Showing papers on "Digital signal published in 2010"

Voice Recognition Algorithms using Mel Frequency Cepstral Coefficient (MFCC) and Dynamic Time Warping (DTW) Techniques

Abstract: — Digital processing of speech signal and voice recognition algorithm is very important for fast and accurate automatic voice recognition technology The voice is a signal of infinite information A direct analysis and synthesizing the complex voice signal is due to too much information contained in the signal Therefore the digital signal processes such as Feature Extraction and Feature Matching are introduced to represent the voice signal Several methods such as Liner Predictive Predictive Coding (LPC), Hidden Markov Model (HMM), Artificial Neural Network (ANN) and etc are evaluated with a view to identify a straight forward and effective method for voice signal The extraction and matching process is implemented right after the Pre Processing or filtering signal is performed The non-parametric method for modelling the human auditory perception system, Mel Frequency Cepstral Coefficients (MFCCs) are utilize as extraction techniques The non linear sequence alignment known as Dynamic Time Warping (DTW) introduced by Sakoe Chiba has been used as features matching techniques Since it’s obvious that the voice signal tends to have different temporal rate, the alignment is important to produce the better performanceThis paper present the viability of MFCC to extract features and DTW to compare the test patterns

Analog to digital converters

Abstract: In one embodiment, an analog to digital converter (ADC) for converting an analog signal to a digital signal includes an input channel for receiving the analog signal, and includes a first and second sampling-integrating units. The first sampling-integrating unit receives the analog signal, samples the analog signal, integrates a superposition of a first feedback signal and a sampled signal of the analog signal, and generates a first output signal. The second sampling-integrating unit receives the first output signal, samples the first output signal, integrates a superposition of a second feedback signal and a sampled signal of the first output signal, and generates a second output signal. The ADC includes a feedback circuit for generating the digital signal according to the second output signal and for providing the first and second feedback signals indicative of the digital signal to the first and second sampling-integrating units respectively.

Battery cell monitoring and balancing circuit

Abstract: A monitoring circuit for accurately monitoring a voltage level from each of a plurality of battery cells of a battery pack includes an analog to digital converter (ADC) and a processor. The ADC is configured to accept an analog voltage signal from each of the plurality of battery cells and convert each analog voltage signal to a digital signal representative of an accurate voltage level of each battery cell. The processor receives such signals and provides a safety alert signal based on at least one of the signals. The ADC resolution may be adjustable. A balancing circuit provides a balancing signal if at least two of the digital signals indicate a voltage difference between two cells is greater than a battery cell balance threshold. An electronic device including such monitoring and balancing circuits is also provided. Various methods are also provided.

EOG-based Human-Computer Interface system development

Abstract: Several Human-Machine/Computer Interfaces (HMI/HCI) had been developed in recent years. Some designs were specifically made for people with disabilities such as injured-vertebra, apoplexy or poliomyelitis, Amyotrophic Lateral Sclerosis (ALS), and Motor Neuron Disease, (MND). In this paper, we proposed an eye-movement tracking system. Based on Electro-Oculography (EOG) technology we detected the signal with different directions in eye-movements and then analyzed to understand what they represented about (e.g. horizontal direction or vertical direction). We converted the analog signal to digital signal and then used as the control signals for Human-Computer Interface (HCI). In order to make the system ''robust'', several applications with EOG-based HCI had been designed. Our preliminary results revealed more than 90% accuracy rate for examining the eye-movement that may become a new useful human-machine user interface in the near future.

European roadmap on superconductive electronics – status and perspectives☆

Abstract: For four decades semiconductor electronics has followed Moore's law: with each generation of integration the circuit features became smaller, more complex and faster. This development is now reaching a wall so that smaller is no longer any faster. The clock rate has saturated at about 3-5 GHz and the parallel processor approach will soon reach its limit. The prime reason for the limitation the semiconductor electronics experiences is not the switching speed of the individual transistor, but its power dissipation and thus heat. Digital superconductive electronics is a circuit- and device-technology that is inherently faster at much less power dissipation than semiconductor electronics. It makes use of superconductors and Josephson junctions as circuit elements, which can provide extremely fast digital devices in a frequency range - dependent on the material - of hundreds of GHz: for example a flip-flop has been demonstrated that operated at 750 GHz. This digital technique is scalable and follows similar design rules as semiconductor devices. Its very low power dissipation of only 0.1 mu W per gate at 100 GHz opens the possibility of three-dimensional integration. Circuits like microprocessors and analogue-to-digital converters for commercial and military applications have been demonstrated. In contrast to semiconductor circuits, the operation of superconducting circuits is based on naturally standardized digital pulses the area of which is exactly the flux quantum Phi(0). The flux quantum is also the natural quantization unit for digital-to-analogue and analogue-to-digital converters. The latter application is so precise, that it is being used as voltage standard and that the physical unit 'Volt' is defined by means of this standard. Apart from its outstanding features for digital electronics, superconductive electronics provides also the most sensitive sensor for magnetic fields: the Superconducting Quantum Interference Device (SQUID). Amongst many other applications SQUIDs are used as sensors for magnetic heart and brain signals in medical applications, as sensor for geological surveying and food-processing and for non-destructive testing. As amplifiers of electrical signals. SQUIDs can nearly reach the theoretical limit given by Quantum Mechanics. A further important field of application is the detection of very weak signals by 'transition-edge' bolo-meters, superconducting nanowire single-photon detectors, and superconductive tunnel junctions. Their application as radiation detectors in a wide frequency range, from microwaves to X-rays is now standard. The very low losses of superconductors have led to commercial microwave filter designs that are now widely used in the USA in base stations for cellular phones and in military communication applications. The number of demonstrated applications is continuously increasing and there is no area in professional electronics, in which superconductive electronics cannot be applied and surpasses the performance of classical devices. Superconductive electronics has to be cooled to very low temperatures. Whereas this was a bottleneck in the past, cooling techniques have made a huge step forward in recent years: very compact systems with high reliability and a wide range of cooling power are available commercially, from microcoolers of match-box size with milli-Watt cooling power to high-reliability coolers of many Watts of cooling power for satellite applications. Superconductive electronics will not replace semiconductor electronics and similar room-temperature techniques in standard applications, but for those applications which require very high speed, low-power consumption, extreme sensitivity or extremely high precision, superconductive electronics is superior to all other available techniques. To strengthen the European competitiveness in superconductor electronics research projects have to be set-up in the following field: - Ultra-sensitive sensing and imaging. - Quantum measurement instrumentation. - Advanced analogue-to-digital converters. - Superconductive electronics technology.

Wireless digital data transmission at 300 GHz

Abstract: Recently, analogue video signal transmission at 300 GHz has been demonstrated using a versatile Schottky mixer based measurement system designed for terahertz communication channel modelling and propagation studies. In this reported work, digital signal transmission at 300 GHz using this system is demonstrated and analysed. The performance of the digital transmission setup is characterised with respect to phase noise and modulation errors. For demonstration, high data rate digital video signals have been transmitted over a distance of up to 52 m.

Systems and methods for implementing pressure sensitive keyboards

Abstract: Systems and methods for implementing pressure sensitive keys to produce digital signals that emulate actuation of conventional “momentary on” digital keys of a conventional keyboard. The pressure sensitive keys may be implemented to generate an alternating open/short digital signal representative of the amount of pressure applied to a given key at any given time. The open/short digital signal may be supplied as a signal representative of applied key pressure to a legacy keyboard key matrix and controller or other processing device of an information handling system that is configured to measure keyboard input based on “momentary-on” digital signals.

Solid-state imaging device and camera system

Abstract: A solid-state imaging device includes a pixel array section including a plurality of pixels, a pixel drive line controlling driving the pixels in each row, a signal line reading an analog signal of the pixels in each column, a pixel drive unit driving the pixels to perform a readout through the pixel drive line, and a readout circuit capable of converting the analog signal into a digital signal. At least the number of pixel drive lines or the number of signal lines is more than one, and the pixels of each pixel group are connected to different lines of either the pixel drive lines or the signal lines. The pixel drive unit sequentially drives the pixels in the pixel group at shifted timings, and the readout circuit includes an analog-to-digital converter sequentially receiving analog signals from the pixel group and sequentially converting the analog signals into digital signals.

SignalLens: Focus+Context Applied to Electronic Time Series

Abstract: Electronic test and measurement systems are becoming increasingly sophisticated in order to match the increased complexity and ultra-high speed of the devices under test. A key feature in many such instruments is a vastly increased capacity for storage of digital signals. Storage of 109 time points or more is now possible. At the same time, the typical screens on such measurement devices are relatively small. Therefore, these instruments can only render an extremely small fraction of the complete signal at any time. SignalLens uses a Focus+Context approach to provide a means of navigating to and inspecting low-level signal details in the context of the entire signal trace. This approach provides a compact visualization suitable for embedding into the small displays typically provided by electronic measurement instruments. We further augment this display with computed tracks which display time-aligned computed properties of the signal. By combining and filtering these computed tracks it is possible to easily and quickly find computationally detected features in the data which are often obscured by the visual compression required to render the large data sets on a small screen. Further, these tracks can be viewed in the context of the entire signal trace as well as visible high-level signal features. Several examples using real-world electronic measurement data are presented, which demonstrate typical use cases and the effectiveness of the design.

Digital feedforward sigma-delta modulator in analog-to-digital converter and modulation method thereof

Abstract: A digital feedforward sigma-delta modulator in an analog-to-digital converter and its modulation method are disclosed The modulator changes a feedforward path from an analog domain to a digital domain and processes it The modulator integrates an analog input by using a plurality of integrators, weights them, quantizes them by using a plurality of quantizers in a digital domain to output digital signals, and then adds up the thusly outputted digital signals by using a digital adder In case of a continuous time digital feedforward sigma-delta modulator (SDM), a digital signal outputted from the digital adder is weighted and then immediately inputted to the digital adder in the digital domain so as to be subtracted, allowing for digital feedforwarding Because the feedforward signal is processed in the digital domain, the area occupied by an analog circuit and power consumption can be reduced Also, because signals are added up in the digital domain, a digital output signal can be immediately used when an excess loop delay needs to be corrected Thus, because there is no need to convert the digital output signal into an analog signal by using a DAC, the DAC can be omitted

Flow rate measuring apparatus

Abstract: A flow rate measuring apparatus includes: a flow rate detecting device placed in an intake passage; a detection circuit for outputting an analog signal varying depending on the flow rate; a conversion circuit for converting the analog signal to a digital signal; a temperature detecting device for detecting an ambient temperature; and a correction circuit for primarily correcting the digital signal using a gain and/or an offset (correction coefficient) that can set the temperature coefficient in any appropriate way. The gain and/or the offset vary depending on the temperature coefficient set in any appropriate way and the ambient temperature detected by the temperature detecting device. Also, a plurality of the gains and/or the offsets are set depending on the flow rate, allowing the temperature characteristic error in flow rate measurement to be reduced.

Digital coherent receiving apparatus

Abstract: A digital coherent receiving apparatus includes a first oscillator for outputting a local light signal of a fixed frequency, a hybrid unit mixing the local light signal with a light signal received by a receiver, a second oscillator for outputting a sampling signal of a sampling frequency, a converter for converting the mixed light signal into digital signal synchronizing with the sampling signal, a waveform adjuster for adjusting a waveform distortion of the converted digital signal, a phase adjustor for adjusting a phase of the digital signal adjusted by the waveform adjustor, a demodulator for demodulating the digital signal adjusted by the phase adjuster, and a phase detector for detecting a phase of the digital signal adjusted by the phase adjuster, and a control signal output unit for outputting a frequency control signal on the basis of the detected phase signal to the second oscillator.

Voice command recognition system based on mfcc and dtw

Abstract: Kurukshetra University, Department of Instrumentation & Control Engineering., H.E.C* Jagadhri, Haryana, 135003, India sachdevaanjali26@gmail.com ABHIJEET KUMAR Mullana University, Department of Electronics and Comm. Engineering., M.M.E.C Mullana, Haryana, 133203, India abhijeetsliet@gmail.com NIDHIKA BIRLA Kurukshetra University, Department of Electronics Engineering., H.E.C Jagadhri, Haryana, 135003, India nidhikabirla@gmail.com Abstract: The Voice is a signal of infinite information. Digital processing of speech signal is very important for high-speed and precise automatic voice recognition technology. Nowadays it is being used for health care, telephony military and people with disabilities therefore the digital signal processes such as Feature Extraction and Feature Matching are the latest issues for study of voice signal. In order to extract valuable information from the speech signal, make decisions on the process, and obtain results, the data needs to be manipulated and analyzed. Basic method used for extracting the features of the voice signal is to find the Mel frequency cepstral coefficients. Mel-frequency cepstral coefficients (MFCCs) are the coefficients that collectively represent the short-term power spectrum of a sound, based on a linear cosine transform of a log power spectrum on a nonlinear mel scale of frequency.This paper is divided into two modules. Under the first module feature of the speech signal are extracted in the form of MFCC coefficients and in another module the non linear sequence alignment known as Dynamic Time Warping (DTW) introduced by Sakoe Chiba has been used as features matching techniques. Since it’s obvious that the voice signal tends to have different temporal rate, the alignment is important to produce the better performance. This paper presents the feasibility of MFCC to extract features and DTW to compare the test patterns.

Method and system for down-converting an electromagnetic signal, and transforms for same

Abstract: Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

A Low THD, Low Power, High Output-Swing Time-Mode-Based Tunable Oscillator Via Digital Harmonic-Cancellation Technique

Abstract: An architectural solution for designing and implementing low THD oscillators is presented. A digital harmonic-cancellation-block is used to suppress the low-frequency harmonics while a passive, inherently linear, filter is used to suppress the high-frequency ones. The proposed technique eliminates the need for typical high-Q BPF to suppress the harmonics. Thus, eradicates the effect of increasing device nonlinearities in the nanometric technologies by having pure digital solution. In addition, eliminating the need for high-Q band-pass-filter (BPF) releases the output swing from the constraints imposed by the linearity of the filter. The prototype is fabricated in 0.13 ?m CMOS technology. Measurement results show -72 dB THD at 10 MHz along with a differential output swing of 228 mVpp. The oscillator prototype can be tuned from 5 MHz to 11 MHz with less than 4.5 dB variations in the THD. The circuit consumes 3.37 mA from 1.2 V supply at 10 MHz and occupies an area of 0.186 mm2. As the performance depends solely on the timing precision of digital signals, the proposed oscillator is considered the best time-mode-based oscillator in literature.

Reduced delay digital active noise cancellation

Abstract: A digital active noise cancellation circuit device (330) includes an oversampled, sigma-delta, A/D converter (204), a digital decimation filter (208), a digital intermediate filter (308), a digital interpolation filter (232), and a sigma-delta, D/A converter (252). The device (330) Is operative to perform the steps of: receiving (904) the analog noise signal (64), converting (908) the analog noise signal into a digital noise signal (261); transferring (912) the digital noise signal to a digital decimation filter, selectively bypassing (916) at least a portion of the digital decimation filter by transferring the digital noise signal to a digital intermediate filter, processing (920) the digital noise signal in the digital intermediate filter to generate a digital anti-noise signal (316), transferring (924) the digital anti-noise signal into a digital interpolation filter operable to up-sample the digital anti-noise signal, selectively bypassing (930) at least a portion of the digital interpolation filter and converting (934) the digital anti-noise signal into an analog anti-noise signal.

Signal processing device and optical receiving device

Abstract: A signal processing device includes: a phase controller configured to control respective phases of an in-phase signal and an quadrature signal, which are obtained by converting an analog signal into a digital signal when a multi-value phase modulation light is demodulated, by digital signal processing; and a control amount provider configured to provide a control amount to the phase controller based on an output of the phase controller.

Digital Analysis and Sorting of Fluorescence Lifetime by Flow Cytometry

Abstract: Frequency-domain flow cytometry techniques are combined with modifications to the digital signal-processing capabilities of the open reconfigurable cytometric acquisition system (ORCAS) to analyze fluorescence decay lifetimes and control sorting. Real-time fluorescence lifetime analysis is accomplished by rapidly digitizing correlated, radiofrequency (RF)-modulated detector signals, implementing Fourier analysis programming with ORCAS' digital signal processor (DSP) and converting the processed data into standard cytometric list mode data. To systematically test the capabilities of the ORCAS 50 MS/sec analog-to-digital converter (ADC) and our DSP programming, an error analysis was performed using simulated light scatter and fluorescence waveforms (0.5-25 ns simulated lifetime), pulse widths ranging from 2 to 15 micros, and modulation frequencies from 2.5 to 16.667 MHz. The standard deviations of digitally acquired lifetime values ranged from 0.112 to >2 ns, corresponding to errors in actual phase shifts from 0.0142 degrees to 1.6 degrees. The lowest coefficients of variation (<1%) were found for 10-MHz modulated waveforms having pulse widths of 6 micros and simulated lifetimes of 4 ns. Direct comparison of the digital analysis system to a previous analog phase-sensitive flow cytometer demonstrated similar precision and accuracy on measurements of a range of fluorescent microspheres, unstained cells, and cells stained with three common fluorophores. Sorting based on fluorescence lifetime was accomplished by adding analog outputs to ORCAS and interfacing with a commercial cell sorter with a RF-modulated solid-state laser. Two populations of fluorescent microspheres with overlapping fluorescence intensities but different lifetimes (2 and 7 ns) were separated to approximately 98% purity. Overall, the digital signal acquisition and processing methods we introduce present a simple yet robust approach to phase-sensitive measurements in flow cytometry. The ability to simply and inexpensively implement this system on a commercial flow sorter will allow both better dissemination of this technology and better exploitation of the traditionally underutilized parameter of fluorescence lifetime.

Mitigation of transmitter passive and active intermodulation products in real and continuous time in the transmitter and co-located receiver

Abstract: A transmitter channel interference mitigation processing method for cancellation of intermodulation products are described. In one embodiment, a method comprising generating continuous and real time IMP cancellation signals (ICS) in the baseband digital signal set of the transmitter based on a transmitter signal set, combining digital IMP cancellation signals with a digital baseband transmitter signal set such that the digital cancellation signals, when converted to analog signals and transmitted as part of an analog transmitter signal set, are cancelled by and so cancel the IMPs generated by the non-linear components in the analog transmitter hardware, including digitally generating the IMP cancellation signals using a process based on a power series description of a non-linear process generating the IMPs, generating 3 rd order IMP cancellation signals by digitally multiplying two or three signals of the transmitter signal set to create 3 rd order IMP cancellation signals, generating 5 th order IMP cancellation signals by digitally multiplying two or three or five signals of the transmitter signal set to create 5 th order IMP cancellation signals, generating 7 th order IMP cancellation signals by digitally multiplying two or three or five or seven signals of the transmitter signal set to create 7 th order IMP cancellation signal, generating odd order IMP cancellation signals (ICS) by digitally multiplying an odd number of digital signals and combining multiplied digital signals with the transmitter baseband digital signals, creating IMP cancellation signals in the receiver, and cancelling one or both of active and passive IMPs generated in a transmitter path that fall within a receiver passband.

Digital signal processed touchscreen system

Abstract: Digital signal processed touchscreen system. The invention employs amplitude ramped signals across a touchscreen. The pattern to which the amplitude ramped electric signals are provided may be located on the surface of the touchscreen, or alternatively on the backside of the touchscreen. The signal processing employed by the invention, using digital signal processing techniques, is operable to discern a user's touch and to determine its location. A dielectric, protective surface is used to enable implementation into a wide variety of applications, including those applications that are environmentally rugged and have, until now, been too rugged for prior art touchscreen systems. The invention employs a user generated unbalanced capacitive load generated on the touchscreen to identify the location of the user's touch.

Optical transmission system

Abstract: An optical transmission system includes an optical transmitter that includes first and second light sources, first and second phase modulators respectively modulating light from the first and the second light sources, and a polarized beam combiner combining the light output from the first and the second phase modulators to output an optical signal; and an optical receiver that includes a local oscillator, a polarization beam splitter splitting, according to polarization, the optical signal transmitted from the optical transmitter, and first and second digital coherent receivers corresponding to the first and the second phase modulators, and including a frontend that mixes light from the local oscillator and the polarization-split optical signal to output an electrical signal of real and imaginary parts, an analog-digital converting unit converting the electrical signal to a digital signal, and a digital signal processing unit estimating phase of the digital signal and extracting a signal.

Asynchronous SAR ADC

Abstract: An asynchronous analog to digital convertor for converting an analog input signal into a digital output is presented. According to an embodiment, the analog to digital convertor comprises a clock input operable to receive an external clock signal having a clock period, a comparator operable to compare the analog input signal to a reference signal, a digital to analog converter operable to generate the reference signal corresponding to a state of a successive approximation register, and a control block connected to the comparator and to the digital to analog converter. The control block is operable to generate and receive a sequence of control signals according to a successive approximation algorithm, to perform a plurality of comparisons, and to update the state of the successive approximation register thereby generating the digital output.

Enhanced Wave Digital Triode Model for Real-Time Tube Amplifier Emulation

Abstract: Electric circuits containing vacuum tubes form an integral part of various audio equipment, such as guitar amplifiers, certain equalizers, microphone preamplifiers, and dynamic range compressors. Although most audio signal processing operations are straightforward to implement with modern computers, real-time digital simulation of vacuum tubes poses a significant challenge due to the dynamic nonlinearities of the tube circuits. Most of the current vacuum-tube emulators model the unidirectional signal path of the circuit using linear filters and nonlinear waveshapers, possibly with signal-dependent parameters. This paper introduces a physical model of a tube stage circuit using wave digital filters. In contrast to previous unidirectional signal models, the wave digital model implements bidirectional signal propagation. This allows realistic simulation of interesting dynamical nonlinearities, such as the bias variation under reactive load. The new model is an extension of the wave digital tube presented in ?Wave digital simulation of a vacuum-tube amplifier? (M. Karjalainen and J. Pakarinen Proc. Int. Conf. Acoustics, Speech, Signal Processing, 2006, vol. V, pp. 153-156). In particular, the enhanced model for the tube grid-to-cathode connection enables the simulation of interstage coupling and blocking distortion.

Audio signal synthesizing

Abstract: An audio synthesizing apparatus receives an encoded signal comprising a downmix signal and parametric extension data for expanding the downmix signal to a multi- sound source signal A decomposition processor (205) performs a signal decomposition of the downmix signal to generate at least a first signal component and a second signal component,where the second signal component is at least partially decorrelated with the first signal component A position processor (207) determines a first spatial position indication for the first signal component in response to the parametric extension data and a binaural processor (211) synthesizes the first signal component based on the first spatial position indication and the second signal component to originate from a different direction The invention may provide improved spatial experience from eg headphones by using a direct synthesis of a main directional signal from the appropriate position rather than as a combination of signals from virtual loudspeaker positions

Digital Controller for DVS-Enabled DC–DC Converter

Abstract: A high-frequency digital controller that includes an optimized analog-digital converter (ADC) with a novel formulation of digital error value based on target clock frequency and converter output voltage is presented in this paper. A programmable look-up table-based digital compensator is implemented for fast processing the feedback error. Limitations of a hybrid digital pulsewidth modulator (DPWM) at high frequency are addressed and solved by an edge-triggered logic. Support for process, voltage, and temperature variations is incorporated in the integrated design. Target clock frequency denotes the frequency of the signal which is driven by dynamic voltage scaling (DVS) processor and corresponds to the reference value of the regulated output voltage. This work realizes the classical digital controller design implementation of a target frequency to minimum required regulated voltage for DVS-enabled adaptive DC-DC converter. A synchronous buck converter of 1 MHz switching frequency and the proposed delay-line-based optimized ADC have been fabricated for realizing and verifying the complete digital controller on a field-programmable gate array-based closed-loop prototype. Experimental results are presented, which demonstrate the fast dynamic response achieved for target clock frequency in the range of 6-16 MHz, corresponding to the regulated output voltage range of 1.6-3.2 V. The complete design of digital controller has been implemented in 0.5 ?m CMOS technology using Cadence and Synopsys tools. The active on-chip area of the proposed delay-line ADC, digital compensator, and edge-triggered hybrid DPWM are 0.08, 0.28, and 0.07 mm2 respectively.

Sensitive White Space Detection with Spectral Covariance Sensing

Abstract: This paper proposes a novel, highly effective spectrum sensing algorithm for cognitive radio and white space applications. The proposed spectral covariance sensing (SCS) algorithm exploits the different statistical correlations of the received signal and noise in the frequency domain. Test statistics are computed from the covariance matrix of a partial spectrogram and compared with a decision threshold to determine whether a primary signal or arbitrary type is present or not. This detector is analyzed theoretically and verified through realistic open-source simulations using actual digital television signals captured in the US. Compared to the state of the art in the literature, SCS improves sensitivity by 3 dB for the same dwell time, which is a very significant improvement for this application. Further, it is shown that SCS is highly robust to noise uncertainty, whereas many other spectrum sensors are not.

Power line communications apparatus

Abstract: Apparatus and system for communicating data via a power line. The apparatus comprises a transmitter comprising a modulator for generating a second digital signal based on input data; a digital buffer for amplifying the second digital signal to generate a third digital signal; a filter for filtering the third digital signal to generate an analog output waveform; and a coupler for coupling the analog output waveform to the power line.

Active 3d monitoring system for traffic detection

Abstract: There is provided a system and a method for detecting the presence of an object in a detection zone using a traffic detection system. The traffic detection system includes an optical unit having an emitter module emitting pulses within a predetermined field of emission; a receiver module receiving a part of the pulses reflected by an object in the field of emission toward a field of view of the receiver module, the field of view including a plurality of adjacent detection channels, the receiver module acquiring and converting the received pulses into a corresponding plurality of a digital signal waveforms; an image sensing module providing an image that encompasses the field of emission of the emitter module and the field of view of the receiver module. The method comprises providing a status overlay image for the field of view including the image and a visual indication on the image of an outline of the plurality of adjacent detection channels; positioning the field of view of the receiver module to cover the detection zone using the status overlay image; obtaining the plurality of digital signal waveforms using the traffic detection system; detecting a signal echo in one of the digital signal waveforms at a position within the field of view, the signal echo being caused by the presence of the object in the field of view; determining a location in the field of view for the object using the position; storing the location for the object.