Patent ID: 8953522
Filing Date: 2015-02-10
Classification: H04B,H04L

Abstract:
1. A method for controlling retransmission by a User Equipment (UE) in a wireless communication system supporting Multiple Input Multiple Output (MIMO) technology, comprising the steps of: initially transmitting a plurality of transport blocks to a Node B, and receiving a negative acknowledgement (NACK) for at least one transport block among the plurality of transport blocks, from the Node B; determining a precoding matrix for retransmission of the at least one transport block in response to the NACK for the at least one transport block; and retransmitting the at least one transport block using the determined precoding matrix, wherein the precoding matrix is determined based on a number of layers corresponding to the at least one transport block negatively acknowledged (NACKed) from the Node B, if the UE does not receive a Physical Downlink Control CHannel (PDCCH) intended for the UE from the Node B.