What is CSI (Channel-State Information)?

Channel state information (CSI) alludes to information that depicts how a signal propagates from the transmitter to the receiver and addresses the joined effect of dispersing, fading, and power decay with distance, etc. The transmitter and receiver can have distinctive CSI. The CSI at the transmitter and the CSI at the receiver are sometimes alluded to as Channel-State Information Transmitter and Channel-State Information Receiver.