  Perception is one of the crucial module of the autonomous driving system,
which has made great progress recently. However, limited ability of individual
vehicles results in the bottleneck of improvement of the perception
performance. To break through the limits of individual perception,
collaborative perception has been proposed which enables vehicles to share
information to perceive the environments beyond line-of-sight and
field-of-view. In this paper, we provide a review of the related work about the
promising collaborative perception technology, including introducing the
fundamental concepts, generalizing the collaboration modes and summarizing the
key ingredients and applications of collaborative perception. Finally, we
discuss the open challenges and issues of this research area and give some
potential further directions.
