Smaller Sub-Band Size for PMI than for CQI

Patent metadata

Field	Value
Publication number	US-2021367652-A1
Application number	US-201916981507-A
Country	US
Kind code	A1
Filing date	Oct 28, 2019
Priority date	Nov 2, 2018
Publication date	Nov 25, 2021
Grant date	—

Abstract

A method performed by a wireless device (510, 700, 1100) is disclosed. The wireless device obtains (601) a configuration for a sub-band channel quality indicator (CQI) granularity and a sub-band precoding matrix indicator (PMI) granularity for the wireless device. The wireless device determines (602) channel state information (CSI) feedback according to the configured sub-band CQI granularity and the sub-band PMI granularity. The sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size. The first sub-band size is smaller than the second sub-band size. The wireless device transmits (603), to a network node (560, 1000), the determined CSI feedback.

First claim

1 .- 44 . (canceled)

45 . A method performed by a wireless device for transmitting channel state information, CSI, feedback using a multi-beam precoder codebook, the method comprising:
obtaining a configuration for a sub-band channel quality indicator, CQI, granularity and a sub-band precoding matrix indicator, PMI, granularity for the wireless device, wherein the sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size; determining CSI feedback according to the configured sub-band CQI granularity and the sub-band PMI granularity, wherein the CSI feedback indicates a linear combination of precoder vectors, wherein the precoder vectors correspond to respective frequency sub-bands having the first sub-band size, wherein the coefficients for the precoder vectors in the linear combination of precoder vectors are parameterized in the frequency-domain as a linear combination of a set of basis vectors and a set of coefficients for the basis vectors in the linear combination of the set of basis vectors; and transmitting, to a network node, the determined CSI feedback, wherein the first sub-band size is smaller than the second sub-band size.

46 . The method of claim 45 , wherein the precoder vectors are DFT vectors.

47 . The method of claim 45 , wherein the CSI feedback is transmitted using a NR Type II codebook.

48 . The method of claim 45 , wherein the CSI feedback is transmitted using Rel-16 enhanced Type II CSI reporting.

49 . The method of claim 45 , wherein the second sub-band size is an integer multiple of the first sub-band size.

50 . The method of claim 45 , wherein the sub-band CQI granularity configuration is obtained from a subbandSize radio resource control parameter in a CSI-ReportConfig.

51 . The method of claim 45 , wherein the sub-band PMI granularity is obtained from a CSI-ReportConfig using a subbandPMI-Size parameter.

52 . A method performed by a network node for receiving channel state information, CSI, feedback using a multi-beam precoder codebook, the method comprising:
receiving CSI feedback from a wireless device according to a sub-band channel quality indicator, CQI, granularity and a sub-band precoding matrix indicator, PMI, granularity, wherein the sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size, wherein the CSI feedback indicates a linear combination of precoder vectors, wherein the precoder vectors correspond to respective frequency sub-bands having the first sub-band size, wherein the coefficients for the precoder vectors in the linear combination of precoder vectors are parameterized in the frequency-domain as a linear combination of a set of basis vectors and a set of coefficients for the basis vectors in the linear combination of the set of basis vectors, and wherein the first sub-band size is smaller than the second sub-band size.

53 . The method of claim 52 , further comprising:
determining the sub-band CQI granularity; determining the sub-band PMI; and configuring the wireless device with the sub-band CQI granularity and the sub-band PMI granularity.

54 . A wireless device for transmitting channel state information, CSI, feedback using a multi-beam precoder codebook, the wireless device comprising:
a receiver; a transmitter; and processing circuitry coupled to the receiver and the transmitter, the processing circuitry configured to:
obtain a configuration for a sub-band channel quality indicator, CQI, granularity and a sub-band precoding matrix indicator, PMI, granularity for the wireless device, wherein the sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size;
determine CSI feedback according to the configured sub-band CQI granularity and the sub-band PMI granularity, wherein the CSI feedback indicates a linear combination of precoder vectors, wherein the precoder vectors correspond to respective frequency sub-bands having the first sub-band size, wherein the coefficients for the precoder vectors in the linear combination of precoder vectors are parameterized in the frequency-domain as a linear combination of a set of basis vectors and a set of coefficients for the basis vectors in the linear combination of the set of basis vectors; and
transmit, to a network node, the determined CSI feedback,
wherein the first sub-band size is smaller than the second sub-band size.

55 . The wireless device of claim 54 , wherein the precoder vectors are DFT vectors.

56 . The wireless device of claim 54 , wherein the CSI feedback is transmitted using a NR Type II codebook.

57 . The wireless device of claim 54 , wherein the CSI feedback is transmitted using Rel-16 enhanced Type II CSI reporting.

58 . The wireless device of claim 54 , wherein the second sub-band size is an integer multiple of the first sub-band size.

59 . The wireless device of claim 54 , wherein the processing circuitry is configured to obtain the sub-band CQI granularity configuration from a subbandSize radio resource control parameter in a CSI-ReportConfig.

60 . The wireless device of claim 54 , wherein the processing circuitry is configured to obtain the sub-band PMI granularity from a CSI-ReportConfig using a subbandPMI-Size parameter.

61 . A network node for receiving channel state information, CSI, feedback using a multi-beam precoder codebook, the network node comprising:
a receiver; a transmitter; and processing circuitry coupled to the receiver and the transmitter, the processing circuitry configured to:
receive CSI feedback from a wireless device according to a sub-band channel quality indicator, CQI, granularity and a sub-band precoding matrix indicator, PMI, granularity, wherein the sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size, wherein the CSI feedback indicates a linear combination of precoder vectors, wherein the precoder vectors correspond to respective frequency sub-bands having the first sub-band size, wherein the coefficients for the precoder vectors in the linear combination of precoder vectors are parameterized in the frequency-domain as a linear combination of a set of basis vectors and a set of coefficients for the basis vectors in the linear combination of the set of basis vectors, and wherein the first sub-band size is smaller than the second sub-band size.

62 . The network node of claim 61 , wherein the processing circuitry is further configured to:
determine the sub-band CQI granularity; determine the sub-band PMI; and configure the wireless device with the sub-band CQI granularity and the sub-band PMI granularity.

Assignees

• Ericsson Telefon Ab L M

Inventors

• Wernersson Niklas
• Faxér Sebastian
• Girnyk Maksym

Classifications

• H04B7/0639

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

• H04B7/0634

  Antenna weights or vector/matrix coefficients · CPC title

• H04B7/0632 Primary

  Channel quality parameters, e.g. channel quality indicator [CQI] · CPC title