Codebook for CSI reporting in advanced wireless communication system

1. A user equipment (UE) capable of channel state information (CSI) reporting, the UE comprising:

a transceiver configured to receive, from a base station (BS), CSI configuration information including a number (L) of beams and a number (T) of CSI reports, wherein L and T are positive integers; and

at least one processor operably connected to the transceiver and configured to generate the T CSI reports, wherein if T equals 1, a single CSI report is generated based on the L beams; else if T is greater than 1, each of the T CSI reports is generated based on a subset of the L beams and each of the T CSI reports is independently decodable;

wherein the transceiver is further configured to transmit, to the BS, the T CSI reports in T CSI reporting instances, respectively.

2. The UE of claim 1 , wherein the at least one processor is further configured to determine whether to perform a single CSI reporting (T=1) or multiple CSI reportings (T>1) based on whether L≤v or L>v, respectively, where v is a fixed value greater or equal to 4.

3. The UE of claim 1 , wherein:

the at least one processor is further configured to generate one or more precoding matrix indicators (PMIs) and one or more rank indicators (RIs) for the T CSI reports, and

each of the T CSI reports includes at least one of the PMIs and only a first in time of the T CSI reports includes at least one of the RIs.

4. The UE of claim 1 , wherein:

the at least one processor is further configured to generate one or more precoding matrix indicators (PMIs) and one or more channel quality indicators (CQIs) for the T CSI reports, and

each of the T CSI reports includes at least one of the PMIs and only one of the T CSI reports includes at least one of the CQIs.

5. The UE of claim 1 , wherein:

the at least one processor is further configured to generate one or more precoding matrix indicators (PMIs) and multiple channel quality indicator (CQIs) for the T CSI reports, and each of the T CSI reports includes at least one of the PMIs and multiple of the T CSI

reports include at least one of the CQIs.

6. The UE of claim 1 , wherein:

the CSI configuration information includes a value of T=1;

the at least one processor is further configured to generate, for the T=1 CSI report, a rank indicator (RI)=2 and a corresponding PMI that includes (i 1,1 , i 1,2 ) indicating the L beams for a first layer CSI reporting and (i 1,3 ) indicating an index pair (k 1 , k 2 ) associated with the L beams for a second layer CSI reporting,

the index pair (k 1 , k 2 ) is identified based on i 1,3 and higher layer signaled parameters N 1 and N 2 according to:

N 1 > N 2 > 1

N 1 = N 2

N 1 = 2, N 2 = 1

N 1 > 2, N 2 = 1

i 1, 3

k 1

k 2

k 1

k 2

k 1

k 2

k 1

k 2

0

0

0

0

0

0

0

0

0

1

 O 1

0

O 1

0

O 1

0

 O 1

0

2

0

O 2

0

O 2

2O 1

0

3

2O 1

0

O 1

O 2

3O 1

 0,

O 1 and O 2 are oversampling factors in first and second dimensions, respectively, the PMI codebook for RI=2 is given by:

L = 1 or Codebook-Config = 1

i 1,2 = 0, . . . , N 2 O 2 − 1

i 1,1

i 2

0

1

0, . . . , N 1 O 1 − 1

W i 1,1 ,i 1,1 +k 1 ,i 1,2 ,i 1,2 +k 2 ,0 (2)

W i 1,1 ,i 1,1 +k 1 ,i 1,2 ,i 1,2 +k 2 ,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

L = 4 or Codebook-Config = 2, N 2 > 1

i 1,2 = 0, . . . , N 2 O 2 /2 − 1

i 1,1

i 2

0

1

2

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 ,2i 1,2 +k 2 ,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 ,2i 1,2 +k 2 ,1 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 ,2i 1,2 +k 2 ,0 (2)

i 1,1

i 2

3

4

5

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 ,2i 1,2 +k 2 ,1 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,1 (2)

i 1,1

i 2

6

7

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,0 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

L = 4 or Codebook-Config = 2, N 2 = 1

i 1,2 = 0

i 1,1

i 2

0

1

2

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 ,2i 1,1 +k 1 ,0,0,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,0,0,1 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,0,0,0 (2)

i 1,1

i 2

3

4

5

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,0,0,1 (2)

W 2i 1,1 +2,2i 1,1 +2+k 1 ,0,0,0 (2)

W 2i 1,1 +2,2i 1,1 +2+k 1 ,0,0,1 (2)

i 1,1

i 2

6

7

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +3,2i 1,1 +3+k 1 ,0,0,0 (2)

W 2i 1,1 +3,2i 1,1 +3+k 1 ,0,0,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

,

and

φ

n

=

e

j

⁢

⁢

π

⁢

⁢

n

/

2

u

m

=

{

[

1

e

j

⁢

⁢

2

⁢

π

⁢

⁢

m

O

2

⁢

N

2

…

e

j

⁢

⁢

2

⁢

π

⁢

⁢

m

⁡

(

N

2

-

1

)

O

2

⁢

N

2

]

N

2

>

1

1

N

2

=

1

.

⁢

v

l

,

m

=

[

u

m

e

j

⁢

⁢

2

⁢

π

⁢

⁢

l

O

1

⁢

N

1

⁢

u

m

…

e

j

⁢

⁢

2

⁢

π

⁢

⁢

l

⁡

(

N

1

-

1

)

O

1

⁢

N

1

⁢

u

m

]

T

7. The UE of claim 1 , wherein:

the at least one processor is further configured to identify one of two subband sizes configured via higher layer signaling for the UE for the CSI reporting per subband based in part on a number of physical resource blocks (PRBs) included in a carrier bandwidth part according to:

Carrier bandwidth part

Subband Size

(PRBs)

(PRBs)

24-60

4, 8

 61-100

 8, 16

101-200

12, 24

201-275

 16, 32,

and

the subband size=N which corresponds to N contiguous PRBs in the carrier bandwidth part.

8. A base station (BS) capable of configuring channel state information (CSI) reporting, the BS comprising:

at least one processor; and

a transceiver operably connected to the at least one processor and configured to:

transmit, to a user equipment (UE), CSI configuration information including a number (L) of beams and a number (T) of CSI reports, wherein L and T are positive integers; and

receive the T CSI reports in T CSI reporting instances, respectively;

wherein if T equals 1, a single CSI report is generated based on the L beams and

else if T is greater than 1, each of the T CSI reports is generated based on a subset of the L beams and each of the T CSI reports is independently decodable.

9. The BS of claim 8 , wherein the BS is configured to indicate to the UE whether to perform a single CSI reporting (T=1) or multiple CSI reportings (T>1) based on whether L≤v or L>v, respectively, where v is a fixed value greater or equal to 4.

10. The BS of claim 8 , wherein each of the T CSI reports includes a precoding matrix indicators (PMI) and only a first in time of the T CSI reports includes a rank indicator (RI).

11. The BS of claim 8 , wherein each of the T CSI reports includes a precoding matrix indicators (PMI) and only one of the T CSI reports includes a channel quality indicator (CQI).

12. The BS of claim 8 , wherein each of the T CSI reports includes a precoding matrix indicator (PMI) and multiple of the T CSI reports include a channel quality indicator (CQI).

13. The BS of claim 8 , wherein:

the CSI configuration information includes a value of T=1;

the transceiver is configured to receive, in the T=1 CSI report, a rank indicator (RI)=2 and a corresponding PMI that includes (i 1,1 , i 1,2 ) indicating the L beams for a first layer CSI reporting and (i 1,3 ) indicating an index pair (k 1 , k 2 ) associated with the L beams for a second layer CSI reporting,

the index pair (k 1 , k 2 ) is identified based on i 1,3 and higher layer signaled parameters N 1 and N 2 according to:

N 1 > N 2 > 1

N 1 = N 2

N 1 = 2, N 2 = 1

N 1 > 2, N 2 = 1

i 1, 3

k 1

k 2

k 1

k 2

k 1

k 2

k 1

k 2

0

0

0

0

0

0

0

0

0

1

 O 1

0

O 1

0

O 1

0

 O 1

0

2

0

O 2

0

O 2

2O 1

0

3

2O 1

0

O 1

O 2

3O 1

 0,

O 1 and O 2 are oversampling factors in first and second dimensions, respectively, the PMI codebook for RI=2 is given by:

L = 1 or Codebook-Config = 1

i 1,2 = 0, . . . , N 2 O 2 − 1

i 1,1

i 2

0

1

0, . . . , N 1 O 1 − 1

W i 1,1 ,i 1,1 +k 1 ,i 1,2 ,i 1,2 +k 2 ,0 (2)

W i 1,1 ,i 1,1 +k 1 ,i 1,2 ,i 1,2 +k 2 ,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

L = 4 or Codebook-Config = 2, N 2 > 1

i 1,2 = 0, . . . , N 2 O 2 /2 − 1

i 1,1

i 2

0

1

2

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 ,2i 1,2 +k 2 ,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 ,2i 1,2 +k 2 ,1 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 ,2i 1,2 +k 2 ,0 (2)

i 1,1

i 2

3

4

5

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 ,2i 1,2 +k 2 ,1 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,1 (2)

i 1,1

i 2

6

7

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,0 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

L = 4 or Codebook-Config = 2, N 2 = 1

i 1,2 = 0

i 1,1

i 2

0

1

2

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 ,2i 1,1 +k 1 ,0,0,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,0,0,1 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,0,0,0 (2)

i 1,1

i 2

3

4

5

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,0,0,1 (2)

W 2i 1,1 +2,2i 1,1 +2+k 1 ,0,0,0 (2)

W 2i 1,1 +2,2i 1,1 +2+k 1 ,0,0,1 (2)

i 1,1

i 2

6

7

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +3,2i 1,1 +3+k 1 ,0,0,0 (2)

W 2i 1,1 +3,2i 1,1 +3+k 1 ,0,0,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

,

and

⁢

⁢

φ

n

=

e

j

⁢

⁢

π

⁢

⁢

n

/

2

u

m

=

{

[

1

e

j

⁢

2

⁢

⁢

π

⁢

⁢

m

O

2

⁢

N

2

…

e

j

⁢

2

⁢

⁢

π

⁢

⁢

m

⁡

(

N

2

-

1

)

O

2

⁢

N

2

]

N

2

>

1

1

N

2

=

1

.

⁢

v

l

,

m

=

[

u

m

e

j

⁢

2

⁢

⁢

π

⁢

⁢

l

O

1

⁢

N

1

⁢

u

m

…

e

j

⁢

2

⁢

⁢

π

⁢

⁢

l

⁡

(

N

1

-

1

)

O

1

⁢

N

1

⁢

u

m

]

T

14. The BS of claim 8 , wherein the UE identifies one of two subband sizes configured via higher layer signaling for the UE for the CSI reporting per subband based in part on a number of physical resource blocks (PRBs) included in a carrier bandwidth part according to:

Carrier bandwidth part

Subband Size

(PRBs)

(PRBs)

24-60

4, 8

 61-100

 8, 16

101-200

12, 24

201-275

 16, 32,

and

the subband size=N which corresponds to N contiguous PRBs in the carrier bandwidth part.

15. A method for channel state information (CSI) reporting by a user equipment (UE), the method comprising:

receiving, from a base station (BS), CSI configuration information including a number (L) of beams and a number (T) of CSI reports, wherein L and T are positive integers;

generating the T CSI reports, wherein if T equals 1, a single CSI report is generated based on the L beams else if T is greater than 1, each of the T CSI reports is generated based on a subset of the L beams and each of the T CSI reports is independently decodable; and

transmitting, to the BS, the T CSI reports in T CSI reporting instances, respectively.

16. The method of claim 15 , further comprising determining whether to perform a single CSI reporting (T=1) or multiple CSI reportings (T>1) based on whether L≤v or L>v, respectively, where v is a fixed value greater or equal to 4.

17. The method of claim 15 , wherein:

generating the T CSI reports comprises generating one or more precoding matrix indicators (PMIs) and one or more rank indicators (RIs), and

each of the T CSI reports includes at least one of the PMIs and only a first in time of the T CSI reports includes at least one of the RIs.

18. The method of claim 15 , wherein:

generating the T CSI reports comprises generating one or more precoding matrix indicators (PMIs) and one or more channel quality indicators (CQIs), and

each of the T CSI reports includes at least one of the PMIs and only one of the T CSI reports includes at least one of the CQIs.

19. The method of claim 15 , wherein:

generating the T CSI reports comprises generating one or more precoding matrix indicators (PMIs) and multiple channel quality indicators (CQI), and

each of the T CSI reports includes at least one of the PMIs and multiple of the T CSI reports include at least one of the CQIs.

20. The method of claim 15 , wherein:

the CSI configuration information includes a value of T=1,

generating the T=1 CSI report comprises generating a rank indicator (RI)=2 and a corresponding PMI that includes (i 1,1 , i 1,2 ) indicating an index pair (k 1 , k 2 ) associated with the L beams for a first layer CSI reporting and (i 1,3 ) indicating the L beams for a second layer CSI reporting,

the index pair (k 1 , k 2 ) is identified based on i 1,3 and higher layer signaled parameters N 1 and N 2 according to:

N 1 > N 2 > 1

N 1 = N 2

N 1 = 2, N 2 = 1

N 1 > 2, N 2 = 1

i 1, 3

k 1

k 2

k 1

k 2

k 1

k 2

k 1

k 2

0

0

0

0

0

0

0

0

0

1

 O 1

0

O 1

0

O 1

0

 O 1

0

2

0

O 2

0

O 2

2O 1

0

3

2O 1

0

O 1

O 2

3O 1

 0,

O 1 and O 2 are oversampling factors in first and second dimensions, respectively, the PMI codebook for RI=2 is given by:

L = 1 or Codebook-Config = 1

i 1,2 = 0, . . . , N 2 O 2 − 1

i 1,1

i 2

0

1

0, . . . , N 1 O 1 − 1

W i 1,1 ,i 1,1 +k 1 ,i 1,2 ,i 1,2 +k 2 ,0 (2)

W i 1,1 ,i 1,1 +k 1 ,i 1,2 ,i 1,2 +k 2 ,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

L = 4 or Codebook-Config = 2, N 2 > 1

i 1,2 = 0, . . . , N 2 O 2 /2 − 1

i 1,1

i 2

0

1

2

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 ,2i 1,2 +k 2 ,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 ,2i 1,2 +k 2 ,1 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 ,2i 1,2 +k 2 ,0 (2)

i 1,1

i 2

3

4

5

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 ,2i 1,2 +k 2 ,1 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,1 (2)

i 1,1

i 2

6

7

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,0 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,2i 1,2 +1,2i 1,2 +1+k 2 ,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

L = 4 or Codebook-Config = 2, N 2 = 1

i 1,2 = 0

i 1,1

i 2

0

1

2

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 ,2i 1,1 +k 1 ,0,0,0 (2)

W 2i 1,1 ,2i 1,1 +k 1 ,0,0,1 (2)

W 2i 1,1 +1,2i 1,1 +1+k 1 ,0,0,0 (2)

i 1,1

i 2

3

4

5

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +1,2i 1,1 +1+k 1 ,0,0,1 (2)

W 2i 1,1 +2,2i 1,1 +2+k 1 ,0,0,0 (2)

W 2i 1,1 +2,2i 1,1 +2+k 1 ,0,0,1 (2)

i 1,1

i 2

6

7

0

,

…

⁢

,

N

1

⁢

O

1

2

-

1

W 2i 1,1 +3,2i 1,1 +3+k 1 ,0,0,0 (2)

W 2i 1,1 +3,2i 1,1 +3+k 1 ,0,0,1 (2)

where

⁢

⁢

W

l

,

l

′

,

m

,

m

′

,

n

(

2

)

=

1

2

⁢

⁢

P

CSI

-

RS

⁡

[

v

l

,

m

v

l

′

,

m

′

φ

n

⁢

v

l

,

m

-

φ

n

⁢

v

l

′

,

m

′

]

.

,

and

⁢

⁢

φ

n

=

e

j

⁢

⁢

π

⁢

⁢

n

/

2

u

m

=

{

[

1

e

j

⁢

2

⁢

⁢

π

⁢

⁢

m

O

2

⁢

N

2

…

e

j

⁢

2

⁢

⁢

π

⁢

⁢

m

⁡

(

N

2

-

1

)

O

2

⁢

N

2

]

N

2

>

1

1

N

2

=

1

.

⁢

v

l

,

m

=

[

u

m

e

j

⁢

2

⁢

⁢

π

⁢

⁢

l

O

1

⁢

N

1

⁢

u

m

…

e

j

⁢

2

⁢

⁢

π

⁢

⁢

l

⁡

(

N

1

-

1

)

O

1

⁢

N

1

⁢

u

m

]

T