US Patent 7991046 Calibrating jitter

Calibrating jitter in a communication channel between test equipment and a connection for a device under test (DUT) includes sampling test data in the communication channel at about a point of the connection to produce sampled data, where the test data travels through the communication channel at a first rate, and where the test data is sampled at a second rate that is less than the first rate, determining a first amount of jitter in the sampled data relative to the test data, and determining a second amount of jitter at about the point of connection based on the first amount of jitter.