Signal Processing Commons^™

"Auto-Tuned" Stereo, Daniel Montes

Electrical Engineering

The purpose of this project is to determine the capability of introducing delay and gain to audio signals to synthesize a “tuned” experience. The project uses audio operational amplifiers, field effect transistors, a class D amplifier, microphones, speakers, a 32-bit microcontroller for design and testing. When implementing the MOSFET into the all pass filter, the phase delay occurs by varying the transistor resulted in minimal change in phase. MOSFETs are used as variable resistors to vary the phase change and gain. By modifying the gain the synthesized distance from each speaker can be adjusted. Varying the phase change provides the …

Digital Guitar Effects Unit And Amplifier, Kevin Salvador

Electrical Engineering

This report outlines the design and implementation of a digital guitar effects unit and amplifier. The main portion of this project consisted of the digital equalizer and effects. Several commercial equalizers were researched in order to decide the typical frequency bands and average amount of bands total. Eventually 8 bands were selected. A range of approximately 20Hz-3kHz was chosen based on test data of guitar signals. Popular effects that were incorporated in this project include Distortion, Echo, Reverb, Chorus and Flanger. The digital processor chosen was a Texas Instruments c6713 floating point processor. Designs for the various filters were done …

Spectral Shape Division Multiplexing (Ssdm): Apparatus, Transmitter, Receiver And Detection, Fausto Daniel Holguín-Sánchez

Master's Theses

Wireless communication companies require to use the frequency spectrum to operate. Both frequency licenses and infrastructure to reuse frequencies are costly resources subject to increasing demand. This work introduces a novel multiplexing method that saves spectrum called Spectral Shape Division Multiplexing (SSDM). Under certain configurations, SSDM displays higher flexibility and throughput than other spectrally efficient methods.

SSDM defines the structure of a wireless multi-carrier by software. It is similar to Orthogonal Frequency Division Multiplexing (OFDM) in that both use overlapped sub-carriers to make efficient use of allocated spectrum. However, SSDM has several advantages. Where OFDM organizes sub-carriers orthogonally, SSDM allows …

Real-Time Musical Analysis Of Polyphonic Guitar Audio, John E. Hartquist

Master's Theses

In this thesis, we analyze the audio signal of a guitar to extract musical data in real-time. Specifically, the pitch and octave of notes and chords are displayed over time. Previous work has shown that non-negative matrix factorization is an effective method for classifying the pitches of simultaneous notes. We explore the effect of window size, hop length, and other parameters to maximize the resolution and accuracy of the output.

Other groups have required prerecorded note samples to build a library of note templates to search for. We automate this step and compute the library at run-time, tuning it specifically …

Study Of Statistical And Computational Intelligence Methods Of Detecting Temporal Signature Of Forest Fire Heat Plume From Single-Band Ground-Based Infrared Video, Daniel G. Kohler

Master's Theses

This thesis will analyze video from land-based, cooled mid-wave infrared cameras to identify temporal features indicative of a heat plume from a forest fire. Desirable features and methods will show an ability to distinguish between heat plume movement and other movements, such as foliage, vehicles, humans, and birds in flight. Features will be constructed primarily using combinations of statistics and principal component analysis (PCA) with intent to detect key characteristics of fire and heat plume: persistence and growth. Several classification systems will combine and filter the features in an attempt to classify pixels as either heat or non-heat. The classification …

Digital Graphic Equalizer Implemented Using An Fpga, Anthony Giardina

Electrical Engineering

A graphic equalizer is a device that adjusts the tonal quality of an audio signal. When sound is converted from a digital format to analog sound waves, there are amplification and transducing steps in-between the two formats. Common devices to perform these tasks are speakers, amplifiers, DACs, etc. Many of these devices exhibit a non-uniform frequency response over the range of human hearing. Thus, it is possible that certain frequency ranges of the audio signal will be amplified and others will be attenuated. To counteract this, an audio equalizer can be used to boost and attenuate certain frequency ranges within …

802.15.4 Low Intermediate Frequency Radio Receiver, Sanjay Avasarala

Electrical Engineering

This project involves the design, building, and testing of a low intermediate frequency 802.15.4 receiver that uses an FPGA to perform final demodulation to baseband.

The Interacting Multiple Models Algorithm With State-Dependent Value Assignment, Rastin Rastgoufard

LSU New Orleans Theses and Dissertations

The value of a state is a measure of its worth, so that, for example, waypoints have high value and regions inside of obstacles have very small value. We propose two methods of incorporating world information as state-dependent modifications to the interacting multiple models (IMM) algorithm, and then we use a game's player-controlled trajectories as ground truths to compare the normal IMM algorithm to versions with our proposed modifications. The two methods involve modifying the model probabilities in the update step and modifying the transition probability matrix in the mixing step based on the assigned values of different target states. …

Converting Three-Component To Four-Component Image (2012), Ronald S. Cok, Michael E. Miller

AFIT Patents

A method of converting a three-or-more-color-component image input signal to an image output signal includes acquiring an input signal having a plurality of pixel signals, each pixel signal having three, or more, color components; determining a residual difference for each color component of each pixel signal; determining a limit value of the residual differences; calculating a common scale factor for each of the color components based upon the limit value; and applying the common scale factor to the image input signal to produce the image output signal.

Multi-Circle Detections For An Automatic Medical Diagnosis System, Dingran Lu

Master's Theses

Real-time multi-circle detection has been a challenging problem in the field of biomedical image processing, due to the variable sizes and non-ideal shapes of cells in microscopic images. In this study, two new multi-circle detection algorithms are developed to facilitate an automatic bladder cancer diagnosis system: one is a modified circular Hough Transform algorithm integrated with edge gradient information; and the other one is a stochastic search approach based on real valued artificial immune systems. Computer simulation results show both algorithms outperform traditional methods such as the Hough Transform and the geometric feature based method, in terms of both precision …

Vision-Based Human Action Recognition: A Sparse Representation Perspective, Zhe Zhang

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The objective of vision-based human action recognition is to label the video sequence with its corresponding action category. In this thesis, the human action recognition problem is solved from a novel sparse representation perspective. First, spatial-temporal interest points are extracted in the video sequences. Then, a cuboid is extracted centered at each spatial-temporal interest point. The histogram of oriented gradients (HOG) and histogram of flow (HOF) descriptors for each cuboid are computed and concatenated into a one-dimensional vector. The K-Means clustering algorithm is used to cluster these cuboid feature vectors into a few visual codewords. Finally, each action instance is …

The Presence Of Regional Accents In Electrolarynx Speech And The Resultant Effect On Overall Intelligibility., Brian Madden, Eugene Coyle

Conference Papers

During voiced speech, the larynx provides quasi-periodic acoustic excitation of the vocal tract. In most electrolarynxes, mechanical vibrations are produced by a linear electromechanical actuator, the armature of which percusses against a metal or plastic plate at a frequency within the range of glottal excitation. In this paper, a phonological analysis of a section of results from an online perceptual intelligibility test was performed which compared speech produced using a novel hands-free electrolarynx and a commercially available electrolarynx. A portion of the test consisted of a closed-set format containing a selection of four sets of four random CVC audio samples …

Robot X, Alan Truong, Alex Haag

Computer Engineering

The following report outlines the design decisions behind Robot X for the 2012 Cal Poly Roborodentia competition held annually during Open House. This investigation includes detailed overview of Robot X's sensory system, driving system, conveyor belt system, and can compartment system. In addition, basic hardware and software design are explored.

Local Histograms For Per-Pixel Classification, Melody L. Massar

Theses and Dissertations

We introduce a rigorous mathematical theory for the analysis of local histograms, and study how they interact with textures that can be modeled as occlusions of simpler components. We first show how local histograms can be computed as a system of convolutions and discuss some basic local histogram properties. We then introduce a probabilistic, occlusion-based model for textures and formally demonstrate that local histogram transforms are natural tools for analyzing the textures produced by our model. Next, we characterize all nonlinear transforms which satisfy the three key properties of local histograms and consider the appropriateness of local histogram features in …

Dismount Threat Recognition Through Automatic Pose Identification, Andrew M. Freeman

Theses and Dissertations

The U.S. military has an increased need to rapidly identify nonconventional adversaries. Dismount detection systems are being developed to provide more information on and identify any potential threats. Current work in this area utilizes multispectral imagery to exploit the spectral properties of exposed skin and clothing. These methods are useful in the location and tracking of dismounts, but they do not directly discern a dismount's level of threat. Analyzing the actions that precede hostile events yields information about how the event occurred and uncovers warning signs that are useful in the prediction and prevention of future events. A dismount's posturing, …

Ofdm-Based Signal Exploitation Using Quadrature Mirror Filter Bank (Qmfb) Processing, Felipe E. Garrido

Theses and Dissertations

By performing QMFB processing with a given signal it is possible to obtain Frequency-Time (F-T) outputs that represent signal features such as bandwidth (W), center frequency (fc), signal duration (Ts), modulation type (AM, FM, BPSK, QAM, etc), frequency content and time allocation. Because of its unique structure, two widely used signals based on Orthogonal Frequency Division Multiplexing (OFDM) were chosen as signals of interest for demonstration. The general implementation of the QMFB process is described along with the basic structure of OFDM signals related to the physical layer perspective of 802.11a Wi-Fi and 802.16e WiMAX frame structures are described. The …

Binary Classification Of An Unknown Object Through Atmospheric Turbulence Using A Polarimetric Blind-Deconvolution Algorithm Augmented With Adaptive Degree Of Linear Polarization Priors, Mu J. Kim

Theses and Dissertations

This research develops an enhanced material-classification algorithm to discriminate between metals and dielectrics using passive polarimetric imagery degraded by atmospheric turbulence. To improve the performance of the existing technique for near-normal collection geometries, the proposed algorithm adaptively updates the degree of linear polarization (DoLP) priors as more information becomes available about the scene. Three adaptive approaches are presented. The higher-order super-Gaussian method fits the distribution of DoLP estimates with a sum of two super-Gaussian functions to update the priors. The Gaussian method computes the classification threshold value, from which the priors are updated, by fitting the distribution of DoLP estimates …

Ladar Range Image Interpolation Exploiting Pulse Width Expansion, Jeramy W. Motes

Theses and Dissertations

Laser Detection and Ranging (LADAR) systems produce both a range image and an intensity image by measuring the intensity of light reflected off a surface target. When the transmitted LADAR pulse strikes a sloped surface, the returned pulse is expanded temporally. This characteristic of the reflected laser pulse enables the possibility of estimating the gradient of a surface. This study estimates the gradient of the surface of an object from a modeled LADAR return pulse that includes accurate probabilistic noise models. The range and surface gradient estimations are incorporated into a novel interpolator that facilitates an effective three dimensional (3D) …

Passive Multistatic Radar Imaging Using An Ofdm Based Signal Of Opportunity, Matthew B. P. Rapson

Theses and Dissertations

This paper demonstrates a proof of concept in using an OFDM-based signal of opportunity for SAR imaging purposes within a passive, multistatic radar construct. Two signal processing methods have been proposed to create phase history data. The same methods are applied in both a simulated software model and an experimental data collection environment to produce simulated SAR images using the CBP imaging algorithm. The images generated from both the experimental and simulated data were observed to be consistent with each other and with expectations in terms of resolution. Coherent addition of the images results in improved image resolution due to …

Simultaneous Range-Velocity Processing And Snr Analysis Of Afit's Random Noise Radar, T. Joel Thorson

Theses and Dissertations

This paper presents two research objectives aimed at advancing the AFIT RNR signal processing algorithm and modeling capability toward the overarching goal of performing collision avoidance on an autonomous vehicle. In both research efforts, analytical, simulated, and measured results are provided and used to draw research conclusions. The first research effort is aimed at reducing the memory required for 2D processing in the time domain in order to distribute the processing algorithm across hundreds of processors on a GPU. Distributed processing reduces the overall 2D processing time and the feasibility of a near real-time implementation is studied. The second effort …