This dissertation proposes new methods for measuring jitter of high-speed digital signals. The proposed techniques are twofold. First, a low-speed jitter measurement environment is realized by using a jitter expansion sensor. This sensor uses a low-frequency reference signal as compared to high-frequency reference signals required in standard high-speed signal jitter measurement instruments. The jitter expansion sensor generates a low-speed signal at the output, which contains jitter content of the original high-speed digital signal. The low-speed sensor output signal can be easily acquired with a low-speed digitizer and then analyzed for jitter. The proposed low-speed jitter measurement environment using the jitter expansion sensor enhances the reliability of current jitter measurement approaches since low-speed signals used as a reference signal and a sensor output signal can be generated and applied to measurement systems with reduced additive noise. The second approach is direct digitization without using a sensor, in which a high-speed digital signal with jitter is incoherently sub-sampled and then reconstructed in the discrete-time domain by using digital signal reconstruction algorithms. The core idea of this technique is to remove the hardware required in standard sampling-based jitter measurement instruments for time/phase synchronization by adopting incoherent sub-sampling as compared to coherent sub-sampling and to reduce the need for a high-speed digitizer by sub-sampling a periodic signal over its many realizations. In the proposed digitization technique, the signal reconstruction algorithms are used as a substitute for time/phase synchronization hardware. When the reconstructed signal is analyzed for jitter in digital post-processing, a self-reference signal is extracted from the reconstructed signal by using wavelet denoising methods. This digitally generated self-reference signal alleviates the need for external analog reference signals. The self-reference signal is used as a timing reference when timing dislocations of the reconstructed signal are measured in the discrete-time domain. Various types of jitter of the original high-speed reference signals can be estimated using the proposed jitter analysis algorithms.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/34661 |
| Date | 06 July 2010 |
| Creators | Choi, Hyun |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Detected Language | English |
| Type | Dissertation |
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