Systems and Communications Commons^™

A Study On Quantization And Hardware Cost Tradeoffs In A 5g Nr Ldpc Decoder On Fpga, Giancarlo Acosta

Master's Theses

The fixed-point implementation of a 5G New Radio LDPC decoder forces a tradeoff between precision and hardware cost, governed by the variable node word length W_L, the check node message width W_R, and the normalized min-sum correction factor α. This thesis characterizes how these three parameters affect both error correction performance and FPGA resource utilization for an LDPC decoder on an established LDPC decoder architecture. A bit-accurate MATLAB core model records bit error rate (BER) and frame error rate (FER) while a verified HDL Coder model generates synthesizable VHDL for Vivado synthesis, and both are swept …

Coherent Synchronization For Distributed Digital Phased Arrays, Zachary C. Numa

Master's Theses

Distributed digital phased arrays are rising technologies that help enable applications such as search and rescue operations, wireless communication, radar navigation, and military operations, among many others. Due to their improved angular resolution, digital phased arrays offer superior direction-finding capabilities compared to traditional analog phased array systems. However, this improvement comes at the cost of increased complexity—specifically, the need for precise synchronization of phase, time, and frequency across physically separated nodes. Without synchronization, the distributed phased array's gain and direction-of-arrival (DoA) estimations deteriorate significantly.

There are multiple aspects to implementing and synchronizing a non-stationary distributed digital phased array. This research …

Modeling W/V-Band Satellite Communications In The Presence Of Noise Jamming, Ryan Michael Eckman

Electrical and Computer Engineering ETDs

Understanding the performance of wideband modulated signals under noise jamming conditions is important for advancing W/V-band military satellite communications. This research developed and validated models to predict performance degradation of a communication channel in the presence of wideband noise jamming. Channel models were developed that included both modulated communication signals and jammer signals. Integrated models included environmental link factors and practical implementation factors. Integrated models were verified and validated using outdoor radio frequency environments utilizing two W/V-band transceivers, a portable W-band jammer, and software defined radios. Experimental results demonstrated excellent agreement with integrated model predictions. Channel degradation due to the …

Learning Proximal Operators With Gaussian Process And Adaptive Quantization In Distributed Optimization, Aldo Duarte Vera Tudela

LSU Doctoral Dissertations

In networks consisting of agents communicating with a central coordinator and working together to solve a global optimization problem in a distributed manner, the agents are often required to solve private proximal minimization subproblems. Such a setting often requires a further decomposition method to solve the global distributed problem, resulting in extensive communication overhead. In networks where communication is expensive, it is crucial to reduce the communication overhead of the distributed optimization scheme. Integrating Gaussian processes (GP) as a learning component to the Alternating Direction Method of Multipliers (ADMM) has proven effective in learning each agent's local proximal operator to …

An Evaluation Of Wi-Fi 802.11b Backscatter, Anthony Chen

All Theses

Internet of Things (IoT) devices are in need of low-power communications systems with longevity and reliability. With the use of backscatter technology, IoT devices can communicate at the cost of almost no power and can last for up to a decade. Furthermore, backscatter technology is compatible with everyday wireless signals such as Wi-Fi and Bluetooth, allowing for easy communication without specific hardware constraints. This thesis aims to evaluate a Wi-Fi backscatter system and analyze its ease in triggering off of such ambient signals and sources. The system will utilize Wi-Fi 802.11b as a backscatter source to trigger the backscatter system …

Neural Networks For Interference Mitigation In Satellite Communication Systems, Martha E. Cash

LSU Master's Theses

The objective of this thesis is to utilize the power of machine learning to develop a neural network-aided receiver in a DVBS-2X satellite communication system to improve the downlink transmission quality in the presence of interference. An emphasis is placed on mitigating the effects caused by non-linear distortions, carrier frequency offset, and additive white Gaussian noise. This thesis proposes a feed-forward neural network with two hidden layers to compensate for the distortions in the received signal. The proposed system model uses 16-APSK modulation scheme. The neural network is tested under varying degrees of non-linear distortion, frequency offsets, and varying levels …

Autonomous Wildfire Detection System, Matthew Pyle, Nick Garrett

Williams Honors College, Honors Research Projects

According to the National Fire Protection Association Journal, federal wildfire suppression costs in the United States have risen from an annual average of about $425 million from 1985 to 1999 up to $1.6 billion from 2000 to 2019. On average, more than 200,000 acres in the United States are burned per year due to wildfires, with more than 700,000 acres burned in 2020 alone. With the risk of wildfire ever rising, there is a need for better early detection of remote wildfires, as existing methods often include long delays like satellites or rely on human lookout towers. The objective is …

An Investigation Into Cognitive Radio System Performance, Courtney Hardy, Lucas F. Feather, William S. Guy

Honors Theses

The objective of this thesis is to explore cognitive radio performance through an in-depth literature review and an implementation of a software-defined radio prototyping system. Specifically, this thesis investigates the spectrum-sensing aspect of cognitive radio by comparing two spectrum-sensing methods. It was found in the literature review that a system utilizing matched filter detection would provide higher probability of detection in low signal-to-noise ratio environments when compared to a system utilizing energy detection. These spectrum sensing methods were thus implemented and compared in the cognitive radio systems presented in this thesis. Additionally, experiments were conducted to determine the most efficient …

Ofdm Simulation, Joseph W. Bednar

Electrical Engineering

The project objective is to provide a tool that will allow the user to simulate an adaptive OFDM (Orthogonal Frequency-Division Multiplexing) communication system in the presence of various types of interference and noise. The open-source code allows students and engineers to adjust the modulation, threshold settings, and distortion effects in the channel while observing the output bit error rate. The results the simulation provides will aid researchers in attempting to characterize the interference of OFDM based systems and their effectiveness in the presence of noise.

Virtual Satcom, Long Range Broadband Digital Communications, Dennis George Watson

Electrical & Computer Engineering Theses & Dissertations

The current naval strategy is based on a distributed force, networked together with high-speed communications that enable operations as an intelligent, fast maneuvering force. Satellites, the existing network connector, are weak and vulnerable to attack. HF is an alternative, but it does not have the information throughput to meet the distributed warfighting need. The US Navy does not have a solution to reduce dependency on space-based communication systems while providing the warfighter with the required information speed.

Virtual SATCOM is a solution that can match satellite communications (SATCOM) data speed without the vulnerable satellite. It is wireless communication on a …

Optimal Capacity And Energy Efficiency Of Massive Mimo Systems, Ahmed Alshammari

Electronic Theses and Dissertations

A lot of effort has been made during the last two decades to study and apply the concepts of MIMO technology in most of the wireless standards. Therefore, a huge improvement in the performance of wireless communications has been made. However, Demand for wireless services has exponentially increased during the past ten years. Hence, high throughput is very important for all users to get the best experience with the offered services. This creates many technical challenges that are difficult to handle with the existing technology. Therefore, massive multiple input multiple output (massive MIMO) is a new technology that has been …

Radio Link Analysis And Characterization Of Past And Future Cal Poly Cubesats, Brian Gilbert Tubb

Electrical Engineering

Cal Poly's satellites design team, PolySat, has three satellites in Low Earth Orbit (LEO) and four more planned to launch within the next two years. Radio communication of past and current orbiting satellites has been an exercise in frustration, prompting significant research into the satellite-side of the radio link by several other Senior Projects and Thesis papers. However, minimal effort has been spent on evaluating why these problems were discovered only once the satellites reached orbit. This paper details the downfalls of relying heavily on link budgets and improper long range test setups, then experimentally determines the sensitivity of PolySat's …

Smart Grid Communications, Christopher W. Asbery

Theses and Dissertations--Electrical and Computer Engineering

Smart grid technologies are starting to be the future of electric power systems. These systems are giving the utilities detailed information about their systems in real time. One of the most challenging things of implementing smart grid applications is employing the communications into the systems. Understanding the available communications can help ease the transition to these smart grid applications. Many of the utility personnel are spending too much time trying to figure out which communication is better for their application or applications. So this thesis presents the different communication types available with discussing the different attributes in which these communication …

Differentially Encoded Quadrature Phase Shift Key Communication And Real-Time Implementation, Robert Walton Conant

Boise State University Theses and Dissertations

Robust communication methods are integral to advances in modern technology. Software defined radios (SDRs) have been the chief instruments of communication for the last three decades. Upcoming generations of wireless networks and phone systems depend on successful implementations of increasingly sophisticated software defined modulation methods. The challenges presented by encoding, modulation, signal conditioning, timing, and decision algorithms are non-trivial. Adapting to the impacts of wired and wireless channels adds further complexity.

While not comprehensive on the subject of communications, this text serves to introduce the practical concepts of binary communications, modulation methods, the digital signal processor (DSP), and software defined …