Patent ID: 8582486
Filing Date: 2013-11-12
Classification: H04L

Abstract:
1. A method of transmitting a reference signal (RS) in a downlink multi input multi output (MIMO) system that supports a first user equipment (UE) and a second UE, the first UE recognizing four predetermined transmitting antennas among eight transmitting antennas and the second UE recognizing the eight transmitting antennas, the method comprising: generating a subframe that can be recognized by both the first UE and the second UE; and transmitting the generated subframe to the first UE and the second UE, wherein the first UE and the second UE recognize all orthogonal frequency division multiplexing (OFDM) symbols of the subframe, wherein reference signals (RSs) of the four predetermined transmitting antennas are mapped on OFDM symbols of the subframe equally to RS positions on a subframe of a system supporting only four transmitting antenna and RSs of the other of the eight transmitting antennas are mapped on other OFDM symbols excluding the OFDM symbols on which the RSs of the predetermined four antennas are mapped, wherein a number of resource elements (REs) allocated per resource block (RB) to the RSs of the four predetermined transmitting antennas and the other of the eight transmitting antennas is given as one of following cases: