Classical Feedback in a Quantum Network

Abstract

Communication over a quantum multiple access channel (MAC) is considered with classical feedback. Since the no-cloning prohibits universal copying of arbitrary quantum states, classical feedback is generated through measurement. An achievable rate region is derived using partial information decoding at each transmitter. Our region generalizes both the classical Cover-Leung region and the generalized feedback region. As an example, we show that the qubit SWAP channel can benefit from feedback.