Wireless device, a network node and methods therein for reporting channel state information (CSI) in a radio communications network

A User Equipment, UE, for determining Channel State Information, CSI, estimates to be transmitted in a CSI report to a base station in a radio communications network, the wireless device comprising one or more processors whereby the wireless device is configured to:

• receive a message comprising an indication to use CSI estimates that are based on CSI measurements performed during a determined period of time on resources configured for the UE;
• discard existing CSI estimates when there is a change in at least one transmission condition for the UE;
• determine CSI estimates to be used in the CSI report to the base station according to the received indication, wherein the CSI estimates are based on a CSI measurement at a single time instant on a Channel State Information Reference Signal, CSI-RS, resource configured for the UE;
• and
• transmit the CSI report to the base station, the CSI report including the determined CSI estimates.

A method performed by a base station for controlling Channel State Information, CSI, estimates transmitted by a User Equipment, UE, in CSI reports to the base station in a radio communications network, the method comprising:

• determining that the CSI estimates from the UE are no longer valid due to a change in at least one transmission condition;
• transmitting, to the UE, a message comprising an indication to use CSI estimates that are based on CSI measurements performed during a determined period of time on resources configured for the UE;
• and
• receiving a CSI report from the UE, the CSI report including CSI estimates determined by the UE after discarding existing CSI estimates and in accordance with the indication to use CSI estimates that are based on CSI measurements performed during a determined period of time on resources configured for the UE, wherein the CSI estimates are based on a CSI measurement at a single time instant on a Channel State Information Reference Signal, CSI-RS, resource configured for the UE.

A base station for controlling Channel State Information, CSI, estimates transmitted by a User Equipment, UE, in a CSI report to the base station in a radio communications network, the base station comprising:

• at least one processor;
• memory storing executable computer programs, whereby when executed by the at least one processor, the base station is configured to:
• determine that the CSI estimates from the UE is no longer valid due to a change in at least one transmission condition;
• transmit, to the UE, a message comprising an indication to use CSI estimates that are determined by the UE after discarding existing CSI estimates and based on CSI measurements performed during a determined period of time on resources configured for the UE.