Bruce M Rubenstein

US Patent:

20040125887, Jul 1, 2004

Filed:

Dec 31, 2002

Appl. No.:

10/335379

Inventors:

Cameron Dryden - West Roxbury MA, US
Bruce Rubenstein - Lexington MA, US

International Classification:

H04B015/00

US Classification:

375/296000

Abstract:

A technique for pre-compensating a digital bit stream for distortion imposed by a transmission path includes adjusting the level of the digital bit stream on a bit-by-bit basis in a manner that simulates the effects of a filter having a transfer function that is substantially the inverse of that of the transmission path. The technique includes generating a plurality of reference levels that correspond to correcting levels of the digital bit stream and switching these levels to the transmission path at high speed in response to the current bit of the digital bit stream and at least one previous bit. When used in an automatic test system, the technique improves signal transmission and reduces jitter, therefore allowing jitter of devices under test to be measured more accurately.