Channel state information reporting
This disclosure relates to techniques for a wireless device to perform channel state information reporting. The wireless device may receive channel state information reporting configuration information. The channel state information reporting configuration information may include an indication to use a wideband precoding matrix indicator format for 3GPP release 16 type II channel state information reporting. The wireless device may perform channel state information reporting using a different reporting configuration than 3GPP release 16 type II channel state information reporting using a wideband precoding matrix indicator format based at least in part on the channel state information reporting configuration information. The wireless device may also or alternatively perform 3GPP type I channel state information reporting using a unified spatial basis selection framework for rank indicators of 3 and 4 for any number of channel state information reference signal ports.
1 . A method, comprising:
by a wireless device:
receiving channel state information (CSI) reporting configuration information, wherein the CSI reporting configuration information configures the wireless device to perform 3GPP type I CSI reporting with a rank indicator (RI) of 3 or 4 and with a number of CSI reference signal (CSI-RS) ports equal to or greater than 16;
performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16 using a first spatial basis selection approach;
receiving CSI reporting configuration information, wherein the CSI reporting configuration information configures the wireless device to perform 3GPP type I CSI reporting with a RI of 3 or 4 and with a number of CSI-RS ports less than 16;
performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports less than 16 using the first spatial basis selection approach;
providing capability information indicating that the wireless device supports using the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16; and
receiving configuration information indicating to use the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16,
wherein performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16 using the first spatial basis selection approach is based at least in part on the configuration information indicating to use the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16.
2 . The method of claim 1 , wherein the method further comprises:
selecting a spatial basis for each data layer according to the first spatial basis selection approach, wherein the selection of the spatial basis for each data layer is independent of the selection of the spatial basis for each other data layer.
3 . The method of claim 1 , wherein the method further comprises:
selecting a spatial basis for each data layer according to the first spatial basis selection approach, wherein a same spatial basis is selected for at least a first set of data layers comprising 2 data layers.
4 . The method of claim 3 ,
wherein an orthogonal cover code is applied between polarizations within a set of layers for which the same spatial basis is selected.
5 . The method of claim 3 ,
wherein a spatial basis for a second set of data layers is selected from a specified subset of possible spatial bases, wherein the specified subset of possible spatial bases comprises spatial bases at specified shifts from the spatial basis selected for the first set of data layers.
6 . An apparatus, comprising:
at least one processor configured to cause a user equipment (UE) to:
receive channel state information (CSI) reporting configuration information, wherein the CSI reporting configuration information configures the UE to perform 3GPP type I CSI reporting with a rank indicator (RI) of 3 or 4 and with a number of CSI reference signal (CSI-RS) ports equal to or greater than 16;
perform 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16 using a first spatial basis selection approach;
receive CSI reporting configuration information, wherein the CSI reporting configuration information configures the UE to perform 3GPP type I CSI reporting with a RI of 3 or 4 and with a number of CSI-RS ports less than 16;
perform 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports less than 16 using the first spatial basis selection approach; and
select a spatial basis for each data layer according to the first spatial basis selection approach, wherein a same spatial basis is selected for at least a first set of data layers comprising 2 data layers, and wherein an orthogonal cover code is applied between polarizations within a set of layers for which the same spatial basis is selected.
7 . The apparatus of claim 6 , wherein the at least one processor is further configured to cause the UE to:
provide capability information indicating that the UE supports using the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16; and
receive configuration information indicating to use the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16,
wherein performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16 using the first spatial basis selection approach is based at least in part on the configuration information indicating to use the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16.
8 . The apparatus of claim 6 , wherein the at least one processor is further configured to cause the UE to:
select a spatial basis for each data layer according to the first spatial basis selection approach, wherein the selection of the spatial basis for each data layer is independent of the selection of the spatial basis for each other data layer.
9 . The apparatus of claim 6 ,
wherein a spatial basis for a second set of data layers is selected from a specified subset of possible spatial bases, wherein the specified subset of possible spatial bases comprises spatial bases at specified shifts from the spatial basis selected for the first set of data layers.
10 . The apparatus of claim 6 , further comprising:
a radio operably coupled to the at least one processor.
11 . A non-transitory computer readable storage medium storing program instructions executable by at least one processor of a user equipment (UE) to cause the UE to:
receive channel state information (CSI) reporting configuration information, wherein the CSI reporting configuration information configures the UE to perform 3GPP type I CSI reporting with a rank indicator (RI) of 3 or 4 and with a number of CSI reference signal (CSI-RS) ports equal to or greater than 16;
perform 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16 using a first spatial basis selection approach;
receive CSI reporting configuration information, wherein the CSI reporting configuration information configures the UE to perform 3GPP type I CSI reporting with a RI of 3 or 4 and with a number of CSI-RS ports less than 16;
perform 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports less than 16 using the first spatial basis selection approach; and
select a spatial basis for each data layer according to the first spatial basis selection approach, wherein a same spatial basis is selected for at least a first set of data layers comprising 2 data layers, wherein a spatial basis for a second set of data layers is selected from a specified subset of possible spatial bases, and wherein the specified subset of possible spatial bases comprises spatial bases at specified shifts from the spatial basis selected for the first set of data layers.
12 . The non-transitory computer readable storage medium of claim 11 , wherein the program instructions are further executable to cause the UE to:
provide capability information indicating that the UE supports using the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16; and
receive configuration information indicating to use the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16,
wherein performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16 using the first spatial basis selection approach is based at least in part on the configuration information indicating to use the first spatial basis selection approach when performing 3GPP type I CSI reporting with the RI of 3 or 4 and with the number of CSI-RS ports equal to or greater than 16.
13 . The non-transitory computer readable storage medium of claim 11 , wherein the program instructions are further executable to cause the UE to:
select a spatial basis for each data layer according to the first spatial basis selection approach, wherein the selection of the spatial basis for each data layer is independent of the selection of the spatial basis for each other data layer.
14 . The non-transitory computer readable storage medium of claim 11 ,
wherein an orthogonal cover code is applied between polarizations within a set of layers for which the same spatial basis is selected.
15 . The non-transitory computer readable storage medium of claim 11 , wherein the at least one processor is a baseband processor.
16 . The non-transitory computer readable storage medium of claim 11 , wherein the at least one processor is further configured to cause the UE to:
establish a wireless link with a serving cellular base station.
17 . The non-transitory computer readable storage medium of claim 16 , wherein establishing the wireless link includes establishing a radio resource control (RRC) connection with the serving cellular base station.
18 . The non-transitory computer readable storage medium of claim 17 , wherein establishing the RRC connection includes configuring one or more parameters for communication between the UE and the cellular base station.
19 . The non-transitory computer readable storage medium of claim 17 , wherein establishing the RRC connection includes establishing context information for the UE.
20 . The non-transitory computer readable storage medium of claim 17 , wherein establishing the RRC connection includes configuring one or more parameters for establishing an air interface for the UE to perform cellular communication with a cellular network associated with the serving cellular base station.