Toward optimum efficiency in a quantum receiver for coded ppm
D. M. Boroson · 2017
Communications systems builders continue to search for signal formats and receiver architectures that can provide the most efficient utilization of their subsystems, which include power amplifiers as well as transmit and receive apertures. Receivers requiring very small amounts of received power are of particular interest in communications links where transmission distances are very long and losses are large, such as from Deep Space. Helstrom and others ([1],[2],[3]) initiated the study of optimum signal reception using quantum mechanical signal models. They derived the mathematical description and predicted performance of receivers that optimize certain criteria, such as Minimum Probability of Error (MPE). Unfortunately, practical implementation of their proposed receivers has still not been achieved. In parallel, technology has advanced to where noiseless photon counters can be used to achieve quite good performance ([4]). We show here that, when an end-to-end error correction code is added, in fact such a system can out-perform the “optimum” MPE system at low signal powers. In this report, we derive the formulation of a quantum receiver that is shown to be uniformly better than either the MPE or photon-counting receiver.