Phase-rotated reference signals for multiple antennas

A base station device for wireless communications in an Orthogonal Frequency Division Multiplexing (OFDM) system, the base station device configured to:

• transmit a first set of reference signals from a first transmit antenna on a plurality of reference signal (RS) resource elements of the OFDM system, the RS resource elements representing a set of time and frequency resources;
• transmit a second set of reference signals from a second transmit antenna on the plurality of RS resource elements, wherein the second set of reference signals is identical to a first phase rotation of the first set of reference signals in a frequency domain;
• transmit a first set of data signals from the first transmit antenna on a plurality of data resource elements;
• and
• transmit a second set of data signals from the second transmit antenna on the plurality of data resource elements, wherein the second set of data signals is identical to the first phase rotation of the first set of data signals in the frequency domain.

A method of wireless communication, comprising:

• configuring a plurality of Multicast-Broadcast Single Frequency Network (MBSFN) subframes;
• transmitting a first set of reference signals from a first transmit antenna on a plurality of reference signal (RS) resource elements during at least one of the plurality of MBSFN subframes, the RS resource elements representing a set of time and frequency resources;
• transmitting a second set of reference signals from a second transmit antenna on the plurality of RS resource elements during the at least one of the plurality of MBSFN subframes, wherein the second set of reference signals is identical to a first phase rotation of the first set of reference signals in a frequency domain;
• transmitting a first set of data signals from the first transmit antenna on a plurality of data resource elements;
• and
• transmitting a second set of data signals from the second transmit antenna on the plurality of data resource elements, wherein the second set of data signals is identical to the first phase rotation of the first set of data signals in the frequency domain.

A base station device for wireless communications, the base station device configured to:

• configure a plurality of Multicast-Broadcast Single Frequency Network (MBSFN) subframes;
• transmit a first set of reference signals from a first transmit antenna on a plurality of reference signal (RS) resource elements during at least one of the plurality of MBSFN subframes, the RS resource elements representing a set of time and frequency resources;
• transmit a second set of reference signals from a second transmit antenna on the plurality of RS resource elements during the at least one of the plurality of MBSFN subframes, wherein the second set of reference signals is identical to a first phase rotation of the first set of reference signals in a frequency domain;
• transmit a first set of data signals from the first transmit antenna on a plurality of data resource elements;
• and
• transmit a second set of data signals from the second transmit antenna on the plurality of data resource elements, wherein the second set of data signals is identical to the first phase rotation of the first set of data signals in the frequency domain.