Analog feedback is a signaling method that the receiver sends back the estimated information to the transmitter with unquantization and uncoding form. Analog feedback is one example of wireless transmission methods which allows to transmit live information without any priory digital signal processing such as quantization and coding . Because of non-digitization, analog transmission has a number of disadvantages including non-compression and non-security protection.
Analog feedback for Channel State Information Edit
The receive can estimate channel state information for the downlink channel. This channel state information is originally analog form since it estimate directly from the received pilot signal without decoding the signaling. Note that we usually do not decode the received pilot signal which contains no information. Hence, we can apply the analog feedback method to deliver the channel state information to the transmitter for transmit beamforming and etc.