Presented by: Sergey Volkovich Vladimir Dibnis Spring 2011 Supervisor: Mony Orbach

Jitter is a significant phenomena at high speed communication lines which strongly affects signal integrity. Therefore it is important to be able to artificially create different types of jitter in order to explore its implications and use it for educational purposes.

 To study the high speed channels jitter phenomena and its types  To artificially create different types of jitter using Tabor’s Arbitrary Waveform Generator via a Matlab GUI  To present the different jitter phenomena using the Agilent Infiniium Scope and analyze them with different methods

Agilent Infiniium Scope Matlab GUI on PC LAN Cable Tabor WX2182 Arbitrary Waveform Generator Software Hardware SMA to BNC Cable

 Dual output configuration with independent waveform control  Operational in each of the following modes: Function generator, Arbitrary waveform generator, Modulation generator, Sequence generator, Pulse generator  12 Bit vertical resolution  32M waveform memory  2 Vp-p into 50Ω, double into open circuit  Complex sequences link and loop segments in user- definable order  Ethernet, USB and GPIB interfaces

 In order to create an arbitrary waveform we store coordinates in the device’s memory and transfer them through a D/A to the oscilloscope according to the clock sampling rate, which is set to 2.1G points/s.  The minimum points needed per data bit is 320. Therefore the maximum data bit rate is 6.56MHz according to the following formula: Data bit rate = sampling rate / segment length

Total Jitter Deterministic Jitter  Periodic Jitter  Bounded Uncorrelated Jitter  Data-Dependent Jitter Random Jitter Inter Symbol Interference Duty Cycle Disorder Jitter is a short term variation in a digital signal from its ideal value in time.

 Deterministic Jitter (DJ): noise with bounded values which is not normally distributed  Periodic Jitter (PJ): has discrete frequency components  Bounded Uncorrelated Jitter (BUJ): signal- independent and bounded in its distribution  Data-Dependent Jitter (DDJ): signal-dependent  Inter Symbol Interference (ISI): caused by near bits influence on the measured bit  Duty Cycle Disorder (DCD): caused by different rise and fall times  Random Jitter (RJ): signal-independent random noise, can be modeled by Normal distribution

Eye Diagram:Time Interval Error Trend: Histogram:Bathtub Curve: Frequency Domain: Random Jitter Random & Periodic Jitter Periodic Jitter - SquaredPeriodic Jitter - Sinusoidal

Receive the GUI parameters Create a signal matrix without a jitter Create the jittered data matrix according to the signal and total jitter effect matrices Create the total jitter effect matrix Send data to the waveform generator to be continuously generated

 Sinusoidal Periodic Jitter:  Random Jitter: x = linspace(0, 2*pi,total_bits); effect_pj = sin(x); effect_rj = rj_mean + rj_stdev.*randn(1,total_bits);  Bounded Uncorrelated Jitter: in the same method same as in RJ but when the values exceed the boundaries they’re being regenerated.  Duty Cycle Disorder: by scanning the signal matrix we find where changes occur and insert a constant value to the corresponding place in the disturbance matrix.  Inter Symbol Interference: by scanning the signal matrix we find where changes occur and the number of the identical preceding bits. We then calculate and insert a constant value to the corresponding place in the disturbance matrix according to the formula:  Jitter Combinations: we sum the different disturbance matrices or calculate their weighted average.

Eye Diagram: Jitter Size = 0.1UI = 20ns

Bathtub Curve: Jitter Size = 0.1UI. It can be seen that the jitter is deterministic.

Time Interval Error (TIE) Trend – Squared: Jitter Size = 0.1UI = 20ns

Time Interval Error (TIE) Trend – Sinusoidal: Jitter Size = 0.1UI = 20ns

Time Interval Error (TIE) Trend – Triangular: Jitter Size = 0.1UI = 20ns

Time Interval Error (TIE) Histogram - Squared: Jitter Size = 0.1UI = 20ns

Time Interval Error (TIE) Histogram - Sinusoidal: Jitter Size = 0.1UI = 20ns

Time Interval Error (TIE) Histogram - Triangular: Jitter Size = 0.1UI = 20ns

Frequency Domain: Zoomed InSquared

Eye Diagram: Standard Deviation = 5

Bathtub Curve – Different Standard Deviations: Standard Deviation = 1Standard Deviation = 2

Time Interval Error (TIE) Trend: The trend isn’t periodic due to the random nature of the jitter

Frequency Domain: There are no discrete values due to the random nature of the jitter

Time Interval Error (TIE) Histogram – Different Standard Deviations: Standard Deviation = 1Standard Deviation = 5

Time Interval Error (TIE) Histogram – Different Means: Standard Deviation = 1, Mean = 0.1UIStandard Deviation = 1, Mean = -0.1UI

Eye Diagram – Different Boundaries: Precedence Boundary = 0.05UIDelay Boundary = 0.05UI

Time Interval Error (TIE) Histogram – Different Distributions: Gaussian Distribution, Jitter Size = 0.2UIUniform Distribution, Jitter Size = 0.4UI

Bathtub Curve – Different distributions, bounded to ±0.05UI: Gaussian Distribution, Standard Deviation = 5Uniform Distribution

Rise Time Delay, Jitter Size = 0.2UIFall Time Delay, Jitter Size = 0.2UI Duty Cycle Disorder:

Rise Time Delay, Jitter Size = 0.2UI Duty Cycle Disorder – Random Signal:

Inter Symbol Interference: Rise Time Delay, τ = 10 → 7% changeFall Time Delay, τ = 10 → 7% change

DCD and ISI Combination: DCD Size = 0.1UI = 20ns, τ of ISI = 10 → 17% change

Duty Cycle Disorder – Bathtub Curve: DCD Size = 0.1UI = 20ns

Inter Symbol Interference - Bathtub Curve : Random Signal, τ = 20Random Signal, τ = 5

Sinusoidal Periodic Jitter and Random Jitter Combination – TIE Trend: Sinusoidal PJ Jitter Size = 0.1UI RJ Standard Deviation = 1 Sinusoidal PJ Jitter Size = 0.1UI RJ Standard Deviation = 3

Sinusoidal Periodic Jitter and Random Jitter Combination – Bathtub Curve: Sinusoidal PJ Jitter Size = 0.1UI RJ Standard Deviation = 1 Sinusoidal PJ Jitter Size = 0.1UI RJ Standard Deviation = 3

Squared Periodic Jitter and Random Jitter Combination – Histogram: Squared PJ Jitter Size = 0.1UI Without the Random Jitter Squared PJ Jitter Size = 0.1UI RJ Standard Deviation = 1

Sinusoidal Periodic Jitter and Random Jitter Combination – Frequency Domain: Without the Random Jitter With the Random Jitter

Bounded Uncorrelated Jitter and Random Jitter - Histogram: BUJ Boundaries = 0.05UI, BUJ Standard Deviation = 1, RJ Standard Deviation = 10

Inter Symbol Interference and Random Jitter Combination – Bathtub Curve: Random Signal, τ of ISI = 3, Without the Random Jitter Random Signal, τ of ISI = 3, RJ Standard Deviation = 3

Sinusoidal Periodic Jitter and Duty Cycle Disorder Combination – Eye Diagram: PJ Jitter Size = 0.2UI = 40ns, Without the Duty Cycle Disorder PJ Jitter Size = 0.2UI = 40ns, DCD Jitter Size = 0.2UI = 40ns

 We have studied the high speed channels jitter phenomena, its types and the different methods to measure and analyze it  We have created a Matlab GUI that allows us to artificially create all the required jitter types, combine them and control their different parameters  We have performed a profound analysis on all of the artificially created jitter types and their different combinations by measuring, analyzing and comparing them to the defined parameters

 We have learned that the signal generator combined with Matlab makes a very powerful tool for arbitrary signal creation and can be used as an educative tool  The main limitation of the signal generator is the minimal number of points needed for creating a bit  The generated wave could be used as an input for other circuits for further applications  In future projects it is possible to recreate other phenomena using the same environment