Patent ID: 9191167
Filing Date: 2015-11-17
Classification: H04B,H04J,H04L,H04W

Abstract:
1. A method for transmitting downlink data to a user equipment (UE) in a wireless communication system, the method comprising: multiplexing a plurality of transmission layers for the downlink data in a resource allocation unit, the resource allocation unit including a plurality of contiguous subcarriers and a plurality of orthogonal frequency division multiplexing (OFDM) symbols; transmitting the transmission layers and demodulation reference signals (DMRSs) of the transmission layers to the UE, wherein the DMRSs are transmitted through a predetermined first time-frequency resource set of the resource allocation unit and a predetermined second time-frequency resource set of the resource allocation unit, the second time-frequency resource set separate from the first time-frequency resource set, wherein each of the DMRSs is transmitted in the first time-frequency resource set or the second time-frequency resource set using one of predetermined orthogonal cover codes (OCCs) according to a predefined mapping rule, and wherein the predefined mapping rule maps each of 8 DMRSs for 8 transmission layers to one of the first and second time-frequency resource sets and to one of the predetermined OCCs.