'Institute of Electrical and Electronics Engineers (IEEE)'
Doi
Abstract
We investigate modulation and coding techniques that approach the fundamental limits of communication and key distribution over optical channels, in the regime of simultaneously high photon and bandwidth efficiencies. First, we develop a simple and robust system design for free-space optical communication that incorporates pulse-position modulation (PPM) over multiple spatial degrees of freedom in order to achieve high photon and spectral efficiency. Further, in the context of key distribution, we determine the optimal rate using a Poisson source of entangled photon pairs and photon detectors, and show how to approach it using PPM parsing of the detected photon stream.United States. Defense Advanced Research Projects Agency. Information in a Photon Program (Contract HR0011-10-C-0159)United States. Army Research Office (Grant W911NF- 10-1-0416)United States. Air Force Office of Scientific Research (Grant FA9550-11-1-0183
