Patent ID: 8917791
Filing Date: 2014-12-23
Classification: H04B,H04L,H04W

Abstract:
1. A base station comprising: a receiver receiving receive feedback information including at least one precoding matrix index (PMI) from a user equipment (UE); and a transmitter transmitting a precoded downlink signal and transmitting precoding information having a predetermined number of bits, wherein the predetermined number of bits is defined according to a number of antenna ports and a transmission mode of the base station, wherein the precoding information of a specific transmission mode includes confirmation information, wherein the confirmation information indicates that the precoding to the downlink signal for a specific resource block (RB) in nth subframe is according to a latest PMI received from the UE on or before n-xth subframe, wherein “n” is an integer and “x” is a predetermined integer or an integer determined by upper layer signaling higher than a physical layer, and wherein the confirmation information is used only for PMI received via a Physical Uplink Shared Channel (PUSCH), except for PMI piggy-backed in the PUSCH.