Search

EP-3429107-B1 - METHOD FOR MEASURING CHANNEL STATE INFORMATION

EP3429107B1EP 3429107 B1EP3429107 B1EP 3429107B1EP-3429107-B1

Inventors

  • ZHANG, LILI
  • LI, GUORONG

Dates

Publication Date
20260506
Application Date
20160331

Claims (6)

  1. A method for measuring channel state information CSI, comprising: determining (101), by a network-side device, configuration information, wherein the configuration information is used to configure user equipment UE to perform CSI measurement on different subframe sets on a flexible frequency band or sub-bands of a flexible frequency band, the subframe sets are determined by the network-side device based on uplink-downlink configurations of subframes on the flexible frequency band or the sub-bands of the flexible frequency band in a target cell and neighboring cells of the target cell, and the flexible frequency band is a frequency band on which a transmission direction is configurable; sending (102), by the network-side device, the configuration information to the UE, so that the UE performs (103) the CSI measurement based on the configuration information, wherein a first subframe set of the different subframe sets comprises subframes in which transmissions in the target cell are in a downlink direction and transmissions in the neighboring cells are not all in a downlink direction, and a second subframe set of the different subframe sets comprises subframes in which transmissions in the target cell and the neighboring cells are all in a downlink direction, sending (104), by the network-side device, CSI reporting trigger information to the UE; and receiving (105), by the network-side device, CSI sent by the UE and corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the CSI reporting trigger information is located, wherein the receiving (105), by the network-side device, CSI sent by the UE and corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the CSI reporting trigger information is located comprises: receiving, by the network-side device, CSI sent by the UE and corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which first CSI reporting trigger information is located and CSI sent by the UE and corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which second CSI reporting trigger information is located, wherein an absolute value of a difference between the CSI corresponding to the subframe set or the subframe subset that comprises and is indicated by the subframe in which the first CSI reporting trigger information is located and the CSI corresponding to the subframe set or the subframe subset that comprises and is indicated by the subframe in which the second CSI reporting trigger information is located is greater than a first preset threshold; or receiving, by the network-side device, CSI corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the first CSI reporting trigger information is located, or CSI corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the second CSI reporting trigger information is located, wherein an absolute value of a difference between the CSI corresponding to the subframe set or the subframe subset that comprises and is indicated by the subframe in which the first CSI reporting trigger information is located and the CSI corresponding to the subframe set or the subframe subset that comprises and is indicated by the subframe in which the second CSI reporting trigger information is located is less than or equal to the first preset threshold.
  2. The method according to claim 1, wherein the configuration information is further used to indicate CSI reference resources configured in the first subframe set and the second subframe set, and/or a subframe configured with the CSI reference resources, and/or a subframe set to which a subframe configured with the CSI reference resources belongs.
  3. A method for measuring channel state information CSI, comprising: receiving, by user equipment UE, configuration information sent by a network-side device, wherein the configuration information is used to configure the UE to perform CSI measurement on different subframe sets on a flexible frequency band or sub-bands of a flexible frequency band, the subframe sets are determined by the network-side device based on uplink-downlink configurations of subframes on the flexible frequency band or the sub-bands of the flexible frequency band in a target cell and neighboring cells of the target cell, and the flexible frequency band is a frequency band on which a transmission direction is configurable; performing, by the UE, the CSI measurement based on the configuration information, wherein a first subframe set of the different subframe sets comprises subframes in which transmissions in the target cell are in a downlink direction and transmissions in the neighboring cells are not all in a downlink direction, and a second subframe set of the different subframe sets comprises subframes in which transmissions in the target cell and the neighboring cells are all in a downlink direction, receiving, by the UE, CSI reporting trigger information sent by the network-side device; and sending, by the UE to the network-side device, CSI corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the CSI reporting trigger information is located, wherein the receiving, by the UE, CSI reporting trigger information sent by the network-side device comprises: receiving, by the UE, first CSI reporting trigger information and second CSI reporting trigger information that are sent by the network-side device; wherein the sending, by the UE to the network-side device, CSI corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the CSI reporting trigger information is located comprises: when an absolute value of a difference between CSI corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the first CSI reporting trigger information is located and CSI corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the second CSI reporting trigger information is located is greater than a first preset threshold, sending, by the UE to the network-side device, the CSI corresponding to the subframe set or the subframe subset that comprises and is indicated by the subframe in which the first CSI reporting trigger information is located and the CSI corresponding to the subframe set or the subframe subset that comprises and is indicated by the subframe in which the second CSI reporting trigger information is located; or when an absolute value of a difference between CSI corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the first CSI reporting trigger information is located and CSI corresponding to a subframe set or a subframe subset that comprises and is indicated by a subframe in which the second CSI reporting trigger information is located is less than or equal to the first preset threshold, sending, by the UE to the network-side device, the CSI corresponding to the subframe set or the subframe subset that comprises and is indicated by the subframe in which the first CSI reporting trigger information is located or the CSI corresponding to the subframe set or the subframe subset that comprises and is indicated by the subframe in which the second CSI reporting trigger information is located.
  4. The method according to claim 3, wherein the configuration information is further used to indicate CSI reference resources configured in the first subframe set and the second subframe set, and/or a subframe configured with the CSI reference resources, and/or a subframe set to which a subframe configured with the CSI reference resources belongs.
  5. The method according to claim 4, wherein the CSI reference resources comprise a cell-specific pilot CRS resource and/or a channel state information reference signal CSI-RS resource.
  6. The method according to any one of claims 3 to 5, wherein the method further comprises: sending, by the UE, group indexes to the network-side device, wherein the group indexes are in a one-to-one correspondence to the subframe sets.

Description

TECHNICAL FIELD Embodiments of the present invention relate to the communications field, and more specifically, to a method for measuring channel state information (CSI), a network-side device, and user equipment. BACKGROUND There are two duplex modes for mobile communications systems: frequency division duplex (FDD) and time division duplex (TDD). In an FDD system, different frequency bands are used for receiving and sending. However, in a TDD system, different times are used for receiving and sending on a same frequency band. As uplink services and downlink services become more asymmetric in a communications system and a ratio of the uplink services to the downlink services change with time, in a conventional Long Term Evolution (LTE) system, use of fixed paired spectrums in FDD and fixed uplink-downlink timeslot allocation in TDD can no longer effectively support the dynamic asymmetry feature of the services. In addition, because a total volume of uplink and downlink services grows explosively, a half-duplex mode can no longer meet requirements in some scenarios, and a full duplex mode becomes a potential technology. In the flexible full duplex, the growth of the total service volume and the asymmetry feature are fully considered, and uplink resources and downlink resources can be adaptively allocated based on distribution of uplink services and downlink services. In this way, TDD, FDD, and full duplex are organically integrated, and system resource utilization is effectively improved, so that a future network requirement is met. US 2015 146557 A1 describes methods and apparatuses for configuring channel measurement and DL CSI feedback, so as to implement measurement in a dynamic TDD system. The method for configuring channel measurement according to the therein-described system comprises: a network side device dividing downlink subframes into multiple downlink subframe groups according to an interference condition on the downlink subframes; and the network side device notifying a user equipment of channel measurement configuration information corresponding to the downlink subframe groups. WO 2015 169147 A1 describes methods and apparatuses for wireless communication. The therein-described apparatus may be a UE. The therein-described UE determines a first CSI subframe set including a first set of subframes of a frame and a second CSI subframe set including a second set of subframes of the frame. Subframes in the first set of subframes are different than subframes in the second set of subframes. US 2014 198677 A1 discloses a CSI reporting method, where the UE sends a CSI to the base station if the difference between the CSI and a previously reported CSI is greater than a threshold. In a flexible frequency band technology, some uplink frequency bands in an FDD system are configured as "flexible frequency bands". In actual application, based on distribution of uplink services and downlink services in a network, "flexible frequency bands" are allocated for an uplink transmission or a downlink transmission, so that uplink and downlink spectrum resources match uplink and downlink service requirements, and spectrum utilization is improved. As shown in FIG. 1, when a downlink service volume is higher than an uplink service volume in a network, a frequency band f4 originally used for an uplink transmission may be configured as a frequency band used for a downlink transmission in the network. In a flexible duplex technology, TDD may be used on the frequency band f4 to transmit uplink and downlink services. Because there are seven different subframe configuration modes in a TDD mode, when different TDD configurations are used in neighboring cells, cross timeslot interference may occur in the neighboring cells. As shown in FIG. 2, in a timeslot in which a macro cell sends a downlink signal, a femto cell is used to receive an uplink signal. Consequently, a base station to base station interference occurs between the two cells: The downlink signal from a base station in the macro cell is directly received by a base station in the femto cell, and this severely affects quality of an uplink signal received from an L-UE (Local UE, L-UE) by the femto cell. In an LTE system, when an evolved NodeB (eNB) schedules user equipment (UE), in order that the eNB selects an appropriate frequency resource, an appropriate modulation and coding scheme (MCS), and the like so that the UE can better receive data, the eNB sends a downlink reference signal in all bandwidths of a cell, and then the UE measures CSI of a cell-specific reference signal in all or some bandwidths according to an upper-layer indication and feeds back the CSI to the eNB. The eNB selects an appropriate time frequency resource and an appropriate MCS based on the CSI reported by the UE, and transmits downlink data. In the foregoing technology, the UE reports uniform CSI to all downlink subframes. For example, in a specific CSI reporting period, the UE may select one d