Unit interval

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The Unit Interval , abbreviated to UI , is an auxiliary unit of measurement for evaluating jitter in the context of digital signal processing and is used, among other things, in ITU-T G.810 and in digital video interfaces such as the Serial Digital Interface (SDI).

A unit interval (1 UI) corresponds to the time it takes to transmit a transmission symbol . Due to jitter, deviations occur in the specific duration, which can lead to transmission errors. Typical limit values ​​for jitter are in the range from 0.1 UI to 0.3 UI. From 0.5 UI, the so-called horizontal opening in the eye diagram is closed and symbol crosstalk occurs.

literature

  • Mike Peng Li: Jitter, Noise, and Signal Integrity at High-Speed . Prentice Hall, Upper Saddle River NJ et al. 2008, ISBN 978-0-13-242961-0 .
  • Dennis Derickson, Marcus Müller: Digital Communications Test and Measurement. High speed physical layer characterization . Prentice Hall, Upper Saddle River NJ et al. 2007, ISBN 978-0-13-220910-6 .

Individual evidence

  1. ITU-T Recommendation G.810: Definitions and Terminology for Synchronization Networks , August 1996
  2. Jitter Measurement for Serial Digital Video Signals . Tektronix Inc. company brochure, 2006 ( PDF ).