Antenna Virtualization in Two-Dimensional Antenna Array

A wireless transmit/receive unit (WTRU), comprising:

• a receiver, the receiver configured at least to receive at least one downlink (DL) reference signal;
• a processor, the processor configured at least to:
• determine, based on the DL reference signal, at least one antenna virtualization matrix of a plurality of antenna virtualization matrices;
• determine a codebook based on the at least one antenna virtualization matrix;
• and
• transform a first at least two-dimensional (2D) antenna array into a second at least 2D antenna array using the at least one antenna virtualization matrix, the second at least 2D array being smaller than the first at least 2D array;
• and
• a transmitter, the transmitter configured at least to send feedback to an evolved-node B (eNB) using at least a part of the codebook.

An evolved-Node B (eNB), comprising:

• a transmitter, the transmitter configured to at least:
• send at least one downlink (DL) reference signal to a wireless transmit/receive unit (WTRU);
• and
• send a plurality of antenna virtualization matrices to the WTRU;
• a receiver, the receiver configured to at least:
• receive an indication of at least one antenna virtualization matrix of the plurality of antenna virtualization matrices;
• and
• receive feedback from the WTRU, the feedback sent using at least a part of the codebook corresponding to the at least one antenna virtualization matrix;
• and
• a processor, the processor configured at least to:
• determine to send to the WTRU at least one of:
• a confirmation of the at least one antenna virtualization matrix, or an indication of another antenna virtualization matrix of the plurality of virtualization matrices.