Methods for temporal spatial frequency (tsf) channel state information (csi) compression mode determination and selection

A method performed by a wireless transmit/receive unit (WTRU), the method comprising:

• receiving configuration information associated with channel state information (CSI) compression, wherein the configuration information indicates that the WTRU is to determine a next compression mode;
• determining a measured performance metric for determining the next compression mode based on CSI measured by the WTRU, wherein the measured performance metric is determined based on a squared generalized cosine similarity (SGCS) between the measured CSI and a historical CSI measurement;
• determining the next compression mode based on the measured performance metric and a first configured threshold, wherein:
• the next compression mode is temporal-spatial-frequency (TSF) if a current compression mode is spatial-frequency (SF) and the measured performance metric exceeds the first configured threshold;
• or
• the next compression mode is SF if a current compression mode is TSF and the measured performance metric is below a second configured threshold;
• and
• sending an indication of the next compression mode to a network.

A wireless transmit/receive unit (WTRU) comprising:

• a processor configured to:
• receive configuration information associated with channel state information (CSI) compression, wherein the configuration information indicates that the WTRU is to determine a next compression mode;
• determine a measured performance metric to determine the next compression mode based on CSI measured by the WTRU, wherein the measured performance metric is determined based on a squared generalized cosine similarity (SGCS) between the measured CSI and a historical CSI measurement;
• determine the next compression mode based on the measured performance metric and a first configured threshold, wherein the processor is configured to:
• determine that the next compression mode is temporal-spatial-frequency (TSF) if a current compression mode is spatial-frequency (SF) and the measured performance metric exceeds the first configured threshold;
• and
• determine that the next compression mode is SF if a current compression mode is TSF and the measured performance metric is below a second configured threshold;
• and
• send an indication of the next compression mode to a network.