Patent ID: 8891647

Claim:
A method for user-specific antenna down tilt, the method comprising: generating, with a first physical antenna, a first antenna beam A having a first down tilt angle; generating, with the first physical antenna, a second antenna beam B having a second down tilt angle different from the first down tilt angle; synthesizing a first virtual antenna from the first and second beams; synthesizing a second virtual antenna from the first and second beams; transmitting a first pilot signal via the first virtual antenna; transmitting a second pilot signal via the second virtual antenna; receiving, from a user equipment (UE), information indicative of a phase difference between the first and second virtual antennas; determining a multiple-input multiple output pre-coding vector according to the information received from the UE; and transmitting user data modulated by the pre-coding vector to the UE via the first and second virtual antennas.