564 research outputs found
Measurement, Modeling, and OFDM Synchronization for the Wideband Mobile-to-Mobile Channel
Wideband measurements of the mobile-to-mobile channel, especially of the harshest channels, are necessary for proper design and certification testing of mobile-to-mobile communications systems. A complete measurement implies that the Doppler and delay characteristics are measured jointly. However, such measurements have not previously been published.
The main objective of the proposed research is to develop channel models for specific scenarios from data obtained in a wideband mobile-to-mobile measurement campaign in the 5.9 GHz frequency band. For this purpose we developed a channel sounding system including a novel combined waveform. In order to quantify and qualify either the recorded channel or the proposed generated channel, we developed a simulation test-bed that includes all the characteristics of the proposed digital short range communications (DSRC) standard. The resulting channel models needed to comply with the specifications required by hardware channel emulators or software channel simulators. From the obtained models, we selected one to be included in the IEEE 802.11p standard certification test. To further aid in the development of software radio based receivers, we also developed an orthogonal frequency division multiplexing (OFDM) synchronization algorithm to analyze and compensate synchronization errors produced by inaccessible system clocks.Ph.D.Committee Chair: Ingram, Mary Ann; Committee Member: Lanterman, Aaron; Committee Member: Li, Ye; Committee Member: Pratt, Thomas G.; Committee Member: Rogers, Peter H
Signal Structure of the Starlink Ku-Band Downlink
We develop a technique for blind signal identification of the Starlink
downlink signal in the 10.7 to 12.7 GHz band and present a detailed picture of
the signal's structure. Importantly, the signal characterization offered herein
includes the exact values of synchronization sequences embedded in the signal
that can be exploited to produce pseudorange measurements. Such an
understanding of the signal is essential to emerging efforts that seek to
dual-purpose Starlink signals for positioning, navigation, and timing, despite
their being designed solely for broadband Internet provision
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