Method, user equipment and system for reducing feedback quantity of pre-coding matrix index number

Disclosed is a method of reducing precoding matrix index number feedback quantity, a user equipment and a communication system, used for the technical field of wireless transmission. The user equipment of the invention adopts the corresponding feedback mode of the precoding matrix index number according to different frequency selective characteristics of the channel, feeds back the precoding matrix index number of the whole bandwidth and the precoding matrix index number of the selected sub-band; the user equipment feeds back the sub-band serial number required to feed back, the channel quality indication information and the precoding matrix index number to a base station through an up link; the base station performs transmitter optimization according to the information fed back by the user equipment, thereby increasing the performance of the system under the premise of compromising the service quality of the wireless district. The invention provides an information feedback method of reducing precoding matrix index number feedback quantity in the up link, performs feedback with high efficiency and simpleness on the information of the down link through unique method, thereby reducing air cost in the up link, saving frequency spectrum resource and increasing the system performance.