Technologies for supporting codebook-based transmissions

An apparatus comprising:

• processing circuitry to:
• identify a first number of antenna element locations, at a base station, in a vertical direction;
• identify a second number of antenna element locations, at the base station, in a horizontal direction, wherein the first number multiplied by the second number is equal to 24, 32, 36, 48 or 64;
• determine a vertical oversampling factor;
• determine a horizontal oversampling factor;
• and
• identify a codebook based on the first number, the second number, the vertical oversampling factor, and the horizontal oversampling factor;
• and
• interface circuitry coupled with the processing circuitry to enable communication.

A method comprising:

• selecting a first spatial basis for transmitting a first layer of a transmission having a rank of two or more;
• identifying a first number of antenna element locations, at a base station, in a vertical direction;
• identifying a second number of antenna element locations, at the base station, in a horizontal direction, wherein the first number multiplied by the second number is equal to 24, 32, 36, 48 or 64;
• and
• determining first and second offsets based on the first and second numbers, wherein the first and second offsets, applied to the first spatial basis, indicate a second spatial basis to be used for transmitting a second layer of the transmission.

A method comprising:

• generating one or more channel state information-reference signals (CSI-RSs) for transmission using more than 32 CSI-RS ports;
• receiving a precoding matrix indicator (PMI) from a user equipment (UE);
• and
• determining, based on the PMI, a first spatial basis for transmitting a first layer of a transmission having a rank of two or more;
• determining, based on the PMI, first and second offsets;
• and
• determining, based on the first spatial basis and the first and second offsets, a second spatial basis to be used for transmitting a second layer of the transmission.