Optimizing Spectrum Sharing: Models and Algorithms for Coexistence
| dc.contributor.author | Jai, Naru | en |
| dc.contributor.committeechair | Hou, Yiwei Thomas | en |
| dc.contributor.committeechair | Shi, Yi | en |
| dc.contributor.committeemember | Olfat, Masoud | en |
| dc.contributor.committeemember | Reed, Jeffrey H. | en |
| dc.contributor.committeemember | Lou, Wenjing | en |
| dc.contributor.department | Electrical and Computer Engineering | en |
| dc.date.accessioned | 2026-11-10T09:00:38Z | en |
| dc.date.available | 2026-11-10T09:00:38Z | en |
| dc.date.issued | 2026-11-09 | en |
| dc.description.abstractgeneral | Spectrum sharing has become increasingly important as growing wireless demand places greater pressure on a limited radio-frequency resource. Enabling multiple systems to operate in the same or adjacent bands, however, requires careful management of interference and access to spectrum. The goal of this dissertation is to address key optimization problems in spectrum sharing and coexistence. Specifically, we study coexistence in two settings: the Citizens Broadband Radio Service (CBRS) band, where commercial users share spectrum with incumbent Navy radars, and the 4.9 GHz band, where commercial 5G systems operate adjacent to radio astronomy. In the CBRS band, we study three problems. First, we study how to assign radio channels to commercial wireless users without causing harmful interference to Navy radar systems operating in the same band. To address this problem, we develop an optimization framework that assigns channels to two classes of commercial users in the CBRS band—Priority Access License (PAL) and General Authorized Access (GAA) users—while ensuring that the Navy radars remain protected. Second, we study the problem of determining which commercial wireless devices need to be turned off when Navy radar systems become active in order to prevent harmful interference. To address this problem, we develop the Optimal Move List (OML) algorithm, which minimizes the number of devices that need to be turned off while giving higher priority to PAL users than to GAA users. Third, we address the fairness problem that arises when the same commercial wireless devices are repeatedly turned off whenever Navy radar systems become active. To address this problem, we develop Revolving Move Lists (R-MLs), which rotate the set of devices that are turned off across different radar activations while continuing to protect Navy radars from harmful interference. In the 4.9 GHz band, we study how transmissions from commercial 5G base stations can interfere with sensitive radio astronomy observations in the adjacent spectrum band (4990–5000 MHz). To address this problem, we develop an iterative power-control algorithm that adjusts the transmit powers of 5G base stations to maximize wireless coverage while keeping the out-of-band (OOB) interference to the radio astronomy receiver below the required limit. | en |
| dc.description.degree | Doctor of Philosophy | en |
| dc.format.medium | ETD | en |
| dc.identifier.other | vt_gsexam:47829 | en |
| dc.identifier.uri | https://hdl.handle.net/10919/143993 | en |
| dc.language.iso | en | en |
| dc.publisher | Virginia Tech | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject | Coexistence | en |
| dc.subject | Interference | en |
| dc.subject | Optimization | en |
| dc.subject | Spectrum Sharing | en |
| dc.title | Optimizing Spectrum Sharing: Models and Algorithms for Coexistence | en |
| dc.type | Dissertation | en |
| thesis.degree.discipline | Computer Engineering | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | doctoral | en |
| thesis.degree.name | Doctor of Philosophy | en |