Method and apparatus for CSI reporting in distributed MIMO
Apparatuses and methods for CSI reporting in distributed MIMO in a wireless communication system is provided. The method includes receiving a channel state information (CSI) report setting about a first type of information CSI(0), . . . , CSI(N CSI-1 ) for N CSI >1, receiving a CSI reference signal (CSI-RS) resource setting about a plurality of CSI-RS resources, CSI-RS(0), . . . , CSI-RS(N RRH −1) transmitted from N RRH groups of CSI-RS ports, wherein N RRH is a number of remote radio heads (RRH). The method further includes measuring the plurality of CSI-RS resources CSI-RS(0), . . . , CSI-RS(N RRH −1), determining, based on the measurement, the first type of information CSI(0), . . . , CSI(N CSI −1); and transmitting information indicating the first type of information CSI(0), . . . , CSI(N CSI −1).
1. A user equipment (UE) comprising:
a transceiver configured to:
receive a channel state information (CSI) report setting about a first type of information CSI(0), . . . , CSI(N CSI-1 ) for N CSI >1; and
receive a CSI reference signal (CSI-RS) resource setting about a plurality of CSI-RS resources, CSI-RS(0), . . . , CSI-RS(N RRH −1) transmitted from N RRH groups of CSI-RS ports, wherein N RRH is a number of remote radio heads (RRH); and
a processor operably coupled to the transceiver, the processor configured, to:
measure the plurality of CSI-RS resources CSI-RS(0), . . . , CSI-RS(N RRH −1); and
determine, based on the measurement, the first type of information CSI(0), . . . , CSI(N CSI −1),
wherein the transceiver is configured to transmit information indicating the first type of information CSI(0), . . . , CSI(N CSI −1).
2. The UE of claim 1 , wherein when N CSI =N RRH , CSI(i) comprises:
a CSI of an i-th RRH for i=0, ⋅ ⋅ ⋅ , N CSI −1; and
an inter-RRH component for the (i)-th RRH for i=1, ⋅ ⋅ ⋅ , N CSI −1.
3. The UE of claim 1 , wherein when
N
CSI
=
∑
j
=
0
N
RRH
-
1
N
g
,
j
,
where
N
g
,
j
is a number of panels at RRH j, CSI(i) comprises a CSI of an n-th panel of a j-th RRH, where
i
=
n
+
∑
k
=
0
j
-
1
N
g
,
k
.
4. The UE of claim 1 , wherein when N CSI =N CSI,perRRH N RRH , where N CSI,perRRH >1 is a number of CSI report settings per RRH, CSI(i·N CSI,perRRH ), . . . , CSI(i·N CSI,perRRH +(N CSI,perRRH −1)) comprise a CSI of an i-th RRH, for i=0, ⋅ ⋅ ⋅ , N RRH −1.
5. The UE of claim 1 , wherein when N CSI =G, where N RRH =Σ g=0 G-1 N RRH,g and N RRH,g is a number of RRHs at a group g, CSI(g) comprises:
a CSI for RRHs in a group g=0, ⋅ ⋅ ⋅ , G−1; and
inter-RRH components for RRHs associated with the group g=0, ⋅ ⋅ ⋅ , G−1.
6. The UE of claim 1 , wherein N CSI =N com +N ind , where each CSI report setting includes either common CSI or individual CSI, N com is a number of CSI report settings that include common CSI, and N ind is a number of CSI report settings that include individual CSI for the RRHs.
7. The UE of claim 1 , wherein:
each CSI report setting corresponds to a CSI report, or
CSI report settings correspond to multiple CSI reports.
8. A base station (BS) comprising:
a processor configured to:
generate a channel state information (CSI) report setting about a first type of information CSI(0), . . . , CSI(N CSI −1) for N CSI >1; and
generate a CSI reference signal (CSI-RS) resource setting about a plurality of CSI-RS resources CSI-RS(0), . . . , CSI-RS(N RRH −1) transmitted from N RRH groups of CSI-RS ports, wherein N RRH is a number of remote radio heads (RRH); and
a transceiver operably coupled to the processor, the transceiver configured to:
transmit the CSI report setting and the CSI-RS resource setting; and
receive information indicating the first type of information CSI(0), . . . , CSI(N CSI −1);
wherein the information indicating the first type of information CSI(0), . . . , CSI(N CSI −1) is based on the at least one CSI report setting, the at least one CSI-RS resource setting, and the plurality of CSI-RS resources CSI-RS(0), . . . , CSI-RS(N RRH −1).
9. The BS of claim 8 , wherein when N CSI =N RRH , CSI(i) comprises:
a CSI of an i-th RRH for i=0, ⋅ ⋅ ⋅ , N CSI −1; and
an inter-RRH component for the (i)-th RRH for i=1, ⋅ ⋅ ⋅ , N CSI −1.
10. The BS of claim 8 , wherein when
N
CSI
=
∑
j
=
0
N
RRH
-
1
N
g
,
j
where
N
g
,
j
is a number of panels at RRH j, CSI(i) comprises a CSI of an n-th panel of a j-th RRH, where
i
=
n
+
∑
k
=
0
j
-
1
N
g
,
k
.
11. The BS of claim 8 , wherein when N CSI =N CSI,perRRH N RRH , where N CSI,perRRH >1 is a number of CSI report settings per RRH, CSI(i·N CSI,perRRH ), . . . , CSI(i·N CSI,perRRH +(N CSI,perRRH −1)) comprise a CSI of an i-th RRH, for i=0, ⋅ ⋅ ⋅ , N RRH −1.
12. The BS of claim 8 , wherein when N CSI =G, where
N
RRH
=
∑
g
=
0
G
-
1
N
RRH
,
g
and
N
RRH
,
g
is a number of RRHs at a group g, CSI(g) comprises:
a CSI for RRHs in a group g=0, ⋅ ⋅ ⋅ , G−1; and
inter-RRH components for RRHs associated with the group g=0, ⋅ ⋅ ⋅ , G−1.
13. The BS of claim 8 , wherein N CSI =N com +N ind , where each CSI report setting includes either common CSI or individual CSI, N com is a number of CSI report settings that include common CSI, and N ind is a number of CSI report settings that include individual CSI for the RRHs.
14. The BS of claim 8 , wherein:
each CSI report setting corresponds to a CSI report, or
CSI report settings correspond to multiple CSI reports.
15. A method for operating a user equipment (UE), the method comprising:
receiving a channel state information (CSI) report setting about a first type of information CSI(0), . . . , CSI(N CSI-1 ) for N CSI >1;
receiving a CSI reference signal (CSI-RS) resource setting about a plurality of CSI-RS resources, CSI-RS(0), . . . , CSI-RS(N RRH −1) transmitted from N RRH groups of CSI-RS ports, wherein N RRH is a number of remote radio heads (RRH);
measuring the plurality of CSI-RS resources CSI-RS(0), . . . , CSI-RS(N RRH −1);
determining, based on the measurement, the first type of information CSI(0), . . . , CSI(N CSI −1); and
transmitting information indicating the first type of information CSI(0), . . . , CSI(N CSI −1).
16. The method of claim 15 , wherein when N CSI =N RRH , CSI(i) comprises:
a CSI of an i-th RRH for i=0, ⋅ ⋅ ⋅ , N CSI −1; and
an inter-RRH component for the (i)-th RRH for i=1, ⋅ ⋅ ⋅ , N CSI −1.
17. The method of claim 15 , wherein when
N
CSI
=
∑
j
=
0
N
RRH
-
1
N
g
,
j
,
where
N
g
,
j
is a number of panels at RRH j, CSI(i) comprises a CSI of an n-th panel of a j-th RRH, where
i
=
n
+
∑
k
=
0
j
-
1
N
g
,
k
.
18. The method of claim 15 , wherein when N CSI =N CSI,perRRH N RRH , where N CSI,perRRH >1 is a number of CSI report settings per RRH, CSI(i·N CSI,perRRH ), . . . , CSI(i·N CSI,perRRH +(N CSI,perRRH −1)) comprise a CSI of an i-th RRH, for i=0, ⋅ ⋅ ⋅ , N RRH −1.
19. The method of claim 15 , wherein when N CSI =G, where
N
RRH
=
∑
g
=
0
G
-
1
N
RRH
,
g
and
N
RRH
,
g
is a number of RRHs at a group g, CSI(g) comprises:
a CSI for RRHs in a group g=0, ⋅ ⋅ ⋅ , G−1; and
inter-RRH components for RRHs associated with the group g=0, ⋅ ⋅ ⋅ , G−1.
20. The method of claim 15 , wherein N CSI =N com +N ind , where each CSI report setting includes either common CSI or individual CSI, N com is a number of CSI report settings that include common CSI, and N ind is a number of CSI report settings that include individual CSI for the RRHs.