WO2017152799A1 - Method for feeding back channel quality, and user equipment and base station - Google Patents

Abstract

The present application discloses a method for feeding back channel quality, a user equipment and a base station. The method comprises: receiving a first downlink signal sent out at a first moment, and estimating a first channel quality value according to the first downlink signal; receiving a second downlink signal sent out at a second moment, which is after the first moment, and estimating a second channel quality value when a base station performs multi-user transmission according to the second downlink signal, wherein the multi-user transmission is downlink transmission to a plurality of UEs, comprising the first UE, conducted by the base station by utilizing the same time-frequency resource; and according to the first channel quality value and the second channel quality value,calculating a channel quality adjustment factor, and feeding the channel quality adjustment factor back to the base station.

Description

Method, user equipment and base station for feedback channel quality Technical field

The present application relates to mobile communication technologies, and in particular, to a method for feeding back channel quality, a user equipment, and a base station.

background

In a wireless communication system, a base station generally needs to feed back a channel quality for a user equipment (UE), and then determines a modulation and coding scheme (MCS) and a time-frequency resource used by each user for downlink transmission according to the channel quality fed back by each UE. Wait.

Technical content

In view of this, the embodiment of the present application provides a method for adjusting channel quality, which aims to improve the accuracy of downlink scheduling. Correspondingly, system throughput and user throughput can also be improved to some extent.

An embodiment of the present application provides a method for feeding back a channel quality, where the method is applied to a first user equipment UE, including:

Receiving a first downlink signal sent at a first moment, and estimating a first channel quality value according to the first downlink signal;

Receiving, at a second moment after the first moment, a second downlink signal, and estimating, according to the second downlink signal, a second channel quality value when the base station performs multi-user transmission, where the multi-user transmission is utilized by the base station Downlink transmission of the same time-frequency resource to a plurality of UEs including the first UE; and

Calculating a channel quality adjustment factor according to the first channel quality value and the second channel quality value, and feeding back the channel quality adjustment factor to a base station, where the base station is configured according to the The channel quality adjustment factor adjusts channel quality of the first UE when the base station estimates multi-user transmission and performs multi-user transmission by using the adjusted channel quality.

An embodiment of the present application provides a user equipment UE, including:

a receiving module, configured to receive a first downlink signal sent at a first moment and a second downlink signal sent at a second moment after the first moment;

An estimation module, configured to estimate a first channel quality value according to the first downlink signal, and estimate, according to the second downlink signal, a second channel quality value when the base station performs multi-user transmission, where the multi-user transmission is a base station Downlink transmission to multiple UEs including the first UE by using the same time-frequency resource;

a calculation module, configured to calculate a channel quality adjustment factor according to the first channel quality value and the second channel quality value; and

a feedback module, configured to feed back the channel quality adjustment factor to the base station, where the base station adjusts, according to the channel quality adjustment factor, the channel quality of the first UE when the base station estimates the multi-user transmission, and uses the adjusted The channel quality is for multi-user transmission.

The embodiment of the present application provides a base station, including:

The sending module is configured to send the first downlink signal at the first moment, so that the first user equipment UE estimates the first channel quality value according to the first downlink signal, and sends the second time after the first moment a second downlink signal, so that the first UE estimates, according to the second downlink signal, a second channel quality value when the base station performs multi-user transmission, and according to the first channel quality value and the second channel a quality value calculation channel quality adjustment factor, wherein the multi-user transmission is a downlink transmission performed by the base station to the multiple UEs including the first UE by using the same time-frequency resource;

a receiving module, configured to receive the channel quality adjustment factor fed back by the first UE;

And a scheduling module, configured to determine, according to the channel quality adjustment factor, a modulation and coding mode MCS used by the downlink signal of the first UE when performing multi-user transmission.

The method of the present invention provides a method for feeding back channel quality, a user equipment, and a base station in the mobile communication system provided by the embodiment of the present application. The UE itself calculates a channel quality adjustment factor, and feeds the channel quality adjustment factor to the base station, so that the base station can learn The channel quality deviation estimated by the UE. Further, the base station can determine the MCS used when transmitting the downlink signal of the UE when the multi-user transmission is actually performed, thereby effectively improving the accuracy of the MCS in the subsequent transmission, and improving the system throughput and the user throughput.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic flowchart of a method for feeding back channel quality in an embodiment of the present application;

FIG. 1b is a schematic flowchart of a method for feeding back channel quality in an embodiment of the present application;

2 is a schematic diagram of multi-user transmission in an embodiment of the present application;

3 is a schematic flowchart of a method for adjusting a CQI in an embodiment of the present application;

4a is a schematic diagram of probability distribution of interference power adjustment values in an embodiment of the present application;

4b is a schematic diagram of probability distribution of interference power adjustment values in an embodiment of the present application;

FIG. 5 is a signaling interaction diagram of a method for adjusting CQI in an embodiment of the present application;

6 is a schematic flowchart of a method for adjusting a CQI in an embodiment of the present application;

FIG. 7 is a schematic structural diagram of a user terminal according to an embodiment of the present application;

FIG. 8 is a schematic structural diagram of a base station according to an embodiment of the present application.

Way of implementing the application

In order to make the objects, technical solutions and advantages of the present application more comprehensible, the present application will be further described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic flowchart of a method for feeding back channel quality according to an embodiment of the present application. The method is applied to a first UE, and includes the following steps.

Step 11: Receive a first downlink signal sent at a first moment, according to the first downlink signal The first channel quality value is estimated.

The first downlink signal (also referred to as the first downlink data) refers to a downlink signal, such as a pilot signal, used by the base station to perform channel estimation, for the first UE. The pilot signal may be a downlink reference signal (RS), such as a cell reference signal (CRS), a UE-specific reference signal (UE-specific RS), and the like.

The channel quality value is a numerical value used to indicate the channel quality. The channel quality value may be, for example, signal to interference plus noise ratio (SINR), signal to noise ratio (SNR), signal to interference ratio (SIR), carrier to interference ratio (CIR), reference signal received quality (RSRQ), and the like.

Step 12: Receive a second downlink signal sent at a second moment after the first moment, and estimate a second channel quality value when the base station performs multi-user transmission according to the second downlink signal.

Multi-user transmission refers to downlink transmission performed by a base station to multiple UEs including the first UE by using the same time-frequency resource.

The second downlink signal (also referred to as the second downlink data) refers to a downlink signal sent by the base station to the first UE for performing multi-user transmission, for example, a multi-user transmission control signal. The first UE may obtain a parameter of the multi-user transmission from the second downlink signal, and estimate the second channel quality value by using the parameter of the multi-user transmission. The parameters of the multi-user transmission may include: a power and a precoding matrix allocated to the first UE when multi-user transmission, and power allocated to at least one of the plurality of UEs.

Step 13: Calculate a channel quality adjustment factor according to the first channel quality value and the second channel quality value, and feed back the channel quality adjustment factor to the base station.

The base station may adjust channel quality of the first UE when the base station estimates the multi-user transmission according to the channel quality adjustment factor, and perform multi-user transmission by using the adjusted channel quality.

In the embodiment of the present application, the UE estimates the multi-user transmission when the multi-user transmission is performed. The channel quality, and the channel quality adjustment factor is calculated according to the channel quality, and the channel quality adjustment factor is fed back to the base station. In this way, the base station can use the channel quality adjustment factor to adjust the estimated channel quality of the UE during multi-user transmission, and perform multi-user transmission according to the adjusted estimated value, thereby effectively improving the accuracy of the MCS in subsequent transmissions, and improving the system. Throughput and user throughput.

FIG. 1b is a schematic flowchart of a method for feeding back channel quality in an embodiment of the present application. The method is applied to the first UE. In this embodiment, the SINR is taken as an example of the channel quality value. The method includes the following steps.

Step 101: Receive first downlink data sent at a first moment, and estimate a first SINR according to the first downlink data.

Herein, the downlink data may refer to user data, pilot data, or control signaling data.

In a particular implementation, the SINR is the ratio of the strength of the received useful signal to the received interference signal and noise strength. The first downlink data may be a downlink reference signal (RS), such as a cell reference signal (CRS). The first UE may obtain the first SINR according to the received RS estimation, which is expressed as:

The SINR ₁ represents the first SINR, the P _RSRP represents the received power of the RS, and the P _Int is the interference power, that is, the sum of the signal powers of the neighboring cells received on the resource blocks occupied by the RS, and N is the noise power.

Step 102: Estimate a second SINR according to the received second downlink data.

The second downlink data is sent at a second moment after the first moment. The second downlink data includes data sent to the first UE. In this way, the first UE estimates a second SINR according to the received data signal, which is expressed as:

Wherein, SINR ₂ represents a second SINR, P _data represents a received power of the received data signal, and P _Int is a sum of signal powers of neighboring cells received on a resource block occupied by data transmitted to the first UE. , N is the noise power.

Step 103: Calculate a CQI adjustment factor (ie, a channel quality adjustment factor) according to the first SINR and the second SINR, and feed back the CQI adjustment factor to the base station.

In an embodiment, calculating the CQI adjustment factor γ can be expressed as:

γ=f(SINR ₁ ,SINR ₂ ) (3)

The SINR ₁ represents a channel quality parameter of the reference signal transmitted by the second downlink data base station, and the SINR ₂ represents a channel quality parameter of the data signal when the second downlink data is actually transmitted. That is to say, from the downlink data to be transmitted to the first UE, SINR ₁ can be understood as an estimated value, and SINR ₂ can be understood as a true value. The CQI adjustment factor is estimated from the difference between SINR ₁ and SINR ₂ , expressed by the function fO.

In a typical scenario of multi-user transmission, as shown in FIG. 2, the base station simultaneously serves a plurality of users UE1, UE2, UE3, and UE4. Depending on whether the resources allocated to the user are orthogonal, the base station can determine whether to employ orthogonal multi-user multiple antenna (MU-MIMO) transmission or non-orthogonal multiple access (NOMA) transmission.

In particular, MU-MIMO transmission belongs to orthogonal multiple access technology, and orthogonal resources are allocated for multiple users, for example, signals are transmitted to UE1 and UE3 in FIG. 2 simultaneously using different spatial resources. In the NOMA transmission, the same resource can be allocated to multiple users. For example, the channel quality difference between UE1 and UE2 is large in FIG. 2, and the base station allocates non-orthogonal resources to UE1 and UE2 during downlink scheduling, for example, The same time-frequency resource block but with different powers. In this way, channel quality differences of multiple users can be converted into multiplexing gain, and serial interference cancellation technology can be used for demultiplexing on the UE side. Similarly, UE3 and UE4 can also adopt the NOMA transmission mode.

For MU-MIMO transmission, UE1 and UE3 are taken as an example, where the first UE may be UE1, and UE1 is unable to know when the downlink data is actually transmitted at the second time (ie, performing multi-user transmission) when receiving the CQI, and is interfered by UE3. Interference generated by other UEs in neighboring cells. Here, since UE1 and UE3 adopt orthogonal resources, the above interference mainly comes from other UEs in the neighboring cells.

For the non-orthogonal resource of the NOMA transmission, the UE1 and the UE2 are taken as an example, and the first UE may be the UE1. Since the two are non-orthogonal in the power dimension, the UE1 cannot know the multi-user transmission and the pairing when the CQI is fed back. The interference introduced by UE2 and the interference generated by other UEs in the neighboring cell, wherein the interference is mainly derived from the paired UE2 in the same cell due to non-orthogonal transmission.

It can be seen that for orthogonal MU-MIMO or non-orthogonal NOMA transmission, the CQI fed back to the base station by UE1 is different from the actual CQI of the actual downlink data transmission, so that the accuracy of the MCS determined when the base station performs scheduling is reduced, therefore, it is required Adjust the CQI referenced during scheduling.

According to the method provided by the foregoing embodiment, the first UE itself estimates the CQI adjustment factor according to the SINR of the two previous moments, and then feeds back to the base station, so that the base station can determine the MCS used by the subsequent multi-user transmission according to the CQI adjustment factor. Effectively improve the accuracy of MCS in multi-user transmissions, thereby increasing system throughput and user throughput.

FIG. 3 is a schematic flowchart diagram of a method for adjusting CQI in another embodiment of the present application. The method is applied to the first UE, and includes the following steps.

In step 301, a plurality of candidate adjustment values are set in advance.

The value of the candidate adjustment value (also referred to as the candidate CQI adjustment value) may be preset to a fixed value by the first UE, or may be quantized by the first UE based on the interference power adjustment value λ. Wherein, the specific method based on the interference power adjustment value λ is given in step 304. The first UE will store the calculated interference power adjustment value λ each time and obtain L by the following steps. An alternative CQI adjustment value α1,...,αL.

Step 3011: Calculate a probability distribution of the interference power adjustment value calculated before the second time.

Step 3012: Determine a probability value p corresponding to each interference power adjustment value according to the probability distribution.

In step 3013, the probability values are grouped.

A probability threshold pth is set in advance, and all probability values p1, . . . , pM greater than the probability threshold are taken out, and then the probability values with similar values are grouped into one group, and the probability values in each group may be the same or different. .

Step 3014, averaging the interference power adjustment values λ corresponding to the probability values in each group, and determining the obtained average value as L candidate CQI adjustment values.

The total number L of the candidate CQI adjustment values may be preset by the first UE, and the value of L will affect the accuracy of the fed back CQI adjustment factor. For example, when L=4, α1=-0.1, α2=0.1, α3=0.23, and α4=0.56. For another example, when L = 8, α1 = -0.3, α2 = -0.15, α3 = 0, α4 = 0.1, α5 = 0.2, α6 = 0.3, α7 = 0.5, and α8 = 0.7. At the same time, the value of L also affects the transmission resources occupied by the feedback CQI adjustment value.

4a is a schematic diagram showing a probability distribution of interference power adjustment values according to an embodiment of the present invention, corresponding to L=4. As shown in FIG. 4a, the horizontal axis is the value of the interference power adjustment value, the number axis is the value of the probability, and each interference power adjustment value corresponds to a probability value, which is represented by a circle with a circle. The probability threshold pth=2%, and the probability value above the probability threshold pth includes a total of 10 values, that is, M=10. The values of the 10 probabilities are divided into four groups according to the principle of numerical proximity, as shown in the identification of "group 1" to "group 4" in Fig. 4a. The group 1 includes four probability values, the group 2 includes one probability value, the group 3 includes two probability values, and the group 4 includes three probability values. The interference power adjustment values corresponding to each set of probability values are averaged to obtain α1 to α4.

FIG. 4b is a schematic diagram of probability distribution of interference power adjustment values according to an embodiment of the present invention; Should be L=8. The probability distribution in Fig. 4b is the same as that in Fig. 4a, and the 10 probability values above the probability threshold pth are divided into eight groups, as indicated by the labels "Group 1" to "Group 8" in Fig. 4b. The "group 2" and the "group 7" each include two probability values, and the other groups each include one probability value. The interference power adjustment values corresponding to each set of probability values are averaged to obtain α1 to α8.

Step 302: Receive first downlink data sent at the first moment, and estimate a first SINR according to the first downlink data.

Step 303: Estimate a second SINR according to the received second downlink data, and obtain a first power allocated to the first UE and a second power allocated to the second UE when the base station sends the second downlink data.

When the base station sends downlink data to multiple UEs, it will notify each UE of the power allocated to all the paired UEs through downlink control signaling. For example, paired with the first UE is a second UE, the base station notifying the first power β ₁ allocated by the first UE to the first UE and the second power β ₂ allocated to the second UE.

Step 304: Calculate a CQI adjustment factor according to the first SINR and the second SINR.

Calculating the interference power adjustment value λ according to the first SINR SINR ₁ , the second SINR SINR ₂ , the first power β _{1 ,} and the second power β ₂ , and determining the interference power adjustment value λ and each candidate CQI adjustment value α1, . . . , αL The difference between the candidate CQI adjustment values corresponding to the smallest difference among the determined differences is taken as the CQI adjustment factor.

In an embodiment, the second UE is paired with the first UE, and the first UE determines, according to the downlink control signaling, whether the spatial resource allocated by the base station to the first UE and the spatial resource allocated to the second UE are the same. Whether the first UE and the second UE perform orthogonal MU-MIMO transmission or non-orthogonal NOMA transmission can be determined according to whether the spatial resources are the same.

Specifically, if the first UE determines that the spatial resource allocated by the base station to the first UE is different from the spatial resource allocated to the second UE, for example, using orthogonal resources to implement MU-MIMO transmission, Then according to the following equation

The interference power adjustment value λ is derived.

If the first UE determines that the spatial resource allocated by the base station to the first UE is the same as the spatial resource allocated to the second UE, if the non-orthogonal resource is used to implement the NOMA transmission, and the first power β _{1 is} greater than or equal to the second power β ₂ When the first UE is a remote user with respect to the second UE, according to the following equation

The interference power adjustment value λ is derived.

For the NOMA transmission, if the first power β _{1 is} smaller than the second power β ₂ , that is, the first UE is a close-range user with respect to the second UE, the CQI adjustment factor does not need to be fed back, and the uplink resource may be used for feedback interference. The information field of the power adjustment value λ is left blank.

It should be noted that the second UE may include at least one UE that is paired with the first UE and uses orthogonal resources (such as different spatial resources). As shown in FIG. 2, if the first UE is UE1, the second UE may be UE3, or the second UE includes UE3 and UE4. When the second UE includes a plurality of paired UEs, the second power β ₂ is the sum of the powers allocated to all the paired UEs.

In another embodiment, the second UE comprises a third UE and a fourth UE, the second power comprising a third power β ₃ allocated to the third UE and a fourth power β ₄ allocated to the fourth UE. The first UE, the third UE, and the fourth UE simultaneously implement orthogonal MU-MIMO transmission and non-orthogonal NOMA transmission. At this time, the first UE determines, according to the downlink control signaling, that the spatial resource allocated by the base station to the first UE and the spatial resource allocated to the third UE are different, that is, the MU-MIMO transmission is implemented between the first UE and the third UE; The spatial resource allocated to the first UE and the spatial resource allocated to the fourth UE are the same, that is, the NOMA transmission is implemented between the first UE and the fourth UE.

As shown in FIG. 2, if the first UE is UE1, the third UE may be UE3, or the third UE includes UE3 and UE4, and the fourth UE may be UE2. When the third UE includes a plurality of UEs, the third power β ₃ is the sum of the powers allocated to all the paired UEs using different spatial resources, such as the sum of the powers allocated to UE3 and UE4. When the fourth UE includes a plurality of UEs, the fourth power β ₄ is the sum of the powers allocated to all the paired UEs using the same spatial resource.

When the first power β _{1 is} greater than the fourth power β ₄ , that is, the first UE is a remote user compared to the fourth UE, according to the following equation

The interference power adjustment value λ is derived.

When the first power β _{1 is} less than or equal to the fourth power β ₄ , that is, the first UE is a close-range user compared to the fourth UE, and the UE1 is a close-range user compared to the UE 2 in FIG. 2 , according to the following formula

The interference power adjustment value λ is derived.

In step 305, the CQI adjustment factor is fed back to the base station.

In this step, whether the UE feeds back the CQI adjustment factor to the base station may be semi-statically configured through higher layer signaling (for example, radio resource control RRC signaling) or dynamically configured by the base station through downlink control signaling.

When it is learned through the received signaling that feedback is needed, the first UE may feed back the CQI adjustment factor to the base station on a Physical Uplink Control Channel (PUCCH) or a Physical Uplink Shared Channel (PUSCH).

FIG. 5 is a signaling diagram of a method for adjusting CQI in an embodiment of the present invention. See Figure 5, Including the following steps:

Step 501: The base station sends a downlink reference signal to the first UE at the first moment.

Step 502: The first UE estimates a first SINR and a first CQI according to the received downlink reference signal.

Step 503: The first UE feeds back the first CQI to the base station.

Step 504: The base station schedules the user according to the received first CQI, and when determining to schedule the first UE, determines the first MCS used by the first UE according to the first CQI.

Step 505: The base station again schedules the first UE, and sends the second downlink data to the first UE according to the first MCS, and notifies the first UE to feed back the CQI adjustment factor by using downlink control signaling.

For example, the base station configures an indication bit in a Physical Downlink Control Channel (PDCCH). After receiving the UE, it is learned according to the indication bit whether the CQI adjustment factor needs to be fed back. The configuration may be dynamically configured, and the UE performs the calculation of the CQI adjustment factor after receiving the indication bit. For example, the base station may calculate a block error rate (BLER) according to a result of a downlink hybrid automatic repeat request (HARQ), and configure an indication bit in the PDCCH when the BLER is greater than a preset threshold.

Step 506: The first UE estimates a second SINR and a second CQI according to the received second downlink data, and calculates a CQI adjustment factor according to the first SINR and the second SINR.

Step 507: The first UE feeds back a second CQI and CQI adjustment factor to the base station.

Step 508: The base station determines, according to the received second CQI and CQI adjustment factors, a second MCS used when subsequently transmitting downlink data of the first UE.

Step 509: The base station again schedules the first UE, encodes and adjusts the data of the first UE according to the second MCS, and sends the third downlink data to the first UE at the third moment.

For the method of determining the MCS according to the SINR or the CQI, reference may be made to the algorithm in the LTE/LTE-A protocol, and details are not described herein again.

FIG. 6 is a schematic flow chart of a method for adjusting CQI according to still another embodiment of the present invention. The party The method is applied to a base station, see FIG. 6, and includes the following steps:

Step 601: Send first downlink data to the first UE at the first moment, so that the first UE estimates the first SINR according to the first downlink data.

In this step, the first UE may simultaneously estimate the first CQI according to the first downlink data, to feed back the first CQI to the base station, and determine, in step 602, the first MCS used when transmitting the second downlink data.

Step 602: Send second downlink data to the first UE at the second moment, so that the first UE estimates the second SINR according to the second downlink data, and calculates a channel quality indicator CQI adjustment factor according to the first SINR and the second SINR.

In this step, the first UE may simultaneously estimate the second CQI according to the second downlink data, to feed back the second CQI to the base station, and determine the second MCS used when the third downlink data is sent in step 604.

Step 603: Receive a CQI adjustment factor fed back by the first UE.

Step 604: Determine, according to the CQI adjustment factor, a second MCS used when transmitting the third downlink data to the first UE.

In this step, the base station calculates a third SINR (represented as SINR ₃ ) according to the first power β ₁ allocated to the first UE when transmitting the second downlink data, the second power β ₂ allocated to the second UE, and the CQI adjustment factor γ. Then, the second MCS used by the third downlink data is determined according to the third SINR. The third downlink data is sent at a third moment after the second moment.

In an embodiment, when the base station again schedules the first UE and the second UE to be paired users, the base station allocates spatial resources for the first UE and the second UE. If the spatial resource allocated to the first UE is different from the spatial resource allocated to the second UE, if the MU-MIMO transmission is implemented by using the orthogonal resource, the third SINR is calculated according to the following formula:

If the spatial resource allocated to the first UE is the same as the spatial resource allocated to the second UE, if the non-orthogonal resource is used to implement NOMA transmission, and the first power β _{1 is} greater than or equal to the second power β ₂ , that is, the first UE Relative to the second UE being a remote user, the third SINR is calculated according to the following formula:

It should be noted that, for the NOMA transmission, if the first power β _{1 is} smaller than the second power β ₂ , that is, the first UE is a close-range user with respect to the second UE, the base station may according to the second CQI fed back by the user (step 602). Said) to determine a third SINR.

In another embodiment, when the base station again schedules the first UE, the third UE, and the fourth UE to be paired users, allocates spatial resources for the first UE, the third UE, and the fourth UE, and implements orthogonal MU-MIMO transmission. And non-orthogonal NOMA transmission. If the spatial resource allocated by the base station to the first UE is different from the spatial resource allocated to the third UE, that is, the MU-MIMO transmission is implemented between the first UE and the third UE; the space resource allocated by the base station to the first UE and allocated to the first The spatial resources of the four UEs are the same, that is, the NOMA transmission is implemented between the first UE and the fourth UE. When the first power is greater than the fourth power, that is, the first UE is a remote user compared to the fourth UE, the third SINR is calculated according to the following formula:

When the first power is less than or equal to the fourth power, that is, the first UE is a close-range user compared to the fourth UE. For example, UE1 is a close-range user compared to UE2, and the third SINR is calculated according to the following formula:

Where γ is the CQI adjustment factor, SINR ₁ is the first SINR, SINR ₂ is the second SINR, β ₁ is the first power, β ₃ is the third power, β ₄ is the fourth power, and N is the noise power.

As described in step 602, when the first UE feeds back the second CQI (denoted as CQI ₂ ) to the base station, the noise power N=1/CQI ₂ in the above formulas (8)-(11).

FIG. 7 is a schematic structural diagram of a user terminal 700 according to an embodiment of the present application, including:

The receiving module 710 is configured to receive a first downlink signal sent at a first moment and a second downlink signal sent at a second moment, where the second moment is after the first moment;

The estimation module 720 is configured to estimate a first channel quality value (such as a SINR) according to the first downlink data received by the receiving module 710, and estimate a second channel quality value when the base station performs multi-user transmission according to the second downlink data.

The calculating module 730 is configured to calculate a channel quality adjustment factor according to the first channel quality value and the second channel quality value obtained by the estimating module 720;

The feedback module 740 is configured to feed back a channel quality adjustment factor to the base station.

In an embodiment, the user terminal 700 further includes a setting module 750 for setting a plurality of candidate adjustment values in advance.

Correspondingly, the receiving module 710 is further configured to: obtain, by receiving the downlink control signaling, a first power allocated to the UE for performing multi-user transmission and a second power allocated to the second UE when the second downlink signal is sent by the base station.

In an embodiment, the calculating module 730 is configured to: calculate an interference power adjustment value according to the first channel quality value, the second channel quality value, the first power and the second power obtained by the receiving module 710; and determine the interference power adjustment value and the setting. The difference between each candidate adjustment value set by the module 750 is used as a channel quality adjustment factor for the candidate adjustment value corresponding to the smallest difference among the determined differences.

In an embodiment, the setting module 750 is configured to: calculate a probability distribution of the interference power adjustment value calculated before the second moment, and determine each interference power adjustment value pair according to the probability distribution. The probability of the probability is taken; the probability values are grouped, and the interference power adjustment values corresponding to the probability values in each group are averaged, and the obtained average value is determined as the candidate adjustment value.

In an embodiment, the estimating module 720 is configured to: obtain a parameter of the multi-user transmission from the second downlink signal, and estimate the second channel quality value by using the parameter of the multi-user transmission, where the multi-user transmits The parameters include: a power and precoding matrix allocated to the first UE, and power allocated to at least one of the plurality of UEs.

In an embodiment, the receiving module 710 is further configured to: receive radio resource control RRC signaling;

The feedback module 740 is further configured to: in response to the RRC signaling received by the receiving module 710, feed back a channel quality adjustment factor to the base station.

In an embodiment, the feedback module 740 is configured to: feed back a channel quality adjustment factor to the base station on a physical uplink control channel PUCCH or a physical uplink shared channel PUSCH.

FIG. 8 is a schematic structural diagram of a base station 800 according to an embodiment of the present invention, including:

The sending module 810 is configured to send the first downlink signal at the first moment, so that the first user equipment UE estimates the first channel quality value according to the first downlink signal, and sends the second downlink signal at the second moment, so that the first a UE estimates, according to the second downlink signal, a second channel quality value when the base station performs multi-user transmission, and calculates a channel quality adjustment factor according to the first channel quality value and the second channel quality value;

The receiving module 820 is configured to receive a channel quality adjustment factor fed back by the first UE.

The scheduling module 830 is configured to determine, according to the channel quality adjustment factor received by the receiving module 820, a modulation and coding mode MCS used by the downlink signal of the first UE.

In an embodiment, the second downlink signal may include: a power and precoding matrix allocated for the multi-user transmission to the first UE, and allocated to at least one second UE of the multiple UEs Power for multi-user transmission.

In an embodiment, the scheduling module 830 is configured to: allocate according to when sending the second downlink signal Calculating a third channel quality value (such as SINR) for the first power of the first UE, the second power allocated to the second UE, and the channel quality adjustment factor, and determining the MCS used by the third downlink signal according to the third channel quality value Wherein the third downlink signal is sent at a third time after the second time.

In an embodiment, the scheduling module 830 is configured to: allocate spatial resources for the first UE and the second UE; if the spatial resources allocated to the first UE and the spatial resources allocated to the second UE are different,

Calculating a third channel quality value; if the spatial resource allocated to the first UE and the spatial resource allocated to the second UE are the same, and the first power is greater than or equal to the second power,

Calculating a third channel quality value; wherein γ is a channel quality adjustment factor, β ₁ is a first power, β ₂ is a second power, and N is a noise power.

In an embodiment, the second UE includes a third UE and a fourth UE, and the second power includes a third power allocated to the third UE and a fourth power allocated to the fourth UE;

The scheduling module 830 is configured to allocate a spatial resource to the first UE, the third UE, and the fourth UE, where the spatial resource allocated to the first UE is different from the spatial resource allocated to the third UE, and the base station is allocated to the first UE. The spatial resource is the same as the spatial resource allocated to the fourth UE; when the first power is greater than the fourth power, according to

Calculating a third channel quality value; when the first power is less than or equal to the fourth power, according to

Calculating a third channel quality value; wherein γ is a channel quality adjustment factor, β ₁ is a first power, β ₃ is a third power, β ₄ is a fourth power, and N is a noise power.

In an embodiment, the base station 800 further includes:

The control module 840 is configured to calculate a block error rate according to the downlink hybrid automatic repeat request result. And sending a control instruction to the sending module 810 when the block error rate is greater than the preset threshold;

Correspondingly, the sending module 810 is further configured to: send the downlink control signaling according to the control instruction to notify the UE to feed back the channel quality adjustment factor.

According to the method for feeding back channel quality according to the embodiment of the present invention, the channel quality adjustment factor is calculated by the UE, and the channel quality adjustment factor is fed back to the base station, so that the base station can learn the channel quality deviation when the UE estimates the multi-user transmission. Further, the base station may determine, according to the channel quality adjustment factor, the MCS used when actually transmitting the downlink signal, thereby effectively improving the accuracy of the MCS in subsequent transmissions and improving the accuracy of the downlink scheduling. .

It should be noted that not all the steps and modules in the foregoing processes and the various structural diagrams are necessary, and some steps or modules may be omitted according to actual needs. The order of execution of each step is not fixed and can be adjusted as needed. The division of each module is only for the convenience of description of the functional division. In actual implementation, one module can be implemented by multiple modules, and the functions of multiple modules can also be implemented by the same module. These modules can be located in the same device. It can also be located in different devices. In addition, the use of "first" and "second" in the above description merely for the convenience of distinguishing two objects having the same meaning does not mean that there is a substantial difference.

The modules in each example can be implemented in hardware or in a hardware platform plus software.

The hardware can be implemented by specialized hardware or hardware that executes machine readable instructions. For example, the hardware can be a specially designed permanent circuit or logic device (such as a dedicated processor such as an FPGA or ASIC) for performing a particular operation. The hardware may also include programmable logic devices or circuits (such as including general purpose processors or other programmable processors) that are temporarily configured by software for performing particular operations.

The software includes machine readable instructions stored in a non-volatile storage medium. Thus, embodiments can also be embodied as software products. The machine readable instructions may cause an operating system or the like operating on a computer to perform some or all of the operations described herein. Non-volatile computer readable storage The medium may be inserted into a memory provided in an expansion board in the computer or written to a memory provided in an expansion unit connected to the computer. The CPU or the like installed on the expansion board or the expansion unit can perform part and all of the actual operations according to the instructions.

The non-transitory computer readable storage medium includes a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, a DVD-RW, a DVD+RW), and a magnetic tape. , non-volatile memory card and ROM. Alternatively, the program code can be downloaded from the server computer by the communication network.

In conclusion, the scope of the claims should not be limited to the embodiments in the examples described above, but the description should be construed as a whole and the broadest explanation.

Claims (20)

1. A method for feeding back a channel quality, where the method is applied to a first user equipment UE, including:

   Receiving a first downlink signal sent at a first moment, and estimating a first channel quality value according to the first downlink signal;

   Receiving a second downlink signal sent at a second moment after the first moment, and estimating, according to the second downlink signal, a second channel quality value when the base station performs multi-user transmission, where the multi-user transmission is utilized by the base station Downlink transmission of the same time-frequency resource to multiple UEs including the first UE;

   Calculating a channel quality adjustment factor according to the first channel quality value and the second channel quality value;

   And the channel quality adjustment factor is fed back to the base station, where the base station adjusts, according to the channel quality adjustment factor, the channel quality of the first UE when the base station estimates the multi-user transmission, and uses the adjusted channel quality to perform Multi-user transmission.
2. The method of claim 1 further comprising:

   Presetting multiple alternative adjustment values;

   Obtaining, by the base station, the first power allocated to the first UE and the second power allocated to the second UE when the second downlink signal is sent;

   The calculating a channel quality adjustment factor according to the first channel quality value and the second channel quality value includes:

   Calculating an interference power adjustment value according to the first channel quality value, the second channel quality value, the first power, and the second power;

   Determining a difference between the interference power adjustment value and each of the candidate adjustment values, and using the candidate adjustment value corresponding to the smallest difference among the determined differences as the channel quality adjustment factor.
3. The method according to claim 2, wherein the presetting a plurality of candidate adjustment values comprises:

   And calculating a probability distribution of the interference power adjustment value calculated before the second time, and determining, according to the probability distribution, a probability value corresponding to each interference power adjustment value;

   The probability values are grouped, and the interference power adjustment values corresponding to the probability values in each group are averaged, and the obtained average value is determined as the candidate adjustment value.
4. The method according to claim 2, wherein the calculating the interference power adjustment value according to the first channel quality value, the second channel quality value, the first power, and the second power comprises:

   Determining, according to the downlink control signaling, whether the spatial resource allocated by the base station to the first UE and the spatial resource allocated to the second UE are the same;

   If it is determined that the spatial resource allocated by the base station to the first UE and the spatial resource allocated to the second UE are different,

   

   Calculating the interference power adjustment value λ;

   If it is determined that the spatial resource allocated by the base station to the first UE is the same as the spatial resource allocated to the second UE, and the first power is greater than or equal to the second power,

   

   Calculating the interference power adjustment value λ;

   The SINR ₁ is the first channel quality value, the SINR ₂ is the second channel quality value, β ₁ is the first power, and β ₂ is the second power.
5. The method according to claim 2, wherein the second UE comprises a third UE and a fourth UE, and the second power comprises a third power allocated to the third UE and is allocated to the first Fourth power of four UEs;

   Determining, according to the first channel quality value, the second channel quality value, the first function The rate and the second power calculation interference power adjustment value include:

   Determining, according to the downlink control signaling, that the spatial resource allocated by the base station to the first UE is different from the spatial resource allocated to the third UE, and the space resource allocated by the base station to the first UE is allocated to the The spatial resources of the fourth UE are the same;

   When the first power is greater than the fourth power, according to

   

   Calculating the interference power adjustment value λ;

   When the first power is less than or equal to the fourth power, according to

   

   Calculating the interference power adjustment value λ;

   Wherein, SINR ₁ is the first channel quality value, SINR ₂ is the second channel quality value, β ₁ is the first power, β ₃ is the third power, and β ₄ is the fourth power. .
6. The method according to claim 1, wherein the estimating, by the second downlink signal, the second channel quality value when the base station performs multi-user transmission comprises:

   Obtaining a parameter of the multi-user transmission from the second downlink signal, and estimating the second channel quality value by using the parameter of the multi-user transmission.
7. The method according to claim 6, wherein the parameters of the multi-user transmission comprise: a power and a precoding matrix allocated to the first UE, and an allocation to at least one of the plurality of UEs The power of the UE.
8. The method according to any one of claims 1 to 7, further comprising: notifying the first UE to feed back the adjustment factor to the base station by radio resource control RRC signaling.
9. A user equipment (UE), comprising:

   a receiving module, configured to receive a first downlink signal sent at a first moment and a second downlink signal sent at a second moment after the first moment;

   An estimation module, configured to estimate a first channel quality value according to the first downlink signal, and estimate, according to the second downlink signal, a second channel quality value when the base station performs multi-user transmission, where the multi-user transmission is a base station Downlink transmission to multiple UEs including the first UE by using the same time-frequency resource;

   a calculation module, configured to calculate a channel quality adjustment factor according to the first channel quality value and the second channel quality value; and

   a feedback module, configured to feed back the channel quality adjustment factor to the base station, where the base station adjusts, according to the channel quality adjustment factor, the channel quality of the first UE when the base station estimates the multi-user transmission, and uses the adjusted The channel quality is for multi-user transmission.
10. The UE according to claim 9, further comprising:

    a setting module for presetting a plurality of alternative adjustment values;

    The receiving module is further configured to: obtain, by receiving the downlink control signaling, a first power that is allocated to the UE when the second downlink signal is sent by the base station, and a second power that is allocated to the second UE;

    The calculating module is configured to: calculate an interference power adjustment value according to the first channel quality value, the second channel quality value, the first power, and the second power; determine the interference power adjustment value and each The difference between the candidate adjustment values is used as the adjustment factor for the candidate adjustment value corresponding to the smallest difference among the determined differences.
11. The UE according to claim 10, wherein the setting module is configured to: calculate a probability distribution of the interference power adjustment value calculated before the second moment, and determine each interference power adjustment according to the probability distribution The probability corresponding to the value is taken; the probability values are grouped, and the interference power adjustment values corresponding to the probability values in each group are averaged, and the obtained average value is determined as the candidate adjustment value.
12. The UE according to claim 10, characterized in that

    The estimating module is configured to: obtain parameters of multi-user transmission from the second downlink signal, Estimating the second channel quality value by using the parameter of the multi-user transmission, where the parameters of the multi-user transmission include: a power and a precoding matrix allocated to the first UE, and are allocated to the multiple UEs The power of at least one second UE.
13. The UE according to any one of claims 9 to 12, wherein the receiving module is further configured to: receive radio resource control RRC signaling;

    The feedback module is further configured to: feed back the channel quality adjustment factor to the base station in response to the RRC signaling received by the receiving module.
14. The UE according to any one of claims 9 to 12, wherein the feedback module is configured to: feed back the channel quality adjustment factor to the physical uplink control channel PUCCH or physical uplink shared channel PUSCH Base station.
15. A base station, comprising:

    a sending module, configured to send a first downlink signal at a first moment, so that the first user equipment UE estimates a first signal interference noise ratio channel quality value according to the first downlink signal; after the first moment Sending, by the second time, the second downlink signal, so that the first UE estimates, according to the second downlink signal, a second channel quality value when the base station performs multi-user transmission, and according to the first channel quality value and The second channel quality value is used to calculate a channel quality indicator channel quality adjustment factor, where the multi-user transmission is a downlink transmission performed by the base station to the multiple UEs including the first UE by using the same time-frequency resource;

    a receiving module, configured to receive the channel quality adjustment factor fed back by the first UE;

    And a scheduling module, configured to determine, according to the channel quality adjustment factor, a modulation and coding mode MCS used by the downlink signal of the first UE when performing multi-user transmission.
16. The base station according to claim 15, wherein the scheduling module is configured to: according to the first power allocated to the first UE when transmitting the second downlink signal, and the second power allocated to the second UE And determining, by the channel quality adjustment factor, a third channel quality value, and determining, according to the third channel quality value, an MCS used by the third downlink signal, where The third downlink signal is sent at a third time after the second time.
17. The base station according to claim 16, wherein the scheduling module is configured to allocate a spatial resource to the first UE and the second UE; if the spatial resource allocated to the first UE is allocated to The spatial resources of the second UE are different, according to

    

    Calculating the third channel quality value; if the spatial resource allocated to the first UE and the spatial resource allocated to the second UE are the same, and the first power is greater than or equal to the second power, then according to

    

    Calculating the third channel quality value; wherein γ is the CQI adjustment factor, β ₁ is the first power, β ₂ is the second power, and N is noise power.
18. The base station according to claim 16, wherein the second UE comprises a third UE and a fourth UE, and the second power comprises a third power allocated to the third UE and is allocated to the first Fourth power of four UEs;

    The scheduling module is configured to allocate a spatial resource to the first UE, the third UE, and the fourth UE, where a spatial resource allocated to the first UE and a third UE are allocated The spatial resources are different, the spatial resources allocated by the base station to the first UE are the same as the spatial resources allocated to the fourth UE; when the first power is greater than the fourth power, according to

    

    Calculating the third channel quality value; when the first power is less than or equal to the fourth power, according to

    

    Calculating the third channel quality value; wherein, γ is the channel quality adjustment factor, β ₁ is the first power, β ₃ is the third power, β ₄ is the fourth power, and N is noise power.
19. The base station according to claim 15, wherein the second downlink signal comprises: a power and a precoding matrix allocated to the first UE, and is allocated to at least one second UE of the plurality of UEs Power.
20. The base station according to any one of claims 15 to 19, further comprising:

    a control module, configured to calculate a block error rate according to the downlink hybrid automatic repeat request result, and send a control instruction to the sending module when the block error rate is greater than a preset threshold;

    The sending module is further configured to: send, according to the control instruction, downlink control signaling, to notify the UE to feed back the channel quality adjustment factor.

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