JP5424222B2 - Method for precoding feedback, precoding feedback system, user equipment, and base station - Google Patents

Description

  The present invention relates to mobile communication technology, and more particularly, to a method for precoding feedback, a precoding feedback system, a user equipment (UE), and a base station (BS).

  The present invention was filed with the Chinese Patent Office on January 15, 2009 and is incorporated herein by reference in its entirety, titled "PRECODING FEEDBACK METHOD, PRECODING FEEDBACK SYSTEM, USER EQUIPMENT, AND BASE STATION". Claims Chinese patent application No. 200910076683.8.

Multiple-input multiple-output (MIMO) technology significantly improves the transmission rate of wireless communication systems without increasing bandwidth, which meets the requirements for high-speed data transmission services. In MIMO systems, precoding techniques are applied for the purpose of transmitting multiple data streams simultaneously to improve the reliability and transmission rate of the transmission link. This precoding technique is performed on the assumption that the sender knows all or part of the channel state information. Therefore, in most cases, the receiving side needs to feed back channel state information to the transmitting side. In a multi-user environment, random beamforming is a possible solution for reducing the amount of feedback. In a multi-user environment, random scheduling can take full advantage of multi-user diversity to improve system throughput. In general, the throughput increases as the amount of users increases. When the user amount is infinite, the functional relationship between the system throughput and the user amount is the optimal sum capacity scaling law. The optimal total capacity scaling law is N _t log log K, where N _t is the number of transmit antennas on the BS side and K is the user quantity. In the random beamforming solution, both the zero forcing (ZF) beamforming technique and the opportunistic orthogonal random beamforming (ORB) technique achieve the optimal total capacity scaling law.

  The inventor has found that at least the following problems exist in the prior art. That is, in the prior art, when the optimum total capacity scaling law needs to be achieved, the feedback overhead from the UE to the BS is large.

  Embodiments of the present invention provide a precoding feedback method, a precoding feedback system, a UE, and a BS to solve a large feedback overhead problem.

One embodiment of the present invention provides a precoding feedback method, where the method comprises:
Receiving a random beam information stream and determining an optimal set of beams according to a signal to interference to noise ratio (SINR) of the random beam information stream;
Obtaining a feedback threshold;
Feeding back information on at least one beam whose SINR is higher than a feedback threshold in the set of optimal beams.

One embodiment of the present invention provides a UE, where the UE
A receiving module configured to receive a random beam information stream and determine an optimal beam set according to the SINR of the random beam information stream;
An acquisition module configured to acquire a feedback threshold;
A feedback module connected to the receiving module and the acquisition module and configured to feed back information about at least one beam whose SINR is higher than a feedback threshold in the set of optimal beams.

One embodiment of the present invention provides a BS, where the BS
Determine a specific feedback threshold for each UE according to at least one parameter of SINR distribution function, total number of UEs, and environmental factors corresponding to each UE, or SINR distribution function, sum of UEs Get a specific feedback threshold for each UE according to the number and parameters of at least one of the environmental factors corresponding to each UE, preconfigured policies and specific feedback for each UE A calculation module configured to obtain a common feedback threshold according to the threshold;
A transmission module connected to the calculation module and configured to transmit the feedback threshold or common feedback threshold of each UE to the UE.

One embodiment of the invention provides a precoding feedback system, where the system comprises:
A BS configured to transmit a random beam information stream and threshold information to the UE;
Connected to the BS, obtains the optimum beam set according to the random beam information, obtains the feedback threshold according to the threshold information, and obtains the SINR from the feedback threshold in the optimum beam set. And a UE configured to feed back information on at least one beam.

  The foregoing technical solution reveals that in the embodiments of the present invention, when a threshold is set and the optimum beam SINR is higher than the threshold, the corresponding information is fed back. Thus, the feedback overhead is reduced in the random beam forming method.

2 is a schematic flowchart of a method according to the first embodiment of the present invention; FIG. 2 is a schematic structural diagram corresponding to the first embodiment of the present invention. 2 is a schematic flow diagram of a first method embodiment for obtaining a feedback threshold according to the first embodiment of the present invention; 4 is a schematic flowchart of a second method embodiment for obtaining a feedback threshold according to the first embodiment of the present invention; 4 is a schematic flowchart of a third method embodiment for obtaining a feedback threshold according to the first embodiment of the present invention; FIG. 6 is a curve diagram of an emulation relationship between a total user amount and a total capacity according to the first embodiment of the present invention. FIG. 6 is a curve diagram of an emulation relationship between SNR and total capacity according to the first embodiment of the present invention. FIG. 6 is a curve diagram of an emulation relationship between the total user amount and the feedback amount according to the first embodiment of the present invention. FIG. 6 is a schematic structural diagram of a UE according to the second embodiment of the present invention. FIG. 6 is a schematic structural diagram of a BS according to a third embodiment of the present invention. FIG. 6 is a schematic structural diagram of a precoding feedback system according to a fourth embodiment of the present invention.

  The technical solutions of the present invention are described below with reference to the accompanying drawings and embodiments.

  FIG. 1 is a schematic flowchart of a method according to the first embodiment of the present invention, and FIG. 2 is a schematic structural diagram corresponding to the first embodiment of the present invention. As shown in FIG. 1, in this embodiment, the method includes the following steps.

  Step 11: The UE receives a random beam information stream and determines an optimal beam set according to the SINR of the random beam information stream.

  Step 12: The UE obtains a feedback threshold.

  The order in which step 11 and step 12 are performed is not limited.

  Step 13: The UE feeds back information on at least one beam whose SINR is higher than the feedback threshold from the set of optimal beams.

  In this embodiment, a feedback threshold is obtained, and corresponding information is fed back when the optimal beam SINR of the UE is higher than the feedback threshold. In this way, feedback overhead is reduced.

  These steps are detailed below.

  Regarding step 11,

Taking the downlink multi-user MIMO system as an example, the number of transmitting antennas of BS is N _t, the number of UE system is K, the number of receive antennas of the respective UE is N _r.

As shown in FIG. 2, when random orthogonal beamforming is applied, BS follows N _t orthonormal vectors according to an isotropic distribution.

Is generated. At time t, φ _m (t) is multiplied by the _mth information stream x _m (t),

To obtain x _m (t) φ _m (t), m = 1, 2,... The transmitter is assumed to satisfy the average power constraint P, ie P, E [x ^H x] ≦ P. The information streams are statistically independent and all antennas have the same average transmit power

Have

Is the transmission signal-to-noise ratio (SNR) of each stream.

  The white Gaussian noise of each UE is

,

Represented by Therefore, the received signal vector for each UE is y _k ,

K = 1,..., K.

The case where different UEs experience different path loss and shadow fading is denoted as γ _k . The channel blocks H _k are independent and H _k εCN (0,1).

  The SINR of the mth information stream received by the kth UE is

K = 1,..., K, m = 1 _,.

When the number of receive antennas is 1, the beam with the largest SINR value forms the optimal beam set, and when the number of UE receive antennas is greater than 1, the N beams with larger SINR values are optimum Form a set of beams, where N ≦ N _r , where N _r is the number of receive antennas for each UE. In the following description, one optimal beam is selected, i.e., the light beam of the kth UE

The formula for calculating is

Assume that

  Regarding step 12,

  The feedback threshold is determined according to the SINR distribution function, the total number of UEs, or environmental factors corresponding to each UE, or any combination thereof, or further determined according to a preset policy. See the embodiments shown in FIGS. 3-5 for a detailed method of obtaining the threshold.

  FIG. 3 is a schematic flow diagram of a first method embodiment for obtaining a feedback threshold according to the first embodiment of the present invention. In this embodiment, the BS generates a threshold corresponding to each UE. As shown in FIG. 3, this embodiment includes the following steps.

Step 301: The BS provides specific feedback to each UE according to the total number of UEs (K), the estimation of different environmental factors (γ _k ) for each UE (such as path loss and shadow fading), and the SINR distribution function. The threshold value β (γ _k , K) is acquired.

  BS

Determines the threshold β (γ _k , K) according to the total number of UEs, ie K and γ _k , where F _k (β (γ _k , K)) is

Is a cumulative distribution function. Based on the above assumptions,

The cumulative distribution function of is

It is. According to the formula for calculating the feedback threshold, it is possible to specify different feedback thresholds for UEs with different path loss and shadow fading to improve fairness. For example, to improve system fairness, UEs with more severe path loss and shadow fading should be assigned a lower feedback threshold β (γ _k , K). The formula for calculating the feedback threshold is determined jointly with the total number of UEs, environmental factors, and SINR distribution function. In practice, the calculation formula may be different. For example, this formula relates only to one or more of the aforementioned parameters.

  Step 302: The BS sends a feedback threshold to the corresponding UE, and each UE gets its own feedback threshold.

  In this embodiment, the BS calculates a feedback threshold specific to each UE so that an appropriate threshold can be determined according to the different conditions of the UE.

  FIG. 4 is a schematic flow diagram of a second method embodiment for obtaining a feedback threshold according to the first embodiment of the present invention. In this embodiment, the BS generates a common feedback threshold for all UEs. As shown in FIG. 4, this embodiment includes the following steps.

  Step 401: This step is the same as step 301 in the previous embodiment.

  Step 402: The BS processes the feedback threshold specific to the UE according to a pre-configured policy to obtain a common feedback threshold, for example, feedback threshold to obtain an average value Calculate the average of the values.

  Step 403: The BS sends a common feedback threshold to each UE, and each UE obtains a common feedback threshold.

  In this embodiment, the BS calculates the same feedback threshold for all UEs so that the UE gets the appropriate common threshold.

  FIG. 5 is a schematic flow diagram of a third method embodiment for obtaining a feedback threshold according to the first embodiment of the present invention. In this embodiment, each UE generates its own feedback threshold. As shown in FIG. 5, this embodiment includes the following steps.

Step 501: The BS transmits the total number K of UEs and different environmental factors (γ _k ) of each UE to the corresponding UEs.

  Step 502: Each UE obtains its own feedback threshold according to the information transmitted by the BS and the SINR distribution function. That is, each UE

Determines the threshold β (γ _k , K) according to the total number of UEs K and γ _k , where F _k (β (γ _k , K)) is

Is a cumulative distribution function. Based on the above assumptions,

The cumulative distribution function of is

It is.

  In this embodiment, the UE calculates its own feedback threshold so that the BS burden is removed.

  Regarding step 13,

For example, when the number of antennas is 1 and the SNR of the optimal beam is higher than the feedback threshold, information about the optimal beam (such as the beam sequence number) is fed back, and the number of UE receive antennas is greater than 1. The SINR is compared to the feedback threshold for the beam in the set of optimal beams composed of N beams, and information about the beam whose SINR is higher than the feedback threshold in the N beams is obtained. In this case, N ≦ N _r , where N _r is the number of receiving antennas for each UE.

  Specifically, each UE k

Is compared to the feedback threshold.

UE k is the most appropriate beam (requires logN _t bits)

If not, UE k does not feed back any information.

Then, the set B _m of UEs that feed back the sequence number of the beam m received by the BS corresponding to each beam _m is

It is.

After obtaining the set of UEs, the BS may further optionally select the UE within each set B _m of the UE and schedule the UE to receive the information stream x _m corresponding to this beam. Is possible. To ensure that more than one beam is not assigned to one UE, Bm do not cross each other.

  After the above threshold-based feedback method is applied, the amount of feedback can be reduced based on obtaining an optimal sum capacity expansion law. The following explains this effect through an emulation diagram.

FIG. 6 is a curve diagram of an emulation relationship between the total user amount and the total capacity according to the first embodiment of the present invention. Basis for the emulation of this embodiment, the number of transmit antennas N _t is 4, the number N _r of receive antennas of the respective UE is 1, SNR (ρ) are those that it is 10 dB. The optimal precoding method is a Dirty-Paper Coding (DPC) method. Other precoding methods are optimal ZF precoding methods, opportunistic ORB precoding methods, and 1-bit feedback precoding methods, as well as 1-bit ORB methods according to embodiments of the present invention, which are covered in the prior art. . As shown in FIG. 6, when the total number of UEs is infinite, the direction of all curves tends to be consistent. That is, the precoding method according to this embodiment achieves the optimal total capacity expansion law. As shown in FIG. 6, when there are a small number of UEs, the curve of the precoding method of this embodiment of the present invention is similar to the optimal precoding curve. That is, even when the total number of UEs is low, the precoding method according to this embodiment of the present invention provides good performance.

FIG. 7 is a curve diagram of an emulation relationship between SNR and total capacity according to the first embodiment of the present invention. Basis for the emulation of this embodiment, the number N _t of transmit antennas is 4, the number N _r of receive antennas of the respective UE is 1, the total number K of the UE is that it is 100. FIG. 7 shows the direction of the respective curves and reveals that this embodiment can also achieve an optimal total capacity expansion law when the SNR changes.

FIG. 8 is a curve diagram of an emulation relationship between the total user amount and the feedback amount according to the first embodiment of the present invention. This curve from top to bottom reflects the relationship between the total number of UEs and the amount of feedback when the number of transmit antennas is 6, 5, 4, and 3, respectively. As shown in FIG. 8, when the total number of UEs is infinite, the extreme values of the curves are 61og6, 51og5, 41og4, and 3log3, respectively. That is, in this embodiment, the average feedback amount is N _t logN _t . In the prior art, no threshold-based feedback mechanism is applied, and the maximum feedback amount for each UE is min (N _t , N _r ) logN _t . The system-wide feedback bits can reach K min (N _t , N _r ) log N _t bits, and therefore the system-wide feedback overhead is excessively large. After this solution is applied, the average value of the total feedback overhead is N _t logN _t bits. Compared with the existing feedback amount of K min (N _t , N _r ) logN _t , the feedback amount can be greatly reduced.

  FIG. 9 is a schematic structural diagram of a UE according to the second embodiment of the present invention. The UE includes a reception module 91, an acquisition module 92, and a feedback module 93. The receiving module 91 is configured to receive the random beam information stream and determine an optimal beam set according to the SINR of each random beam information stream. The acquisition module 92 is configured to acquire a feedback threshold. The feedback module 93 is configured to feed back information about at least one beam whose SINR is higher than the feedback threshold acquired by the acquisition module 92 from the set of optimal beams acquired by the receiving module 91. The

  The acquisition module 92 is specifically configured to receive a feedback threshold sent by the BS corresponding to each UE, where the feedback threshold corresponding to the UE is a SINR distribution function, Determined by the BS according to the total number of UEs and at least one parameter of the environmental factors corresponding to the UE, or the acquisition module 92 is shared in detail by all UEs and transmitted by the BS A common feedback threshold configured to receive a common feedback threshold, in which case shared by all UEs, is the SINR distribution function, the total number of UEs, and the environmental factors corresponding to each UE Determined by the BS according to at least one parameter, or any combination thereof and a pre-set policy Or the acquisition module 92 is specifically transmitted by the BS so that the UE can determine a feedback threshold according to one of the parameters of the SINR distribution function, the total number of UEs, and environmental factors. Configured to receive the total number of UEs and environmental factors.

  In this embodiment, a threshold value is obtained and information about the optimal beam is fed back when the SINR of the optimal beam is higher than the threshold. In this way, the feedback amount is reduced.

  FIG. 10 is a schematic structural diagram of a BS according to the third embodiment of the present invention. This BS includes a calculation module 101 and a transmission module 102. The calculation module 101 is configured to calculate a feedback threshold, and the transmission module 102 is configured to transmit the feedback threshold obtained by the calculation module 101 to the UE. This UE feeds back information on at least one beam whose SINR is higher than the feedback threshold to the BS.

  In detail, the calculation module 101 determines a specific feedback threshold for each UE according to at least one parameter of the SINR distribution function, the total number of UEs, and the environmental factors corresponding to each UE. Or a preconfigured policy that obtains a specific feedback threshold for each UE according to parameters of at least one of: SINR distribution function, total number of UEs, and environmental factors corresponding to each UE And a common feedback threshold according to a feedback threshold specific to each UE.

  Further, in this embodiment, the BS receives the beam information transmitted by each UE, generates a set of UEs corresponding to each beam, and UEs corresponding to the same beam information in the set of UEs. And a selection module configured to transmit the beam data to the arbitrarily selected UE.

  In this embodiment, the feedback threshold is obtained by calculation and this feedback threshold is sent to the UE. Therefore, when the SINR of the optimum beam is higher than its feedback threshold, the UE feeds back corresponding information and the feedback amount is reduced.

  FIG. 11 is a schematic structural diagram of a precoding feedback system according to the fourth embodiment of the present invention. This system includes BS 111 and UE 112. The BS 111 is configured to transmit a random beam information stream and threshold information, and the UE 112 obtains a set of optimal beams according to the random beam information transmitted by the BS 111, and the threshold information transmitted by the BS 111. Is configured to obtain a feedback threshold and feed back information about at least one beam whose SINR is higher than the feedback threshold in the set of optimal beams.

  Specifically, this threshold information may be a feedback threshold corresponding to each UE, and BS 111 specifically describes the SINR distribution function, the total number of UEs, and the environment corresponding to each UE. The UE 112 is configured to determine a feedback threshold specific to each UE according to at least one parameter of the factors, and the UE 112 specifically determines a feedback threshold obtained by the BS 111 corresponding to the UE 112. Configured to receive.

  Alternatively, this threshold information may be a common feedback threshold for all UEs, and BS 111 specifically corresponds to the SINR distribution function, the total number of UEs, and each UE. Determine feedback thresholds specific to each UE according to at least one parameter of environmental factors, and provide common feedback according to pre-configured policies and feedback thresholds specific to each UE The UE 112 is configured to obtain a threshold, and in particular is configured to receive a common feedback threshold shared by all UEs and obtained by the BS 111.

  Alternatively, BS 111 is specifically configured to transmit the total number of UEs and environmental factors corresponding to each UE to the corresponding UE, and UE 112 is configured to have a SINR distribution function, a total number of UEs, and an environment. Determine its own feedback threshold according to at least one parameter of the factors.

  Furthermore, BS111 receives the beam information transmitted by each UE, generates a set of UEs corresponding to each beam, and arbitrarily selects UEs corresponding to the same beam information within the set of UEs. The beam data can be configured to be transmitted to the arbitrarily selected UE.

  In this embodiment, the feedback threshold is acquired in a different mode, and information about the optimal beam is fed back when the SINR of the optimal beam is higher than the feedback threshold. In this way, the feedback amount is reduced.

  Those skilled in the art should understand that all or part of the method steps of the embodiments of the present invention can be implemented by a program instructing relevant hardware. This program can be stored in a computer-readable storage medium. When the program executes, it executes the method steps of the embodiments of the present invention. This storage medium may be any medium that can store program codes, such as a ROM, RAM, magnetic disk, or optical disk.

  Finally, it should be noted that the above embodiments are provided only to illustrate the technical solutions of the present invention, but are not intended to limit the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. The present invention is intended to cover those modifications and variations provided that they fall within the scope of protection defined by the following claims or their equivalents. Intended.

91 Receiver module
92 Acquisition module
93 Feedback module
101 calculation module
102 Transmission module
111 BS
112 UE

Claims (12)

A precoding feedback method,
Receiving a random beam information stream and determining a set of optimal beams according to a signal to interference noise ratio (SINR) of the random beam information stream;
Obtaining a feedback threshold;
Feeding back information about at least one beam whose SINR is higher than the feedback threshold in the set of optimal beams;
With
Obtaining the feedback threshold comprises:
Receiving the feedback threshold transmitted by the base station (BS) corresponding to each user equipment (UE), or
Receiving a common feedback threshold sent by the BS for all UEs, or after receiving the total number of UEs sent by the BS and environmental factors corresponding to the UEs, the SINR distribution function the total number of the UE, and the environmental factors Accordingly, by the UE, determining the feedback threshold,
With
The feedback threshold value corresponding to each UE is, SINR distribution function, the total number of UE, and environmental factors corresponding to the UE thus being determined by the BS,
Said common feedback threshold, the SINR distribution function, the total number of the UE, and said environmental factor of each UE, according to the policy set in advance is determined by the BS,
The environmental factors include path loss and shadow fading,
The pre-configured policy includes a policy for processing a feedback threshold specific to each UE to obtain a common feedback threshold. The SINR distribution function, the total number of the UE, and the environmental factors Accordingly, the calculation formula for determining the feedback threshold,

Where β (γ _k , K) is the feedback threshold of the kth UE,
K is the total number of UEs,
N _r is the number of receiving antennas of the UE,
The expression of the function F _k is

Where
N _t is the number of transmit antennas of the BS,
ρ is the signal-to-noise ratio (SNR) of each transmit antenna,
The method according to claim 1, wherein γ _k is the environmental factor corresponding to the k th UE. The SINR distribution function, the total number of the UE, and said environmental factors corresponding to each UE, in accordance with the policy which the are preconfigured, the step of determining the common feedback threshold,
The SINR distribution function, the total number of the UE, and the environmental factors corresponding to the respective UE Therefore, acquiring a particular said feedback threshold to each UE,
Obtaining a common feedback threshold according to the preconfigured policy and the feedback threshold specific to each UE;
The method of claim 1, comprising: Determining an optimal set of beams according to the SINR of the random beam information stream;
When the number of receiving antennas of the UE is 1, determine the beam having the maximum SINR value as the set of optimal beams,
Determining N beams having a larger SINR value as the set of optimal beams when the number of receiving antennas of the UE is greater than 1,
N ≦ N _r
The method of claim 1, wherein N _r is the number of receiving antennas of each UE. User equipment (UE),
A receiving module configured to receive a random beam information stream and determine an optimal set of beams according to a signal to interference to noise ratio (SINR) of the random beam information stream;
An acquisition module configured to acquire a feedback threshold;
A feedback module connected to the receiving module and the acquisition module and configured to feed back information about at least one beam whose SINR is higher than the feedback threshold in the set of optimal beams;
With
The acquisition module is configured to receive a feedback threshold transmitted by a base station (BS) corresponding to the UE; or
The acquisition module is configured to receive a common feedback threshold transmitted by the BS for all UEs, or the acquisition module includes a total number of UEs transmitted by the BS and the It receives environmental factors corresponding to the UE, SINR distribution function, the total number of the UE, and the environmental factors Accordingly, being configured to determine said feedback threshold,
The feedback threshold corresponding to the UE, SINR distribution function, the total number of UE, and environmental factors corresponding to the UE thus being determined by the BS,
Said common feedback threshold, the SINR distribution function, the total number of the UE, and said environmental factors corresponding to each UE, in accordance with the policy set in advance is determined by the BS,
The environmental factors include path loss and shadow fading,
The user equipment (UE), wherein the preset policy includes a policy for processing a feedback threshold specific to each UE to obtain a common feedback threshold. A base station (BS),
Signal to interference noise ratio (SINR) distribution function, the total number of a user equipment (UE), a and hence the environmental factors corresponding to each UE, or to determine the specific feedback threshold to each UE, or the SINR distribution function, the total number of the UE, and the particular the environmental factors to each UE Therefore, to obtain the feedback threshold value corresponding to each UE, and policies that are set in advance, respectively A calculation module configured to obtain a common feedback threshold according to the feedback threshold specific to the UE;
A transmission module connected to the calculation module and configured to transmit the feedback threshold of each UE or the common feedback threshold to the UE;
With
The environmental factors include path loss and shadow fading,
The preset policy includes a policy for processing a feedback threshold specific to each UE to obtain a common feedback threshold. The computing module, the SINR distribution function, the total number of the UE, and thus the environmental factors, the official calculation to determine certain of the feedback threshold to each UE,

Where β (γ _k , K) is the feedback threshold of the kth UE,
K is the total number of UEs,
N _r is the number of receiving antennas of the UE,
The expression of the function F _k is

Where
N _t is the number of transmit antennas of the BS,
ρ is the signal-to-noise ratio (SNR) of each transmit antenna,
7. The BS according to claim 6, wherein γ _k is an environmental factor corresponding to the k-th UE.   Receive beam information transmitted by each UE, generate a set of specific UEs for each beam, arbitrarily select UEs corresponding to the same beam information within the set of UEs, and 7. The BS of claim 6, further comprising a selection module configured to transmit to the arbitrarily selected UE. A precoding feedback system,
A base station (BS) configured to transmit a random beam information stream and threshold information to a user equipment (UE);
Connected to the BS, acquires an optimal beam set according to the random beam information, acquires a feedback threshold according to the threshold information, and a signal-to-interference noise ratio (SINR) is within the optimal beam set. The UE configured to feed back information on at least one beam that is higher than the feedback threshold of
With
The threshold information transmitted by the BS is the feedback threshold specific to each UE;
The BS is, SINR distribution function, the total number of UE, and thus the environmental factors corresponding to each UE, is configured to determine a particular said feedback threshold to each UE,
The UE is configured to receive the feedback threshold obtained by the BS corresponding to the UE;
The precoding feedback system according to claim 1, wherein the environmental factors include path loss and shadow fading. The threshold information transmitted by the BS is a common feedback threshold;
The BS is, SINR distribution function, the total number of UE, and environmental factors corresponding to the respective UE Therefore, to determine the specific the feedback threshold in each of the UE, the policy set in advance, Configured to obtain the common feedback threshold according to the feedback threshold specific to each UE;
The UE is configured to receive the common feedback threshold;
The method of claim 9, wherein the preset policy includes a policy for processing a feedback threshold specific to each UE to obtain a common feedback threshold. system. The threshold information transmitted by the BS is the total number of UEs and environmental factors corresponding to each UE;
The BS is configured to transmit the total number of UEs and the environmental factors corresponding to each UE to the corresponding UEs;
The UE, SINR distribution function, the total number of UE, and environmental factors Accordingly, the system according to claim 9, characterized in that it is configured to determine its own feedback threshold.   The BS receives the beam transmitted by each UE, generates a set of UEs corresponding to each beam, arbitrarily selects UEs corresponding to the same beam information within the set of UEs, and 10. The system of claim 9, further configured to transmit beam data to the arbitrarily selected UE.

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