Data-dependent jitter (DDJ) is a specific class of timing

jitter In electronics and telecommunications, jitter is the deviation from true periodicity of a presumably periodic signal, often in relation to a reference clock signal. In clock recovery applications it is called timing jitter. Jitter is a significa ...

. In particular, it is a form of deterministic jitter which is correlated with the sequence of bits in the data stream. It is also a form of ISI.

Properties

Depending on characteristics of the

signal In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The '' IEEE Transactions on Signal Processing' ...

and

transmission Transmission may refer to: Medicine, science and technology * Power transmission ** Electric power transmission ** Propulsion transmission, technology allowing controlled application of power *** Automatic transmission *** Manual transmission *** ...

topology, previously transmitted symbols can affect the edge cross over time. This creates a

probability distribution In probability theory and statistics, a probability distribution is the mathematical function that gives the probabilities of occurrence of different possible outcomes for an experiment. It is a mathematical description of a random phenomenon i ...

for the timing of the signal edge, which is usually recorded in a

PDF Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. ...

. DDJ's

is always a series of

pulses In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the nec ...

at the locations where a specific bit pattern experiences a cross over. Therefore, in order to get an accurate measure of the DDJ in a particular system, a large number of bit patterns must be analyzed (often just a PRBS) unless an analytical solution can be found.

References

Data transmission Packets (information technology) {{Telecomm-stub