Method of enhanced interference measurements for channel state information (CSI) feedback
Embodiments of providing enhanced interference measurements for CSI feedback are generally described herein. In some embodiments, CSI-IM resources are used by UE to perform interference measurements. The serving cell determines a hopping pattern for varying a position of the determined CSI-IM resources in subframes transmitted to the served UE. The determined CSI-IM resources and the determined CSI-IM resources hopping pattern are transmitted to the served UE. The serving node transmits a zero-power (ZP) CSI-RS. The serving node receives an interference measurement from the served UE based on CSI-IM and ZP CSI-RS provided to the served UE from the serving cell. Collisions between the CSI-IM of the serving node and CSI-IM of the non-serving nodes are minimized by the determined CSI-IM resources hopping pattern.
1. A User Equipment (UE) comprising:
a processor configured to process signals associated with communications;
a transceiver configured to transmit and receive signals associated with the communications;
wherein the processor is further configured to:
receive CSI-IM resources from a serving cell from the transceiver;
process the received CSI-IM resources to perform interference measurements on cells including the said serving cell;
process a zero-power (ZP) CSI-RS according to the CSI-IM resources received at the transceiver from the said serving cell;
perform the interference measurements associated with the cells including the said serving cell based on the CSI-IM resources and ZP CSI-RS received at the transceiver from the said serving cell; and
provide channel state information feedback to the said serving cell based on the interference measurements, wherein the processor is further configured to process a CSI-IM resources hopping pattern received at the transceiver from the said serving cell for varying a position of the CSI-IM resources in subframes and to receive CSI-IM and the ZP CSI-RS from the said serving cell in positions in subframes according to the received CSI-IM resources hopping pattern.
2. The UE of claim 1 , wherein the processor is further configured to receive CSI-IM and the ZP CSI-RS from the said serving cell in subframes according to a subframe periodicity and an offset for the subframes defined by the said serving cell and provided in the CSI-IM resources received from the said serving cell.
3. The UE of claim 1 , wherein the hopping pattern is defined according to:
f
ih
(
n
S
)
=
{
0
(
∑
i
=
0
7
c
(
8
⌊
n
S
/
2
⌋
+
i
)
·
2
i
)
mod
N
CSI
-
IM
if
CSI
-
IM
hopping
is
disabled
if
CSI
-
IM
hopping
is
enabled
,
mod N CSI-IM
is CSI-IM hopping is disabled
is CSI-IM hopping is enabled,
where f ih is a random value for selecting the CSI-IM from a configured CSI-IM resource pool, P CSI-IM , (n s ) is an identifier of a subframe, N CSI-IM is a number of CSI-IM resources in the configured CSI-IM resource pool and c(i) is a pseudo-random sequence generated from a length-31 Gold sequence.
4. The UE of claim 1 , wherein the receiving CSI-IM resources from a serving cell further comprises receiving CSI-IM resources that include at least two parameter sets comprising {resourceConfig0, subframeConfig0} and {subframeConfig1} and wherein the processor is further configured to process the at least two parameter sets, the processor further configured to perform interference measurements associated with cells including the said serving cell based on the processed at least two parameter sets.
5. The UE of claim 4 , wherein the at least two parameter sets reside on different types of subframes, a first subframe configuration and resource configuration residing on a first type of subframe and a second subframe configuration residing on a second type of subframe, the processor further configured to perform interference measurements based on the processed at least two parameter sets residing on different types of subframes.
6. The UE of claim 4 , wherein the at least two parameter sets are configured to provide independent interference measurements for flexible and non-flexible subframes.
7. At least one non-transitory machine readable medium comprising instructions that, when executed by the machine, cause the machine to perform operations comprising:
receiving CSI-IM resources from a serving cell;
processing the received CSI-IM resources to perform interference measurements on cells including the serving cell;
processing a zero-power (ZP) CSI-RS according to the CSI-IM resources received from the serving cell;
performing the interference measurements associated with the cells including the serving cell based on the CSI-IM resources and ZP CSI-RS received from the serving cell;
providing channel state information feedback to the serving cell based on the interference measurements;
processing a CSI-IM resources hopping pattern received from the serving cell for varying a position of the CSI-IM resources in subframes; and
receiving CSI-IM and the ZP CSI-RS from the serving cell in positions in subframes according to the received CSI-IM resources hopping pattern.
8. The non-transitory computer-readable medium of claim 7 , wherein the instructions further configure cause the machine to receive CSI-IM and the ZP CSI-RS from the serving cell in subframes according to a subframe periodicity and an offset for the subframes defined by the serving cell and provided in the CSI-IM resources received from the serving cell.
9. The non-transitory computer-readable medium of claim 7 , wherein the hopping pattern is defined according to:
f
ih
(
n
S
)
=
{
0
(
∑
i
=
0
7
c
(
8
⌊
n
S
/
2
⌋
+
i
)
·
2
i
)
mod
N
CSI
-
IM
if
CSI
-
IM
hopping
is
disabled
if
CSI
-
IM
hopping
is
enabled
,
mod N CSI-IM
is CSI-IM hopping is disabled
is CSI-IM hopping is enabled,
where f ih is a random value for selecting the CSI-IM from a configured CSI-IM resource pool, P CSI-IM , (n s ) is an identifier of a subframe, N CSI-IM is a number of CSI-IM resources in the configured CSI-IM resource pool and c(i) is a pseudo-random sequence generated from a length-31 Gold sequence.
10. The non-transitory computer-readable medium of claim 7 , wherein the instructions further cause the machine to:
receive CSI-IM resources that include at least two parameter sets comprising {resourceConfig0, subframeConfig0} and {subframeConfig1};
process the at least two parameter sets; and
perform interference measurements associated with cells including the serving cell based on the processed at least two parameter sets.
11. The non-transitory computer-readable medium of claim 10 , wherein the at least two parameter sets reside on different types of subframes, a first subframe configuration and resource configuration residing on a first type of subframe and a second subframe configuration residing on a second type of subframe, and wherein the instructions further cause the machine to perform interference measurements based on the processed at least two parameter sets residing on different types of subframes.
12. The non-transitory computer-readable medium of claim 10 , wherein the at least two parameter sets are configured to provide independent interference measurements for flexible and non-flexible subframes.
13. A method to be implemented by a User Equipment (UE), the method comprising:
receiving CSI-IM resources from a serving cell;
processing the received CSI-IM resources to perform interference measurements on cells including the serving cell;
processing a zero-power (ZP) CSI-RS according to the CSI-IM resources received from the serving cell;
performing the interference measurements associated with the cells including the serving cell based on the CSI-IM resources and ZP CSI-RS received from the serving cell;
providing channel state information feedback to the serving cell based on the interference measurements;
processing a CSI-IM resources hopping pattern received from the serving cell for varying a position of the CSI-IM resources in subframes; and
receiving CSI-IM and the ZP CSI-RS from the serving cell in positions in subframes according to the received CSI-IM resources hopping pattern.
14. The method of claim 13 , further comprising:
receiving CSI-IM and the ZP CSI-RS from the serving cell in subframes according to a subframe periodicity and an offset for the subframes defined by the serving cell and provided in the CSI-IM resources received from the serving cell.
15. The method of claim 13 , wherein the hopping pattern is defined according to:
f
ih
(
n
S
)
=
{
0
(
∑
i
=
0
7
c
(
8
⌊
n
S
/
2
⌋
+
i
)
·
2
i
)
mod
N
CSI
-
IM
if
CSI
-
IM
hopping
is
disabled
if
CSI
-
IM
hopping
is
enabled
,
mod N CSI-IM
is CSI-IM hopping is disabled
is CSI-IM hopping is enabled,
where f ih is a random value for selecting the CSI-IM from a configured CSI-IM resource pool, P CSI-IM , (n s ) is an identifier of a subframe, N CSI-IM is a number of CSI-IM resources in the configured CSI-IM resource pool and c(i) is a pseudo-random sequence generated from a length-31 Gold sequence.
16. The method of claim 13 , wherein the receiving CSI-IM resources from a serving cell further comprises receiving CSI-IM resources that include at least two parameter sets comprising {resourceConfig0, subframeConfig0} and {subframeConfig1} and wherein the method further comprises processing the at least two parameter sets and performing interference measurements associated with cells including the serving cell based on the processed at least two parameter sets.
17. The method of claim 16 , wherein the at least two parameter sets reside on different types of subframes, a first subframe configuration and resource configuration residing on a first type of subframe and a second subframe configuration residing on a second type of subframe, the processor further configured to perform interference measurements based on the processed at least two parameter sets residing on different types of subframes.
18. The method of claim 16 , wherein the at least two parameter sets are configured to provide independent interference measurements for flexible and non-flexible subframes.
19. A serving cell, comprising:
memory for storing data thereon;
a processor, coupled to the memory, for processing signals associated with communications including data from the memory;
a transceiver, coupled to the processor, arranged to transmit and receive signals associated with communications; and
at least one antenna for radiating signals for transmission and intercepts signals for reception;
wherein the processor is further arranged to:
determine CSI-IM resources for use by a served user equipment (UE) served by the serving cell to perform interference measurements;
provide the determined CSI-IM resources to the transceiver for transmission to the served UE;
provide, to the transceiver for transmission to the served UE, a zero-power (ZP) CSI-RS according to the determined CSI-IM resources to remove serving cell interference; and
process a received interference measurement from the served UE based on CSI-IM received by the served UE and the ZP CSI-RS provided to the served UE from the serving cell.
20. The serving cell of claim 19 , wherein the processor is further arranged to generating pseudo-random numbers and to define a position value of the CSI-IM resources to cause the position of the CSI-IM resources in subframes to vary in a time domain using the pseudo-random numbers.
21. The serving cell of claim 19 , wherein the processor further selecting a subframe periodicity and an offset for the subframes, wherein the processor is further arranged to determine a hopping pattern for varying a position of the determined CSI-IM resources in subframes transmitted to a served UE and to provide the determined CSI-IM resources and the determined CSI-IM resources hopping pattern to the transceiver for transmission to the served UE using the selected periodicity and offset, wherein collisions between the CSI-IM transmitted by the transceiver and CSI-IM of neighboring nodes are minimized by the determined hopping pattern.
22. The serving cell of claim 21 , wherein the processor is further arranged to determine the hopping pattern according to:
f
ih
(
n
S
)
=
{
0
(
∑
i
=
0
7
c
(
8
⌊
n
S
/
2
⌋
+
i
)
·
2
i
)
mod
N
CSI
-
IM
if
CSI
-
IM
hopping
is
disabled
if
CSI
-
IM
hopping
is
enabled
,
mod N CSI-IM
is CSI-IM hopping is disabled
is CSI-IM hopping is enabled, where f ih is a random value for selecting the CSI-IM from a configured CSI-IM resource pool, P CSI-IM , (n s ) is an identifier of a subframe, N CSI-IM is a number of CSI-IM resources in the configured CSI-IM resource pool and c(i) is a pseudo-random sequence generated from a length-31 Gold sequence.
23. The serving cell of claim 19 , wherein the processor is further arranged to determine CSI-IM resources by determining at least two parameter sets comprising {resourceConfig0, subframeConfig0} and {subframeConfig1}, the two parameter sets residing on different types of subframes, a first subframe configuration and a first resource configuration residing on a first type of subframe and a second subframe configuration residing on a second type of subframe.
24. The serving cell of claim 23 , wherein the processor is further arranged to provide independent interference measurements for flexible and non-flexible subframes.