Transmitter Side Research Articles

GiTMO: An HDR10 Compatible Generic Tone-Mapping for Real-Time Video Play

Though the market of HDR displays for consumers is gaining maturity, low dynamic range (LDR) displays still hold a majority share in the consumer market. Many tone-mapping operators (TMO) have been developed to convert the HDR contents into a form suitable for LDR displays. This work proposes a generic tone-mapping operator (GiTMO) that can represent all global TMOs in a generic form of a one-dimensional array of a few coefficients. We use these coefficients and the existing HDR10 delivery pipeline to produce a tone-mapped version of the HDR content at the receiver end in real time. In our framework, coefficients are sent to the receiver as supplemental enhancement information (SEI) message of High Efficiency Video Coding (HEVC). Thus, HDR10, which is designed for HDR display, becomes compatible with LDR displays too. This can relieve the content producers from the need to release separate copies of HDR and LDR content. GiTMO, being generic and efficient, can generate LDR faithfully for all global TMOs, making the consumer end oblivious of the TMO used at the transmitter side. We perform extensive evaluations to validate the accuracy and efficiency of the GiTMO and the proposed content delivery format, and their benefits over the existing approaches.

A Wireless DC Motor Drive Using LCCC-CCL Compensated Network With Bidirectional Motion Capability

This paper proposes an LCCC and CCL compensated wireless servo motor control circuitry utilizing the merits of fundamental and third harmonic. With this circuitry, the motor side needs no additional power supply and controller, which significantly reduces the difficulty of maintenance. Besides, benefiting from the proposing of CCL compensating topology and utilizing of the self-driven circuitry, the secondary operates in fully resonant state and the motor direction control H-bridge is self-driven by the LC frequency selecting circuitry (FSC). Moreover, compared with the conventional motor control circuitry, because of the use of fundamental and third harmonic, the power equalization becomes significantly easier, and zero voltage switch (ZVS) can be realized at the same time; Besides, motion direction control of the motor is simpler with only a single pole double throw (SPDT) at the transmitter side. In addition, system resource consumption is reduced compared with conventional motor drive topologies. In this paper, an 180W prototype is built for experimental verification, and the result shows a good power equalization capability and a transfer efficiency reaching up to 90% at the distance of 10cm.

Flexible Fast-Convolution Processing for Cellular Radio Evolution

Orthogonal frequency-division multiplexing (OFDM) has been selected as a baseline waveform for long-term evolution (LTE) and fifth-generation new radio (5G NR). Fast-convolution (FC)-based frequency-domain signal processing has been recently considered as an effective tool for transmitter and receiver side subband filtering of OFDM-based waveforms. However, for the original continuous FC-based model, the filtering can, in general, be configured in time-direction only with the granularity of half subframe, corresponding to 7, 14, or 28 symbols with 15kHz, 30kHz, or 60kHz subcarrier spacing, respectively. In this paper, we present a symbol-synchronous FC-processing scheme flexibly allowing filter re-configuration with the time resolution equal to one OFDM symbol while supporting tight carrier-wise filtering for 5G NR in mixed-numerology scenarios with adjustable subcarrier spacings, center frequencies, and subband bandwidths, as well as providing co-existence with LTE. Proposed approach segments each stream of time-domain OFDM symbols into overlapping processing blocks of fixed size. Symbol synchronous processing is achieved by dynamically adjusting the overlap between the processing blocks while aligning the payload part of the processing blocks with the boundaries of the OFDM symbols. The proposed scheme is demonstrated to support the envisioned use cases of 5G NR and provide a flexible starting point for sixth generation (6G) development.

A Review of Compensation Topologies and Control Techniques of Bidirectional Wireless Power Transfer Systems for Electric Vehicle Applications

Owing to the constantly rising energy demand, Internal Combustion Engine (ICE)-equipped vehicles are being replaced by Electric Vehicles (EVs). The other advantage of using EVs is that the batteries can be utilised as an energy storage device to increase the penetration of renewable energy sources. Integrating EVs with the grid is one of the recent advancements in EVs using Vehicle-to-Grid (V2G) technology. A bidirectional technique enables power transfer between the grid and the EV batteries. Moreover, the Bidirectional Wireless Power Transfer (BWPT) method can support consumers in automating the power transfer process without human intervention. However, an effective BWPT requires a proper vehicle and grid coordination with reasonable control and compensation networks. Various compensation techniques have been proposed in the literature, both on the transmitter and receiver sides. Selecting suitable compensation techniques is a critical task affecting the various design parameters. In this study, the basic compensation topologies of the Series–Series (SS), Series–Parallel (SP), Parallel–Parallel (PP), Parallel–Series (SP), and hybrid compensation topology design requirements are investigated. In addition, the typical control techniques for bidirectional converters, such as Proportional–Integral–Derivative (PID), sliding mode, fuzzy logic control, model predictive, and digital control, are discussed. In addition, different switching modulation schemes, including Pulse-Width Modulation (PWM) control, PWM + Phase Shift control, Single-Phase Shift, Dual-Phase Shift, and Triple-Phase Shift methods, are discussed. The characteristics and control strategies of each are presented, concerning the typical applications. Based on the review analysis, the low-power (Level 1/Level 2) charging applications demand a simple SS compensation topology with a PID controller and a Single-Phase Shift switching method. However, for the medium- or high-power applications (Level 3/Level 4), the dual-side LCC compensation with an advanced controller and a Dual-Side Phase-Shift switching pattern is recommended.

Phase-Assisted Dynamic Tag-Embedding Message Authentication for IoT Networks

Security is a critical issue in Internet of Things (IoT) networks and it has been under investigation by researchers worldwide. Different from other wireless networks, IoT networks suffer from conventional security mechanisms due to complexity and resource consumption which cannot be tolerated in IoT networks. Among the recently proposed security schemes for IoT networks is the tag-embedding message authentication scheme in which a tag is embedded to the modulated message and concurrently sent over the same channel. Although it has avoided significant resource expenditure, its performance still requires improvement especially in terms of immunity against nearby eavesdroppers. In this article, a novel scheme is proposed that is able to enhance the authentication rate and the tag confidentiality without inducing any extra requirements. The proposed scheme implies performing tag puncturing at the transmitter side where only a part of the tag is embedded to the message based on the instantaneous channel phase. The performance of the proposed scheme is mathematically analyzed where the authentication failure probability is derived in closed-form expression, and compared to the conventional tag-embedding scheme.

Contactless Measurement of Current and Mutual Inductance in Wireless Power Transfer System Based on Sandwich Structure

The mutual inductance between the transmitter and receiver sides is critical for the efficiency of a wireless power transfer (WPT) system. This article proposes a novel online mutual inductance measurement method based on a local detection coil with a sandwich structure. The mutual inductance and the receiver current are obtained by measuring the induced voltage of the sandwich coil and the output voltage of the inverter, with contactless measurement from the receiver side. Using the ferrite substrate as the skeleton of the sandwich detection coil not only increases the differential mutual inductance between the receiver coil and the sandwich coil but also maintains the differential mutual inductance almost constant when horizontal misalignment occurs. Moreover, the differential mutual inductance is used to calculate the mutual inductance between the transmitter and receiver coils and the orthogonal eigenvalue expansion method is exploited to analyze the sandwich detection coil in a finite region. Then, the factors affecting the differential mutual inductance are analyzed and optimized, and a stable differential mutual inductance is obtained by formulating a standard coil design procedure. Finally, a prototype is built to verify the proposed method. The experimental results show that the differential mutual inductance remains almost constant when the horizontal misalignment reaches 50% of the outer radius of the transmitter/receiver coil, and the maximum calculated error of the detected mutual inductance is 2.18%.

Robust Analog Beamforming for Periodic Broadcast V2V Communication

We generalize an existing low-cost analog signal processing concept that takes advantage of the periodicity of vehicle-to-vehicle broadcast service to the transmitter side. In particular, we propose to process multiple antennas using either an analog beamforming network (ABN) of phase shifters, or an antenna switching network (ASN) that periodically alternates between the available antennas, to transmit periodic messages to receivers that have an analog combining network (ACN) of phase shifters, which has been proposed in earlier work. To guarantee robustness, we aim to minimize the burst error probability for the worst receiving vehicular user, in a scenario of bad propagation condition that is modeled by a single dominant path between the communicating vehicles. In absence of any form of channel knowledge, we analytically derive the optimal parameters of both ABN and ASN. The ABN beamforming vector is found to be optimal for all users and not only for the worst receiving user. Further, we demonstrate that Alamouti scheme for the special case of two transmit antennas yields similar performance to ABN and ASN. At last, we show that the derived parameters of the two proposed transmission strategies are also optimal when hybrid ACN-maximal ratio combining is used at the receiver.

Simulation Analysis of 4G/5G OFDM Systems by Optimal Wavelets with BPSK Modulator

LTE (Long-Term Evolution) is one of the appropriate technologies to sever the requirement of the IoT (Internet of Things) together with mobile UE (User Equipment), because of priority services, high data rate, low latency, etc. LTE has received OFDM for the transmission because it meets the necessity of LTE-like range flexibility and empowers the cost gainful responses for the wide carriers. LTE offers big-data values, allows spectrum reframing, reduces cost, etc. We proposed a 4G/5G adopted OFDM based on the multi-equalizer and BPSK (Binary-Phase Shift Keying). The BER (Bit Error Rate) of the system is reduced through the optimal wavelet coefficient at the transmitter side. This optimal wavelet coefficient is obtained by applying a DWT (Discrete Wavelet Transform) to the input signal through a BFF (Binary Firefly) algorithm. The serial to parallel process is carried out through the BPSK modulation. At last, the multi-equalizer like MMSE (Minimized Mean Square Error) and MLE (Maximum Likelihood) is applied to the OFDM model to reduce the BER. The system is analyzed using the parameter like SER (Symbol Error Rate), spectral efficiency, MSE (Mean Square Error), and BER. The proposed methodology provides a better outcome than the other existing approaches.

Unified Simultaneous Wireless Information and Power Transfer for IoT: Signaling and Architecture With Deep Learning Adaptive Control

In this article, we propose a unified simultaneous wireless information and power transfer (SWIPT) signaling and architecture to take advantage of both single tone and multitone signaling by adjusting only the power allocation ratio of a unified signal. Toward this, we design a unified and integrated receiver architecture for the proposed unified SWIPT signaling via an envelope detection with low power consumption. To lower the computational complexity of the receiver, we propose an adaptive control algorithm where the transmitter adjusts the communication mode through temporal convolutional network (TCN)-based <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">asymmetric processing</i> . To this end, the transmitter optimizes the modulation index and power allocation ratio in short-term scale while updating the mode switching threshold in long-term scale. We demonstrate that the proposed unified SWIPT system improves the achievable rate under the self-powering condition at low-power Internet of Things (IoT) devices. Consequently we will facilitate the effective deployment of low-power IoT networks that concurrently supply both information and energy <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">wirelessly</i> to the devices by using the proposed unified SWIPT and adaptive control algorithm at the transmitter side.

Wireless power transfer system with dual‐frequency operation in transmitter side for motor control application

AbstractIn this paper, a transmitter‐side control method is proposed in inductive wireless power transfer (I‐WPT) model for the speed and power control of a single‐phase induction motor (SPIM). Resonant tanks with an electronic driving mechanism are used in the proposed configuration. The receiver side employs two resonant circuits with two full wave rectifiers, comparator, and two gate drivers for the management of the motor speed and power. The resonant circuits and electronic motor drive are presented through detailing the mathematical model and system design. In addition, a comparative section of the proposed model with the previous art is introduced to address the contributions of the paper. Moreover, a prototype model of the proposed topology has been created in simulation environment and tested in a variety of scenarios. The proposed I‐WPT model has a power rating of 140 W, whereas the SPIM has a power rating of 120 W. At full power operation, a 130 W power is supplied from the source during 118 W power consumption of SPIM, indicating that the system's efficiency is over 90%. The motor speed control has been tested by lowering the operation frequency of the motor terminal voltage from 60 to 40 Hz and from 40 to 20 Hz. The dynamic motor power has been also analyzed by reducing the load power from 100% to 70%. The findings reveal that the proposed transmitter‐side controlled I‐WPT system operates in a wide range of circumstances.

Interference immunity and energy efficiency of digital communications systems in multipath channel with fading

In the study of measures to improve channel efficiency, we developed and presented a performance analysis of a digital communication system for image transmission in a multipath channel with fading, in the MATLAB/Simulink environment, one of the main advan tages being that it provides high interference immunity in the presence of noise and interference and signal delays. The scheme has been investigated for bit error rate (BER) on additive white Gaussian noise (AWGN) channel and multipath Rice and Rayleigh fading channel operating under the influence of inter-symbol interference (hereinafter ISI) and different parameters for the channel, where we considered cases of signal delay similar for EPA (extended pedestrian a model (EPA) standards). In this paper, we estimate the effectiveness of compensation for signal distortion in radio channels with fading on the basis coded orthogonal frequency-division multiplexing (COFDM) technology, an adaptive equalizer, amplifiers on the transmitter side and a normalizer on t he receiver side, which is an acute problem in the field of wireless communication. This system can be applied to transmit better quality high-resolution radiological images over a wireless network inside a building and for a model analogous of pedestrian traffic.

Delay Alignment Modulation: Enabling Equalization-Free Single-Carrier Communication

This letter proposes a novel broadband transmission technology, termed <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">delay alignment modulation</i> (DAM), which enables the low-complexity equalization-free single-carrier communication, yet without suffering from inter-symbol interference (ISI). The key idea of DAM is to deliberately introduce appropriate delays for information-bearing symbols at the transmitter side, so that after propagating over the time-dispersive channel, all multi-path signal components will arrive at the receiver simultaneously and constructively. We first show that by applying DAM for the basic multiple-input single-output (MISO) communication system, an ISI-free additive white Gaussian noise (AWGN) system can be obtained with the simple zero-forcing (ZF) beamforming. Furthermore, the more general DAM schemes are studied with the ISI-maximal-ratio transmission (MRT) and the ISI-minimum mean-square error (MMSE) beamforming. Simulation results are provided to show that when the channel is sparse and/or the antenna dimension is large, DAM not only resolves the notorious practical issues suffered by orthogonal frequency-division multiplexing (OFDM), such as high peak-to-average-power ratio (PAPR) and vulnerability to carrier frequency offset (CFO), but also achieves higher spectral efficiency due to the saving of guard interval overhead.

HW/SW Platform for Measurement and Evaluation of Ultrasonic Underwater Communications.

The purpose of this work is to present a flexible system that supports the study of wideband underwater acoustic communications (UAC). It has been developed both to measure channels and to test transmission techniques under realistic conditions in the ultrasonic band. This platform consists of a hardware (HW) part that includes multiple hydrophones, projectors, analog front-ends, acquisition boards, and computers, and a software (SW) part for the generation, reception, and management of acoustic sounding signals and noise. UAC channels are among the most hostile ones and exhibit an important attenuation and distortion, essentially due to both multipath propagation, which results in a very long channel impulse response, and time-varying behavior, which produces a notable Doppler spread. To cope with this challenging medium, sophisticated transmission techniques must be employed. In this sense, adequate signal processing algorithms have been designed aiming not only at the analysis and characterization of underwater communication channels but also at the evaluation of diverse modulation, detection, and coding schemes, from Orthogonal Frequency Division Multiplexing (OFDM) to single-carrier digital modulations with a single-input multiple-output (SIMO) configuration that takes advantage of diversity techniques. Wideband sounding signals, to be injected into the sea from the transmitter side, are created with patterns that allow multiple tests on a batch. With offline processing of the captured data at the receiver side, different trials can be carried out in a very flexible manner. The different aspects of the platform are described in detail: the HW equipment used, the SW interface to control acquisition boards, and the signal processing algorithms to estimate the UAC channel response. The platform allows the analysis and design of new proposals for underwater communications systems that improve the performance of the current ones.

Interoperability study of wireless charging system with unipolar and bipolar coils based on capacitor–inductor–capacitor–capacitor–series​ topology

Wireless charging for electric vehicles (EVs) enjoys advantages such as automation, safety, and convenience. For the most popular magnetic induction wireless power transfer (WPT) technology, different coupled coils are utilized such as the unipolar coil, the bipolar coil, and the quadruple coil. Thus, the interoperability of different coil types should be solved. Particularly, the transmitter should be interoperable with different receiving coil types, able to charge different EVs This paper proposes an interoperable solution for the two most popular coil types: the unipolar coil and the bipolar coil. The unipolar and bipolar coils are adopted on the transmitter side. Based on the transmitter-side capacitor–inductor–capacitor–capacitor (CLCC) compensation and the alteration of the switching pattern, when the receiving coil is a unipolar coil, the transmitter-side unipolar coil can work as the power transmission coil and the bipolar coil can work as the compensating inductor; when the receiving coil is a bipolar coil, the transmitter-side bipolar coil can work as the power transmission coil and the unipolar coil can work as the compensating inductor. In this way, the transmitter can be interoperable with the unipolar or bipolar receiving coil. The mathematical mode is built. A simulation model and an experimental prototype is established to validate the effectiveness of the proposal. The experimental results show that the interoperability of the receiver-side unipolar or bipolar coil can be achieved.

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.

Performance Assessments of Joint Linear and Nonlinear Pre-Equalization Schemes in Next Generation IM/DD PON

Nonlinear distortions in passive optical network (PON) systems degrade signal transmission performance. Joint linear and nonlinear pre-equalizers based on the Volterra series, memory polynomials and artificial neural networks (ANNs) are utilized to mitigate linear and nonlinear impairments. Centralized pre-equalization at the transmitter side of the optical line terminal (OLT) keeps the receiver side digital signal processing (DSP) at the optical network unit (ONU) simple. In this study, performance assessments of these three different pre-equalization schemes in intensity modulation and direct detection (IM/DD)-based 25-GBaud PON systems were evaluated. The joint linear and nonlinear pre-equalization schemes were based on the weight coefficients and the model obtained by channel estimation on the receiver side. We studied and compared the performance of three pre-equalization methods under various implementation conditions, such as received optical power (ROP), number of equalizer taps, and semiconductor optical amplifier (SOA) current. Besides, we studied the equalization performance under different modulation orders, which were applied for data rate optimization to support different power budgets, being the potential solutions for future PON systems with various fiber-reach and split-ratio distributions. As a proof-of-concept, the equalization performance of the 25-Gbaud signals modulated with non-return-to-zero (NRZ), four-level pulse amplitude modulation (PAM-4) and PAM-8 formats, corresponding to 25-, 50-, and 75-Gbps data rates, respectively, were tested. Both numerical simulations and experimental demonstrations were conducted to assess the performance of different pre-equalization schemes. With ANN pre-equalization, more than 4dB improvement in power budget was achieved for 25-GBaud PAM4 and PAM8 signals after 20 km fiber transmission. ANN-based pre-equalizer performed better than ANN-based post-equalizer even when the received signals were in low SNR. The power budgets of the 25-Gbaud NRZ, PAM4 and PAM8 signals after 20 km fiber transmission were 36.2 dB, 29.5 dB and 18 dB, respectively.

Effects of Different Intensity Modulator On The Generation of MM-Waves in RoF System

The increasing demand of wireless network has strongly take interests of new transmission systems. A phase shift of 80 GHz – 120 GHz is achieved for the millimeter wave by using SBS technique that is beneficial for the 5G networks. RoF technique requires the optical modulators in the transmitter side. Performance of different modulators such as Amplitude Modulator, Phase Modulator, Electro Absorption Modulator, and Mach Zehnder Modulator is analyzed in this demonstrated work. Performance comparison of all modulators shows that the SNR (93.32) and output power (71.56) of the system is maximum in MZM. Results shows that the system has the high power, good SNR and enhanced frequency shifts.

Pulse Density Modulation Based Mutual Inductance and Load Resistance Identification Method for Wireless Power Transfer System

In wireless power transfer (WPT) system, the information of mutual inductance and load resistance is usually needed for the front-end to regulate power and efficiency. To acquire the values of these two parameters without wireless communication system and without affecting the output power, this article proposes an identification method based on the pulse density modulation (PDM) technique. The underlying principle is to obtain a range of interharmonics by altering the sequence of PDM. First, the PDM strategy brings in interharmonics, which can be identified through fast Fourier transmission (FFT). Then, these interharmonics are used to established multiple sets of equation related to front-end impedance and the two unknowns. Finally, with the least-square approximation, mutual inductance and load resistance can be estimated. This article notices that the sequence of PDM strategy could affect the amplitudes of interharmonics, and selects the sequences to maximize the magnitudes for less sensitivity to measurement errors. Experimental results show that the relative errors of identification are less than 5&#x0025; when the nominal values of capacitors are the same as actual values, and reach 7.40&#x0025; when considering the nominal values may deviate from the actual values. Besides, the output power and efficiency are not affected during the identification process. This proposal requires only magnitudes of voltage and current in the transmitter side, no other hardware is needed, and works with the fixed frequency, which is suitable for any frequency range.

3-D Analytical Model of Bipolar Coils With Multiple Finite Magnetic Shields for Wireless Electric Vehicle Charging Systems

The bipolar pad is one of the most promising topologies in inductive power transfer (IPT) systems for electric vehicles. However, there is scant literature on the analytical model of the bipolar pad. In this article, a three-dimensional (3-D) analytical model of the IPT system including a bipolar transmitter and a square receiver is developed based on the superposition of two 2-D subdomain analytical models. Ferrite and the aluminum shields with finite dimension are taken into account on the transmitter and receiver sides. An analytical calculation of the mutual inductance is then carried out with respect to the main parameters of the IPT system, namely the dimension of the coils, the conductivity, and the permeability of the shield. Three study cases are demonstrated to highlight how the proposed method can accelerate speed up the pad design process. Calculation results of the proposed model are compared with both a finite-element analysis (FEA) model and experimental measurements, demonstrating that the proposed model is nine times faster than the FEA method. When comparing with the experimental results, computational error of the proposed model is less than 6% in most of the study cases.

Deep learning-based Human Body Communication baseband transceiver for WBAN IEEE 802.15.6

Recently, Wireless Body Area Network (WBAN) has revolutionized e-health-care. WBAN boosts monitoring vital signs utilizing tiny wireless sensors implanted in or around the human body. In February 2012, the IEEE 802.15.6 WBAN standard was released for low-power and short-range communication around the human body. The standard defines one medium access control layer and three different physical layers: narrow band , ultra-wideband, and Human Body Communication (HBC) layers. We are motivated by exploiting the human body as a communication medium. We propose a novel optimized architecture for the HBC baseband transceiver based on deep learning. The receiver utilizes two deep neural networks: one for frame synchronization to recover data and timing precisely and the other for the channel decoder to improve transceiver performance and reduce power consumption. In addition, low-complexity Preamble/SFD generator, Walsh modulation, and FSC spreader modules are proposed to reduce the power consumption while preserving the transceiver performance. Compared with the traditional hard-decision channel decoder, the proposed neural network decoder improves the block error rate by 2 dB. The proposed HBC transceiver supports 1.312 Mbps data rate at 42 MHz clock rate. The transceiver is implemented in RTL and synthesized on 90 nm CMOS technology. It consumes 493 pJ/bit on the receiver side and 105 pJ/bit on the transmitter side.