摘要

This paper proposes a quantum two-branch transmit diversity scheme based on quantum maximal-ratio receiver combining (QMRRC) with one sender and two receivers. Exploiting two senders and one receiver, this scheme provides the same diversity order as that of one sender and two receivers. It can be generalized for two senders and M receivers to distribute quantum information with diversity order 2M for M >= 2. It has the advantage that it does not require any bandwidth expansion and feedback from the receiver to the sender, and its computation complexity is similar to QMRRC. As a consequence, it may transmit quantum information with more efficiency than the previous quantum key distribution (QKD) schemes.