Showing papers on "Digital signal processing published in 2017"
Posted Content•
TL;DR: Graph Signal Processing (GSP) as discussed by the authors aims to develop tools for processing data defined on irregular graph domains, including sampling, filtering, and graph learning, which can be used for processing sensor network data, biological data, and image processing and machine learning.
Abstract: Research in Graph Signal Processing (GSP) aims to develop tools for processing data defined on irregular graph domains. In this paper we first provide an overview of core ideas in GSP and their connection to conventional digital signal processing. We then summarize recent developments in developing basic GSP tools, including methods for sampling, filtering or graph learning. Next, we review progress in several application areas using GSP, including processing and analysis of sensor network data, biological data, and applications to image processing and machine learning. We finish by providing a brief historical perspective to highlight how concepts recently developed in GSP build on top of prior research in other areas.
463 citations
TL;DR: The proposed photonics-based radar is an effective solution to overcome the limitations on operation bandwidth and processing speed of current radar imaging technologies, which may enable applications where high-resolution and real-time radar imaging is required.
Abstract: A photonics-based radar with generation and de-chirp processing of broadband linear frequency modulated continuous-wave (LFMCW) signal in optical domain is proposed for high-resolution and real-time inverse synthetic aperture radar (ISAR) imaging. In the proposed system, a broadband LFMCW signal is generated by a photonic frequency quadrupler based on a single integrated electro-optical modulator, and the echoes reflected from the targets are de-chirped to a low frequency signal by a microwave photonic frequency mixer. The proposed radar can operate at a high frequency with a large bandwidth, and thus achieve an ultra-high range resolution for ISAR imaging. Thanks to the wideband photonic de-chirp technique, the radar receiver could apply low-speed analog-to-digital conversion and mature digital signal processing, which makes real-time ISAR imaging possible. A K-band photonics-based radar with an instantaneous bandwidth of 8 GHz (18-26 GHz) is established and its performance for ISAR imaging is experimentally investigated. Results show that a recorded two-dimensional imaging resolution of ~2 cm × ~2 cm is achieved with a sampling rate of 100 MSa/s in the receiver. Besides, fast ISAR imaging with 100 frames per second is verified. The proposed radar is an effective solution to overcome the limitations on operation bandwidth and processing speed of current radar imaging technologies, which may enable applications where high-resolution and real-time radar imaging is required.
190 citations
TL;DR: This tutorial paper explores the digital signal processing (DSP) utilized in a coherent transceiver with a focus on multilevel modulation formats and some of the open research challenges in the field.
Abstract: Digital coherent transceivers have revolutionized optical fiber communications due to their superior performance offered compared to intensity modulation and direct detection based alternatives. As systems employing digital coherent transceivers seek to approach their information theoretic capacity, the use of multilevel modulation formats combined with appropriate forward error correction becomes essential. Given this context, in this tutorial paper, we, therefore, explore the digital signal processing (DSP) utilized in a coherent transceiver with a focus on multilevel modulation formats. By way of an introduction, we open by discussing the photonic technology required to realize a coherent transceiver. After discussing this interface between the analog optical channel and the digital domain, the rest of the paper is focused on DSP. We begin by discussing algorithms that correct for imperfections in the optical to digital conversion, including IQ imbalance and timing skew. Next, we discuss channel equalization including means for their realization for both quasi-static and dynamic channel impairments. Synchronization algorithms that correct for the difference between the transmitter and receiver oscillators both optical and electrical are then discussed and issues associated with symbol decoding highlighted. For most of the cases, we start with polarization division multiplexed quadrature phase-shift keying format as a basis and then discuss the extension to allow for high-order multilevel formats. Finally, we conclude by discussing some of the open research challenges in the field.
181 citations
TL;DR: An approximate multiplier that is high speed yet energy efficient is proposed that is to round the operands to the nearest exponent of two improving speed and energy consumption at the price of a small error.
Abstract: In this paper, we propose an approximate multiplier that is high speed yet energy efficient. The approach is to round the operands to the nearest exponent of two. This way the computational intensive part of the multiplication is omitted improving speed and energy consumption at the price of a small error. The proposed approach is applicable to both signed and unsigned multiplications. We propose three hardware implementations of the approximate multiplier that includes one for the unsigned and two for the signed operations. The efficiency of the proposed multiplier is evaluated by comparing its performance with those of some approximate and accurate multipliers using different design parameters. In addition, the efficacy of the proposed approximate multiplier is studied in two image processing applications, i.e., image sharpening and smoothing.
109 citations
22 Mar 2017
TL;DR: Mel Frequency Cepstral Coefficient (MFCC) technique is used to recognize emotion of a speaker from their voice and the efficiency was found to be about 80%.
Abstract: Speech is a complex signal consisting of various information, such as information about the message to be communicated, speaker, language, region, emotions etc. Speech Processing is one of the important branches of digital signal processing and finds applications in Human computer interfaces, Telecommunication, Assistive technologies, Audio mining, Security and so on. Speech emotion recognition is important to have a natural interaction between human being and machine. In speech emotion recognition, emotional state of a speaker is extracted from his or her speech. The acoustic characteristic of the speech signal is Feature. Feature extraction is the process that extracts a small amount of data from the speech signal that can later be used to represent each speaker. Many feature extraction methods are available and Mel Frequency Cepstral Coefficient (MFCC) is the commonly used method. In this paper, speaker emotions are recognized using the data extracted from the speaker voice signal. Mel Frequency Cepstral Coefficient (MFCC) technique is used to recognize emotion of a speaker from their voice. The designed system was validated for Happy, sad and anger emotions and the efficiency was found to be about 80%.
107 citations
TL;DR: The proposed radar architecture is a reliable solution to overcome the limitations of current radar on operation bandwidth and processing speed, and it is hopefully to be used in future radars for real-time and high-resolution target detection and imaging.
Abstract: Real-time and high-resolution target detection is highly desirable in modern radar applications. Electronic techniques have encountered grave difficulties in the development of such radars, which strictly rely on a large instantaneous bandwidth. In this article, a photonics-based real-time high-range-resolution radar is proposed with optical generation and processing of broadband linear frequency modulation (LFM) signals. A broadband LFM signal is generated in the transmitter by photonic frequency quadrupling, and the received echo is de-chirped to a low frequency signal by photonic frequency mixing. The system can operate at a high frequency and a large bandwidth while enabling real-time processing by low-speed analog-to-digital conversion and digital signal processing. A conceptual radar is established. Real-time processing of an 8-GHz LFM signal is achieved with a sampling rate of 500 MSa/s. Accurate distance measurement is implemented with a maximum error of 4 mm within a range of ~3.5 meters. Detection of two targets is demonstrated with a range-resolution as high as 1.875 cm. We believe the proposed radar architecture is a reliable solution to overcome the limitations of current radar on operation bandwidth and processing speed, and it is hopefully to be used in future radars for real-time and high-resolution target detection and imaging.
101 citations
Book•
01 Jan 2017
TL;DR: In this article, the authors introduce the theory of interferometry and Synthesis Imaging, analyze the response of the interferometer response, and design of the Analog Receiving System.
Abstract: Preface -- Introduction and Historical Review -- Introductory Theory of Interferometry and Synthesis Imaging -- Analysis of the Interferometer Response -- Geometric Relationships and Polarimetry -- Antennas and Arrays -- Response of the Receiving System -- Design of the Analog Receiving System -- Digital Signal Processing -- Very-Long-Baseline Interferometry -- Calibration and Fourier Transformation of Visibility Data -- Deconvolution, Adaptive Calibration and Applications -- Interferometer Techniques for Astrometry and Geodesy -- Propagation Effects -- Van Cittert-Zernike Theorem, Spatial Coherence and Scattering -- Radio Interference -- Related Techniques -- Principal Symbols -- Index.
100 citations
TL;DR: This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems.
Abstract: This paper reviews digital signal processing techniques that compensate, mitigate, and exploit fiber nonlinearities in coherent optical fiber transmission systems.
99 citations
TL;DR: A 56-Gb/s PAM4 wireline transceiver testchip is implemented in 16-nm FinFET, and the ADC-based receiver incorporates hybrid analog and digital equalizations.
Abstract: A 56-Gb/s PAM4 wireline transceiver testchip is implemented in 16-nm FinFET. The current mode logic transmitter incorporates an auxiliary current injection at the output nodes to maintain PAM4 amplitude linearity. The ADC-based receiver incorporates hybrid analog and digital equalizations. The analog equalization is performed using two identical stages of continuous time linear equalizer, each having a constant of ~0-dB dc-gain and a maximum peaking of ~7 dB peaking at 14 GHz. A 28-GSample/s 32-way time-interleaved SAR ADC converts the equalized analog signal into digital domain for further equalization using digital signal processing. The transceiver achieves <1e-8 bit error rate over a backplane channel with 31-dB loss at 14-GHz and 3.5-mVrms additional crosstalk, using a fixed ~10-dB TX equalization and an adaptive hybrid RX equalization, with the DSP configured to have a 24-tap feed forward equalizer and a 1-tap decision feedback equalizer. The transceiver consumes 550-mW power at 56 Gb/s, excluding the power of the on-chip configurable DSP that cannot be accurately measured as it is implemented as part of a larger test structure.
95 citations
Posted Content•
TL;DR: In this paper, a deep neural network with four hidden layers is used to estimate ideal critical band gains, while a more traditional pitch filter attenuates noise between pitch harmonics, which achieves significantly higher quality than a traditional minimum mean squared error spectral estimator.
Abstract: Despite noise suppression being a mature area in signal processing, it remains highly dependent on fine tuning of estimator algorithms and parameters In this paper, we demonstrate a hybrid DSP/deep learning approach to noise suppression A deep neural network with four hidden layers is used to estimate ideal critical band gains, while a more traditional pitch filter attenuates noise between pitch harmonics The approach achieves significantly higher quality than a traditional minimum mean squared error spectral estimator, while keeping the complexity low enough for real-time operation at 48 kHz on a low-power processor
89 citations
TL;DR: The implementation of an inductively-powered seizure-predicting microsystem for monitoring and treatment of intractable epilepsy is presented and is validated in the control of chronic seizures in vivo in freely moving rats.
Abstract: First, existing commercially available open-loop and closed-loop implantable neurostimulators are reviewed and compared in terms of their targeted application, physical size, system-level features, and performance as a medical device. Next, signal processing algorithms as the primary strength point of the closed-loop neurostimulators are reviewed, and various design and implementation requirements and trade-offs are discussed in details along with quantitative examples. The review results in a set of guidelines for algorithm selection and evaluation. Second, the implementation of an inductively-powered seizure-predicting microsystem for monitoring and treatment of intractable epilepsy is presented. The miniaturized system is comprised of two miniboards and a power receiver coil. The first board hosts a 24-channel neurostimulator system on chip [15] fabricated in a $0.13\;\mu \text{m}$ CMOS technology and performs neural recording, on-chip digital signal processing, and electrical stimulation. The second board communicates recorded brain signals as well as signal processing results wirelessly. The multilayer flexible coil receives inductively-transmitted power. The system is sized at 2 $\times$ 2 $\times$ 0.7 $\text{cm}^3$ and weighs 6 g. The approach is validated in the control of chronic seizures in vivo in freely moving rats.
TL;DR: This paper describes the important system and hardware requirements for the four main subsystems found in the DPD linearized transmitter: RF/analog, data converters, digital signal processing, and the D PD architecture and algorithms, and illustrates how the overall DPD system architecture is influenced by the design choices that may be made in each of these subsystems.
Abstract: Over the past 25 years or so there has been much interest in the use of digital pre-distortion (DPD) techniques for the linearization of RF and microwave power amplifiers. In this paper, we describe the important system and hardware requirements for the four main subsystems found in the DPD linearized transmitter: RF/analog, data converters, digital signal processing, and the DPD architecture and algorithms, and illustrate how the overall DPD system architecture is influenced by the design choices that may be made in each of these subsystems. We shall also consider the challenges presented to future applications of DPD systems for wireless communications, such as higher operating frequencies, wider signal bandwidths, greater spectral efficiency signals, resulting in higher peak-to-average power ratios, multiband and multimode operation, lower power consumption requirements, faster adaption, and how these affect the system design choices.
TL;DR: This tutorial describes the key enabling technologies and principle for the realization of ultra-high speed, large capacity mm-wave signal transmission, which can effectively improve the transmission capacity and distance, as well as reduce the required bandwidth for optical and electrical devices.
Abstract: High-speed millimeter-wave (mm-wave) wireless transmission at 40 Gb/s or higher will be required in the near future. Due to bottleneck in electrical devices, mm-wave wireless signal at such high bit rates cannot be generated in an all-electrical method. Photonics-assisted mm-wave generation technology has become an effective solution to handle this problem of bandwidth limitation. Recent efforts with a single modulator to generate optical mm-wave signal largely simplify the architecture of the optical transmitter. Heterodyne detection based on advanced digital signal processing can overcome nonlinear effects in optical and electrical devices, and it also can improve the spectral efficiency and receiver sensitivity. Multidimensional multiplexing techniques can reduce the baud rate of each subchannel, and hence it can realize mm-wave signal long distance transmission. In this tutorial, we will describe these key enabling technologies and principle for the realization of ultrahigh speed, large capacity mm-wave signal transmission. These enabling technologies can effectively improve the transmission capacity and distance, as well as reduce the required bandwidth for optical and electrical devices.
TL;DR: A new architecture, design flow, and field-programmable gate array (FPGA) implementation analysis of a neuromorphic binaural auditory sensor, designed completely in the spike domain, is presented, allowing researchers to implement their own parameterized neuromorphic auditory systems in a low-cost FPGA in order to study the audio processing and learning activity that takes place in the brain.
Abstract: This paper presents a new architecture, design flow, and field-programmable gate array (FPGA) implementation analysis of a neuromorphic binaural auditory sensor, designed completely in the spike domain. Unlike digital cochleae that decompose audio signals using classical digital signal processing techniques, the model presented in this paper processes information directly encoded as spikes using pulse frequency modulation and provides a set of frequency-decomposed audio information using an address-event representation interface. In this case, a systematic approach to design led to a generic process for building, tuning, and implementing audio frequency decomposers with different features, facilitating synthesis with custom features. This allows researchers to implement their own parameterized neuromorphic auditory systems in a low-cost FPGA in order to study the audio processing and learning activity that takes place in the brain. In this paper, we present a 64-channel binaural neuromorphic auditory system implemented in a Virtex-5 FPGA using a commercial development board. The system was excited with a diverse set of audio signals in order to analyze its response and characterize its features. The neuromorphic auditory system response times and frequencies are reported. The experimental results of the proposed system implementation with 64-channel stereo are: a frequency range between 9.6 Hz and 14.6 kHz (adjustable), a maximum output event rate of 2.19 Mevents/s, a power consumption of 29.7 mW, the slices requirements of 11141, and a system clock frequency of 27 MHz.
TL;DR: The Radio Frequency Spectrometer (RFS) as discussed by the authors is a two-channel digital receiver and spectrometer, which will make remote sensing observations of radio waves and in situ measurements of electrostatic and electromagnetic fluctuations in the solar wind.
Abstract: The Radio Frequency Spectrometer (RFS) is a two channel digital receiver and spectrometer, which will make remote sensing observations of radio waves and in situ measurements of electrostatic and electromagnetic fluctuations in the solar wind. A part of the FIELDS suite for Solar Probe Plus (SPP), the RFS is optimized for measurements in the inner heliosphere, where solar radio bursts are more intense and the plasma frequency is higher compared to previous measurements at distances of 1 AU or greater. The inputs to the RFS receiver are the four electric antennas mounted near the front of the SPP spacecraft, and a single axis of the SPP search coil magnetometer (SCM). Each RFS channel selects a monopole or dipole antenna input, or the SCM input, via multiplexers. The primary data products from the RFS are auto and cross spectra from the selected inputs. The spectra are calculated using a polyphase filter bank (PFB), which enables the measurement of low amplitude signals of interest in the presence of high amplitude narrowband noise generated by spacecraft systems. We discuss the science signals of interest driving the RFS measurement objectives, describe the RFS analog design and digital signal processing, and show examples of current performance.
TL;DR: A review of the existing methods following their historical evolution, and discussing pros and cons of each approach with relation to the room characteristics, as well as instrumental and perceptual measures, is presented in this article.
Abstract: Room response equalization aims at improving the sound reproduction in rooms by applying advanced digital signal processing techniques to design an equalizer on the basis of one or more measurements of the room response. This topic has been intensively studied in the last 40 years, resulting in a number of effective techniques facing different aspects of the problem. This review paper aims at giving an overview of the existing methods following their historical evolution, and discussing pros and cons of each approach with relation to the room characteristics, as well as instrumental and perceptual measures. The review is concluded by a discussion on emerging topics and new trends.
TL;DR: The proposed photonic-assisted receiver is able to simplify the architecture and improve performance for the multispectral sensing application.
Abstract: In this paper, a photonics-based dual-band linear frequency-modulated continuous wave (LFMCW) radar receiver is proposed. The system core is a microwave photonic in-phase and quadrature (I/Q) mixer, whose inherent large bandwidth, high I/Q balance and favorable uniformity enable the receiver to operate over an extremely wide frequency range. An integrated dual-band waveform offers the possibility of independent detection, allowing the sharing of hardware resources and joint dechirp processing of dual bands. In the proof-of-concept experiment, the distance measurements of S- and C-bands are implemented, with a high and uniform image rejection exceeding 28 and 30 dB, respectively. The image rejections of the two bands can be further improved to 43 and 41 dB at least by digital signal processing (DSP). The proposed photonic-assisted receiver is thus able to simplify the architecture and improve performance for the multispectral sensing application.
TL;DR: The launch power dynamic range and maximum transmission distance for the bio-inspired method were 2.7 dBm and 240 km greater, respectively, than those of the maximum likelihood estimation algorithm, demonstrating its usability for digital signal processing in coherent systems.
TL;DR: In this article, a dual-sideband (DSB) chirped lidar for simultaneous real-time ranging and velocimetry is proposed and demonstrated, in which a Mach-Zehnder modulator (MZM) is applied to generate the required optical DSB frequency-modulated continuous-wave (FMCW) signal.
Abstract: A dual-sideband (DSB) chirped lidar for simultaneous real-time ranging and velocimetry is proposed and demonstrated, in which a Mach–Zehnder modulator (MZM) is applied to generate the required optical DSB frequency-modulated continuous-wave (FMCW) signal. The inherent opposite frequency chirp and contrary wavelength offset to the optical carrier of the two generated sidebands make it possible to measure the distance and velocity by frequency mixing without complex post digital signal processing, meanwhile, make the measurement of velocity immune to the nonlinearity of the FMCW optical signals. An experiment is carried out, in which an 8–18 GHz saw-tooth FMCW signal is used to drive an MZM, generating a wideband optical DSB FMCW signal. The distance and the velocity are simultaneously derived from the real-time frequency spectra. Accurate velocimetry with a nonlinear FMCW signal is also investigated.
TL;DR: In this article, the use of a low-loss, high-index-contrast stoichiometric silicon nitride waveguide is presented as a practical material platform for realizing high-performance optical signal processors and points toward photonic RF filters with digital signal processing level flexibility, hundreds-GHz bandwidth, MHz-band frequency selectivity, and full system integration on a chip scale.
Abstract: Integrated optical signal processors have been identified as a powerful engine for optical processing of microwave signals. They enable wideband and stable signal processing operations on miniaturized chips with ultimate control precision. As a promising application, such processors enables photonic implementations of reconfigurable radio frequency (RF) filters with wide design flexibility, large bandwidth, and high-frequency selectivity. This is a key technology for photonic-assisted RF front ends that opens a path to overcoming the bandwidth limitation of current digital electronics. Here, the recent progress of integrated optical signal processors for implementing such RF filters is reviewed. We highlight the use of a low-loss, high-index-contrast stoichiometric silicon nitride waveguide which promises to serve as a practical material platform for realizing high-performance optical signal processors and points toward photonic RF filters with digital signal processing (DSP)-level flexibility, hundreds-GHz bandwidth, MHz-band frequency selectivity, and full system integration on a chip scale.
TL;DR: Traditional and novel demodulation methods applicable to amplitude-modulation atomic force microscopy are implemented on a widely used digital processing system and the performance metrics tracking bandwidth, implementation complexity and sensitivity to other frequency components are experimentally evaluated for each method.
Abstract: In this review paper, traditional and novel demodulation methods applicable to amplitude-modulation atomic force microscopy are implemented on a widely used digital processing system. As a crucial bandwidth-limiting component in the z-axis feedback loop of an atomic force microscope, the purpose of the demodulator is to obtain estimates of amplitude and phase of the cantilever deflection signal in the presence of sensor noise or additional distinct frequency components. Specifically for modern multifrequency techniques, where higher harmonic and/or higher eigenmode contributions are present in the oscillation signal, the fidelity of the estimates obtained from some demodulation techniques is not guaranteed. To enable a rigorous comparison, the performance metrics tracking bandwidth, implementation complexity and sensitivity to other frequency components are experimentally evaluated for each method. Finally, the significance of an adequate demodulator bandwidth is highlighted during high-speed tapping-mode atomic force microscopy experiments in constant-height mode.
TL;DR: In this article, the authors proposed an approach by combining independent component analysis (ICA) with travelling wave theory and support vector machine (SVM) to locate and recognize faults in highvoltage (HV) transmission lines, while the acquired signals are noisy.
TL;DR: In this paper, a structural health monitoring (SHM) guided wave system for advance carbon fiber reinforced plastic (CFRP) composite materials is presented, where a circular defect of 10mm in diameter was drilled in the plate, which is similar to the delamination size introduced by a low velocity impact event in a composite plate.
Abstract: This investigation aimed to adapt the total focusing method (TFM) algorithm (originated from the synthetic aperture focusing technique in digital signal processing) to accommodate a circular array of piezoelectric sensors (PZT) and characterise defects using guided wave signals for the development of a structural health monitoring system. This research presents the initial results of a broader study focusing on the development of a structural health monitoring (SHM) guided wave system for advance carbon fibre reinforced plastic (CFRP) composite materials. The current material investigated was an isotropic (aluminium) square plate with 16 transducers operating successively as emitter or sensor in pitch and catch configuration enabling the collection of 240 signals per assessment. The Lamb wave signals collected were tuned on the symmetric fundamental mode with a wavelength of 17 mm, by setting the excitation frequency to 300 kHz. The initial condition for the imaging system, such as wave speed and transducer position, were determined with post processing of the baseline signals through a method involving the identification of the waves reflected from the free edge of the plate. The imaging algorithm was adapted to accommodate multiple transmitting transducers in random positions. A circular defect of 10 mm in diameter was drilled in the plate, which is similar to the delamination size introduced by a low velocity impact event in a composite plate. Images were obtained by applying the TFM to the baseline signals, Test 1 data (corresponding to the signals obtained after introduction of the defect) and to the data derived from the subtraction of the baseline to the Test 1 signals. The result shows that despite the damage diameter being 40 % smaller than the wavelength, the image (of the subtracted baseline data) demonstrated that the system can locate where the waves were reflected from the defect boundary. In other words, the contour of the damaged area was highlighted enabling its size and position to be determined.
TL;DR: Theoretical and experimental results performed FIR band pass filter suggests that the window design method is relatively simple and easy to use because of the availability of well-defined equation and synthesis results show that the discussed technique can substantial help in lessening the equipment assets.
Abstract: Digital signal processing (DSP) circuits are extremely important in computing and communications areas One application of DSP is a Finite impulse response (FIR) filter The principle objective of this exploration is to present a methodology for an upgraded framework of a FIR digital filter from software level to the hardware level It includes the selection of design method, structure and cost effective hardware utilization Theoretical and experimental results performed FIR band pass filter suggests that the window design method is relatively simple and easy to use because of the availability of well-defined equation Comparison presented that Kaiser window gives the minimum main-lobe width and a sharp cut-off which means this window has less transition width and the study showed that the Direct-Form structure approach is simpler and offers a better performance than other common filter structures It results in low cost, reduced area and more robust to withstand the quantization errors For effi
TL;DR: This paper addresses the case in which the processing task is "detection" of a sparse signal in additive white Gaussian noise, with applications e.g. in radar systems, and proposes two estimators for estimating the degree of sparsity of the detected signal.
TL;DR: In this article, a detailed comparison of applying three advanced modulation formats including pulse amplitude modulation-8 (PAM-8), carrierless amplitude and phase modulation-64 QAM (CAP-64), and discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S OFDM) with a bandwidth limited direct-detection receiver for 100 Gb/s/λ optical transmission systems is presented.
Abstract: We present a detailed comparison of applying three advanced modulation formats including pulse amplitude modulation-8 (PAM-8), carrier-less amplitude and phase modulation-64 QAM (CAP-64), and discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S OFDM) with a bandwidth-limited direct-detection receiver for 100 Gb/s/λ optical transmission systems. These modulation formats are all experimentally demonstrated with corresponding digital signal processing (DSP) algorithms. The comparison is carried out to evaluate the performance of each modulation format in terms of nonlinear equalization, received optical power and optical signal to noise ratio (OSNR). Our experimental results show that only 112 Gbit/s DFT-S OFDM is successfully achieved over 50 km of SSMF under the hard decision-forward error correction (HD-FEC) threshold of 3.8 × 10−3.
TL;DR: An image processing algorithm that transforms the image into three colorspaces, which are processed simultaneously, which outperforms few existing works in literature in terms of accuracy and computation time.
TL;DR: In this article, a variable ratio threshold and zero-crossing detection based digital signal processing method is proposed for ultrasonic gas flow meter, where the ultrasonic echo signal is normalized, and the ratio value is used as the threshold value to determine the feature point.
Posted Content•
TL;DR: By pairing a small computational footprint with specialized digital signal processing (DSP) chips, this work is able to achieve low power consumption while continuously listening for a keyword.
Abstract: We present a cascade architecture for keyword spotting with speaker verification on mobile devices. By pairing a small computational footprint with specialized digital signal processing (DSP) chips, we are able to achieve low power consumption while continuously listening for a keyword.
01 Sep 2017
TL;DR: A processing array designed to consistently achieve timing closure at 100% of the peak DSP clock rate with standard FPGA tools for matrix multiplication and convolution, the most compute-intensive operations of a convolutional neural network (CNN).
Abstract: FPGA-based neural-networks typically leave performance on the table because the DSP resources run at less than a third of the peak clock rate. This paper presents a processing array architected to consistently achieve timing closure at 100% of the peak DSP clock rate with standard FPGA tools. In the HDL design environment, our processing array operates at the peak DSP clock rates on Xilinx UltraScale (741 MHz) and UltraScale+ (891 MHz) devices. To enhance portability and consistency of timing closure, this array operates at a high clock rate while data SRAMs run at a fraction of this rate. As a proof of concept, this paper outlines a processing array for matrix multiplication and convolution, the most compute-intensive operations of a convolutional neural network (CNN).