Multi-channel Analog Signal Research Articles

Design of an acoustic direction finding system based on split array frequency domain beamforming algorithm

According to the technical requirement, the principle of the acoustic direction finding and positioning algorithm is introduced, and based on the engineering implementation requirements of split array frequency domain beam forming algorithm, a hardware implementation method based on FPGA +DSP is introduced, which use FPGA to realize the logic control and two pieces of MS320C6678 multi-core DSP to realize the digital beam forming. The hardware system design scheme can realize the program-controlled amplification, filtering, collection, real-time data storage and beam forming processing of the multi-channel acoustic analog signals for acoustic receiving array. At the same time, it can also communicate with the upper computer to achieve upper computer instructions, data transmission, and parameter settings. It has been verified through engineering practice that this scheme has high data processing efficiency and reliable direction finding calculation effect.

Silicon photonic architecture for training deep neural networks with direct feedback alignment

There has been growing interest in using photonic processors for performing neural network inference operations; however, these networks are currently trained using standard digital electronics. Here, we propose on-chip training of neural networks enabled by a CMOS-compatible silicon photonic architecture to harness the potential for massively parallel, efficient, and fast data operations. Our scheme employs the direct feedback alignment training algorithm, which trains neural networks using error feedback rather than error backpropagation, and can operate at speeds of trillions of multiply–accumulate (MAC) operations per second while consuming less than one picojoule per MAC operation. The photonic architecture exploits parallelized matrix–vector multiplications using arrays of microring resonators for processing multi-channel analog signals along single waveguide buses to calculate the gradient vector for each neural network layerin situ. We also experimentally demonstrate training deep neural networks with the MNIST dataset using on-chip MAC operation results. Our approach for efficient, ultra-fast neural network training showcases photonics as a promising platform for executing artificial intelligence applications.

Design of Small Platform Sonar Data Acquisition and Storage System Based on NI-CRIO

The signal acquisition system is an important part of the sonar system. This paper presents a stable multi-channel underwater acoustic signal acquisition system based on NI-CompactRIO, aiming at the compact feature of the small platform sonar system. It realizes the simultaneous acquisition of multi-channel analog signals and the function of storing mass original data. The acquisition system basically comprises of sampling using the self-made acquisition module and storing using U disk. The software is programmed by LabVIEW. Finally, the stability of the system is verified by the experiment on the lake.

Multi-Channel Data Acquisition System Based on FPGA and STM32

In order to realize the acquisition and storage of underwater acoustic signals for aiming at the requirements of multi-channel, low power consumption and small volume for underwater receiver extension of sonar system, a multi-channel signal acquisition and storage system based on FPGA and STM32 with variable number of working channels and sampling frequency is designed, in which the system is consisted of 8 pieces, 8 channel and 24 bits high dynamic range Δ-Σ ADS1278 ADC chip to synchronous multi-channel analog signal acquisition. FPGA, as the acquisition sequence and logic control, reads and collates the ADC chip data and writes it into the internal high-capacity FIFO, and adds corresponding operations according to the characteristics of FIFO in an application. SMT32 single-chip microcomputer reads the FIFO data through the high-speed SPI interface with FPGA and writes the multi-channel data into the high-capacity SD card. The testing results have verified that the system has characteristics such as stable and reliable, easy configuration, low power consumption, can guarantee the multichannel data serial transmission, storage, accurate, up to 64 analog signals at the same time the real-time collection and storage, top 20 kHz sampling rate, the system total power of the system of about 3W, data rates up to 100 Mb/s, fully meet the needs of underwater sound acquisition system.

A proof-of-concept study demonstrating a multi-plate ion balance analyzer

This paper demonstrates a multi-plate ion balance analyzer with inverse distance weighted interpolation for characterizing ionizer performance. The proposed analyzer design uses ultra-high input impedance charge induced meter to measure the electrostatic potential of multiple ion receiving plates. An embedded microcontroller processes the multi-channel analog signals synchronously and presents the results on a graphical display. Data interpolation enables high resolution results from the multi-plate measurements. This developed analyzer is suitable for ion balance characterization in small footprint devices sensitive to electrostatic discharges, such as a single-chip integrated circuit, or the head gimbals assembly of a hard disk drive.

A Multi-Channel Large-Capacity Acquisition and Storage System

In this paper, a multi-channel large-capacity acquisition and storage system is prototyped to meet the urgent need of multi-channel analog signals’ acquisition and analysis. Composed of an acquisition board and storage board based on FPGA, the system could acquire 4 channel signals and store them in 512GB flash array. Gigabit Ethernet is used to connect the system and PC, which ensures high throughout between them. Ping-pong operation and pipeline technology are applied to cover the programming time of flash to improve the access speed. The system is portable, stable, and expansible, and could be used in various areas.

A Multiplexer with Split Devices for High Channel Isolation

A multiplexer with split devices for high channel isolation was proposed in this paper. The multiplexer is the most essential circuitry for multi-channel video signal acquisition systems. In the multi-channel applications, high isolation performance is required basically for the efficient signal processing. The noise propagation between channels is unexpected. The split devices technique is employed in the design work. Redundant transistors are inserted between the split cells to realize the noise grounded. This multiplexer is simulated and verified in the commercial CMOS process, and the isolation of more than 70dB was achieved. It has been embedded in a multi-channel analog signal processing system.

Multi-Tasking Based on ARM9-μC/OSII A/D Acquisition System Design and Implementation

In order to achieve fast and efficient data acquisition and digital-to-analog conversion, based on ARM9 Micro-controller S3C2410 and embedded real-time operating system μC/OS-II of multi-tasking A / D acquisition system. Not only able to finish with high precision, reliable, stable, real-time multi-channel analog signals and on-off signal data acquisition, and displays it on the LCD in real time. Completed in ADS1.2 compiled environment, system software using C language and assembly language mix programming, which makes full use of the advantages of different languages. This paper constructs the system's overall design, hardware circuit design method is given in detail, at the same time describes key transplant μC/OS-II embedded operating systems and software design.

Simulation of A/D Conversion with LabView

Simulation technology was a very important technology in the parallel signal processing research. A type of antomatic controlling simulation system was introduced, which was built by taking LabVIEW as the software platform, using LabVIEW user interface interacting with the Simulink model. Simulation of processing often requires algorithm and performance evaluation of parallel environment. Signal processing often requires simultaneous acquisition of multi-channel analog signals. Taking dual-channel A/D conversion processes as an example, using LabVIEW with VC, it achieves a simulation of parallel signal process of A/D conversion process.

Design and Implementation of Development and Testing Platform for Airbag Control System

In the late-stage of designing an airbag control system, a lot of collision experiments should be done to verify the performance of the system, but collision experiments cost a lot of time and money. In this paper, we design a new development and testing platform that can generate multi-channel acceleration analog signals and provide multi-channel airbag ignition interfaces. The platform receives the acceleration data customized on PC via a USB interface, then, the PC issues a command to start the output of the acceleration waveforms. The airbag ignition interface has the same electrical characteristics with real airbag, when it receives an ignition current, the platform will ignite the virtual airbag, and record the time. The experimental results show that the platform designed in this paper can precisely simulate the acceleration waveforms collected in collision experiments.

Design of Data Acquisition and Storage System for Digital and Analog Signal Based on FPGA

This paper mainly introduces a FPGA-based data acquisition system which is designed to acquire multi-channel analog signal and one channel digital signal. Analog data and digital data are stored into a FLASH memory in a mixed frame format. When the acquisition finished, the data in the FLASH was read out via the LVDS communication interface to a data-read device, and the host computer receives the data through the USB bus, so the subsequent data processing and analysis can be accomplished and the information we needed can be got. The design is applied successfully to a remote measurement system, and the data acquired is reliable and precise.

A Multi-Channel Data Acquisition System and its Performance Analysis Method Based on FPGA

The multiplexer act as the inputs of analog signals, enabling multi-channel analog signal acquisition; then filtered through a certain signal processing to ensure the most effective analog signals into the ADC; after conversion, the digital output is saved in the temporary buffer zone of the FPGA. The whole process is controlled by the FPGA. Finally, apply to the DAC-ADC joint debugging, in compare to the results, 14bit precision is guaranteed.

The Design of a Multi-Channel Data Acquisition Module Based on FPGA

This paper reports the basic principle and implementation process of FPGA-based multi-channel analog signal acquisition module. The emphasis of the full text is the principle of Data acquisition and the system implementation process. Multi-channel data acquisition module is composed of signal conditioning circuit、multi-channel analog multiplexers、A/D conversion and the central control system. The design uses LM324 for input signal conditioning; uses AD's 16 analog input signal chip ADG706 for channel selection; uses AD's 12-bit precision A/D converter AD7492 as the core chip of acquisition module for completing the A/D conversion; uses Xilinx's programmable logic device XC2S100 as part of the core control to achieve control of each module. Under the control of the design software, this design can take advantage of FPGA control multi-channel analog switch、A/D conversion、data compilation and uploading the data to PC to store and analyze.

Performances of Microwave-Band Analog Signal Transmission Using Wafer-Fused Long Wavelength VCSELs

The modulation characteristics of wafer-fused long-wavelength vertical-cavity surface-emitting lasers (VCSELs) for multichannel microwave-band analog signal transmission were investigated within a large-signal behavioral model based on a commercial microwave electronic computer-aided design (E-CAD) tool. To enhance the fitting precision, a step-by-step extraction procedure is implemented numerically, optimizing at each step no more than five parameters. The simulation and experimental results of intermodulation distortions are in perfect agreement.

Multichannel signal processors for multielement IR FPA

Structure and circuit solutions for implementing adaptive multichannel analog and digital signal preprocessing circuits integrated with readout circuits are considered. Experimental results of investigating multichannel signal preprocessing readout circuits and IR FPA based on them are represented.

Multichannel recorder–display system based on an Apple II microcomputer

An Apple II microcomputer-based system for recording, viewing, and plotting of multichannel analog signal is described. The system described is inexpensive and flexible and requires a minimum of interfacing effort.

Asynchronous time multiplexing

The use of asynchronous adaptive sampling for multiplexing multichannel analog signals and data over a synchronous digital facility is examined. This method promises to provide an efficient and consistent way to digitally transmit voice, line-scanned graphics or text, and data. Buffer analysis, computer simulations, and laboratory prototypes are described. When multiplexing speech using extremal sampling, quality of about 32 000-bit companded pulse-code modulation (PCM) is achieved at an average bit rate of 13 000 bit/s per user. Idle spaces, up to 20 percent of the link capacity, can also be filled with indirect data. The potential demonstrated in the laboratory indicates that effort should be directed toward reducing system complexities so as to achieve an efficient, practical system.