Year: 2018
Type: dissertation
Abstract: : As the demand for wireless systems increases exponentially, it has become necessary\n\nfor different wireless modalities, like radar and communication systems, to share the\n\navailable bandwidth. One approach to realize coexistence successfully is for each\n\nsystem to adopt a transmit waveform with a unique nonlinear time-varying phase\n\nfunction. At the receiver of the system of interest, the waveform received for process-\n\ning may still suffer from low signal-to-interference-plus-noise ratio (SINR) due to the\n\npresence of the waveforms that are matched to the other coexisting systems. This\n\nthesis uses a time-frequency based approach to increase the SINR of a system by estimating the unique nonlinear instantaneous frequency (IF) of the waveform matched\n\nto the system. Specifically, the IF is estimated using the synchrosqueezing transform,\n\na highly localized time-frequency representation that also enables reconstruction of\n\nindividual waveform components. As the IF estimate is biased, modified versions of\n\nthe transform are investigated to obtain estimators that are both unbiased and also\n\nmatched to the unique nonlinear phase function of a given waveform. Simulations\n\nusing transmit waveforms of coexisting wireless systems are provided to demonstrate\n\nthe performance of the proposed approach using both biased and unbiased IF estimators.
Author: Vineet Sunil Gattani
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2912712381