Patent ID: 8676133
Filing Date: 2014-03-18
Classification: H04B,H04L,H04W

Abstract:
1. A method used in a wireless communications system, comprising: identifying at least two groups of user equipment (UEs); signaling a different number of antenna ports to the least two groups of UEs; creating a number of antenna ports for each group of UEs, wherein each antenna port corresponds to a linear combination of a subset of a number of physical transmit antennas and the number of created antenna ports is the number of antenna ports signaled to that group of UEs, and wherein the linear combination employed for different antenna ports for a particular group of UEs is linearly independent; and transmitting a first reference signal for each of the antenna ports signaled to a first group of UEs using the linearly independent combination of transmit antennas associated with each antenna port for the first group of UEs and transmitting a second reference signal for each of the antenna ports signaled to a second group of UEs using the linearly independent combination of transmit antennas associated with each antenna port for the second group of UEs, wherein the first group of UEs comprises at least one non-legacy UE and the second group of UEs comprises at least one legacy UE, wherein the first group of UEs supports a greater number of antenna ports than the second group of UEs.