Method and apparatus for CSI reporting based on a window of basis vectors

A base station (BS) in a 3rd generation partnership project (3GPP) communication system, the BS comprising:

• a processor;
• and
• a transceiver operably coupled to the processor, the transceiver configured to:
• transmit a configuration about a channel state information (CSI) report, the configuration including information about (i) NTRP non-zero power (NZP) CSI-reference signal (RS) resources, where NTRP≥1, and (ii) a parameter codebookType set to type-II-CJT-r18 or type-II-PortSelection-CJT-r18, where TRP is an abbreviation of transmit and receive point and CJT is an abbreviation of a coherent joint transmission;
• and
• receive the CSI report including, for each layer l=1, . . . , v, a Pl bits for an indicator i1,8,l, wherein the indicator i1,8,l is for indicating a strongest coefficient among
• K
• l
• NZ
• coefficients, where
• K
• l
• NZ
• is a total number of non-zero coefficients that are associated with Z NZP CSI-RS resources, and Z≤NTRP,
• wherein:
• when codebookType=type-II-CJT-r18, a value of Pl depends on:
• a value of
• K
• l
• NZ
• ,
• when v=1, and
• a value of
• ∑
• r
• =
• 1
• Z
• ⁢
• L
• σ
• r
• ,
• when 1<v≤4, and
• when codebookType=type-II-PortSelection-CJT-r18, the value of Pl depends on a value of
• 2
• ⁢
• M
• υ
• ⁢
• ∑
• r
• =
• 1
• Z
• ⁢
• L
• σ
• r
• ,
• for all values of v, and
• wherein v is a rank Lσr is a number of first vectors associated an r-th NZP CSI-RS resource from the Z NZP CSI-RS resources, where r=1, . . . , Z, Mv is a number of second vectors.

A method performed by a user equipment (UE) in a 3rd generation partnership project (3GPP) communication system, the method comprising:

• receiving a configuration about a channel state information (CSI) report, the configuration including information about (i) NTRP non-zero power (NZP) CSI-reference signal (RS) resources, where NTRP≥1, and (ii) a parameter codebookType set to type-II-CJT-r18 or type-II-PortSelection-CJT-r18, where TRP is an abbreviation of transmit and receive point and CJT is an abbreviation of a coherent joint transmission;
• determining, based on the configuration, for each layer l=1, . . . , v:
• an indicator i1,8,l for indicating a strongest coefficient among
• K
• l
• NZ
• coefficients, where
• K
• l
• NZ
• is a total number of non-zero coefficients that are associated with Z NZP CSI-RS resources, and Z≤NTRP,
• transmitting the CSI report including, for each layer l=1, . . . , v, Pl bits for the indicator i1,8,l,
• wherein:
• when codebookType=type-II-CJT-r18, a value of Pl depends on:
• a value of
• K
• l
• NZ
• ,
• when v=1, and
• a value of
• ∑
• r
• =
• 1
• Z
• ⁢
• L
• σ
• r
• ,
• when 1<v≤4, and
• when codebookType=type-II-PortSelection-CJT-r18, the value of Pl depends on a value of
• 2
• ⁢
• M
• υ
• ⁢
• ∑
• r
• =
• 1
• Z
• ⁢
• L
• σ
• r
• for all values of v, and
• wherein v is a rank, Lσr is a number of first vectors associated with an r-th NZP CSI-RS resource from the Z NZP CSI-RS resources, where r=1, . . . , Z, Mv is a number of second vectors.