Method for UE (user equipment) to report CSI (channel state information), method for triggering the UE (user equipment) to report to the CSI (channel state information), and corresponding devices

The invention discloses a method for UE (user equipment) to report CSI (channel state information), a method for triggering the UE (user equipment) to report to the CSI (channel state information), and corresponding devices. The method for the UE to report the CSI includes the step that the UE determines CSI reference resources and reports CSI on the CSI reference resources, wherein the CSI reference resources are one or more sub frames in the time domain and are one or more narrow bands in the frequency domain. The device for the UE to report the CSI includes a CSI reference resource determination module and a reporting module. The method for triggering the UE to report to the CSI includes the step that a network side sends reference signals, periodically-reported relevant resource information and/or relevant resource information reported in a triggered manner to the UE. The device for triggering the UE to report to the CSI includes a first sending module and a second sending module. With the methods provided by the embodiments of the invention adopted, the UE can report narrowband CSI. The methods are especially suitable for user equipment with limited reception capacity.