Signal Processing Commons^™

Ultra-Wideband Power Amplifier Design For Large Signal Application, Ragavan Krishnamoorthy

Student Works (2020-2029)

Broadband power amplifier design has become one of the most critical enabling block in today’s wireless communication technology. Numerous research efforts have been carried out throughout the years to establish high efficiency over wideband RF transmitter. This research work presents two approaches in achieving ultra-broadband power amplifier for RF transmitter. Firstly, a new technique for the design of ultra-broadband RF power amplifier is introduced, in which a combination of the reactance compensation and third-harmonic tuning are adopted. The design goal is to achieve 40 dBm (10W) output power across a wide frequency bandwidth operation. Theoretical design equations were developed to …

Video And Image Super-Resolution Via Deep Learning With Attention Mechanism, Xuan Xu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Image demosaicing, image super-resolution and video super-resolution are three important tasks in color imaging pipeline. Demosaicing deals with the recovery of missing color information and generation of full-resolution color images from so-called Color filter Array (CFA) such as Bayer pattern. Image super-resolution aims at increasing the spatial resolution and enhance important structures (e.g., edges and textures) in super-resolved images. Both spatial and temporal dependency are important to the task of video super-resolution, which has received increasingly more attention in recent years. Traditional solutions to these three low-level vision tasks lack generalization capability especially for real-world data. Recently, deep learning methods …

Development Of A Software-Defined Underwater Acoustic Communication System, Zijian Zhu

Dissertations, Master's Theses and Master's Reports

This report started with a brief history and recent development of underwater acoustic communication systems as well as software-defined radio technologies. Then, some challenges from underwater acoustic channels and available underwater acoustic communication modems are discussed. After finished introducing the basics of SDR and GNU Radio, a detailed description of implementing a software-defined acoustic communication system in GNU Radio are presented, along with some key concepts of the system.

Then, some hardware specifications are presented, following by detailed documentation on a software-defined acoustic communication system experiment with a host computer, a USRP, an acoustic hydrophone, and a hydrophone. At the …

Aperture-Level Simultaneous Transmit And Receive (Star) With Digital Phased Arrays, Ian Cummings

Dissertations, Master's Theses and Master's Reports

In the signal processing community, it has long been assumed that transmitting and receiving useful signals at the same time in the same frequency band at the same physical location was impossible. A number of insights in antenna design, analog hardware, and digital signal processing have allowed researchers to achieve simultaneous transmit and receive (STAR) capability, sometimes also referred to as in-band full-duplex (IBFD). All STAR systems must mitigate the interference in the receive channel caused by the signals emitted by the system. This poses a significant challenge because of the immense disparity in the power of the transmitted and …

Anomalous Event Detection And Localization Based On Deep Generative Adversarial Networks For Surveillance Videos, Thittaporn Ganokratanaa

Chulalongkorn University Theses and Dissertations (Chula ETD)

Anomaly detection is of great significance for intelligent surveillance videos. Current works typically struggle with object detection and localization problems due to crowded scenes and lack of sufficient prior information of the objects of interest during training, resulting in false-positive detection results. Thus, in this thesis, we propose two novel frameworks for video anomaly detection and localization. We first propose a Deep Spatiotemporal Translation Network (DSTN), a novel unsupervised anomaly detection and localization method based on Generative Adversarial Network (GAN) and Edge Wrapping (EW). In this work, we introduce (i) a novel fusion of background removal and real optical flow …

Object Identification In Radar Imaging Via The Reciprocity Gap Method, Matthew Charnley, Aihua W. Wood

Faculty Publications

In this paper, we present an experimental method for locating and identifying objects in radar imaging, specifically problems that could arise in physical situations. The data for the forward problem are generated using a discretization of the Lippmann‐Schwinger equation, and the inverse problem of object location is solved using the reciprocity gap approach to the linear sampling method. The main new development in this paper is an exploration of determining the permittivity of the object from the back‐scattered data, utilizing another discretization of the Lippmann‐Schwinger equation.
Abstract © AGU.