Digital Signal Processing Platform Research Articles

Research on Active Noise Reduction Systems at Building Openings

This paper proposes an active noise reduction system design based on a digital signal processing (DSP) platform to address the impact of external noise on the indoor environment. The system is specially designed to be installed in the openings of a building and adopts the FxLMS (Filtered-x Least Mean Squares) algorithm to control the intrusion of noise effectively. By comprehensively considering the design of the hardware system and software systems' design, this paper verifies the feasibility of the proposed active noise reduction system and discusses its noise reduction performance in depth. Through experiments, this paper analyses the effect of secondary acoustic feedback on the system performance and the coherence between the reference signal and the error signal on the impact of the multi-channel active noise cancellation system. This paper provides a practical basis for further developing active noise reduction technology in practical applications.

Trajectory Control Approach for Single-Stage Soft-Switching Grid-Tied Inverters

This paper presents a trajectory control model using finite state machines for a single-stage soft-switching grid-tied inverter designed with a fast dynamic response. The targeted application is a module-integrated inverter for a single photovoltaic (PV) panel which interfaces distributed energy sources with the grid. To minimize switching lossd provide advanced grid-connected functionality, the soft-switching operation is achieved through a resonant filter using a trajectory control scheme. In recent years, controllers based on digital signal processing platforms have been able to handle complex and high-speed control algorithms with precision for real-time control. In real-time control applications, the finite state machine (FSM) approach enhances responsiveness by minimizing latency with limited memory resources by executing rapid state transitions. The proposed model effectively manages the switching states of the single-stage soft-switching inverters during complex DC/AC bidirectional operations. By directly controlling the energy within the series resonant circuit, the model delivers a fast transient response while minimizing switching actions across all quadrants of operation. The control scheme has been digitally implemented on a Texas Instruments (TI) digital signal processor and validated through Hardware-In-the-Loop (HIL) testing.

Experimental study of a distributed active noise control system with multi-device nodes based on augmented diffusion strategy.

Recently, distributed active noise control (DANC) algorithms have been explored as a way to reduce computational complexity while ensuring system stability, thereby outperforming conventional centralized and decentralized algorithms. Most existing DANC algorithms assume that each node has only one pair of loudspeaker and microphone, limiting their flexibility in practical applications. In contrast, this paper proposes a DANC algorithm with general multi-device nodes based on the recently developed augmented diffusion strategy, allowing flexible and scalable ANC applications. A real-time distributed ANC system based on a multi-core digital signal processor platform is developed in order to compare the control performance of the proposed extended augmented diffusion algorithm with that of existing centralized, decentralized and augmented diffusion algorithms. Real-time experiments demonstrate that the proposed algorithm exhibits noise reduction performance consistent with that of the centralized algorithm while achieving lower global computational complexity and avoiding the system instability risk of the decentralized algorithm. Further, the new algorithm improves convergence speed and reduces the global communication cost compared to the previous augmented diffusion algorithm. Experimental results indicate the application potential of the proposed DANC algorithm for a generalized system configuration.

KTz Neuron in Electromagnetic Radiation with a Novel Flux-Controlled Memristor

In this paper, a novel discrete flux-controlled generalized memristor is proposed to be used in Electromagnetic Radiation (EMR) KTz neuron. The introduction of flux-controlled memristor can simulate the behavior changes of the neuron under EMR. The stability of flux-controlled memristor EMR KTz Neuron (EKN) map is discussed, and the fixed point of the system is characterized. With the change of parameters, the complex and rich dynamical characteristics of the EKN map are demonstrated. The firing patterns under different initial values are also investigated, and discharge waveforms similar in general shape and structure to human heart and brain disease phenomena are analyzed. Finally, the hardware implementation is verified on the Digital Signal Processing (DSP) platform. The results show that these findings are of great value for the practical applications of neural networks, with a theoretical basis provided.

Flexible and Reconfigurable OFDM Implementation in DSP Platform for Various Purposes and Applications.

In the modern technological era of sophisticated applications and high-quality communications, a platform of clever strategy and quickly updated systems is needed. It should be capable of withstanding the fastest emerging problems like signal attenuation and hostile actions intended to harm the whole network. The main contributions of this work are the production of an OFDM system (with low cost) that can sustain high-speed communications and be easily adjusted with new integrated code while exhibiting the feasibility of implementing a transmitter-receiver system in the same DSP and demonstrating the holistic approach with the qualitative integration of such an architecture in a warfare scenario. Specifically, in this research, the point of view is toward three facts. The first is to show a method of quick self-checking the operational status of a digital signal processor (DSP) platform and then the pedagogical issues of how to fast check and implement an updated code inside DSPs through simple schematics. The second point is to present the prototype system that can easily be programmed using a graphical user interface (GUI) and can change its properties (such as the transmitted modulated sinusoids-orthogonal frequency division multiplexing subcarriers). Alongside the presentation, the measurements are presented and discussed. These were acquired with the use of an oscilloscope and spectrum analyzer. The third point is to qualitatively show the application of such a system inside a modern warfare environment and to recommend various potential system responses according to the development of such a platform of reconfigurable implemented OFDM systems. The implementation was performed for two types of systems: (1) transmitter and (2) transmitter-receiver system. Notably, the system acts quickly with a delay of about 1 msec in the case of transmitting and receiving in the same DSP, suggesting excellent future results under real conditions.

Digital Signal Processing Oriented Electronic Communication Engineering Applications and Practices

This paper first describes the applications of digital signal processors in software radio, speech compression coding, modems and GPS systems, demonstrating the versatility of digital signal processors in practical communication systems. Next, digital signal processing oriented electronic communication practices are presented in the system design section to design high performance communication systems for specific communication needs and environmental conditions. The digital signal processing platform used in the platform architecture is optimized for signal processing and data transmission. The BER is 0.008% when the signal-to-noise ratio is -10 dB. The time complexity of digital signal processing is 7.2 ms when the number of communication nodes is 1000. It shows that digital signal processing oriented electronic communication engineering is important for improving the performance, reliability and efficiency of communication systems.

Complex Dynamical Characteristics of the Fractional-Order Cellular Neural Network and Its DSP Implementation

A new fractional-order cellular neural network (CNN) system is solved using the Adomian decomposition method (ADM) with the hyperbolic tangent activation function in this paper. The equilibrium point is analyzed in this CNN system. The dynamical behaviors are studied as well, using a phase diagram, bifurcation diagram, Lyapunov Exponent spectrum (LEs), and spectral entropy (SE) complexity algorithm. Changing the template parameters and the order values has an impact on the dynamical behaviors. The results indicate that rich dynamical properties exist in the system, such as hyperchaotic attractors, chaotic attractors, asymptotic periodic loops, complex coexisting attractors, and interesting state transition phenomena. In addition, the digital circuit implementation of this fractional-order CNN system is completed on a digital signal processing (DSP) platform, which proves the accuracy of ADM and the physical feasibility of the CNN system. The study in this paper offers a fundamental theory for the fractional-order CNN system as it applies to secure communication and image encryption.

Model-Free Predictive Current and Disturbance Rejection Control of Dual Three-Phase PMSM Drives Using Optimal Virtual Vector Modulation

Model-based predictive current control (MBPCC) relies heavily on adequate system modeling and accurate parameters. The detailed models of dual three-phase permanent magnet synchronous motors (PMSMs) contain mutual cross-coupling dynamics which make it difficult to extract accurate parameters. Also, some of the physical parameters of PMSMs are generally nonlinear functions of current and rotor position. In this article, a model-free predictive current control (MFPCC) based on an ultralocal model and an extended state observer is proposed for an asymmetrical dual three-phase (ADTP) PMSM. The MFPCC method is shown to provide superior current regulation when compared to the standard MBPCC approach under uncertain parameter conditions. Furthermore, the harmonic currents and the current ripple in the ADTP PMSM drive have been regulated to near-zero values by using optimized voltage vectors comprised of virtual vectors and null vectors. A generalized center-aligned pulsewidth modulation (PWM) scheme is presented to facilitate the synthesis of the optimal virtual voltage vectors for implementation on a low-cost digital signal processing platform. The performance improvements of the MFPCC with optimal virtual vector modulation are verified and compared with the conventional MBPCC method in both simulations and experiments on a surface-mount type dual three-phase PMSM.

Multipartite Entanglement in a Microwave Frequency Comb.

Significant progress has been made with multipartite entanglement of discrete qubits, but continuous variable systems may provide a more scalable path toward entanglement of large ensembles. We demonstrate multipartite entanglement in a microwave frequency comb generated by a Josephson parametric amplifier subject to a bichromatic pump. We find 64 correlated modes in the transmission line using a multifrequency digital signal processing platform. Full inseparability is verified in a subset of seven modes. Our method can be expanded to generate even more entangled modes in the near future.

Impulse power detection for fusion power supply based on cascaded quasi-proportion resonance

Impulse power detection for fusion power supply based on cascaded quasi-proportion resonance

Decentralized space vector pulse width modulation method for multilevel single-phase half bridge converters

This study presents a space vector pulse width modulation (PWM) method for a multilevel single-phase decentralized power converter (DPC) called MSPDPC. The proposed model is built by connecting half-bridge cells in series. The output voltage can be adjusted according to demand by adding or subtracting cells. Cells use communication protocols to transmit and receive information with two neighboring cells. The received data contains information for the decentralized space vector pulse width modulation (DSVPWM) method proposed in this paper. In the proposed DSVPWM method, cells set up links to exchange information such as cell position, total cells in a phase, reference voltage amplitude, and reference frequency. The PWM control signals of each cell are calculated based on the information received. The study also focuses on evaluating the ability to adjust the switching vector and the corresponding dwell time of the cells when the structure of the DPC changes. The ability to dynamically reconfigure the DPC is a crucial feature that ensures uninterrupted power supply in case of one or several cell failures. The system automatically establishes a new state with the active cells. The proposed configuration and communication method between cells provide very fast configuration times. The load voltage of the DPC is adjusted to 0.5 times the voltage per cell, which allows the modulation voltage amplitude to be adjusted best according to the load requirements. The study used Matlab/Simulink software to review the initial assessments. The proposed model and algorithms will be verified on the Digital Signal Processor (DSP) platform with a 220V/500W load.

TWO DISCRETE MEMRISTIVE CHAOTIC MAPS AND ITS DSP IMPLEMENTATION

In this paper, a discrete model of memristor is adopted and analyzed. The new discrete maps are built by introducing this discrete memristor model into a two-dimensional discrete map. Interestingly, introducing this discrete memristor model from different locations can lead to two new chaotic map models. The dynamical behaviors of the two maps are studied by means of bifurcation diagrams, phase diagrams and Lyapunov exponential spectra (LEs). The simulation results show that both chaotic systems have rich dynamical behaviors. In addition, they are experimentally found to have multi-stable properties, where the M-XM map has infinite attractors coexistence. Finally, we complete the hardware implementation of the two maps based on Digital Signal Processing (DSP) platform for the application of discrete chaotic systems.

Dynamical Analysis of a Novel Fractional-Order Chaotic System Based on Memcapacitor and Meminductor

In this paper, a chaotic circuit based on a memcapacitor and meminductor is constructed, and its dynamic equation is obtained. Then, the mathematical model is obtained by normalization, and the system is decomposed and summed by an Adomian decomposition method (ADM) algorithm. So as to study the dynamic behavior in detail, not only the equilibrium stability of the system is analyzed, but also the dynamic characteristics are analyzed by means of a Bifurcation diagram and Lyapunov exponents (Les). By analyzing the dynamic behavior of the system, some special phenomena, such as the coexistence of attractor and state transition, are found in the system. In the end, the circuit implementation of the system is implemented on a Digital Signal Processing (DSP) platform. According to the numerical simulation results of the system, it is found that the system has abundant dynamical characteristics.

A Bidirectional DHC-LT Resonant DC-DC Converter with Research on Improved Fundamental Harmonic Analysis Considering Phase Angle of Load Impedance

This paper presents a novel 400 V–50 V bidirectional DHC-LT resonant DC-DC converter. By adding a resonant capacitor and an auxiliary transformer based on LLC, zero-voltage switching (ZVS) and zero-current switching (ZCS) are achieved, while the output voltage gain range is broadened in two directions. Operation principles and robustness are discussed with equations. Then, the error factor of fundamental harmonic analysis (FHA) in resonant converters is analyzed. Considering the phase difference between the output voltage and resonant tank current, an improved method is proposed to describe the behavior of the DHC-LT converter more precisely. A comparison is conducted to prove the effectiveness of the proposed FHA. Furthermore, in order to reduce the output voltage and provide a ripple-free charging current, a fixed-frequency phase-shift strategy is introduced in the DHC-LT converter. ZVS can be realized through the reasonable design of dead time and phase-shift angle. Finally, a 2.5 kW prototype of the DHC-LT resonant DC-DC converter with a digital signal processor (DSP) platform and a battery/PV DC test system is established in the lab to validate the theoretical analysis.

Study of a novel conservative chaotic system with special initial offset boosting behaviors

Conservative systems are increasingly being studied, while little research on fractional-order conservative systems has been reported. In this paper, a novel five-dimensional conservative chaotic system is proposed and solved in a fractional-order form using the Adomian decomposition method. This system is dissipative in the phase volume, but the sum of all Lyapunov exponents is zero. During the exploration, some special dynamical behaviors are analyzed in detail by using phase diagrams, bifurcation diagrams, Lyapunov exponential spectra, timing diagrams, and so on. After extensive simulation, several rare dynamical behaviors, including completely homogeneous, homogeneous, and heterogeneous initial offset boosting behaviors, are revealed. Among them, the initial offset boosting behaviors with identical phase trajectory structures have not been reported before, and the previously proposed homogeneous phase trajectories are locally different. By comparing with the integer-order system, two influence factors that affect the system to produce completely homogeneous and heterogeneous conservative flows are discovered. Eventually, the circuit is built on the digital signal processing (DSP) platform to demonstrate the physical realizability of the system. The experimental results are shown by the oscilloscope and agree with the theoretical analysis.

An Extremely Multistable Complex Chaotic System Under Boosting Control

In order to explore the phenomenon of coexisting attractors in complex chaotic systems, a multistable complex chaotic system is designed by using a cosine function and a control parameter to control the Sprott B system in this paper. The basic features of the complex chaotic system are analyzed from the perspectives of symmetry, dissipation, equilibrium points and stability. The analysis results indicate that the complex chaotic system is a symmetrical and dissipative system. It is particularly interesting to note that the system has infinitely many unstable equilibrium points, which generate infinitely many attractors. The dynamical characteristics of the complex chaotic system are evaluated through bifurcation diagrams, spectral entropy complexity and Lyapunov exponents spectrum. The dynamical evaluations illustrate that the system has complex dynamical performances, such as chaotic states, periodic states, especially infinitely many coexisting attractors. Then a chaotic circuit based on the complex chaotic system is designed and simulated by Multisim software. And the hardware circuit is implemented by using digital signal processor (DSP) platform. The hardware experimental results are consistent with the Multisim simulation results.

Multi-Band Transmission Using Reconfigurable Complex Multi-Band Delta Sigma Polar Modulator

This brief presents a new reconfigurable complex multi-band delta sigma polar modulator (CMB-DSPM) architecture for multi-band transmission. In this brief, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6^{\mathrm{ th}}$ </tex-math></inline-formula> order band-pass delta sigma modulator (DSM) is designed and implemented for reconfigurable triple-band transmission. The proposed DSM architecture utilizes the advantage of a complex DSM structure to reduce the required processing block and polar quantizer to reduce the quantization noise. The proposed CMB-DSPM architecture improves the in-band and out-of-band performance in terms of signal-to-noise distortion ratio (SNDR) and coding efficiency (CE), respectively. The proposed scheme is validated in MATLAB/SIMULINK-based digital signal processing platform using three 5 MHz long-term evolution (LTE) signals. The results show up to 12.4 dB improvement in SNDR and 12.3% improvement in CE compared to the standard cartesian DSM architecture. The measured EVM is below 3%, which shows the good in-band performance of the proposed scheme.

A Real-Time Hardware Experiment Platform for Closed-Loop Electrophysiology.

Targeted stimulation of nervous system has become an increasingly important research tool as well as therapeutic modality, and the stimulation signal acquisition based on the expected signal needs a closed-loop system. Due to the difficulty of biological experiments, the real-time simulation of neural activity is of great significance for the mechanism analysis and the performance improvement of neuromodulation techniques. This paper proposes a real-time hardware experimental platform for closed-loop electrophysiology. The platform integrates a neural computing module and a real-time control module on TMS320F28377D digital signal processors (DSP), and it reserves a programmable interface for users to call the required modules and set module parameters simultaneously. The platform has high compatibility and can be used for closed-loop electrophysiological experiments with different models, different control algorithms and different clamps. We implement the thalamocortical relay neural computing model and iteration improves proportional-integral algorithm on the platform for experimental verification in this paper. The neuron firing waveforms of the DSP platform and the MATLAB R2020b simulation waveforms are consistent. Under the same physiological time, the simulation speed of DSP platform is 3 times faster than that of the Intel Core i5-8400 CPU computer, and the neural firing rate of DSP platform is due to the real-time. This platform can be used as a tool to explore the working mechanism of the nervous system. It may promote the development of neuroscience, especially the field of closed-loop neuroscience.

РЕАЛІЗАЦІЯ ПІДХОДІВ ДО ІМІТУВАННЯ ДИНАМІЧНОЇ РАДІОЕЛЕКТРОННОЇ ОБСТАНОВКИ В ШИРОКІЙ СМУЗІ ЧАСТОТ

One of the main principles of the armed conflict in the east of Ukraine remains warfare in a dynamic change of complex electronic environment. The constant increase frequency bands occupancy, the use of various types of data transmission protocols necessitates an increase in the level of training of military specialists in the field of technical analysis of signals and radio emissions recognition. This, in turn, necessitates the development of approaches to simulating wideband scenarios for use in training process. The formation of the electronic environment using the technology of software-defined radio allows us to create a scenario of almost any complexity. Wideband scenarios can be generated in real time or be pre-generated and recorded in desired format. It is advisable to use the GNU Radio digital signal processing platform to develop software modules for generating real-time radio signals. Using this software it is possible to generate signals with analog and digital types of modulation, including frequency hopping and spread spectrum signals. The maximum bandwidth of the scenario corresponds to the maximum sampling frequency of the transceiver used. With this approach, you can change the power and carrier frequency of all components online. The limitations of real-time signal generation using GNU Radio are due to the fact that the bandwidth and complexity of the signal environment that can be generated depends on the performance of the computer's processor. Wideband scenario can be generated in any format using the high-level Python programming language. Further such files can be used for their analysis offline using appropriate software or as a signal source for radiation by software-defined radio systems.

Fast IQ Amplitude Approximation Method for ASIC Digital System

In some modules of digital systems, such as Fast Fourier Transform (FFT), Discrete Fourier transform (DFT), IQ (in-phase and quadrature components) modulation/ demodulation, the outputs use the complex data formed , and the calculation of its magnitude value √ are required. In software digital signal processing platform, the multiplication and square root operations are executed by using its math library; however, in Application specific integrated circuit (ASIC) digital system design, the implementation of those operators via Coordinate Rotation Digital Computer (CORDIC) algorithm requires the numerous resources and delays. So, in this paper, we present a fast approximation method for above problem which takes a small delay but acceptable accuracy for AISC digital system design. Keywords—ASIC, Digital system design, FFT, DFT, Fast amplitude approximation, Max-Min approximation.