WO2017050213A1

WO2017050213A1 - Self-adaptive method and device for link

Info

Publication number: WO2017050213A1
Application number: PCT/CN2016/099467
Authority: WO
Inventors: 朱莉; 鲍坤超; 严朝译; 胥恒
Original assignee: 华为技术有限公司
Priority date: 2015-09-25
Filing date: 2016-09-20
Publication date: 2017-03-30
Also published as: CN106559167A; CN106559167B

Abstract

Disclosed are a self-adaptive method and device for a link, which relate to the technical field of communications and are invented for solving the problem existing in the prior art that the reported CQI is not accurate. The method comprises: receiving a terminal capability report message sent by a user equipment; according to the terminal capability possessed by the user equipment and a transmission mode counting result of the user equipment within a current counting period, sending a channel quality indicator (CQI) report indication message to the user equipment, wherein the CQI report indication message is used for instructing the user equipment to report a CQI in a manner corresponding to the terminal capability and the counting result; and according to the CQI reported by the user equipment and a current transmission mode of the user equipment, conducting MCS order selection. The present invention is mainly applied to the self-adaptive process of a link.

Description

Link adaptation method and device

The present application claims priority to Chinese Patent Application No. 201510623918.6, entitled "A Method and Apparatus for Link Adaptation", filed on September 25, 2015, the entire contents of which are incorporated herein by reference. In this application.

Technical field

The present invention relates to the field of communications technologies, and in particular, to a link adaptation method and apparatus.

Background technique

In cellular mobile communication systems, link adaptation techniques are typically employed to estimate the performance of a wireless channel. Link adaptation technology refers to the system adaptively adjusting the behavior of system transmission parameters according to the currently acquired channel information to overcome or adapt to the impact of current channel changes. In general, the link adaptation technology, as shown in FIG. 1 , mainly includes the following three aspects: the first aspect, accurately and efficiently acquiring current channel environment parameters for accurate channel estimation; The channel indication parameter accurately reflecting the condition of the channel; in the third aspect, the transmission parameter is adjusted and the feedback information is returned in time through the feedback channel. In general, the Channel Quality Indicator (CQI) is used to represent the current channel quality. The channel estimation is also the value of the current CQI of the acquisition channel. The implementation of link adaptation technology is based on accurate acquisition of CQI. There are two methods for obtaining CQI in the prior art, which are as follows:

First, the terminal estimates the signal to interference plus noise ratio (SINR) based on a cell-specific reference signal (CRS), quantizes the SINR to obtain a CQI, and then reports it to the base station. The process of calculating SINR based on CRS can refer to the following formula (1):

Wherein, RSRP _CRS represents the received power of the CRS; I _n represents the interference of the neighboring cell n to the CRS; and N represents the noise. In addition, I _{n is} specifically: when the physical cell identifier (PCI) mode 3 conflicts, only the interference of the neighboring cell CRS to the CRS of the local cell is included; when the PCI mode 3 does not collide, only the neighbor cell data area is included for the CRS of the local cell. interference.

Second, the terminal measures the SINR based on the Channel State Information-Reference Signal (CSI-RS), quantizes the SINR to obtain the CQI, and then reports it to the base station. The process of calculating SINR based on CSI-RS can refer to the following formula (2):

The RSRP _CSI-RS indicates the received power of the CSI-RS; I _n indicates the interference of the neighboring cell n to the CSI-RS of the local cell; and N indicates the noise. In addition, I _n includes interference of the neighbor cell data region with the data region of the cell.

However, the link adaptation method in the prior art cannot accurately report the CQI in some application scenarios, and thus cannot perform accurate link adaptation. For example, in the beamforming (BF) application scenario, both the CRS resource and the CSI-RS resource cannot perceive the BF weighted gain, so the measured CQI is also inaccurate, which affects the accuracy of the link adaptation process.

Summary of the invention

The invention provides a link adaptation method and device, which can report a relatively accurate CQI, and can accurately perform link adaptive adjustment.

In order to achieve the above object, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a link adaptation method, including:

Receiving a terminal capability report message sent by the user equipment;

Transmitting, by the user equipment, a channel quality indication CQI reporting indication message to the user equipment according to the terminal capability of the user equipment and the transmission mode statistics of the user equipment in the current statistical period, where the CQI reporting indication message is used to indicate the User equipment adoption and end Reporting CQI in a manner corresponding to the statistical result;

The modulation and coding policy MCS is selected according to the CQI reported by the user equipment and the current transmission mode of the user equipment.

With reference to the first aspect, in a first implementation manner of the first aspect, the sending, according to a terminal capability of the user equipment, and a transmission mode statistics result of the user equipment in a current statistical period, sending the result to the user equipment The channel quality indicator CQI report indication message, where the CQI report indication message is used to indicate that the user equipment reports the CQI in a manner corresponding to the terminal capability and the statistics result, and specifically includes:

When the user equipment is capable of measuring the user-specific reference signal DRS and the transmission mode of the user equipment in the current statistical period includes at least the beamforming BF mode, the CQI reporting indication message is sent to the user equipment, and the CQI is reported. The indication message is used to instruct the user equipment to report at least the DRS-based CQI.

With reference to the first implementation manner of the first aspect, in a second implementation manner of the first aspect, the CQI reporting indication message includes a CQI reporting configuration field in a BF mode;

When the user equipment is capable of measuring the user-specific reference signal DRS and the transmission mode of the user equipment in the current statistical period includes at least the beamforming BF mode, sending a CQI reporting indication message to the user equipment, The CQI report indication message is used to indicate that the user equipment reports at least the DRS-based CQI, and specifically includes:

When the user equipment has the capability of measuring the DRS and the ratio of the multiple input multiple output MIMO mode in the current statistical period is equal to the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to the first value The CQI report indication message is used to indicate that the user equipment periodically reports the CRSI based on the DRS and the CQI based on the cell-specific reference signal CRS or the CQI based on the channel state reference information signal CSI-RS;

or

When the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, the CQI reporting in the BF mode is configured. The value of the field is set to a second value, the CQI reporting indication message is used to indicate that the user equipment reports the DRS-based CQI aperiodically, and periodically reports the CRSI based on the CRS or CSI-RS;

or

When the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is smaller than the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to a third value, The CQI reporting indication message is used to indicate that the user equipment periodically reports the DRS-based CQI, and the CRS or CSI-RS-based CQI is reported aperiodically.

With the second implementation of the first aspect, in a third implementation manner of the first aspect, when the user equipment has the capability of measuring DRS and the ratio of the MIMO mode in the current statistical period is equal to the ratio of the BF mode, And the CQI reporting indication message is further configured to: when the user equipment does not schedule the DRS resource in the current reporting period, set the BF CQI field of the codeword 0/1 in the reported message to a specific value.

With reference to the second implementation manner of the first aspect, in a fourth implementation manner of the first aspect, when the user equipment is capable of measuring DRS, and the proportion of the MIMO mode in the current statistical period is greater than the BF mode In the case of a ratio, the CQI reporting indication message further includes a downlink control information format DCI0, where the DCI0 is used to indicate that the user equipment periodically reports the physical uplink shared channel PUSCH resource used by the DRS-based CQI, and indicates that the user equipment only The signal corresponding to the DRS of the downlink subframe in which the DCI0 is located is compared with the interference plus noise ratio SINR.

With the second implementation of the first aspect, in a fifth implementation manner of the first aspect, the CQI reporting indication message is further used to indicate that the user equipment periodically reports a CQI based on a CRS or a CSI-RS. When the resource conflicts between the DRS-based CQIs are reported in a non-periodical manner, only the DRS-based CQIs are reported; when the DRS-based CQIs are periodically reported and the CRSIs used by the CRSs or CSI-RSs are reported periodically. Only the CQI based on CRS or CSI-RS is reported.

With reference to the second implementation manner of the first aspect, in a sixth implementation manner of the first aspect, the performing the modulation and coding policy MCS selection according to the CQI reported by the user equipment and the current transmission mode of the user equipment Specifically, including:

Receiving, according to the user equipment, the DRS-based CQI and the CRS-based CSI-C-based CQI and the current transmission mode of the user equipment in the BF mode are received in the current reporting period. The DRS-based CQI performs MCS selection;

or

When the DRS-based CQI and the CRS-CSI-RS-based CQI are periodically reported in the current reporting period, and the current transmission mode of the user equipment is the MIMO mode, the user equipment is reported according to the user equipment. The CRS based on CRS or CSI-RS performs MCS selection;

or

When the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the MIMO mode, according to the CRS or CSI-RS based CQI performs MCS selection;

or

If the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the BF mode, if the user equipment is not received in the current reporting period The DRS-based CQI is reported, and the MCS is selected according to the DRS-based CQI; otherwise, the MCS is selected according to the CRS or CSI-RS based CQI;

or

When the DRS-based CQI periodically reported by the user equipment is received in the current reporting period, and the current transmission mode of the user equipment is the BF mode, the MCS selection is performed according to the DRS-based CQI.

or

When the DRS-based CQI periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the MIMO mode, if the user equipment is also received in the current reporting period, the non-periodicity is The CRSI based on the CRS or the CSI-RS is reported, and the MCS is selected according to the CRSI based on the CRS or the CSI-RS. Otherwise, the MCS is selected according to the DRS-based CQI.

With reference to the sixth implementation manner of the first aspect, in a seventh implementation manner of the first aspect, the performing the modulation and coding policy MCS selection according to the CQI reported by the user equipment and the current transmission mode of the user equipment Thereafter, the method further includes:

Determining a value of the first MCS according to the DRS-based CQI when receiving the DRS-based CQI and the CRS- or CSI-RS-based CQI reported by the user equipment in a current reporting period; according to the CRS-based or CSI The CQI of the RS determines a value of the second MCS; when the value of the first MCS is greater than the value of the second MCS, determining that the next transmission mode of the user equipment is the BF mode; otherwise, determining the user equipment The next transmission mode is MIMO mode.

In combination with the first aspect, or any one of the first, second, third, fourth, fifth, sixth, and seventh implementations of the first aspect, in the first aspect In the eight implementation manners, the terminal capability report message includes a first field, where the first field is used to indicate whether the terminal supports measurement DRS.

In a second aspect, the present invention also provides a link adaptation apparatus, including:

a receiving unit, configured to receive a terminal capability report message sent by the user equipment;

a sending unit, configured to send a channel quality indication CQI reporting indication message to the user equipment according to a terminal capability of the user equipment and a transmission mode statistics result of the user equipment in a current statistical period, where the CQI reporting indication message Instructing the user equipment to report the CQI in a manner corresponding to the terminal capability and the statistical result;

The receiving unit is further configured to receive a CQI reported by the user equipment;

The processing unit is configured to perform modulation and coding policy MCS selection according to the CQI reported by the user equipment and the current transmission mode of the user equipment.

With reference to the second aspect, in a first implementation manner of the second aspect, the sending unit is specifically configured to:

With reference to the first implementation manner of the second aspect, in a second implementation manner of the second aspect, the sending, by the sending unit, the CQI reporting indication message includes a CQI reporting configuration field in a BF mode, where the sending unit is configured, Specifically used for:

or

When the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to the second value, The CQI reporting indication message is used to indicate that the user equipment reports the DRS-based CQI aperiodically, and periodically reports the CRS or CSI-RS based CQI;

or

When the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is smaller than the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to a third value, The CQI reporting indication message is used to indicate the user setting The DRS-based CQI is periodically reported, and the CRS or CSI-RS-based CQI is reported aperiodically.

With the second implementation of the second aspect, in a third implementation manner of the second aspect, the CQI reporting indication message that is sent by the sending unit is further configured to: when the user equipment has the capability of measuring DRS, When the proportion of the MIMO mode in the current statistical period is equal to the ratio of the BF mode, when the user equipment is instructed to not schedule DRS resources in the current reporting period, the BF CQI field of the codeword 0/1 in the reported message is set to Specific value.

With reference to the second implementation manner of the second aspect, in a fourth implementation manner of the second aspect, when the user equipment is capable of measuring DRS, and the ratio of the MIMO mode in the current statistical period is greater than the BF mode In the case of the ratio, the CQI reporting indication message sent by the sending unit further includes a downlink control information format DCI0, where the DCI0 is used to indicate that the user equipment periodically reports the physical uplink shared channel PUSCH resource used by the DRS-based CQI; Instructing the user equipment to measure only the signal corresponding to the DRS of the downlink subframe in which the DCI0 is located, and the interference plus noise ratio SINR.

With the second implementation of the second aspect, in a fifth implementation manner of the second aspect, the CQI reporting indication message that is sent by the sending unit is further used to indicate that the user equipment periodically reports the CRS based When the CQI of the CSI-RS conflicts with the resource used by the DRS-based CQI, only the DRS-based CQI is reported; when the CRSI based on the DRS is periodically reported and the CQI based on the CRS or CSI-RS is reported aperiodically When the resources used are in conflict, only the CQI based on CRS or CSI-RS is reported.

With the second implementation of the second aspect, in a sixth implementation manner of the second aspect, the processing unit is specifically configured to:

Or

or

When the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the MIMO mode, according to the CQI based on the CRS or the CSI-RS Perform MCS selection;

or

If the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the BF mode, if the user equipment is not received in the current reporting period Performing MCS selection based on the DRS-based CQI; otherwise, performing MCS selection according to the CRS or CSI-RS based CQI;

or

When only the DRS-based CQI periodically reported by the user equipment is received in the current reporting period, and the current transmission mode of the user equipment is the BF mode, the MCS selection is performed according to the DRS-based CQI;

or

With reference to the sixth implementation manner of the second aspect, in a seventh implementation manner of the second aspect, the processing unit is further configured to receive, when the current reporting period, the base reported by the user equipment Determining a value of the first MCS according to the CRSI of the DRS according to the CQI of the DRS and the CQI based on the CRS or the CSI-RS; determining a value of the second MCS according to the CRSI based on the CRS or the CSI-RS; When the value of the first MCS is greater than the value of the second MCS, determining that the next transmission mode of the user equipment is the BF mode; otherwise, determining that the next transmission mode of the user equipment is the MIMO mode.

The method and the device for adapting the link according to the present invention, according to the terminal capability of the terminal device and the statistical result of the transmission mode of the user equipment, instruct the user equipment to report the CQI in a manner corresponding to the statistic result of the capability and the transmission mode, and then report the CQI according to the user. The CQI reported by the device performs MCS selection to adjust the transmission parameters in the link adaptation process, and the present invention not reports the transmission mode of the user equipment, and reports the CQI based on CRS or CSI-RS. The link adaptation method is provided to take into account the transmission mode of the user equipment, and instruct the user equipment to report a more accurate CQI, thereby implementing more accurate link adaptation on this basis.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a schematic diagram of an overall implementation process of a link adaptation method;

2 is a schematic flowchart of a link adaptation method according to an embodiment of the present invention;

FIG. 3 is a schematic flowchart diagram of another link adaptation method according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of a link adaptation apparatus according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of another link adaptation apparatus according to an embodiment of the present invention.

detailed description

The technical solutions in this embodiment will be clearly and completely described in the following with reference to the accompanying drawings in the embodiments. It is obvious that the described embodiments are only a part of the embodiments of the present invention, instead of All embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The embodiment of the invention provides a link adaptation method, which can be applied to a Long Term Evolution (LTE) or other communication system with common pilot and user-specific pilot. The method is mainly applied to a base station. In the process of interaction with the user equipment, the specific implementation process of the present invention is described below by using the base station as an execution body. As shown in FIG. 2, the method includes:

101: Receive a terminal capability report message sent by the user equipment.

The base station and the user equipment need to first negotiate the capabilities of the user equipment terminal. Different types of user equipments have different terminal capabilities. For example, a terminal with a terminal protocol version of R8 only supports measurement of CRS, and a terminal of R11 can support measurement of CRS or measurement of CSI-RS.

In the specific implementation process of this step, the DL-drs-cqi-measure field needs to be added in the UE Capability Information, and the field is used to indicate whether the user equipment supports measurement of the user-specific reference signal (UE-specific reference). Signal, DRS) reports CQI. For example, when the value of the dl-drs-cqi-measure field is 1, it indicates that the user equipment supports measurement DRS; when the value of the dl-drs-cqi-measure field is 0, it indicates that the user equipment does not support measurement DRS.

Step 102: Send a channel quality indication CQI reporting indication message to the user equipment according to the terminal capability of the user equipment and the transmission mode statistics of the user equipment in the current statistical period, where the CQI reporting indication message is used to indicate The user equipment reports the CQI in a manner corresponding to the terminal capability and the statistical result.

At present, a total of ten transmission modes of TM1 to TM10 are defined in LTE. Among them, TM1 to TM6 mainly adopt Multiple-Input Multiple-Output (MIMO) technology, which belongs to MIMO transmission mode; TM7 to TM10 adopt beam assignment. Beamforming (BF) technology belongs to the BF transmission mode. Therefore, at some time, the transmission mode of the user equipment may be BF mode or MIMO mode.

The statistics of the transmission mode of the user equipment in the current statistical period in this step refers to the statistics of the transmission mode of the user equipment at intervals. For example: every half The statistics of the transmission mode of the user equipment during this period are obtained. The statistical result is that the user equipment is 80% of the time in the current statistical period, and is in the BF mode transmission mode, and 20% of the time is in the MIMO mode.

The base station configures the CQI reporting mode and the specific content that the user equipment needs to report according to the terminal capability of the user equipment and the transmission mode statistics of the user equipment in the current statistical period.

In the specific implementation process of this step, when the user equipment has the capability of measuring the user-specific reference signal DRS and the transmission mode of the user equipment in the current statistical period includes at least the beamforming BF mode, the user equipment is sent to the user equipment. The CQI reports an indication message, where the CQI reporting indication message is used to indicate that the user equipment reports at least the DRS-based CQI.

The user-specific reference signal (DRS) can sense the interference of the physical resource block (PRB) of the neighboring cell to the data area of the cell, and the DRS can be perceived by the precoding matrix to be aware of the BF weighted gain. The "reporting DRS-based CQI" referred to in the implementation process includes reporting only the DRS-based CQI, and also reporting the DRS-based CQI and reporting the CRS or CSI-RS based CQI.

When the user equipment only has the capability of measuring the CRS or the CSI-RS, the user equipment sends a CQI report indication message for instructing the user equipment to report the CQI based on the CRS or the CSI-RS.

103: Perform modulation and coding policy MCS selection according to the CQI reported by the user equipment and the current transmission mode of the user equipment.

After receiving the CQI reported by the user equipment, the base station needs to select a CQI corresponding to the current transmission mode of the user equipment to determine the value of the Modulation and Coding Scheme (MCS) reasonably and accurately. For example, when the DRS-based CQI and the CRS-based or CSI-RS-based CQI reported by the user equipment are simultaneously received and the current transmission mode of the user equipment is the BF mode, the MCS selection is performed according to the DRS-based CQI, and the value of the MCS is determined.

The link adaptation method provided by the present invention is based on the terminal capabilities of the terminal device and The statistic result of the transmission mode of the user equipment indicates that the user equipment reports the CQI in a manner corresponding to the capability and the transmission mode statistics result, and then performs the MCS selection according to the CQI reported by the user equipment to implement the adjustment of the transmission parameter in the link adaptation process. The link adaptation method provided by the present invention takes the transmission mode of the user equipment into consideration, and indicates the user, compared with the CQI of the CRS or the CSI-RS, which is not considered in the prior art. The device reports a more accurate CQI, which in turn enables more accurate link adaptation.

For a clear explanation of the method shown in FIG. 1, in the specific implementation process of step 102, the CQI reporting indication message includes a CQI reporting configuration (cqi_report_mode_BF_config) field in the BF mode, which corresponds to a different CQI reporting manner. The base station can determine whether the CRS/CSI-RS CQI and the DRS CQI are simultaneously reported according to the ratio of the MIMO mode and the BF mode, or whether the CRS/CSI-RS CQI is dominant, or the DRS CQI is dominant to flexibly configure the field. value.

Therefore, in step 102, when the user equipment has the capability of measuring the user-specific reference signal DRS and the transmission mode of the user equipment in the current statistical period includes at least the beamforming BF mode, the CQI reporting indication message is sent to the user equipment. ", specifically including the following three situations:

In the first case, when the user equipment has the capability of measuring DRS and the ratio of the multiple input multiple output MIMO mode in the current statistical period is equal to the ratio of the BF mode, the value of the CQI reporting configuration field in the BF mode is set. For the first value, the CQI reporting indication message is used to indicate that the user equipment periodically reports the DRS-based CQI and the cell-specific reference signal CRS-based CQI or the channel state reference information signal CSI-RS-based CQI.

The second case: when the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, that is, the main transmission mode of the user equipment is the MIMO mode. The value of the CQI reporting configuration field in the BF mode is set to a second value, where the CQI reporting indication message is used to indicate that the user equipment reports the DRS-based CQI aperiodically, and periodically reports the CRS based Or CQI of CSI-RS;

a third case: when the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is smaller than the ratio of the BF mode, that is, the main transmission mode of the user equipment is the BF mode, The value of the CQI report configuration field in the BF mode is set to a third value, where the CQI report indication message is used to indicate that the user equipment periodically reports the DRS-based CQI, and the non-periodical report is based on the CRS. Or CQI of CSI-RS.

In either case, the specific implementation manner of the DQ-based CQI of the user equipment is: (1) if there is a normally scheduled BF subframe, the normal scheduled BF subframe is measured to obtain a DRS-based CQI; (2) If there is no BF subframe that is normally scheduled, the DRS-based CQI is obtained by using the mode of scheduling the BF subframe.

In addition, when the user equipment only has the capability of measuring the CRS or the CSI-RS, the value of the CQI reporting configuration field in the BF mode is a fourth value, and the CQI reporting indication message is used to indicate that the user equipment is only reported based on CQI of CRS or CSI-RS.

Therefore, for the application scenario that the user equipment mainly works in the BF mode and the user equipment supports the measurement of the DRS, in the prior art, the user equipment is instructed to report the CQI based on the CRS or the CSI-RS. In the present invention, the user equipment is instructed to report the DRS-based CQI, which has the following beneficial effects:

For example, it is assumed that the CQI=12 reported by the CRS, the number of transmitting antennas of the base station is 8T, the number of receiving antennas of the user is 2R, and the weight of the BF is 2. If the user reports the CQI based on the DRS, the CQI=14 is reported. Then, if the coding modulation mode is selected according to the CQI reported by the CRS, the base station will work in the 12th order; if the coding modulation mode is selected according to the CQI reported by the DRS, the base station will work in the 14th order. The spectral efficiency corresponding to CQI=12 is 3.9023, and the spectral efficiency corresponding to CQI=14 is 5.1152. If the CQI based on DRS is used for encoding and modulation mode selection, the spectrum efficiency can be improved (5.1152-3.9023)/3.9023=31.08%. Considering the loss caused by retransmission, assuming the most extreme case, the terminal has a retransmission rate of 0 in the 12th order and a retransmission rate of 10% in the 14th order, the most conservative throughput gain is {5.1152*(1). -10%)-3.9023}/3.9023=17.97%.

As a specific application to the above situation, the meaning of the field value of the newly added field of the CQI reporting configuration field in the BF mode is as shown in Table 1 below:

Table I

The first value, the second value, and the third value referred to in the above are respectively corresponding to three values of “01”, “10”, and “11”; the fourth value in the above corresponds to the table. The value of "00" in one.

The base station side can flexibly select the CQI reporting mode according to the transmission mode of the user equipment. If the transmission mode of the user equipment is mainly BF mode, you only need to configure cqi_report_mode_BF_config=11. The user equipment only needs to periodically report the DQ-based CQI, and then report the CRS/CSI-RS based on the event trigger. CQI, which can accurately measure the BF gain while minimizing overhead. If the transmission mode of the user equipment is mainly MIMO mode, only the cqi_report_mode_BF_config=“10” needs to be configured. The user equipment only needs to periodically report the CQI based on the CRS/CSI-RS, and only reports the DRS based on the event triggering. CQI, this can minimize overhead.

The content of the DQ-based CQI reported on the user equipment side is as follows in Tables 2 to 4:

Table II

字段Field	比特位宽(单位：比特)Bit width (unit: bit)
宽带CQIBroadband CQI	44
BF CQIBF CQI	44

Table 3

Table 4

The content of the CQI report based on CRS or CSI-RS is as shown in Tables 5 to 7 below:

Table 5

字段Field	比特位宽(单位：比特)Bit width (unit: bit)
宽带CQIBroadband CQI	44

Table 6

Table 7

It is to be noted that, when the user equipment has the capability of measuring DRS and the ratio of the MIMO mode in the current statistical period is equal to the BF mode, the DRS-based CQI is reported and the In addition to the CQI of the CRS or the CSI-RS, the CQI reporting indication message is further used to indicate that the user equipment reports the BF CQI field of the codeword 0/1 in the message when the DRS resource is not scheduled in the current reporting period. Set to a specific value. Wherein, according to the agreement, the specific value may be 1111.

It should be further added that, in case the user equipment has the capability of measuring DRS and the proportion of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, the CQI reporting indication message is used for indication. The user equipment reports the CQI based on the CRS or the CSI-RS in a periodic reporting manner, and reports the DQ-based CQI in a non-periodic reporting manner. The CQI reporting indication message further includes a downlink control information format 0 (DCI0). The DCI0 is used to indicate that the user equipment periodically reports a Physical Uplink Shared Channel (PUSCH) resource used by the DRS-based CQI; and instructs the user equipment to measure only the The signal-to-interference plus noise ratio (SINR) corresponding to the DRS of the downlink subframe in which the DCI0 is located. The CQI reporting indication message is further used to indicate that the user equipment periodically reports CQI and aperiodic based on CRS or CSI-RS. When the resource conflicts used by the DRS-based CQI are reported, only the DRS-based CQI is reported. Similarly, when the CRSI based on the DRS is periodically reported and the resource conflict used by the CQI based on the CRS or the CSI-RS is reported aperiodically, only the CQI based on the CRS or the CSI-RS is reported.

As a specific implementation of the method shown in FIG. 2, in the specific implementation process of performing the modulation and coding policy MCS selection according to the CQI reported by the user equipment and the current transmission mode of the user equipment, the following specifically includes the following: Six situations:

The first case is: when the DRS-based CQI and the CRS-based or CSI-RS-based CQI that are periodically reported by the user equipment are received in the current reporting period, and the current transmission mode of the user equipment is the BF mode, according to The DRS-based CQI reported by the user equipment performs MCS selection.

The second case is: when the DRS-based CQI and the CRS-based or CSI-RS-based CQI periodically reported by the user equipment are received in the current reporting period, and the current transmission mode of the user equipment is the MIMO mode, according to The CRS based on the CRS or CSI-RS reported by the user equipment performs MCS selection.

The third case is: when the CRSI based on the CRS or the CSI-RS periodically reported by the user equipment is received in the current reporting period, and the current transmission mode of the user equipment is the MIMO mode, according to the CRS-based Or the CQI of the CSI-RS performs MCS selection.

The fourth case: when the CRSI based on CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is BF mode, if the current reporting period is still received, And performing, by the DRS-based CQI, the MCS selection according to the DRS-based CQI; otherwise, performing MCS selection according to the CRS or CSI-RS-based CQI.

The fifth case is: when only the DRS-based CQI periodically reported by the user equipment is received in the current reporting period, and the current transmission mode of the user equipment is the BF mode, then the root The MCS selection is performed according to the DRS-based CQI.

The sixth case is: when the DRS-based CQI periodically reported by the user equipment is received in the current reporting period, and the current transmission mode of the user equipment is the MIMO mode, if the current reporting period is further received in the current reporting period The CRSI based on the CRS or the CSI-RS that is periodically reported by the user equipment performs the MCS selection according to the CRSI based on the CRS or the CSI-RS. Otherwise, the MCS is selected according to the CRSI based on the DRS.

It should be added that if the user equipment is switched from the MIMO mode to the BF mode and the current user equipment is in the BF mode, the DRS-based CQI sent by the user equipment may not be received in the current period, and the BF subframe may be scheduled by using the probe. The method obtains the MCS selection based on the DRS-based CQI, or performs the MCS selection by using the CRSI based on the CRS or the CSI-RS in the first period, and then receives the DRS-based CQI periodically transmitted by the user equipment, and then uses the DRS based The CQI performs MCS selection.

In addition to the method shown in the above figures, after the step 103 "the modulation and coding strategy MCS is selected according to the CQI reported by the user equipment and the current transmission mode of the user equipment", as shown in FIG. The method further includes:

201: When receiving the DRS-based CQI and the CRS or CSI-RS-based CQI reported by the user equipment in a current reporting period, determining, according to the DRS-based CQI, a value of the first MCS; Or determining, by the CQI of the CSI-RS, a value of the second MCS; when the value of the first MCS is greater than a value of the second MCS, determining that the next transmission mode of the user equipment is the BF mode; otherwise, determining the The next transmission mode of the user equipment is MIMO mode.

After the MCS is selected, if both the DRS-based CQI and the CRS or CSI-RS-based CQI are received in the current period, the corresponding MCS values are determined according to the two CQIs, and then according to the MCS. The size of the value determines the next transmission mode of the user device.

As a specific implementation of the method shown in the foregoing figures, the embodiment of the present invention further provides a device for link adaptation, as shown in FIG. 4, which specifically includes:

The receiving unit 301 is configured to receive a terminal capability report message sent by the user equipment.

The sending unit 302 is configured to send, according to the terminal capability of the user equipment and the transmission mode statistics of the user equipment in the current statistical period, a channel quality indication CQI reporting indication message, where the CQI reporting indication is sent to the user equipment. The message is used to instruct the user equipment to report the CQI in a manner corresponding to the terminal capability and the statistical result.

The receiving unit 301 is further configured to receive the CQI reported by the user equipment;

The processing unit 303 is configured to perform modulation and coding policy MCS selection according to the CQI reported by the user equipment and the current transmission mode of the user equipment.

Further, the sending unit 302 is specifically configured to:

Further, the CQI reporting indication message sent by the sending unit 302 includes a CQI reporting configuration field in the BF mode, and the sending unit 302 is specifically configured to:

or

Further, the CQI reporting indication message sent by the sending unit 302 is further configured to: when the user equipment has the capability of measuring DRS, and the ratio of the MIMO mode in the current statistical period is equal to the ratio of the BF mode, the indication When the user equipment does not schedule the DRS resource in the current reporting period, the BF CQI field of the codeword 0/1 in the reported message is set to a specific value.

Further, when the user equipment is capable of measuring the DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, the CQI reporting indication message sent by the sending unit 302 further includes downlink control. An information format DCI0, where the DCI0 is used to indicate that the user equipment periodically reports the physical uplink shared channel PUSCH resource used by the DRS-based CQI, and that the user equipment is instructed to measure only the DRS corresponding to the downlink subframe in which the DCI0 is located. Signal to interference plus noise ratio SINR.

Further, the CQI report indication message sent by the sending unit 302 is further used to indicate that the user equipment periodically reports the CQI based on the CRS or the CSI-RS and the resource used in the non-periodically reporting the DRS-based CQI. In the case of a collision, only the CRSI based on the DRS is reported; when the CQI based on the DRS is periodically reported and the resource conflicts reported by the CQI based on the CRS or the CSI-RS are reported periodically, only the CQI based on the CRS or the CSI-RS is reported.

Further, the processing unit 303 is specifically configured to:

or

Further, the processing unit 303 is further configured to:

As a specific implementation of the method shown in the foregoing figures, an embodiment of the present invention further provides a link adaptation apparatus, as shown in FIG. 5, specifically including a receiver 401, a processor 402, a transmitter 403, a memory 404, and Bus 405, and receiver 401, processor 402, transmitter 403, and memory 404 are interconnected by bus 405, where:

The receiver 401 is configured to receive a terminal capability report message sent by the user equipment.

The processor 402 is configured to determine a CQI reporting manner according to the terminal capability of the user equipment and the transmission mode statistics of the user equipment in the current statistical period.

The transmitter 403 is configured to send a channel quality indication CQI reporting indication message to the user equipment, where the CQI reporting indication message is used to indicate that the user equipment reports the CQI by using a CQI reporting manner determined by the processor 402.

The receiver 401 is further configured to receive the CQI reported by the user equipment.

The processor 402 is further configured to perform modulation and coding policy MCS selection according to the CQI reported by the user equipment and the current transmission mode of the user equipment.

Further, the processor 402 is further configured to:

When the user equipment is capable of measuring the user-specific reference signal DRS and the transmission mode of the user equipment in the current statistical period includes at least the beamforming BF mode, determining that the CQI reporting manner of the user equipment is to report at least DRS-based reporting Correspondingly, the transmitter 403 sends a CQI report indication message to the user equipment, where the CQI report indication message is used to indicate that the user equipment reports at least a DRS-based CQI.

Further, the CQI reporting indication message sent by the transmitter 403 includes a CQI reporting configuration field in the BF mode, where:

or

Further, the CQI reporting indication message sent by the transmitter 403 is further configured to: when the user equipment has the capability of measuring DRS, and the ratio of the MIMO mode in the current statistical period is equal to the ratio of the BF mode, the indication When the user equipment does not schedule the DRS resource in the current reporting period, the BF CQI field of the codeword 0/1 in the reported message is set to a specific value.

Further, when the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, the CQI reporting indication message sent by the transmitter 403 further includes downlink control. The information format DCI0 is used to indicate that the user equipment periodically reports the physical uplink sharing used by the DRS-based CQI. a channel PUSCH resource; and a signal to interference plus noise ratio SINR indicating that the user equipment only measures the DRS of the downlink subframe in which the DCI0 is located.

Further, the CQI reporting indication message sent by the transmitter 403 is further used to indicate that the user equipment periodically reports the CQI based on the CRS or the CSI-RS and the resource used in the non-periodically reporting the DRS-based CQI. In the case of a collision, only the CRSI based on the DRS is reported; when the CQI based on the DRS is periodically reported and the resource conflicts reported by the CQI based on the CRS or the CSI-RS are reported periodically, only the CQI based on the CRS or the CSI-RS is reported.

Further, the processor 402 is specifically configured to:

or

If the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the BF mode, if the user equipment is not received in the current reporting period a DRS-based CQI, which performs MCS selection according to the DRS-based CQI; otherwise, according to the CRS-based or CSI-RS CQI for MCS selection;

or

Further, the processor 402 is further configured to determine, according to the DRS-based CQI, when receiving the DRS-based CQI and the CRS or CSI-RS-based CQI reported by the user equipment in a current reporting period. a value of the MCS; determining a value of the second MCS according to the CRSI based on the CRS or CSI-RS; determining a next transmission of the user equipment when the value of the first MCS is greater than a value of the second MCS The mode is the BF mode; otherwise, the next transmission mode of the user equipment is determined to be the MIMO mode.

It should be noted that the processor 402 in the embodiment of the present invention may be a processor or a collective name of multiple processing elements. For example, the processor may be a central processing unit (CPU), or may be an application specific integrated circuit (ASIC), or one or more configured to implement the embodiments of the present invention. An integrated circuit, such as one or more digital signal processors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs).

The memory 404 may be a storage device or a collective name of a plurality of storage elements, and is used to store executable program code or the like. And the memory may include random access memory (RAM), and may also include non-volatile memory, such as disk storage. Flash (Flash), etc.

The bus 405 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is shown in Figure 5, but it does not mean that there is only one bus or one type of bus.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general hardware, and of course, by hardware, but in many cases, the former is a better implementation. . Based on the understanding, the technical solution of the present invention, which is essential or contributes to the prior art, can be embodied in the form of a software product stored in a readable storage medium, such as a floppy disk of a computer. A hard disk or optical disk, etc., includes instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform the methods described in various embodiments of the present invention. The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention.

Claims

A link adaptation method, comprising:

Receiving a terminal capability report message sent by the user equipment;

Transmitting, by the user equipment, a channel quality indication CQI reporting indication message to the user equipment according to the terminal capability of the user equipment and the transmission mode statistics of the user equipment in the current statistical period, where the CQI reporting indication message is used to indicate the The user equipment reports the CQI in a manner corresponding to the terminal capability and the statistical result;

The modulation and coding policy MCS is selected according to the CQI reported by the user equipment and the current transmission mode of the user equipment.
The link adaptation method according to claim 1, wherein the user equipment is provided according to the terminal capability of the user equipment and the transmission mode statistics of the user equipment in the current statistical period. The sending channel quality indication CQI reporting indication message specifically includes:

When the user equipment is capable of measuring the user-specific reference signal DRS and the transmission mode of the user equipment in the current statistical period includes at least the beamforming BF mode, the CQI reporting indication message is sent to the user equipment, and the CQI is reported. The indication message is used to instruct the user equipment to report at least the DRS-based CQI.
The link adaptation method according to claim 2, wherein the CQI reporting indication message includes a CQI reporting configuration field in a BF mode;

When the user equipment is capable of measuring the user-specific reference signal DRS and the transmission mode of the user equipment in the current statistical period includes at least the beamforming BF mode, sending a CQI reporting indication message to the user equipment, The CQI report indication message is used to indicate that the user equipment reports at least the DRS-based CQI, and specifically includes:

When the user equipment has the capability of measuring the DRS and the ratio of the multiple input multiple output MIMO mode in the current statistical period is equal to the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to the first value The CQI reporting indication message is used to refer to The user equipment is periodically reported to report the CRSI based on the DRS and the CQI based on the cell-specific reference signal CRS or the CQI based on the channel state reference information signal CSI-RS;

or

When the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to the second value, The CQI reporting indication message is used to indicate that the user equipment reports the DRS-based CQI aperiodically, and periodically reports the CRS or CSI-RS based CQI;

or

When the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is smaller than the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to a third value, The CQI reporting indication message is used to indicate that the user equipment periodically reports the DRS-based CQI, and the CRS or CSI-RS-based CQI is reported aperiodically.
The link adaptation method according to claim 3, wherein when the user equipment has the capability of measuring DRS and the ratio of the MIMO mode in the current statistical period is equal to the ratio of the BF mode, the CQI is reported. The indication message is further used to indicate that the user equipment sets the BF CQI field of the codeword 0/1 in the report message to a specific value when the DRS resource is not scheduled in the current reporting period.
The method of link adaptation according to claim 3, wherein when the user equipment has the capability of measuring DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, The CQI reporting indication message further includes a downlink control information format DCI0, where the DCI0 is used to indicate that the user equipment periodically reports the physical uplink shared channel PUSCH resource used by the DRS-based CQI, and indicates that the user equipment only measures the DCI0 The DRS corresponding to the downlink subframe has a signal to interference plus noise ratio SINR.
The method of link adaptation according to claim 3, wherein said said The CQI reporting indication message is further used to indicate that the user equipment reports only the DRS-based CQI when periodically reporting the CQI based on the CRS or the CSI-RS and the CQI used by the non-periodically reporting the DRS-based CQI; When the CRSI based on the DRS is reported and the resource conflict used by the CQI based on the CRS or the CSI-RS is reported aperiodically, only the CQI based on the CRS or the CSI-RS is reported.
The link adaptation method according to claim 3, wherein the modulating and coding policy MCS is selected according to the CQI reported by the user equipment and the current transmission mode of the user equipment, and specifically includes:

Receiving, according to the user equipment, the DRS-based CQI and the CRS-based CSI-C-based CQI and the current transmission mode of the user equipment in the BF mode are received in the current reporting period. The DRS-based CQI performs MCS selection;

or

When the DRS-based CQI and the CRS-CSI-RS-based CQI are periodically reported in the current reporting period, and the current transmission mode of the user equipment is the MIMO mode, the user equipment is reported according to the user equipment. The CRS based on CRS or CSI-RS performs MCS selection;

or

When the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the MIMO mode, according to the CRS or CSI-RS based CQI performs MCS selection;

or

If the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the BF mode, if the user equipment is not received in the current reporting period The DRS-based CQI is reported, and the MCS is selected according to the DRS-based CQI; otherwise, according to the CRS-based Or CSI of CSI-RS for MCS selection;

or

When the DRS-based CQI periodically reported by the user equipment is received in the current reporting period, and the current transmission mode of the user equipment is the BF mode, the MCS selection is performed according to the DRS-based CQI.

or

When the DRS-based CQI periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the MIMO mode, if the user equipment is also received in the current reporting period, the non-periodicity is The CRSI based on the CRS or the CSI-RS is reported, and the MCS is selected according to the CRSI based on the CRS or the CSI-RS. Otherwise, the MCS is selected according to the DRS-based CQI.
The method according to claim 7, wherein after the modulating and encoding the MCS is performed according to the CQI reported by the user equipment and the current transmission mode of the user equipment, the method further includes:

Determining a value of the first MCS according to the DRS-based CQI when receiving the DRS-based CQI and the CRS- or CSI-RS-based CQI reported by the user equipment in a current reporting period; according to the CRS-based or CSI The CQI of the RS determines a value of the second MCS; when the value of the first MCS is greater than the value of the second MCS, determining that the next transmission mode of the user equipment is the BF mode; otherwise, determining the user equipment The next transmission mode is MIMO mode.
The method according to any one of claims 1 to 8, wherein the terminal capability report message comprises a first field, and the first field is used to indicate whether the terminal supports measurement DRS.
A device for link adaptation, comprising:

a receiving unit, configured to receive a terminal capability report message sent by the user equipment;

a sending unit, configured to send a channel quality indication CQI reporting indication message to the user equipment according to a terminal capability of the user equipment and a transmission mode statistics result of the user equipment in a current statistical period, where the CQI reporting indication message Instructing the user equipment to report the CQI in a manner corresponding to the terminal capability and the statistical result;

The receiving unit is further configured to receive a CQI reported by the user equipment;

The processing unit is configured to perform modulation and coding policy MCS selection according to the CQI reported by the user equipment and the current transmission mode of the user equipment.
The apparatus for link adaptation according to claim 10, wherein the sending unit is specifically configured to:

When the user equipment is capable of measuring the user-specific reference signal DRS and the transmission mode of the user equipment in the current statistical period includes at least the beamforming BF mode, the CQI reporting indication message is sent to the user equipment, and the CQI is reported. The indication message is used to instruct the user equipment to report at least the DRS-based CQI.
The link adaptation device of claim 11 wherein:

The CQI reporting indication message sent by the sending unit includes a CQI reporting configuration field in the BF mode, where the sending unit is specifically configured to:

When the user equipment has the capability of measuring the DRS and the ratio of the multiple input multiple output MIMO mode in the current statistical period is equal to the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to the first value The CQI report indication message is used to indicate that the user equipment periodically reports the CRSI based on the DRS and the CQI based on the cell-specific reference signal CRS or the CQI based on the channel state reference information signal CSI-RS;

or

When the user equipment is capable of measuring the DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, the value of the CQI reporting configuration field in the BF mode is set to a second value. The CQI reporting indication message is used to indicate that the user equipment reports the DRS-based CQI aperiodically, and periodically reports the CQI based on CRS or CSI-RS;

or

When the user equipment has the capability of measuring the DRS and the ratio of the MIMO mode in the current statistical period is smaller than the ratio of the BF mode, setting the value of the CQI reporting configuration field in the BF mode to a third value, The CQI reporting indication message is used to indicate that the user equipment periodically reports the DRS-based CQI, and the CRS or CSI-RS-based CQI is reported aperiodically.
The apparatus for link adaptation according to claim 12, wherein the CQI reporting indication message sent by the sending unit is further configured to: when the user equipment has the capability of measuring DRS and MIMO in a current statistical period When the ratio of the mode is equal to the ratio of the BF mode, the user equipment is instructed to set the BF CQI field of the codeword 0/1 in the report message to a specific value when the DRS resource is not scheduled in the current reporting period.
The device for link adaptation according to claim 12, wherein when the user equipment has the capability of measuring DRS and the ratio of the MIMO mode in the current statistical period is greater than the ratio of the BF mode, The CQI reporting indication message sent by the sending unit further includes a downlink control information format DCI0, where the DCI0 is used to indicate that the user equipment periodically reports the physical uplink shared channel PUSCH resource used by the DRS-based CQI, and indicates the user equipment. Only the signal corresponding to the DRS of the downlink subframe in which the DCI0 is located is compared with the interference plus noise ratio SINR.
The link adaptation apparatus according to claim 12, wherein the CQI report indication message sent by the sending unit is further used to indicate that the user equipment periodically reports CRS or CSI-RS based When the CQI conflicts with the resource used by the DRS-based CQI, it only reports the DRS-based CQI; when the CRSI based on the DRS is periodically reported and the CQI that is reported on the CRS or CSI-RS is not periodically reported Only CQI based on CRS or CSI-RS is reported.
The apparatus for link adaptation according to claim 12, wherein the processing unit is specifically configured to:

Receiving, according to the user equipment, the DRS-based CQI and the CRS-based CSI-C-based CQI and the current transmission mode of the user equipment in the BF mode are received in the current reporting period. The DRS-based CQI performs MCS selection;

or

When the DRS-based CQI and the CRS-CSI-RS-based CQI are periodically reported in the current reporting period, and the current transmission mode of the user equipment is the MIMO mode, the user equipment is reported according to the user equipment. The CRS based on CRS or CSI-RS performs MCS selection;

or

When the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the MIMO mode, according to the CQI based on the CRS or the CSI-RS Perform MCS selection;

or

If the CRSI based on the CRS or CSI-RS periodically reported by the user equipment is received in the current reporting period and the current transmission mode of the user equipment is the BF mode, if the user equipment is not received in the current reporting period Performing MCS selection based on the DRS-based CQI; otherwise, performing MCS selection according to the CRS or CSI-RS based CQI;

or

When only the DRS-based CQI periodically reported by the user equipment is received in the current reporting period, and the current transmission mode of the user equipment is the BF mode, the MCS selection is performed according to the DRS-based CQI;

or

Receiving the DRS periodically reported by the user equipment during the current reporting period And the CQI based on the CRS or CSI-RS that is not periodically reported by the user equipment in the current reporting period, if the CQI is the PDCCH mode and the current transmission mode of the user equipment is the MIMO mode. The CQI of the CSI-RS performs MCS selection, otherwise MCS selection is performed according to the DRS-based CQI.
The device of claim 16 wherein:

The processing unit is further configured to determine a value of the first MCS according to the DRS-based CQI when receiving the DRS-based CQI and the CRS or CSI-RS-based CQI reported by the user equipment in a current reporting period. Determining a value of the second MCS according to the CRSI based on the CRS or the CSI-RS; determining that the next transmission mode of the user equipment is the BF mode when the value of the first MCS is greater than the value of the second MCS Otherwise, it is determined that the next transmission mode of the user equipment is MIMO mode.