Beam domain preprocessor input type selection and parameter determination
Systems, methods, and instrumentalities are disclosed herein for beam domain preprocessor input type selection and parameter determination. A device may determine a beam domain preprocessing input type based on at least one of: a rank threshold, a performance metric, or a channel condition. The device may preprocess channel state information (CSI) based on the beam domain preprocessing input type. The device may compress the preprocessed CSI. The device may send the compressed preprocessed CSI (e.g., and an indication of the beam domain preprocessing input type).
1 . A device comprising:
a processor configured to:
determine a beam domain preprocessing input type based on at least one of: a rank threshold, a performance metric, or a channel condition;
preprocess channel state information (CSI) based on the beam domain preprocessing input type to generate beam domain CSI;
compress the beam domain CSI; and
send the compressed beam domain CSI and an indication of the determined beam domain preprocessing input type.
2 . The device of claim 1 , wherein the processor being configured to determine the beam domain preprocessing input type based on at least one of: the rank threshold, the performance metric, or the channel condition comprises the processor being configured to determine the beam domain preprocessing input type based on the rank threshold and the channel condition, and the processor being configured to determine the beam domain preprocessing input type based on the rank threshold and the channel condition comprises the processor being configured to:
determine a measured rank based on the channel condition;
on a condition that the measured rank is less than or equal to the rank threshold, select eigenvector as the beam domain preprocessing input type; and
on a condition that the measured rank is greater than the rank threshold, select full channel matrix as the beam domain preprocessing input type.
3 . The device of claim 1 , wherein the processor being configured to determine the beam domain preprocessing input type based on at least one of: the rank threshold, the performance metric, or the channel condition comprises the processor being configured to determine the beam domain preprocessing input type based on the performance metric and the channel condition, and the processor being configured to determine the beam domain preprocessing input type based on the performance metric and the channel condition comprises the processor being configured to:
determine a performance of a first beam domain preprocessing input type based on the performance metric and the channel condition;
determine a performance of a second beam domain preprocessing input type based on the performance metric and the channel condition;
compare the performance of the first beam domain preprocessing input type to the performance of the second beam domain preprocessing input type; and
select the beam domain preprocessing input type based on the comparison.
4 . The device of claim 1 or 3 , wherein the performance metric comprises a normalized mean squared error or a squared generalized cosine similarity.
5 . The device of claim 1 , wherein the processor is further configured to determine a beam domain preprocessing parameter associated with the determined beam domain preprocessing input type, and preprocessing the CSI is further based on the beam domain preprocessing parameter.
6 . The device of claim 5 , wherein the beam domain preprocessing parameter comprises one or more of:
a parameter related to a transformation matrix used for beam domain preprocessing;
a discrete Fourier transform basis of a beam codebook;
an oversampling factor of the beam codebook;
a maximum number of transmit beams;
a maximum number of receive beams,
an index of a selected transmit beam;
an index of a selected receive beam;
polarization information; or
an input type for beam domain preprocessing.
7 . The device of claim 1 , wherein the processor is further configured to receive, from a network entity, an input type selection indication that indicates for the device to determine the beam domain preprocessing input type.
8 . The device of claim 1 , wherein the beam domain preprocessing input type comprises full channel matrix or eigenvector.
9 . A method to be performed by a device, the method comprising:
determining a beam domain preprocessing input type based on at least one of: a rank threshold, a performance metric, or a channel condition;
preprocessing channel state information (CSI) based on the beam domain preprocessing input type to generate beam domain CSI;
compressing the beam domain CSI; and
sending the compressed beam domain CSI and an indication of the determined beam domain preprocessing input type.
10 . The method of claim 9 , wherein determining the beam domain preprocessing input type based on at least one of: the rank threshold, the performance metric, or the channel condition comprises determining the beam domain preprocessing input type based on the rank threshold and the channel condition, and determining the beam domain preprocessing input type based on the rank threshold and the channel condition comprises:
determining a measured rank based on the channel condition;
on a condition that the measured rank is less than or equal to the rank threshold, selecting eigenvector as the beam domain preprocessing input type; and
on a condition that the measured rank is greater than the rank threshold, selecting full channel matrix as the beam domain preprocessing input type.
11 . The method of claim 9 , wherein determining the beam domain preprocessing input type based on at least one of: the rank threshold, the performance metric, or the channel condition comprises determining the beam domain preprocessing input type based on the performance metric and the channel condition, and determining the beam domain preprocessing input type based on the performance metric and the channel condition comprises:
determining a performance of a first beam domain preprocessing input type based on the performance metric and the channel condition;
determining a performance of a second beam domain preprocessing input type based on the performance metric and the channel condition;
comparing the performance of the first beam domain preprocessing input type to the performance of the second beam domain preprocessing input type; and
selecting the beam domain preprocessing input type based on the comparison.
12 . The method of claim 9 or 11 , wherein the performance metric comprises a normalized mean squared error or a squared generalized cosine similarity.
13 . The method of claim 9 , wherein the method further comprises determining a beam domain preprocessing parameter associated with the determined beam domain preprocessing input type, and preprocessing the CSI is further based on the beam domain preprocessing parameter.
14 . The method of claim 13 , wherein the beam domain preprocessing parameter comprises one or more of:
a parameter related to a transformation matrix used for beam domain preprocessing;
a discrete Fourier transform basis of a beam codebook;
an oversampling factor of the beam codebook;
a maximum number of transmit beams;
a maximum number of receive beams,
an index of a selected transmit beam;
an index of a selected receive beam;
polarization information; or
an input type for beam domain preprocessing.
15 . The method of claim 9 , wherein the method further comprises receiving, from a network entity, an input type selection indication that indicates for the device to determine the beam domain preprocessing input type.
16 . The method of claim 9 , wherein the beam domain preprocessing input type comprises full channel matrix or eigenvector.