Peter Driessen
University of Victoria, Electrical and Computer Engineering, Faculty Member
This paper presents an efficient deep learning framework for long-term monitoring of acoustic events from hydrophone big data. The large-scale noisy ONC (Ocean Networks Canada) data may contain rare acoustic events, which can be... more
This paper presents an efficient deep learning framework for long-term monitoring of acoustic events from hydrophone big data. The large-scale noisy ONC (Ocean Networks Canada) data may contain rare acoustic events, which can be automatically recognized by utilizing a deep convolutional neural network. Few works have been reported in the area of deep learning for the recognition of different kinds of marine mammal calls which however is crucial for many applications such as marine navigation. In this proposed scheme, deep learning feature sets are adopted and processed by a support vector machione (SVM) classifier. The proposed method is tested with 28685 minutes of data, spanning a single year with 5573 whale calls/acoustic events, and using a human operator's annotations. The experimental results show that the average accuracy rate of recognition using deep feature learning are 98.69% (two-class) and 94.48% (multi-class), respectively, for the proposed recognition scheme, which outperforms the MFCC-based method.
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ABSTRACT
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The mathematical theory of the time-compression overlap add scheme for radio communications is presented. A simple time-shifting model is developed to explore performance in AWGN and multipath Rayleigh fading channels. Equivalent... more
The mathematical theory of the time-compression overlap add scheme for radio communications is presented. A simple time-shifting model is developed to explore performance in AWGN and multipath Rayleigh fading channels. Equivalent multirate filter structures for both the transmit and receive processes are developed and used to analyze the spectrum of the transmitted signal as it relates to the spectrum of the message signal.
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— A Class-AB microwave-photonic link is presented as a means to reduce noise associated with DC-bias. By operating with two complementary, approximately half-wave-rectified, optical sources and generating the difference in a balanced... more
— A Class-AB microwave-photonic link is presented as a means to reduce noise associated with DC-bias. By operating with two complementary, approximately half-wave-rectified, optical sources and generating the difference in a balanced detector, linear modulation with high modulation efficiency is achieved with near zero DC. Using two mode-converter intensity modulators, we demonstrate a 5 dB reduction in shot noise and elimination of intensity noise, relative to a quadrature-biased Mach-Zehnder, for the same received RF signal power. Index Terms — Microwave-photonic, analog links, subcarrier, low-bias, intensity-noise suppression, class AB.
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This paper discusses an evolution in North Indian instruments in the designing of technology to capture gestures from a performing artist. Modified traditional instruments use sensor technology and microcontrollers to digitize gestures,... more
This paper discusses an evolution in North Indian instruments in the designing of technology to capture gestures from a performing artist. Modified traditional instruments use sensor technology and microcontrollers to digitize gestures, enabling a computer to analyze performance to synthesize sound and visual meaning. Specifically, systems were built to capture data from three traditional North Indian instruments: the tabla (a pair of tonal hand drums), the dholak (a barrel shaped folk drum played by two people), and the sitar (a 19-stringed, gourd-shelled instrument). This paper will discuss how these instruments are modified to capture gestural movement, how these signals are mapped to sounds and graphical feedback, and show examples of the new instruments being used in live performance. The hardware is built to try and preserve the techniques passed down from generations of tradition; however, modified performance techniques with the aid of a laptop are also introduced. 1
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Abstract: Using the MPEG-4 Advanced Audio Coder (AAC) music as an example of streaming applications, we investigate the improvement of error performance for the streaming service by link-adaptation and power-control techniques in an... more
Abstract: Using the MPEG-4 Advanced Audio Coder (AAC) music as an example of streaming applications, we investigate the improvement of error performance for the streaming service by link-adaptation and power-control techniques in an Enhanced General Packet Radio Services (EGPRS) cellular network. A low packet error rate and variability are essential in providing short error-burst length so that error concealment techniques can be effectively applied to music packets. In this paper, we study the effects of a combined link adaptation and power control scheme (referred to as the error-based schme) for achieving a target error rate and reducing error variability. By simulation, we compare the error performance of the error-based scheme at both the EGPRS block and AAC frame level with another adaptation algorithm (referred to as the throughput-based scheme) with a goal of maximizing overall network throughput. It is found that when offered with similar traffic load, the former scheme can...
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This convention paper has been reproduced from the author’s advance manuscript, without editing, corrections, or consideration by the Review Board. The AES takes no responsibility for the contents. Additional papers may be obtained by... more
This convention paper has been reproduced from the author’s advance manuscript, without editing, corrections, or consideration by the Review Board. The AES takes no responsibility for the contents. Additional papers may be obtained by sending request and remittance to Audio Engineering Society, 60 East 42nd Street, New York, New York 10165-2520, USA; also see www.aes.org. All rights reserved. Reproduction of this paper, or any portion thereof, is not permitted without direct permission from the Journal of the Audio Engineering Society.
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We introduce a new scheme that integrates the Time Compression OverLap-Add (TC-OLA) spread spectrum technique into radar systems, more specifically the Linear Frequency Modulation Pulse Compression (LFM-PC) radar. This technique increases... more
We introduce a new scheme that integrates the Time Compression OverLap-Add (TC-OLA) spread spectrum technique into radar systems, more specifically the Linear Frequency Modulation Pulse Compression (LFM-PC) radar. This technique increases the signal to noise ratio (SNR) and, as a consequence, enables a greater processing gain compared to the traditional radar LFM-PC systems. In addition, TC-OLA allows the radar designer to control the spreading of the signal and therefore provides a better immunity against powerful jamming techniques. In our simulation, we extend the conventional LFM-PC radar model by appropriately adding Time Compression (TC) and Overlap-add (OLA) blocks at the transmitter and receiver, respectively. The evaluation performance of the proposed system and the convention LFM are done under AWGN and under one of the smart jamming technique called Convolution Noise Jamming (CNJ) using different Constant False Alarm Rate (CFAR) algorithms, namely, Cell-Average (CA), Grea...
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The University of Victoria has a new centre for computer music and digital media called MISTIC (Music Intelligence and Sound Technology Interdisciplinary Centre). Research and educational activities pertaining to MISTIC are described.
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In this paper, we review 2nd and 3rd generation wireless telephony systems, both in terms of technology and service concepts. We point out some of the technical and service issues that may a ect the functionality and performance from the... more
In this paper, we review 2nd and 3rd generation wireless telephony systems, both in terms of technology and service concepts. We point out some of the technical and service issues that may a ect the functionality and performance from the user point of view. In particular, we focus on one technical and one service concept important for long term success of 3rd generation systems: transmit diversity to increase capacity (quantity),and context-sensitive applications to increase user ac-
This paper proposes a novel method for anomaly and quality detection of marine mammal sounds using multitaper spectrogram and hydrophone big data. The proposed method is aimed to automatically detect anomaly, such as high-frequency vessel... more
This paper proposes a novel method for anomaly and quality detection of marine mammal sounds using multitaper spectrogram and hydrophone big data. The proposed method is aimed to automatically detect anomaly, such as high-frequency vessel noise, Doppler noise, in sperm whale (SPW) sound as well as the quality of the sound. A new signature function derived from a multi-taper spectrogram is able to detect the anomaly in the data and a new anomaly distortion measure can detect the sound quality into good/bad. The proposed method, is tested with 1905 minutes of data spanning a single year, and using a human operator's annotations. The experimental results reveal that the proposed multitaper spectrogram based approach is efficient in detecting anomaly as well as sperm whale sound quality for hydrophone big data and high detection accuracy (>85%) is achieved for raw input hydrophone data.
This paper presents a new radar system that combines any number and any kind of radar signals and transmits them simultaneously, thereby obtaining all the advantages of each of the radar waveforms used. This new system is based on a... more
This paper presents a new radar system that combines any number and any kind of radar signals and transmits them simultaneously, thereby obtaining all the advantages of each of the radar waveforms used. This new system is based on a low-rate coded time compression overlap-add (TC-OLA) technique, and allows radar designers to address the challenge of having many features, such as high-time resolution, high-Doppler tolerance, low-sidelobe level, and low probability of intercept (LPI), in a single waveform. Since different types of radar waveforms usually offer different features, the new system allows the designers to obtain optimality via pluralism. The performance evaluation of the new radar system shows its superiority when examined under noise and heavy-tailed clutter background over the classical radar system and other methods of combination by operating on $N$-radar signals simultaneously, making use of features from each waveform, canceling the Doppler from a Doppler-intolerant...
Acoustic musical instruments enable very rich and subtle control when used by experienced musicians. Musicology has traditionally focused on analysis of scores and more recently audio recordings. However, most music from around the world... more
Acoustic musical instruments enable very rich and subtle control when used by experienced musicians. Musicology has traditionally focused on analysis of scores and more recently audio recordings. However, most music from around the world is not notated, and many nuances of music performance are hard to recover from audio recordings. In this chapter, we describe hyperinstruments, i. e., acoustic instruments that are augmented with digital sensors for capturing performance information and in some cases offering additional playing possibilities. Direct sensors are integrated onto the physical instrument, possibly requiring modifications. Indirect sensors such as cameras and microphones can be used to analyze performer gestures without requiring modifications to the instrument. We describe some representative case studies of hyperinstruments from our own research as well as some representative case studies of the types of musicological analysis one can perform using this approach, such ...
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A variant of time-compression overlap-add (TC-OLA) is proposed as an alternate physical layer scheme for ultrawideband communications. Although the construction of the transmitted signal is identical to other TC-OLA applications, this... more
A variant of time-compression overlap-add (TC-OLA) is proposed as an alternate physical layer scheme for ultrawideband communications. Although the construction of the transmitted signal is identical to other TC-OLA applications, this letter explores block-based receiver structures using frequency domain equalization (FDE) techniques that allow for a longer delay spread relative to the window size than time-domain TC-OLA processing. An important and novel contribution of this method is the reduction or elimination of the cyclic prefix (CP) overhead due to the way that redundancy is added to the transmitted signal by the TC-OLA process. Unlike overlap FDE, the CP overhead is eliminated without the increased processing load required to maintain a practically useful bit error rate floor. For very high delay spread channels, such as CM8, a long effective CP length can be obtained without requiring a much longer fast Fourier transform block length to maintain efficiency.
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In this paper, we present a novel method for detection of low frequency signals less than 100 Hz in hydrophone data sampled at 96 KHz. The low-frequency activities (e.g. particular whale calls) in the hydrophone data are detected based on... more
In this paper, we present a novel method for detection of low frequency signals less than 100 Hz in hydrophone data sampled at 96 KHz. The low-frequency activities (e.g. particular whale calls) in the hydrophone data are detected based on B-spline approximations of the hydrophone data. The error pattern of the incoming/detected signal and template signal is derived by calculating the MSEs (mean-square errors) between their B-spline approximations and compared with that of the reference signal and template signal. Here, the incoming signal is a detected (new/non-labeled) hydrophone data, whereas the reference signal is the ensemble of labeled hydrophone data and the template is a target signal that controls the detection. In the decision module, the threshold is selected based on the skewness of the error patterns. The performance of the method is evaluated using real recorded hydrophone data showing promising results.
In this paper, we present a new framework of multiple classifiers fusion to classify acoustic events in ONC (Ocean Network Canada) hydrophone data. The outputs of three different classifiers are fused based on aggregation of a generated... more
In this paper, we present a new framework of multiple classifiers fusion to classify acoustic events in ONC (Ocean Network Canada) hydrophone data. The outputs of three different classifiers are fused based on aggregation of a generated decision matrix. An ensemble class label is thereby obtained for the classification of acoustic events into multiple classes of whale calls, boat sounds and noise. The classification performances are evaluated using real recorded hydrophone data showing an overall improvement of the classification accuracy by 10% for the proposed method over the average accuracy of the individual classifiers.
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In this paper, we address the problem of multi-class classification of hydrophone data for acoustic events using low-dimensional features. A new iterative multiclass classification scheme is proposed based on the combination of adaptive... more
In this paper, we address the problem of multi-class classification of hydrophone data for acoustic events using low-dimensional features. A new iterative multiclass classification scheme is proposed based on the combination of adaptive MFCC feature set and an improved HMM-GMM classifier. The adaptive window length for MFCC is important since for acoustic sounds in the ocean, the optimum window length may be different unlike the window length of 16 - 32 msec, which is optimum for speech signals. Further, in order to increase the classification performance, we perform the B-spline approximation to the generated Gaussians parameters of the multi model HMM-GMM classifier to enhance the separation of the decision region. Experimental results for the real recorded hydrophone data show that our improved iterative scheme efficiently classifies the acoustic events with high mean accuracy (96%), sensitivity (95%), and specificity (97%).
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ABSTRACT Sub-pixel accuracy takes up a significant portion of the motion estimation with respect to the computational complexity of video coding. The error criterion function of motion estimation is well represented by a mathematical... more
ABSTRACT Sub-pixel accuracy takes up a significant portion of the motion estimation with respect to the computational complexity of video coding. The error criterion function of motion estimation is well represented by a mathematical expression such as quadratic and linear model around the optimal point. Pre-computed error criterion values computed at full-pixel accuracy can be used to derive the motion vector and the error criterion values at sub-pixel accuracy. Based on a linear model function, explicit solutions of the motion vector and the error criterion values at sub-pixel accuracy are derived, which results in the dramatic reduction of computing complexity during the motion estimation process. In addition, a gradient based method is proposed and applied in search of the optimal point which improves further the motion estimation performance while the complexity increase remains negligible.
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Abstract. The paper gives an overview of the multiple-input multiple-output (MIMO) systems and discusses their benefits enabling an increase in the system capacity and an increase of system reliability. The former is attained by signal... more
Abstract. The paper gives an overview of the multiple-input multiple-output (MIMO) systems and discusses their benefits enabling an increase in the system capacity and an increase of system reliability. The former is attained by signal multiplexing and the later by space encoding. ...
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An improved frame synchronization technique is proposed for mobile and portable packet radio systems which use standard VLSI synchronous input/output (SIO) hardware devices for data transmission. This technique overcomes the performance... more
An improved frame synchronization technique is proposed for mobile and portable packet radio systems which use standard VLSI synchronous input/output (SIO) hardware devices for data transmission. This technique overcomes the performance limitations inherent in the SIO 2-byte hardware frame sync function by using a multiple-byte marker and additional software for frame sync. When compared to systems using a dedicated multibyte
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ABSTRACT Although the optimal detection of signals in a K-user CDMA synchronous system has been proved to be NP-hard, some suboptimal methods do exist to approximate the optimal one. The authors develop a new multistage detector using the... more
ABSTRACT Although the optimal detection of signals in a K-user CDMA synchronous system has been proved to be NP-hard, some suboptimal methods do exist to approximate the optimal one. The authors develop a new multistage detector using the transformation proposed by Carter (1984) to approach the optimal solution. The transformation modifies the diagonal elements of the hessian matrix of the quadratic function corresponding to the optimal receiver and brings the continuous minimum of the transformed function as closely to the optimal solution as possible. The convergence of the new multistage algorithms is studied. The computational complexity is essentially linear with the number of users except that a few computations of a quadratic function are needed. The numerical results for the detection of synchronous CDMA signals are shown to be very encouraging
In this paper, a new image based method for detecting and extracting events in noisy hydrophone data sequence is developed. The method relies on dominant orientation and its robust reconstruction based on mutual information (MI) measure.... more
In this paper, a new image based method for detecting and extracting events in noisy hydrophone data sequence is developed. The method relies on dominant orientation and its robust reconstruction based on mutual information (MI) measure. This new reconstructed dominant orientation map of the spectrogram image can provide key segments corresponding to various acoustic events and is robust to noise. The proposed method is useful for long-term monitoring and a proper interpretation for a wide variety of marine ...
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ABSTRACT The use of multiple element antennas-both transmitting and receiving-has great potential for increasing the capacity of wireless systems. The capacity is derived as a function of the eigenvalues of the channel matrix and computed... more
ABSTRACT The use of multiple element antennas-both transmitting and receiving-has great potential for increasing the capacity of wireless systems. The capacity is derived as a function of the eigenvalues of the channel matrix and computed for an “edge-excited cell” with 3 base sites and a subscriber terminal with a 3 element array, for line-of-sight channels. In an attempt to approach this capacity, we use a blind source separation technique at the receiver, and in the case when the smallest eigenvalue makes a negligible contribution to the capacity, we propose a way of using different transmitting schemes through link adaptation. These techniques allow multiple co-channel signals to coexist within the cell and thus capacity is increased. We present simulation results to compare their performance to the great capacity announced by information theory
ABSTRACT The use of multiple element antennas-both transmitting and receiving-has great potential for increasing the capacity of wireless systems. The capacity is derived as a function of the eigenvalues of the channel matrix and computed... more
ABSTRACT The use of multiple element antennas-both transmitting and receiving-has great potential for increasing the capacity of wireless systems. The capacity is derived as a function of the eigenvalues of the channel matrix and computed for an “edge-excited cell” with 3 base sites and a subscriber terminal with a 3 element array, for line-of-sight channels. In an attempt to approach this capacity, we use a blind source separation technique at the receiver. We show that the multiple-input multiple-output system, implemented with such innovative signal processing, offers great enhanced capacity compared to conventional single-input single-output (SISO) systems
ABSTRACT The use of multiple element antennas-both transmitting and receiving-has great potential for increasing the capacity of wireless systems. The maximum capacity is computed for an “edge-excited” cell with 3 base sites and a... more
ABSTRACT The use of multiple element antennas-both transmitting and receiving-has great potential for increasing the capacity of wireless systems. The maximum capacity is computed for an “edge-excited” cell with 3 base sites and a subscriber terminal with a 3 element array, for line-of-sight channels. In an attempt to approach this capacity, we show that the use of innovative signal processing at the receiver (blind source separation technique) seems to allow the system to achieve a significant portion of this great capacity promised by information theory
1 GHz complex impulse response data in mountainous terrain is measured at closely spaced locations, and is processed as data from a synthetic aperture array. Experimental data from linear and crossed arrays with 50 or 100 elements is... more
1 GHz complex impulse response data in mountainous terrain is measured at closely spaced locations, and is processed as data from a synthetic aperture array. Experimental data from linear and crossed arrays with 50 or 100 elements is considered. The direction of arrival for each delayed component is identified, and contour plots of the receiver power at bearings and distances
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ABSTRACT The performance of the 40 bit frame synchronization sequence adopted for ATCS (automatic train-control systems) is examined in detail. A general expression is derived for the probability of synchronization as a function of the... more
ABSTRACT The performance of the 40 bit frame synchronization sequence adopted for ATCS (automatic train-control systems) is examined in detail. A general expression is derived for the probability of synchronization as a function of the bit error and erasure probability, the overlap n , and the number of bit errors/erasures which are tolerated in the frame sync word. The probability P D of successful frame sync with errors-and-erasures decoding is compared to P D with errors-only decoding. For a given bound on false alarms, a significant improvement in P D is found on random error channels if the receiver contains an erasure zone. An improved frame synchronization scheme which uses the preamble is shown to follow a higher error tolerance for a given false-alarm probability, and thus a higher P D
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The capacity of multiple input, multiple output (MIMO) wireless channels is computed for Ricean channels. The novelty is a geometrical (ray-tracing) interpretation of the MIMO channel capacity formula to find array geometries which... more
The capacity of multiple input, multiple output (MIMO) wireless channels is computed for Ricean channels. The novelty is a geometrical (ray-tracing) interpretation of the MIMO channel capacity formula to find array geometries which greatly enhance channel capacity compared to single input--single output (SISO) systems.
Abstract A new method to combat the adjacent channel interference (ACI) encountered with multichannel receivers is presented. In the case of a two-channel receiver, components of the desired signal may become present in the reference to... more
Abstract A new method to combat the adjacent channel interference (ACI) encountered with multichannel receivers is presented. In the case of a two-channel receiver, components of the desired signal may become present in the reference to the interference rendering ...
Any mobile radio data communications system can carry many more messages per hour than a conventional voice system; however, the full potential throughput capacity of a digital system is not generally realized in practice. With high speed... more
Any mobile radio data communications system can carry many more messages per hour than a conventional voice system; however, the full potential throughput capacity of a digital system is not generally realized in practice. With high speed (4800 bps) modems, the maximum throughput of a mobile radio data communications system is limited by radio transmit/receive switching time and signal presence detection time. The factors contributing to these times are outlined, and network design approaches which minimize their effect on throughput are described.
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The El-Lamellophone (El-La) is a Lamellophone hyperinstrument incorporating electronic sensors and integrated DSP. Initial investigations have been made into digitallycontrolled physical actuation of the acoustic tines. An embedded Linux... more
The El-Lamellophone (El-La) is a Lamellophone hyperinstrument incorporating electronic sensors and integrated DSP. Initial investigations have been made into digitallycontrolled physical actuation of the acoustic tines. An embedded Linux micro-computer supplants the laptop. A piezoelectric pickup is mounted to the underside of the body of the instrument for direct audio acquisition providing a robust signal with little interference. The signal