomposition is used to approximate log-likelihood ratios. Next, the basis functions obtained through the first step are approximated by piecewise-linear curves. Numerical optimization techniques are employed for the PARAFAC decomposition and its piecewise-linear approximation whose parameters are then stored in a lookup table. It has been verified through computer simulations that the proposed scheme clearly outperforms the scheme proposed in the paper “Reduced-complexity noncoherent soft-decision-aided DAPSK dispensing with channel estimation,” (IEEE Trans. Veh. Technol., vol. 62, pp. 2633–2643, 2013.), while also having lower computational cost. Moreover, it is shown that the performance of the exact sum-log demapper and the proposed demapper is very close for \text2\times \text4 and \text4\times \text16 DAPSK constellations. [ABSTRACT FROM AUTHOR]

This paper investigates and evaluates the performance of a single-phase split-source inverter (SSI), where an alternative unidirectional dc–ac configuration is used. Such configuration is utilized in order to use two common-cathode diodes in a single device instead of using two separate diodes, resulting in minimum parasitic inductance in the commutation paths. In this paper, the analysis and modulation of the single-phase SSI using this alternative configuration is discussed, and the analysis of the low-frequency component in the dc side is introduced. Moreover, the features behind employing the triangular, the trailing-edge sawtooth, and the leading-edge sawtooth carriers with the single-phase SSI are discussed, and the differences among these carriers are highlighted. In order to highlight the performance of the proposed SSI, a comparative study is conducted with the two-stage architecture and the single-phase quasi-Z-source inverter (qZSI). The introduced analysis is enhanced with simulation results using MATLAB/PLECS models, where a 1-kVA single-phase SSI is designed and simulated. Finally, the designed 1-kVA single-phase SSI is implemented experimentally and tested at different operating points, i.e., at different voltage gains, and a maximum efficiency of $95.5\%$ is obtained. [ABSTRACT FROM PUBLISHER]

In this paper, we study the user pairing in a downlink non-orthogonal multiple access (NOMA) network, where the base station allocates the power to the pairwise users within the cluster. In the considered NOMA network, a user with poor channel condition is paired with a user with good channel condition, when both their rate requirements are satisfied. Specifically, the quality of service for weak users can be guaranteed, since the transmit power allocated to strong users is constrained following the concept of cognitive radio. A distributed matching algorithm is proposed in the downlink NOMA network, aiming to optimize the user pairing and power allocation between weak users and strong users, subject to the users’ targeted rate requirements. Our results show that the proposed algorithm outperforms the conventional orthogonal multiple access scheme and approaches the performance of the centralized algorithm, despite its low complexity. In order to improve the system’s throughput, we design a practical adaptive turbo trellis coded modulation scheme for the considered network, which adaptively adjusts the code rate and the modulation mode based on the instantaneous channel conditions. The joint design work leads to significant mutual benefits for all the users as well as the improved system throughput. [ABSTRACT FROM PUBLISHER]

This paper presents the first network-coded multiple access (NCMA) system prototype operated on high-order modulations up to 16-QAM. NCMA jointly exploits physical-layer network coding (PNC) and multiuser decoding (MUD) to boost throughput of multipacket reception systems. Direct generalization of the existing NCMA decoding algorithm, originally designed for BPSK, to high-order modulations, will lead to huge performance degradation. The throughput degradation is caused by the relative phase offset between received signals from different nodes. To circumvent the phase offset problem, this paper investigates an NCMA system with multiple receive antennas at the access point, referred to as MIMO-NCMA. We put forth a low-complexity symbol-level NCMA decoder that, together with MIMO, can substantially alleviate the performance degradation induced by relative phase offset. To demonstrate the feasibility and advantage of MIMO-NCMA for high-order modulations, we implemented our designs on software-defined radio. Our experimental results show that the throughput of QPSK MIMO-NCMA is double that of both BPSK NCMA and QPSK MUD at SNR = 10 dB. For higher signal-to-noise ratios at which 16-QAM can be supported, the throughput of MIMO-NCMA can be as high as 3.5 times that of BPSK NCMA. Overall, this paper provides an implementable framework for high-order modulated NCMA. [ABSTRACT FROM PUBLISHER]

Finite state model predictive control (MPC) has been recently applied to several converter topologies, as it can provide many advantages over other MPC techniques. The advantages of MPC include fast dynamics, multitarget control capability, and relatively easy implementation on digital control platforms. However, its inherent variable switching frequency and lower steady-state waveform quality with respect to standard control, which includes an appropriate modulation technique, represent a limitation to its applicability. Modulated model predictive control (M2 PC) combines all the advantages of MPC with the fixed switching frequency characteristic of pulse-width modulation algorithms. The work presented in this paper focuses on the indirect matrix converter (IMC), where the tight coupling between rectifier stage and inverter stage has to be taken into account in the M2PC design. This paper proposes an M2PC solution, suitable for IMC, with a switching pattern that emulates the desired waveform quality features of space vector modulation for matrix converters. The switching sequences of the rectifier stage and inverter stage are rearranged in order to always achieve zero-current switching on the rectifier stage, thus simplifying the current commutation strategy. [ABSTRACT FROM AUTHOR]

In modern communication systems, high-order modulation schemes have been widely employed to improve the spectral efficiency. In this context, soft decision methods are usually preferred, due to their superior performance over hard decisions. Soft decoders use metrics such as the log-likelihood ratios (LLRs) to measure the reliability of their decisions. Typically, the complexity of the exact channel LLR calculation increases exponentially with the modulation order of the system. The most well-known LLR approximation, the Max-Log-MAP symbol-to-bit demapper, still demands a large number of operations. In this paper, we present a novel simplified scheme that greatly reduces the complexity of the LLR demapper at high-order PSK and APSK modulations compared to the Max-Log-MAP soft-demapper. Moreover, it is shown that the proposed method has a negligible overall system performance loss compared to the same method. [ABSTRACT FROM PUBLISHER]

A multilevel inverter topology for a four-pole induction-motor drive is presented in this paper, which is constructed using the induction-motor stator winding arrangement. A single dc source with a less magnitude when compared with conventional five-level inverter topologies is used in this topology. Therefore, power balancing issues (which are major challenges in conventional multilevel inverters) are minimized. As this configuration uses a single dc source, it provides a path for zero-sequence currents because of the zero-sequence voltages present in the output, which will flow through the motor phase winding and power electronic switches. To minimize these zero-sequence currents, sine–triangle pulsewidth modulation (SPWM) is used, which will shift the lower order harmonics near to switching frequency in the linear modulation region. However, in the case of overmodulation, harmonic voltages will be introduced close to the fundamental frequency. In this regard, a modified SPWM technique is proposed in this paper to operate the drive in the overmodulation region up to the modulation index of 2/\!\surd3. The proposed quad two-level inverter topology is experimentally verified with a laboratory prototype on a four-pole 5-hp induction motor. Experimental results show the effectiveness of the proposed topology in the complete linear modulation region and the overmodulation region. [ABSTRACT FROM PUBLISHER]

This paper presents an extended behavioral model for the modeling of microwave amplifiers, namely harmonics dynamic X-parameters. This model aims at providing a powerful analysis capability for the prediction of fundamental and harmonic large-signal responses with long-term memory effects for the power amplifier. Several major problems faced by current commercial nonlinear vector network analyzers have yet to be addressed, such as external stimulation in pulsed envelope domain measurement and synchronization. Therefore, an unlimited and alternative method for the extraction of harmonics dynamic X-parameters is also introduced in this paper. In the extraction procedure, the modulated RF step signal shows significant advantages in revealing the relationship between the past inputs and the current output. However, attempts to validate the effectiveness of this model have been limited by both the hardware and software requirements. First, the advanced phase reference is not open to the public and is only available in the manufacturer's internal R&D laboratory; it is required for the phase calibration procedure of the narrow tone spacing. Second, the two-tone signal experiment is not suitable for the validation of the output prediction of harmonics. Therefore, a novel validation method that utilizes the narrow step signal as stimulus signal was carried out on a Mini-Circuits ZFL-11AD+microwave amplifier. An excellent agreement between the measurements-based behavioral model and the measured output is achieved, with a maximum error less than 5%. [ABSTRACT FROM AUTHOR]