Methods and apparatuses with CSI omission for linear combination port-selection codebook

A method performed by a network node for receiving a channel state information (CSI) report generated by a User Equipment (UE), in a wireless communications system, the method comprising:

• transmitting to the UE, a CSI report configuration for enabling the UE to determine based on the transmitted CSI report configuration a number of precoder coefficients for Rank Index (RI) transmission layers of a precoder vector or matrix;
• to group the precoder coefficients of the RI transmission layers into at least two coefficient subsets, each coefficient subset comprising a plurality of precoder coefficients;
• to assigning an ordering to said at least two coefficient subsets and an ordering to the precoder coefficients within each coefficient subset;
• and to divide said at least two coefficient subsets into two or more CSI groups having associated priority levels;
• and
• receiving from the UE over an uplink channel, an UCI including the CSI report generated by the UE, the CSI report comprising a CSI part 1 and a CSI part 2, wherein the CSI part 1 has a fixed payload size and comprises information indicating the size of the payload of the CSI part 2, wherein the CSI part 2 includes the precoder coefficients of at least one of the two or more CSI groups;
• and wherein, each precoder coefficient is associated with four indices (l, p, d, n), wherein the first index, l, is a layer index, the second index, p, is a port or spatial beam index, the third index, d, is a delay index, and the fourth index, n, is a Doppler component index, and wherein the precoder coefficients of the RI transmission layers are grouped into the at least two coefficient subsets based on at least one of the delay index d or the Doppler component index n.

A User Equipment (UE) comprising a processor and a memory, said memory containing instructions executable by said processor whereby said UE is operative to:

• receive a CSI report configuration from a network node;
• determine based on the received CSI report configuration, a number of precoder coefficients for Rank Index (RI) transmission layers of a precoder vector or matrix;
• group the precoder coefficients of the RI transmission layers into at least two coefficient subsets, each coefficient subset comprising a plurality of precoder coefficients;
• assign an ordering to said at least two coefficient subsets and an ordering to the precoder coefficients within each coefficient subset;
• divide said at least two coefficient subsets into two or more CSI groups having associated priority levels;
• generate a CSI report comprising a CSI part 1 and a CSI part 2, wherein the CSI part 1 has a fixed payload size and comprises information indicating the size of the payload of the CSI part 2, wherein the CSI part 2 includes the precoder coefficients of at least one of the two or more CSI groups;
• and
• transmit an uplink control information (UCI) including the CSI report over an uplink (UL) channel to the network node,
• wherein each precoder coefficient is associated with four indices (l, p, d, n), wherein the first index, l, is a layer index, the second index, p, is a port or spatial beam index, the third index, d, is a delay index, and the fourth index, n, is a Doppler component index, and wherein said UE is operative to group the precoder coefficients of the RI transmission layers into the at least two coefficient subsets based on at least one of the delay index d or the Doppler component index n.

A network node comprising a processor and a memory, said memory containing instructions executable by said processor whereby said network node is operative to:

• transmit to a User Equipment (UE), a channel state information (CSI) report configuration for enabling the UE to determine based on the transmitted CSI report configuration a number of precoder coefficients for Rank Index (RI) transmission layers of a precoder vector or matrix;
• to grouping the precoder coefficients of the RI transmission layers into at least two coefficient subsets, each coefficient subset comprising a plurality of precoder coefficients;
• to assigning an ordering to said at least two coefficient subsets and an ordering to the precoder coefficients within each coefficient subset;
• and to divide said at least two coefficient subsets into two or more CSI groups having associated priority levels;
• and
• receive from the UE over an uplink channel, an UCI including the CSI report generated by the UE, the CSI report comprising a CSI part 1 and a CSI part 2, wherein the CSI part 1 has a fixed payload size and comprises information indicating the size of the payload of the CSI part 2, wherein the CSI part 2 includes the precoder coefficients of at least one of the two or more CSI groups;
• and wherein, each precoder coefficient is associated with four indices (l, p, d, n), wherein the first index, l, is a layer index, the second index, p, is a port or spatial beam index, the third index, d, is a delay index, and the fourth index, n, is a Doppler component index, and wherein the precoder coefficients of the RI transmission layers are grouped into the at least two coefficient subsets based on at least one of the delay index d or the Doppler component index n.