Patent ID: 9749107
Date: 2017-08-29
CPC Classifications: H04B,H04J,H04L,H04W

Claim:
1. A method for transmitting, by a base station (BS), reference signals to a user equipment (UE) in a wireless communication system, the method comprising: multiplexing, by the BS, a multiple number N of demodulation reference signals (DMRSs) for downlink data of layers 0 to N−1 on at least one of first and second time-frequency resource sets using predefined orthogonal cover codes (OCCs) according to a predefined mapping rule; and transmitting, by the BS, the downlink data and the multiple number N of DMRSs in a subframe, wherein the first time-frequency resource set is separate from the second time-frequency resource set, and wherein the predefined mapping rule maps 4 DMRSs for layers 0, 1, 4 and 6 to the first time-frequency resource set and 4 DMRSs for layers 2, 3, 5 and 7 to the second time-frequency resource set.