UP	Paper 1265	US-W-Y	AT BOTTOM
Optical PPM Combining Loss for Photon Counting Receivers
Quirk,Kevin		Jet Propulsion Laboratory, California Institute of Technology
Gin,Jonathan		Jet Propulsion Laboratory, California Institute of Technology
The performance of an equal gain combining architecture for an array of photon counting receivers used in an optical PPM communication system operating in low-flux conditions is analyzed in the presence of synchronization errors. Comparisons are made to an equal gain combiner with perfect synchronization as well as to the performance of a system with timing synchronization error associated with a single large aperture. These comparisons allow one to ascertain the absolute loss due to synchronization as well as the relative loss due to independent synchronization of the elements in this optical array receiver.
Kevin J. Quirk received the B.S. degree in computer engineering in 1993 and the M.S. and Ph.D. degrees in electrical engineering from the University of California at San Diego, La Jolla, CA, in 1997 and 2000, respectively. From 2000 to 2002, he was with the Jet Propulsion Laboratory, Pasadena, CA, as a Member of the Digital Signal Processing Research Group. From 2003 to 2004 he was a post-doctoral researcher with the Department of Electrical Engineering at the University of California at San Diego. Since 2004 he has been a contractor in the Communication Architectures and Research Section at the Jet Propulsion Laboratory, Pasadena, CA. He was a lecturer at the University of California Los Angeles, the University of California San Diego, and is currently a lecturer with the Department of Electrical Engineering at the California Institute of Technology. His research interests include communication theory, coding theory, signal processing, free space optical communications, and spread-spectrum communications.