Hybrid Common/Independent FD-Basis for Type II CSI Enhancement

Patent metadata

Field	Value
Publication number	US-2020322012-A1
Application number	US-202016904842-A
Country	US
Kind code	A1
Filing date	Jun 18, 2020
Priority date	Nov 2, 2018
Publication date	Oct 8, 2020
Grant date	—

Abstract

A method performed by a wireless device ( 510, 700, 1000 ) for transmitting a channel state information (CSI) report for a downlink channel comprises obtaining ( 601 ) a first set of candidate frequency-domain components and determining ( 602 ) a set of spatial-domain components. The method comprises determining ( 603 ) a second set of candidate frequency-domain components as a subset of the first set of candidate frequency-domain components. The method comprises determining ( 604 ), for each spatial-domain component of the set of spatial-domain components, a spatial-domain component-specific set of frequency-domain components as a subset of the second set of candidate frequency-domain components. The method comprises transmitting ( 605 ), to a network node ( 560, 900 ), the CSI report.

First claim

1 .- 34 . (canceled)

35 . A method performed by a wireless device for transmitting a channel state information (CSI) report for a downlink channel, the CSI report indicating a plurality of precoder vectors, wherein each of the precoder vectors corresponds to a frequency sub-band of the bandwidth of the downlink channel, a precoder vector being expressed as a linear combination of spatial-domain components and frequency-domain components, and wherein indicating the plurality of precoder vectors comprises indicating the frequency-domain components and a set of linear combination coefficients, the method comprising:
determining a set of spatial-domain components; determining a second set of candidate frequency-domain components as a subset of a first set of candidate frequency-domain components; determining, for each spatial-domain component of the set of spatial-domain components, a spatial-domain component-specific set of one or more frequency-domain components as a subset of the second set of candidate frequency-domain components, wherein each frequency-domain component in the spatial-domain component-specific set of one or more frequency-domain components is associated with a non-zero coefficient of the set of linear combination coefficients; and transmitting, to a network node, the CSI report comprising an indication of: the determined second set of candidate frequency-domain components; the determined spatial-domain component-specific sets of one or more frequency-domain components; and the non-zero coefficients of the set of linear combination coefficients.

36 . The method of claim 35 , wherein, for at least one spatial-domain component, the spatial-domain component-specific set of one or more frequency-domain components includes fewer frequency-domain components than the second set of candidate frequency-domain components.

37 . The method of any claim 35 , wherein the candidate frequency-domain components are orthogonal basis vectors.

38 . The method of claim 36 , wherein the orthogonal basis vectors are discrete Fourier transform vectors.

39 . The method of claim 35 , wherein a size of the frequency sub-band is an integer number of physical resource blocks (PRBs).

40 . The method of claim 35 , wherein determining the second set of candidate frequency-domain components as a subset of the first set of candidate frequency-domain components comprises:
creating a common basis for all the spatial-domain components.

41 . A method performed by a network node for receiving a channel state information (CSI) report for a downlink channel, the CSI report indicating a plurality of precoder vectors, wherein each of the precoder vectors corresponds to a frequency sub-band of the bandwidth of the downlink channel, a precoder vector being expressed as a linear combination of spatial-domain components and frequency-domain components, and wherein indicating the plurality of precoder vectors comprises indicating the frequency-domain components and a set of linear combination coefficients, the method comprising:
receiving, from a wireless device, the channel state information (CSI) report comprising an indication of: a second set of candidate frequency-domain components being a subset of a first set of candidate frequency-domain components; one or more spatial-domain component-specific sets of one or more frequency-domain components being subsets of the second set of candidate frequency-domain components, each frequency-domain component in the one or more spatial-domain component-specific sets of one or more frequency-domain components being associated with a non-zero coefficient of the set of linear combination coefficients; and the non-zero coefficients; and determining one or more precoder vectors based upon the indication received in the CSI report.

42 . The method of claim 41 , wherein, for at least one spatial-domain component, the spatial-domain component-specific set of one or more frequency-domain components includes fewer frequency-domain components than the second set of candidate frequency-domain components.

43 . The method of claim 41 , further comprising:
using one of the determined one or more precoder vectors to perform a transmission to the wireless device.

44 . The method of claim 41 , wherein a size of the frequency sub-band is an integer number of physical resource blocks (PRBs).

45 . A wireless device configured to transmit a channel state information (CSI) report for a downlink channel, the CSI report indicating a plurality of precoder vectors, wherein each of the precoder vectors corresponds to a frequency sub-band of the bandwidth of the downlink channel, a precoder vector being expressed as a linear combination of spatial-domain components and frequency-domain components, and wherein indicating the plurality of precoder vectors comprises indicating the frequency-domain components and a set of linear combination coefficients, the wireless device comprising:
a receiver; a transmitter; and processing circuitry coupled to the receiver and the transmitter, the processing circuitry configured to: determine a set of spatial-domain components; determine a second set of candidate frequency-domain components as a subset of a first set of candidate frequency-domain components; determine, for each spatial-domain component of the set of spatial-domain components, a spatial-domain component-specific set of one or more frequency-domain components as a subset of the second set of candidate frequency-domain components, wherein each frequency-domain component in the spatial-domain component-specific set of one or more frequency-domain components is associated with a non-zero coefficient of the set of linear combination coefficients; and transmit, to a network node, the CSI report comprising an indication of: the determined second set of candidate frequency-domain components; the determined spatial-domain component-specific sets of one or more frequency-domain components; and the non-zero coefficients of the set of linear combination coefficients.

46 . The wireless device of claim 45 , wherein, for at least one spatial-domain component, the spatial-domain component-specific set of one or more frequency-domain components includes fewer frequency-domain components than the second set of candidate frequency-domain components.

47 . The wireless device of claim 45 , wherein the candidate frequency-domain components are orthogonal basis vectors.

48 . The wireless device of claim 47 , wherein the orthogonal basis vectors are discrete Fourier transform vectors.

49 . The wireless device of claim 45 , wherein a size of the frequency sub-band is an integer number of physical resource blocks (PRBs).

50 . The wireless device of claim 45 , wherein the processing circuitry configured to determine the second set of candidate frequency-domain components as a subset of the first set of candidate frequency-domain components is further configured to:
create a common basis for all the spatial-domain components.

51 . A network node configured to receive a channel state information (CSI) report for a downlink channel, the CSI report indicating a plurality of precoder vectors, wherein each of the precoder vectors corresponds to a frequency sub-band of the bandwidth of the downlink channel, a precoder vector being expressed as a linear combination of spatial-domain components and frequency-domain components, and wherein indicating the plurality of precoder vectors comprises indicating the frequency-domain components and a set of linear combination coefficients, the

Assignees

• Ericsson Telefon Ab L M

Inventors

• Wernersson Niklas
• Faxér Sebastian
• Girnyk Maksym

Classifications

• H04B7/0481 Primary

  using subset selection of codebooks · CPC title

• H04B7/0639

  Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection · CPC title

• H04B7/0626

  Channel coefficients, e.g. channel state information [CSI] · CPC title

• H04W72/04

  Wireless resource allocation · CPC title

• H04B7/10

  Polarisation diversity; Directional diversity · CPC title