Method, device, and system for transmitting signals in unlicensed band

1. A user equipment used in a cellular wireless communication system, the user equipment comprising:

a wireless communication module; and

a processor,

wherein the processor is configured to:

receive, from a base station, Channel State Information-Reference Signal (CSI-RS) configuration information indicating one of plurality of CSI-RS configuration information included in a CSI-RS configuration information set for a downlink cell, and

receive, from the base station, CSI-RS in a slot of the downlink cell according to the CSI-RS configuration information,

wherein the CSI-RS is transmitted using at least one of antenna ports 15 to 22 ,

wherein the CSI-RS configuration information set is a first CSI-RS configuration information set or a second CSI-RS configuration information set based on whether the downlink cell operates in an unlicensed band,

wherein the second CSI-RS configuration information set is part of the first CSI-RS configuration set, wherein when an index of the slot is not #0, #1, #10, or #11:

when the CSI-RS is not used for Discovery RS (DRS), an initialization value of a sequence of the CSI-RS is determined based on a first value, wherein the first value is equal to the index of the slot, and

when the CSI-RS is used for DRS, the initialization value of the sequence of the CSI-RS is determined based on a second value, wherein the second value is not equal to the index of the slot.

2. The user equipment of claim 1 ,

wherein when the downlink cell operates in a licensed band, the first CSI-RS configuration information set including one or more first CSI-RS configuration information related to Orthogonal Frequency Division Multiplexing (OFDM) symbols #5/#6, one or more second CSI-RS configuration information related to OFDM symbols #9/#10, and one or more third CSI-RS configuration information related to OFDM symbols #12/#13,

wherein when the downlink cell operates in an unlicensed band, the second CSI-RS configuration information set,

wherein the second CSI-RS configuration information set does not comprise the one or more third CSI-RS configuration information.

3. The user equipment of claim 2 , wherein the second CSI-RS configuration information set does not comprise the one or more first CSI-RS configuration information.

4. The user equipment of claim 2 , wherein the first CSI-RS configuration information set is a CSI-RS configuration {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19} and the second CSI-RS configuration information set is a CSI-RS configuration {1, 2, 3, 6, 7, 8, 12, 13, 14, 15, 16, 17}.

5. The user equipment of claim 4 , wherein the OFDM symbols for CSI-RS according to a CSI-RS configuration information is given by the following Table.

Number of CSI reference signals configured

1 or 2

4

8

CSI-RS

OFDM symbol

OFDM symbol

OFDM symbol

configuration

index

index

index

0

5, 6

5, 6

5, 6

1

 9, 10

 9, 10

 9, 10

2

 9, 10

 9, 10

 9, 10

3

 9, 10

 9, 10

 9, 10

4

12, 13

12, 13

12, 13

5

5, 6

5, 6

6

 9, 10

 9, 10

7

 9, 10

 9, 10

8

 9, 10

 9, 10

9

12, 13

12, 13

10

5, 6

11

5, 6

12

 9, 10

13

 9, 10

14

 9, 10

15

 9, 10

16

 9, 10

17

 9, 10

18

12, 13

19

 12, 13.

6. The user equipment of claim 1 , wherein when the downlink cell operates in the unlicensed band and the CSI-RS is configured to DRS, the processor is further configured to perform a Radio Resource Management (RRM) measurement using the CSI-RS.

7. The user equipment of claim 1 , wherein the initialization value of the sequence of the CSI-RS is given by the following Equation,

c init =2 10 ·(7·( n s +1)+ l+ 1)·(2· N ID CSI +1)+2· N ID CSI +N CP

Here, l represents an OFDM symbol index within a slot,

N ID CS: represents a value configured by higher layers or a physical cell identifier,

N CP has 0 or 1 depending on a Cyclic Prefix (CP) type, and

n s has the first value or the second value.

8. The user equipment of claim 1 ,

wherein when the CSI-RS is transmitted using a single of an antenna, a port of the single of the antenna is 15,

wherein when the CSI-RS is transmitted using 2 antennas, ports of the 2 antennas are 15 to 16,

wherein when the CSI-RS is transmitted using 4 antennas, ports of the 4 antennas are 15 to 18,

wherein when the CSI-RS is transmitted using 8 antennas, ports of the 8 antennas are 15 to 22.

9. The user equipment of claim 1 ,

wherein the CSI-RS sequence is given by the following Equation

r

l

,

n

s

⁡

(

m

)

=

1

2

⁢

(

1

-

2

·

c

⁡

(

2

⁢

m

)

)

+

j

⁢

1

2

⁢

(

1

-

2

·

c

⁡

(

2

⁢

m

+

1

)

)

,

⁢

m

=

0

,

1

,

…

⁢

,

N

R

⁢

B

max

,

DL

-

1

Here, N∧max,DL_RB is maximum number of RB in downlink and c(i) is pseudo-random sequence.

10. The user equipment of claim 1 ,

wherein when the CSI-RS is used for DRS, a period of transmission of the DRS is 40 ms or 80 ms or 160 ms.

11. The base station of claim 4 , wherein the OFDM symbols for CSI-RS according to a CSI-RS configuration information is given by the following Table.

Number of CSI reference signals configured

1 or 2

4

8

CSI-RS

OFDM symbol

OFDM symbol

OFDM symbol

configuration

index

index

index

0

5, 6

5, 6

5, 6

1

 9, 10

 9, 10

 9, 10

2

 9, 10

 9, 10

 9, 10

3

 9, 10

 9, 10

 9, 10

4

12, 13

12, 13

12, 13

5

5, 6

5, 6

6

 9, 10

 9, 10

7

 9, 10

 9, 10

8

 9, 10

 9, 10

9

12, 13

12, 13

10

5, 6

11

5, 6

12

 9, 10

13

 9, 10

14

 9, 10

15

 9, 10

16

 9, 10

17

 9, 10

18

12, 13

19

 12, 13.

12. A base station used in a cellular wireless communication system, the base station comprising:

a wireless communication module; and

a processor,

wherein the processor is configured to:

transmit, to a user equipment, Channel State Information-Reference Signal (CSI-RS) configuration information indicating one of plurality of CSI-RS configuration information included in a CSI-RS configuration information set for a downlink cell, and

transmit, to the user equipment, CSI-RS in a slot of the downlink cell according to the CSI-RS configuration information,

wherein the CSI-RS is transmitted using at least one of antenna ports 15 to 22 ,

wherein the CSI-RS configuration information set is a first CSI-RS configuration information set or a second CSI-RS configuration information set based on whether the downlink cell operates in an unlicensed band,

wherein the second CSI-RS configuration information set is part of the first CSI-RS configuration set,

wherein when an index of the slot is not #0, #1, #10, or #11:

when the CSI-RS is not used for Discovery RS (DRS), an initialization value of a sequence of the CSI-RS is determined based on a first value, wherein the first value is equal to the index of the slot, and

when the CSI-RS is used for DRS, the initialization value of the sequence of the CSI-RS is determined based on a second value, wherein the second value is not equal to the index of the slot.

13. The base station of claim 12 , wherein when the downlink cell operates in a licensed band, the first CSI-RS configuration information set including one or more first CSI-RS configuration information related to Orthogonal Frequency Division Multiplexing (OFDM) symbols #5/#6, one or more second CSI-RS configuration information related to OFDM symbols #9/#10, and one or more third CSI-RS configuration information related to OFDM symbols #12/#13,

wherein when the downlink cell operates in an unlicensed band, the second CSI-RS configuration information set,

wherein the second CSI-RS configuration information set does not comprise the one or more third CSI-RS configuration information.

14. The base station of claim 13 , wherein the second CSI-RS configuration information set does not comprise the one or more first CSI-RS configuration information.

15. The base station of claim 13 , wherein the first CSI-RS configuration information set is a CSI-RS configuration {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19} and the second CSI-RS configuration information set is a CSI-RS configuration {1, 2, 3, 6, 7, 8, 12, 13, 14, 15, 16, 17}.

16. The base station of claim 12 , wherein when the downlink cell operates in the unlicensed band and the CSI-RS is configured to DRS, the processor is further configured to perform a Radio Resource Management (RRM) measurement using the CSI-RS.

17. The base station of claim 12 , wherein the initialization value of the sequence of the CSI-RS is given by the following Equation,

c init =2 10 ·(7·( n s +1)+ l+ 1)·(2· N ID CSI +1)+2· N ID CSI +N CP

Here, l represents an OFDM symbol index within a slot,

N ID CS: represents a value configured by higher layers or a physical cell identifier,

N CP has 0 or 1 depending on a Cyclic Prefix (CP) type, and

n s has the first value or the second value.

18. The user equipment of claim 12 ,

wherein when the CSI-RS is transmitted using a single of an antenna, a port of the single of the antenna is 15,

wherein when the CSI-RS is transmitted using 2 antennas, ports of the 2 antennas are 15 to 16,

wherein when the CSI-RS is transmitted using 4 antennas, ports of the 4 antennas are 15 to 18,

wherein when the CSI-RS is transmitted using 8 antennas, ports of the 8 antennas are 15 to 22.

19. The user equipment of claim 12 ,

wherein the CSI-RS sequence is given by the following Equation

r

l

,

n

s

⁡

(

m

)

=

1

2

⁢

(

1

-

2

·

c

⁡

(

2

⁢

m

)

)

+

j

⁢

1

2

⁢

(

1

-

2

·

c

⁡

(

2

⁢

m

+

1

)

)

,

⁢

m

=

0

,

1

,

…

⁢

,

N

R

⁢

B

max

,

DL

-

1

Here, N∧max,DL_RB is maximum number of RB in downlink and c(i) is pseudo-random sequence.

20. The user equipment of claim 12 ,

wherein when the CSI-RS is used for DRS, a period of transmission of the DRS is 40 ms or 80 ms or 160 ms.