  Future wireless communication system embraces physical-layer signal detection
with high sensitivity, especially in the microwave photon level. Currently, the
receiver primarily adopts the signal detection based on semi-conductor devices
for signal detection, while this paper introduces high-sensitivity photon-level
microwave detection based on superconducting structure. We first overview
existing works on the photon-level communication in the optical spectrum as
well as the microwave photon-level sensing based on superconducting structure
in both theoretical and experimental perspectives, including microwave
detection circuit model based on Josephson junction, microwave photon counter
based on Josephson junction, and two reconstruction approaches under background
noise. In addition, we characterize channel modeling based on two different
microwave photon detection approaches, including the absorption barrier and the
dual-path Handury Brown-Twiss (HBT) experiments, and predict the corresponding
achievable rates. According to the performance prediction, it is seen that the
microwave photon-level signal detection can increase the receiver sensitivity
compared with the state-of-the-art standardized communication system with
waveform signal reception, with gain over $10$dB.
