Showing papers on "Digital signal published in 2018"

A Digital Multibeam Array With Wide Scanning Angle and Enhanced Beam Gain for Millimeter-Wave Massive MIMO Applications

Abstract: A novel full-digital multibeam array with wide scanning angle and enhanced beam gain is proposed for millimeter-wave massive multiple-input multiple-output applications. The array consists of 16 dual exponentially tapered slot antenna (DETSA) elements. Each element is integrated with a radio frequency receiver, an intermediate frequency chain, and an analog-to-digital converter (ADC). The H-plane radiation pattern of the proposed DETSA is very wide to enable the beam scanning in the azimuth plane. The beam gain is further enhanced by employing a 1-D multilayered planar lens that transforms the spherical wave into a plane wave in the E-plane for increasing the beam gain and keeping the phase compensation unaltered in the H-plane. Meanwhile, the planar lens is optimized to guarantee the wide scanning angle. In addition, all the signals received by the 16 independent channels are converted to a digital signal via ADC simultaneously and then used for synthesizing the multibeam patterns in the digital domain. Furthermore, the calibration and the verification of the synthesizing weights are discussed in detail. The measured results show that a scanning coverage of ±40° in the H-plane (or in horizontal plane) and an estimated maximum gain of 24.8 dBi with a gain tolerance of 3 dB can be achieved by the proposed 16-element array with a 1-D lens.

Performance, Power, and Area Design Trade-offs in Millimeter-Wave Transmitter Beamforming Architectures.

Abstract: Millimeter wave (mmW) communications is the key enabler of 5G cellular networks due to vast spectrum availability that could boost peak rate and capacity. Due to increased propagation loss in mmW band, transceivers with massive antenna array are required to meet link budget, but their power consumption and cost become limiting factors for commercial systems. Radio designs based on hybrid digital and analog array architectures and the usage of radio frequency (RF) signal processing via phase shifters have emerged as potential solutions to improve energy efficiency and deliver performances close to digital arrays. In this paper, we provide an overview of the state-of-the-art mmW massive antenna array designs and comparison among three architectures, namely digital array, sub-array, and fully-connected hybrid array. The comparison of performance, power, and area for these three architectures is performed for three representative 5G use cases, which cover a range of pre-beamforming SNR and multiplexing regimes. This is the first study to comprehensively model and analyze all design aspects and criteria including: 1) optimal linear precoder, 2) impact of quantization error in DAC and phase shifters, 3) RF signal distribution network, 4) power and area estimation based on state-of-the-art mmW circuits including baseband precoding, digital signal distribution, DACs, oscillators and mixers, phase shifters, RF signal distribution, and power amplifiers. The results show that the digital array is the most power and area efficient compared against optimal design for each architecture. Our analysis shows digital array benefits greatly from multi-user multiplexing. The analysis also reveals that sub-array is limited by reduced beamforming gain due to array partitioning, and system bottleneck of the fully-connected hybrid architecture is the excessively power hungry RF signal distribution network.

Method for identifying a sound event

Abstract: The present invention relates to a method for identifying a sound event, and problems of low accuracy of sound identification and poor robustness under a strong interference condition in the prior artare mainly solved. The method comprises a step of collecting and processing sound under different interference environments and forming a sound digital signal, a step of carrying out sub-band filtering on the sound digital signal by a filter group and obtaining a cochlear spectrum of an audio signal, a step of training a part of the cochlear spectrum into a convolution neural network model and establishing a sound recognition template, and a step of substituting the other part of the cochlear spectrum into the convolution neural network model and detecting the accuracy of sound recognition. According to the above method, the problem is solved, and the method can be used for identifying the sound event in a traffic environment.

SigMF: The Signal Metadata Format

Abstract: The Signal Metadata Format (SigMF) specifies a way to describe sets of recorded digital signal samples with metadata written in JSON. SigMF can be used to describe general information about a collection of samples, the characteristics of the system that generated the samples, and features of the signal itself. It is designed to be a simple and portable format that is easily used by memory-limited applications with real-time requirements and minimal dependencies.

Quantum Representation and Basic Operations of Digital Signals

Abstract: This paper presented a quantum representation and some basic operations for one-dimensional finite length digital signal. For the representation, similar to the existing flexible representation of quantum audio (FRQA), two sets of qubits are used to represent the amplitudes and positions of the signal, respectively, wherein the amplitude is represented by an (n + 1)-bit signed number in twos complement, including one sign bit, m integer bits and n − m fractional bits. The basic operations include the addition, subtraction, multiplication, division, and circular convolution of two digital signals. We designed the quantum circuits that implements these basic operations, analyzed the computational complexity, and verified the correctness of these circuits by simulations on classical computers.

Sigma-Delta ADC Topology Implementation Based on Partial Discharge Detection using Rogowski Coil Sensor

Abstract: Partial discharge (PD) diagnostic on high voltage (HV) power cables is a modern technology in order to investigate the insulation health. The trending technology such as wireless sensor network (WSN) and internet of thing (IoT) are mostly process in digital signal by microprocessor where looking toward on automatic system. The high performance of analog to digital converter (ADC) in term of sampling rate which is much expensive in order to convert the high frequency of analog PD signal that captured by Rogowski coil (RC) sensor. Thus, this paper propose the implementation of the Sigma-Delta (∑Δ) ADC topology in Altera DE0-Nano development board as an effective method in this work to replace the conventional ADC chip and the cost is minimal. Then, peak PD detection technique is applied after the conversion of the digital PD signal. The Verilog hardware description language (VHDL) is used in Quartus II software which corporate with Altera DE0-nano development board for the prototype development. In order to achieve the accurate digital sampling of high frequency PD signal, the N-bit of voltage resolution is paramount.

Digital Soft Start Implementation for Minimizing Start Up Transients in High Power DAB-IBDC Converter

Abstract: The dual active bridge isolated bidirectional DC-DC converter (DAB-IBDC) is one of the prime converters used in dual active bridge renewable energy storage system (RESS) applications, particularly where a high-power density is required. The digital DSP (Digital Signal Processer) control technique also provides intelligence to applications and achieves a super compact elegant system by reducing the complicated control hardware. All power converters, including the DAB-IBDC converter, often draw an inrush current, which is many times higher than their steady state current. The inrush current is the maximum current drawn by a converter for a very few milliseconds while being freshly energized. Although it appears for only a very few milliseconds, it can cause severe damage to the entire energy storage system, including the sources and loads. To save the RESS system from the starting inrush current and peak overshoot voltages, this paper proposes a five-phase digital soft-start control algorithm for a high-power DAB-IBDC converter that was implemented at a renewable energy storage system aimed at developing an intelligent self-powered energy zone. The proposed five phase digital soft-start algorithm can alone solve the startup transients without the use of any additional hardware. First, it prevents the output current and voltages from transients, such as the inrush current and peak overshoot voltages, by ensuring that the output current does not increase too rapidly while starting up. Second, it also eliminates the large backflow inrush current released by a partially discharged energy storage device at the starting period. Third, it helps achieve a simple super compact size DAB-IBDC converter with a simple elegant design by ensuring the control and soft-start in digital technology.

Docking station with dual-display synchronous output

Abstract: A docking station includes electrical module that includes circuit board having conducting contacts and circuit layout arranged thereon, control system including a main control unit, an image signal processing unit for receiving a display port signal and converting it into an analog signal and a digital signal for synchronous output and a USB signal processing unit for converting a USB signal into multiple USB signals for output, a transmission cable assembly electrically connected to the control system for the connection of an external electronic apparatus, an image output interface including an analog signal output port and a digital signal output port for receiving analog and digital signals from the image signal processing unit for output to respective external display devices for display and a connector module for receiving the multiple USB signals from the USB signal processing unit for output to multiple external apparatuses for two-way power and data transmission.

A Continuous-Time Digital IIR Filter With Signal-Derived Timing and Fully Agile Power Consumption

Abstract: Presented is the first continuous-time (CT) digital infinite impulse response (IIR) filter working on signal-derived timing in lieu of a clock. We introduce a novel design method which enables the design of high-order IIR filters using only two tap delays. An event-grouping technique is also introduced to prevent parasitic oscillations in the presence of tap delay mismatches. The 1.2-V, 65-nm CMOS prototype implements a sixth-order IIR filter, with a maximum input rate of 20 Msample/s and a stop-band rejection of more than 80 dB. Without using any power-down circuitry, the chip’s power consumption tracks the input activity in a fully agile manner, and varies by more than $50\times $ , from 0.04 to 2.32 mW. The filter achieves an figure of merit (FoM) which competes with that of discrete-time (DT) filters, while avoiding the use of a clock and an antialiasing filter. Compared to prior art in CT digital signal processings, the prototype achieves 45-dB improvement in stop-band rejection and 9 $\times $ smaller delay line area. For the first time, the filtered CT digital signal is converted to synchronous mode at the end of signal chain, allowing integration with DT digital systems.

The Design of a Single-Bit CMOS Image Sensor for Iris Recognition Applications.

Abstract: This paper presents a single-bit CMOS image sensor (CIS) that uses a data processing technique with an edge detection block for simple iris segmentation. In order to recognize the iris image, the image sensor conventionally captures high-resolution image data in digital code, extracts the iris data, and then compares it with a reference image through a recognition algorithm. However, in this case, the frame rate decreases by the time required for digital signal conversion of multi-bit digital data through the analog-to-digital converter (ADC) in the CIS. In order to reduce the overall processing time as well as the power consumption, we propose a data processing technique with an exclusive OR (XOR) logic gate to obtain single-bit and edge detection image data instead of multi-bit image data through the ADC. In addition, we propose a logarithmic counter to efficiently measure single-bit image data that can be applied to the iris recognition algorithm. The effective area of the proposed single-bit image sensor (174 × 144 pixel) is 2.84 mm2 with a 0.18 μm 1-poly 4-metal CMOS image sensor process. The power consumption of the proposed single-bit CIS is 2.8 mW with a 3.3 V of supply voltage and 520 frame/s of the maximum frame rates. The error rate of the ADC is 0.24 least significant bit (LSB) on an 8-bit ADC basis at a 50 MHz sampling frequency.

Event-triggered Natural Hazard Monitoring with Convolutional Neural Networks on the Edge

Abstract: In natural hazard warning systems fast decision making is vital to avoid catastrophes. Decision making at the edge of a wireless sensor network promises fast response times but is limited by the availability of energy, data transfer speed, processing and memory constraints. In this work we present a realization of a wireless sensor network for hazard monitoring based on an array of event-triggered single-channel micro-seismic sensors with advanced signal processing and characterization capabilities based on a novel co-detection technique. On the one hand we leverage an ultra-low power, threshold-triggering circuit paired with on-demand digital signal acquisition capable of extracting relevant information exactly and efficiently at times when it matters most and consequentially not wasting precious resources when nothing can be observed. On the other hand we utilize machine-learning-based classification implemented on low-power, off-the-shelf microcontrollers to avoid false positive warnings and to actively identify humans in hazard zones. The sensors' response time and memory requirement is substantially improved by quantizing and pipelining the inference of a convolutional neural network. In this way, convolutional neural networks that would not run unmodified on a memory constrained device can be executed in real-time and at scale on low-power embedded devices. A field study with our system is running on the rockfall scarp of the Matterhorn H\"ornligrat at 3500 m a.s.l. since 08/2018.

Device and method for echo cancellation, and computer-readable storage medium

Abstract: The embodiment of the invention provides a method and device for echo cancellation, and a computer-readable storage medium. The device comprises a loudspeaker, which is configured to play an acousticsignal corresponding to an analog audio signal; the device further comprises a microphone, which is configured to convert a received mixed acoustic signal into a mixed audio signal; the mixed acousticsignal includes echo of the played acoustic signal and an acoustic signal from a user; the device further comprises an analog-to-digital converter, which is configured to convert the analog audio signal into a digital signal served as an echo reference signal; and the device further comprises an echo canceller, which is configured to cancel the echo component in the mixed audio signal by utilization of the echo reference signal, so that the audio signal of the user corresponding to the acoustic signal from the user is obtained. By means of the embodiment of the invention, the echo cancellation performance can be improved; and furthermore, the voice interaction experience can be improved.

Design automation methodology and tools for superconductive electronics

Abstract: Josephson junction-based superconducting logic families have been proposed to implement analog and digital signals, which can achieve low energy dissipation and ultra-fast switching speed. There are two representative technologies: DC-biased RSFQ (rapid single flux quantum) technology and its variants that achieve a verified speed of 370 Ghz, and AC-biased AQFP (adiabatic quantum-flux-parametron) that achieves an energy dissipation near quantum limits. Despite extraordinary characteristics of the superconducting logic families, many technical challenges remain, including the choice of circuit fabrics and architectures that utilize the SFQ technology and the development of effective design automation methodologies and tools. This paper presents our work on developing design flows and tools for DC- and AC-biased SFQ circuits, leveraging unique characteristics and design requirements of the SFQ logic families. More precisely, physical design algorithms, including placement, clock tree routing, and signal routing algorithms targeting RSFQ circuits are presented first. Next, a majority/minority gate-based automatic synthesis framework targeting AQFP logic circuits is described. Finally, experimental results to demonstrate the efficacy of the proposed framework and tools are presented.

Wireless Wearable Brain Blood-Oxygen Monitoring System

Abstract: The wireless wearable brain blood-oxygen monitoring system provided by the present Application comprises a monitoring control device, a detection device, a fixing device and a flexible printed circuit board; said monitoring control device is used for processing a first optical signal to generate a digital signal and sending said digital signal to a portable mobile terminal; said detection device is used for receiving the first optical signal sent by said monitoring control device, and calculating a degree of blood-oxygen saturation in a detected area according to an incident light intensity and an emergent light intensity of the first optical signal; said flexible printed circuit board is used for fixing a photoelectric conversion means in said detection device; said fixing device is used for fitting said monitoring control device and said detection device to the forehead. The present Application can make the brain blood-oxygen monitoring system to monitor in real time and can make it portable.

Apparatus and a method for driving an ultrasonic sensor

Abstract: An apparatus for driving an ultrasonic sensor according to an embodiment of the present invention may comprise: a driving unit for providing a transmission pulse to the ultrasonic sensor to transmit an ultrasonic wave and for receiving an ultrasonic echo for the ultrasonic wave; an amplifier for amplifying an electrical signal for the ultrasonic echo; an analog-to-digital converter for converting the amplified electrical signal into an original digital signal; a signal processing unit for performing envelope-extraction-processing on the original digital signal and generating an envelope-extraction-processed signal; and a control unit for outputting a distance between the ultrasonic sensor and an external object based on the original digital signal and the envelope-extraction-processed signal, wherein the control unit monitors a frequency or phase change of vibration of a transducer of the ultrasonic sensor based on the original digital signal at least during a second period and analyses the envelope-extraction-processed signal during at least a third period.

Air coupled ultrasonic phased array detection device

Abstract: The invention discloses an air coupled ultrasonic phased array detection device. Parameters such as a transmitting frequency, a sampling frequency, voltage energy and the like of each channel and a detection process are set through an ultrasonic transceiver and a signal collecting and processing unit; a transmitted signal is transmitted to an air coupled or contact-type ultrasonic probe by the ultrasonic transceiver, and an ultrasonic wave excited by the probe comes to the interior of a detected test piece at a certain angle; and an ultrasonic signal is refracted and reflected in the detectedtest piece, finally an echo signal containing internal defect information of the test piece is received by the ultrasonic probe and transmitted to a signal receiver, the signal is converted into a digital signal by a signal acquisition unit, the digital signal enters a data processing unit, and scanning result imaging at a certain angle is completed through time delay superposition and imaging processing. The device has the advantages that parameter setting is carried out on a transmitted waveform in an early stage, so that the length of a focal column, the size of a focal point and the direction of an acoustic beam can be optimally controlled; and the device has a certain superiority in the aspects of resolution, signal-to-noise ratio, defect detection rate and the like.

Optical fiber sensing system

Abstract: The invention provides an optical fiber sensing system. The system comprises a laser which is used for transmitting continuous light of a designated frequency, an acousto-optic modulator which is usedfor receiving the continuous light and modulating the continuous light into a differential delay pulse pair, a circulator which is used for receiving the differential delay pulse pair and outputtingthe differential delay pulse pair to a sensor, the sensor which is used for processing the differential delay pulses output by the circulator to form a light pulse and sending the light pulse to a detector through the circulator, the detector which is used for receiving the light pulse to form an interference light signal, converting the interference light signal into an interference electrical signal and sending the interference electrical signal to an analog-digital converter, the analog-digital converter which is used for converting the interference electrical signal into an interference digital signal and sending the interference digital signal to an FPGA module, and the FPGA module which is used for controlling a driver to generate radio frequency pulse signals of different frequencies, and carrying out phase algorithm processing according to the interference digital signal to acquire phase information. According to the invention, the acousto-optic modulator is used, which effectively reduces the cost; and a front-end MZ interferometer is eliminated, which can effectively eliminate the interference of the environmental noise.

Adaptive composite control method of permanent magnet synchronous motor systems

Abstract: With the development of digital signal processes, the relative differences of PMSM single loop in control periods between the speed loop and current loops are becoming smaller or even vanishing Th

Estimation and compensation methods of time delay and phase offset in hybrid filter bank DACs

Abstract: This Letter studies the non-ideal analogue filters performance, time delay and phase offset in hybrid filter bank (HFB) DACs. After compensating the non-ideal filters performance using a digital signal, a linear phase function containing time delay and phase was deduced based on the auto-power spectrum of the HFB DAC output in the overlapped frequency band. ‘Three-point’ method was used to simultaneously estimate these two errors by unwrapping the phase affected the principal value interval of the inverse trigonometric function. These two errors were compensated by the digital pre-distortion technique. Finally, simulation results were provided to verify the effectiveness of this proposed method.

Motor vibration control method and apparatus

Abstract: The present invention relates to the technical field of electronic devices, and discloses a motor vibration control method and apparatus. The method comprises: acquiring an input signal obtained according to a desired motor vibration curve; inputting a digital signal sequence of the input signal into an equalizer to obtain an output signal processed by an equalizer; and inputting the output signalto the motor to control vibration of the motor, wherein the equalizer is a digital filter constructed according to a damping coefficient zeta, a resonance frequency [omega]n, a preset system samplingrate fs, a preset damping coefficient [zeta]d and a preset cutoff frequency [omega]d of the motor. The motor vibration control method and apparatus provided by embodiments of the present invention have an advantage that an actual vibration effect of the motor can conform to a desired motor vibration curve.

Smart sound box and voice control method thereof

Abstract: The invention provides a smart sound box comprising a microphone module configured to collect sound from the outside, process the sound into an audio digital signal, and provide the audio digital signal for a main control processing module; a loudspeaker module configured to receive the audio digital signal from the main control processing module, process the audio digital signal into sound and output the sound to the outside; a communication module configured to establish a communication connection with other devices to perform communication; a storage module configured to store a smart voicelibrary, wherein the smart voice library contains multiple voice control command texts; and the main control processing module configured to: perform voice recognition on the audio digital signal from the microphone module to generate voice text information, match the voice text information with plurality of control commands in the intelligent voice library; and execute a corresponding control command in response to matching success; or send the control command to other devices through the communication module so as to control the other devices.

Digital frequency-division phase-locked loop

Abstract: A digital frequency-division phase-locked loop, including a time-to-digital converter (TDC), a digital loop filter (DLF), a digital-controlled oscillator (DCO), a feedback frequency divider (DIV), a sigma-delta modulator (SDM), and a calibration apparatus, where the calibration apparatus compensates for, based on a frequency control word and a frequency-division control word generated by the SDM, a digital signal output by the TDC to obtain a calibration signal. The DLF performs digital filtering on the calibration signal to obtain an oscillator frequency control signal and set the oscillator frequency control signal as an output signal of the DCO.

Feasibility Analysis on the Use of Ultrasonic Communications for Body Sensor Networks.

Abstract: Ultrasonic waves have good propagation in the human body and have been widely applied in biomedical device design without any reported side effects. Therefore, ultrasonic waves can provide an alternative method as an information carrier for body sensor networks (BSNs). This paper presents a novel wireless communication method that uses ultrasonic sound waves as a medium for healthcare systems. We investigated the feasibility of our proposal by testing it in a real digital communication experimental setup. To find an acceptable modulation method, the functionality of the proposed ultrasound-based digital communication approach was tested involving three principal modulation methods: amplitude shift keying (ASK), frequency shift keying (FSK), and phase shift keying (PSK). The modulated digital signals obtained from the experiments were compared with the simulated signals. Analysis of the results shows that ultrasonic waves are feasible and can be used for digital communication.

Computer-Assisted Teaching Environment for Digital Signal Recognition Course Learning

Abstract: In this paper, we present a computer-assisted teaching system for digital signal recognition using the computer as an interactive partner in problem solving activities. The software is designed to help students solve problems according to their own decision, or those arranged by their instructor. It can be used as a tool for digital signal course learning, spectrum recognition training, optical data processing, and providing feedbacks and advice upon request. The system includes an interactive interface, a spectrum simulator for graphical display of students' spectrum, a database which contains data of chemical groups and related information. The results showed that the developed system was effective in improving students' ability in spectrum interpretation.

Integrated radiation effect detector for three-dimensional high-energy particles

Abstract: The invention provides an integrated radiation effect detector for three-dimensional high-energy particles. The detector comprises an LET spectrum detector, a radiation dose detector, a different potential detector, a digital data collection circuit, a data processing unit and a communication module; the LET spectrum detector, the radiation dose detector and the different potential detector measure the particle radiation LET spectrum, the radiation dose and the satellite surface different potential respectively, a generated voltage signal is converted into a digital signal by the digital signal collection circuit, and the digital signal is output to the data processing unit, the data processing unit analyzes the voltage amplitude and trend of the digital signal, data reflecting the LET spectrum, the radiation dose and the satellite surface different potential information is obtained, and the data processing unit makes data interaction with a satellite after being connected to the satellite via the communication module. According to the detector, three independent space detection functions are integrated to detect different indexes of the space environment in an integrated manner, the integrated degree is improved, and the cost and weight are reduced.

Direct Sampling in Multi-channel Synchronous TDEMI Measurements

Abstract: This paper shows possible benefits of multi-channel synchronous time-domain electromagnetic interference (TDEMI) measurements. The setup was developed with respect to low-frequency conducted Electromagnetic Interference (EMI) measurements in high power, fast switching systems using a low-cost solution. Using an 8-channel digitizer voltages, currents and magnetic fields were simultaneously recorded. Using digital signal post-processing investigations were performed on the relation between switching currents and magnetic fields, while also investigating the time variance of the load impedance.

A Rogowski Digital Integrator With Comb Filter Signal Processing System

Abstract: In this paper, a new type of Rogowski digital integrator signal processing system has been developed for the dc test platform which located in the Institute of Plasma Physics. This signal processing system is mainly composed of the dual-coil subtraction structure and the digital signal filtering processing method that comb filter combined with high-pass filter (HPF) and low-pass filter (LPF). Trigger noise comes from the converter; it can be coupled to the integrator through distributive capacitance between dc bus bar and Rogowski coil; it will affect the integrator seriously; for example, the amplifier in integrator will be saturation, and the integrator cannot work, burrs lying in integration result. The dual-coil subtraction structure can attenuate the trigger noise significantly from hardware perspective and is convenient for the integrator to take a high gain without saturation. The comb filter combined with HPF and LPF can attenuate the trigger noise further and smooth the integration result. The experiment indicates that the approach proposed in this paper can reduce the impact of trigger noise on the integrator and improve the measurement accuracy.