WO2011160387A1

WO2011160387A1 - Method and base station for scheduling resources of multiple input multiple output

Info

Publication number: WO2011160387A1
Application number: PCT/CN2010/078841
Authority: WO
Inventors: 宁迪浩; 朱登魁; 梁婷; 李子荣
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-06-21
Filing date: 2010-11-17
Publication date: 2011-12-29
Also published as: CN102291834A; CN102291834B

Abstract

A method and base station for scheduling resources of multiple input multiple output are disclosed by the present invention, wherein, the method comprises that the base station selects the user equipments suitable for a MU scheduling mode and the user equipments suitable for a SU scheduling mode from multiple user equipments; the base station respectively selects a user equipment with the highest priority from the user equipments of the MU scheduling mode and the SU scheduling mode as a main user equipment; the priorities of the two selected main user equipments are compared; when the priority of the main user equipment of the MU scheduling mode is not lower than the priority of the main user equipment of the SU scheduling mode, the base station determines whether there are any user equipments that have the most approximate orthogonal channel characteristics between the user equipments and the main user equipment in the user equipments suitable for the MU scheduling mode except the main user equipment; if there are such user equipments, the resource blocks to be scheduled are used to transmit data between the base station and the user equipment with the highest priority of these user equipments. The present invention solves the problem of low resource utilization rate.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a resource scheduling method and a base station for multiple input and multiple output. BACKGROUND Multiple Input Multiple Output (MIMO) technology is a major breakthrough in smart antenna technology in the field of wireless mobile communications. The technology can multiply the capacity and spectrum utilization of the communication system without increasing the bandwidth; multipath reception can be used to mitigate multipath fading; and the common channel interference can be effectively eliminated, and the reliability of the channel can be improved. Reducing the bit error rate is a key technology that must be used in a new generation of mobile communication systems. At present, in the mature or near-mature 3G/B3G wireless communication system, the base station side and the terminal side are widely used by configuring multiple sets of transmit/receive antennas in combination with MIMO signal processing. This method is called single user. MIMO (SU-MIMO), because its essence is still the point-to-point transmission data between the base station (BS) and the terminal (MS). In the recent wireless communication ten-party standard, for example, 3GPP's LTE-A and IEEE802.16m ten-party standards support multi-user MIMO (MU-MIMO). The channel from the base station to the user terminal is referred to as the downlink channel. Compared with downlink single-user MIMO, the downlink MU-MIMO 4 bar has a point-to-point channel extension between one BS and one MS as one BS and multiple

The point-to-multipoint channel between the MSs, through the difference in spatial characteristics in the base station side antenna array caused by the spatially dispersed users, the base station can simultaneously communicate with multiple users in the same frequency channel.

The MU-MIMO system should be designed with more obvious factors than SU-MIMO. The base station needs to consider the difference of their channel space characteristics when determining the number of users to use MU-MIMO transmission, that is, whether it is orthogonal or close. Orthogonal, their respective channel quality parameters SINR, and the user's own scheduling priority, etc. Therefore, for MU-MIMO systems, the design of the scheduling algorithm is very important. Especially in the B3G/4G system, Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Division Multiple Access (OFDMA) technologies are widely used. In an OFDMA system, multi-user access is achieved by providing a partially available subcarrier for each user. In this way, different users from different frequencies transmit data on different frequencies. For a wireless communication system based on OFDM or OFDMA, the radio resource mapping is mainly based on the frame structure of the wireless communication system, the frame structure describes the control structure of the radio resources in the time domain, and the frame structure divides the radio resources into different levels in the time domain. Units such as Superframe, Frame, Subframe, and Symbol. In the time-frequency two-dimensional structure, a resource block including X subcarriers consecutive in frequency and Y symbols consecutive in the time domain is defined as a physical resource unit (PRU), and includes N consecutive cells. The resource block of the PRU is a subband (Subband). Therefore, for a communication system using OFDM+MIMO, in the scheduling process, a certain logical resource unit needs to be allocated to a certain user to transmit information at a certain time, and the logical resource is a physical resource unit on the frequency. A certain mapping, that is, the above-mentioned subcarriers, symbols, subbands, and the like are mapped to frequencies, since the MIMO system allocates one resource to a plurality of users. Therefore, when the same physical resource is allocated to multiple users, the scheduling process implemented by different scheduling methods is different, and the resource utilization rate is also different. However, the inventors found that the resource utilization rate of the current resource scheduling scheme is not high. SUMMARY OF THE INVENTION The main object of the present invention is to provide a resource scheduling method and a base station for multiple input and multiple output, so as to at least solve the problem that the resource scheduling solution cannot allocate the same physical resource to multiple users reasonably and the resource utilization rate is low. According to an aspect of the present invention, a resource scheduling method for multiple input and multiple output is provided, including: a base station selecting a user equipment suitable for a multi-user MU scheduling mode from a plurality of user equipments, and not including the plurality of user equipments The selected user equipment is used as the user equipment of the single-user SU scheduling mode. The base station selects the user equipment with the highest priority as the primary user equipment of the MU scheduling mode in the user equipment of the MU scheduling mode, and is in the SU scheduling mode. The user equipment with the highest priority is selected as the primary user equipment of the SU scheduling mode; the priority of the two selected primary user equipments is compared; the priority of the primary user equipment selected in the MU scheduling mode is not low. When the priority of the primary user equipment is selected in the foregoing SU scheduling mode, the base station determines whether the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode has the MU scheduling The channel characteristics between the primary user equipments of the mode are closest to the orthogonal user equipment; In, the base station with the above-described channel characteristics closest The user equipment with the highest priority among the nearly orthogonal user equipments uses the resource blocks to be scheduled to transmit data. According to another aspect of the present invention, a base station is provided, including: a mode determining unit, a selecting unit, a channel comparing unit, a device determining unit, and a transmitting unit, wherein the mode determining unit is configured to select from a plurality of user equipments. a user equipment suitable for the multi-user MU scheduling mode, and the unselected user equipment of the plurality of user equipments as the user equipment of the single-user SU scheduling mode; the selecting unit is used in the user equipment of the MU scheduling mode Selecting the user equipment with the highest priority as the primary user equipment of the MU scheduling mode, and selecting the user equipment with the highest priority among the user equipments in the SU scheduling mode as the primary user equipment of the SU scheduling mode; Comparing the priority of the two primary user equipments selected as described above; the device determining unit, the priority of the primary user equipment selected in the MU scheduling mode is not lower than the primary user equipment selected in the foregoing SU scheduling mode. Determining the above-mentioned user equipment suitable for the MU scheduling mode Whether the user equipment in the user equipment other than the primary user equipment of the MU scheduling mode is the most orthogonal to the channel characteristics of the primary user equipment in the MU scheduling mode; the foregoing transmission unit is configured to exist in the presence of the MU When the channel feature between the primary user equipments in the scheduling mode is closest to the orthogonal user equipment, the user equipment with the highest priority among the user equipments with the highest priority in the channel element closest to the above-mentioned channel characteristics uses the resource blocks to be scheduled to transmit data. In the present invention, by selecting a primary user equipment in a suitable MU scheduling mode and a user equipment for communicating with the primary user equipment that meets the conditions, the base station can utilize a user equipment whose resource block is closest to the channel characteristics and orthogonal to the channel. Data is transferred between them to achieve reasonable scheduling of resource blocks. The resource block may be various wireless parameters, such as bandwidth, symbols, frequency points, time slots, sub-bands, sub-carriers, PRUs, and the like. In addition, in the process of determining that the channel characteristics are closest to the orthogonal user equipment, there are also multiple user equipment selection methods, which improves resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 1 is a schematic diagram of an OFDM system architecture according to an embodiment of the present invention; FIG. 2 is a flowchart of Embodiment 1 of the present invention; FIG. 3 is a flowchart of the present invention; The flowchart of the second embodiment; Figure 4 is a flow chart of a third embodiment of the present invention; Figure 5 is a flow chart of a fourth embodiment of the present invention; Figure 6 is a flow chart of a fifth embodiment of the present invention Figure 7 is a block diagram of a sixth embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. Referring to the structure diagram shown in FIG. 1, for an OFDM system of MU-MIMO, K user data, that is, user data 1 to user data K are processed by MU-MIMO, and then performed between the base station and each user data. Data interaction. During the data process, the base station needs to determine the channel quality established between each user equipment, thereby selecting different transmission modes, and reasonably scheduling the resource blocks to transmit data to each user equipment. The following is a detailed description of the flow chart of the first embodiment shown in FIG. 2. Referring to FIG. 2, the multiple input multiple output resource scheduling method includes the following steps: S11. The base station selects a multi-user MU scheduling mode from multiple user equipments. a user equipment, and the unselected user equipment of the plurality of user equipments is used as a user equipment of a single-user SU scheduling mode;

512, the base station selects the user equipment with the highest priority as the primary user equipment in the MU scheduling mode, and selects the user equipment with the highest priority among the user equipments in the SU scheduling mode as the SU in the user equipment in the MU scheduling mode. Primary user equipment in scheduling mode;

513. Compare priorities of the two selected primary user equipments.

514, when the priority of the primary user equipment selected in the MU scheduling mode is not lower than the priority of the primary user equipment selected in the foregoing SU scheduling mode, the base station determines, in addition to the foregoing, the user equipment suitable for the MU scheduling mode. Whether there is a user equipment in the user equipment other than the primary user equipment in the MU scheduling mode that is closest to the channel characteristics of the primary user equipment in the MU scheduling mode;

S15. If yes, the base station is superior to the user equipment that is closest to the channel characteristics. The highest priority user equipment uses the resource blocks to be scheduled to transmit data. In the preferred embodiment, by selecting a primary user equipment in a suitable MU scheduling mode and a user equipment for communicating with the primary user equipment that meets the conditions, the base station can utilize a resource block to be orthogonal to the channel characteristics. Data is transmitted between user equipments, thereby achieving reasonable scheduling of resource blocks. Preferably, the resource block may be various wireless parameters such as bandwidth, symbols, frequency points, time slots, sub-bands, sub-carriers, PRUs, and the like. Preferably, the foregoing base station determines whether the channel characteristics between the user equipments other than the primary user equipment of the MU scheduling mode and the primary user equipment of the MU scheduling mode are orthogonal to each other in the user equipment suitable for the MU scheduling mode. The step of the user equipment includes: prioritizing the user equipments other than the user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode; according to the order of priority from high to low or low to high It is determined whether the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode is the user equipment that is closest to the channel feature between the primary user equipment of the MU scheduling mode. Preferably, if the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode does not have the user equipment that is closest to the channel feature between the primary user equipment of the MU scheduling mode And the method further includes: transmitting, by the foregoing base station, the resource block with the highest priority among the user equipments with the highest priority in the SU scheduling mode. Preferably, after comparing the priorities of the two selected primary user equipments, the method further includes: when the priority of the primary user equipment selected in the MU scheduling mode is lower than the priority of the primary user equipment selected in the foregoing SU scheduling mode. In the case of the level, the base station and the user equipment with the highest priority in the SU scheduling mode use the resource block to be scheduled to transmit data. Preferably, the base station selects the user equipment with the highest priority as the primary user equipment of the MU scheduling mode, and selects the user equipment with the highest priority among the user equipments in the SU scheduling mode as the user equipment in the MU scheduling mode. The step of the primary user equipment in the SU scheduling mode includes: calculating, by using a proportional fairness formula, a priority of each user equipment in the MU scheduling mode and a priority of each user equipment in the foregoing SU scheduling mode; selecting in the MU scheduling mode The user equipment with the highest priority, and the user equipment with the highest priority is selected in the foregoing SU scheduling mode; wherein the above proportional fairness formula includes: In the formula, the current priority of the user equipment k is represented, indicating the current channel quality CQI of the user equipment k; the weighted average of the historical scheduling capacity of the user equipment k before the current scheduling; t is the sequence number of each scheduling. Preferably, the step of determining whether there is a user equipment that is closest to the channel characteristics of the primary user equipment in the MU scheduling mode is: the foregoing base station obtains, in the foregoing user equipment suitable for the MU scheduling mode, a master of the MU scheduling mode. Channel characteristic data of the user equipment other than the user equipment; using the channel characteristic data of each user equipment obtained as described above, respectively, and calculating channel characteristic data of the primary user equipment in the MU scheduling mode to obtain corresponding chord distances and projections The norm distance, or the Ferrobinius distance; the distances calculated according to the above are sorted from large to small, and the two user equipments corresponding to the largest distance are selected. Preferably, the step of obtaining the channel feature data of the user equipment other than the primary user equipment of the MU scheduling mode in the foregoing user equipment suitable for the MU scheduling mode includes at least one of the following: the foregoing base station obtains the user suitable for the MU scheduling mode. The encoded codebook index PMI information fed back by the user equipment other than the primary user equipment, the base station calculates corresponding channel characteristic data by using each PMI information; the base station passes the foregoing user equipment suitable for the MU scheduling mode, except the above The uplink measurement pilot signal sent by the user equipment other than the primary user equipment in the MU scheduling mode obtains a corresponding channel response coefficient matrix H, and performs singular value decomposition on the channel coefficient matrix H to obtain a right singularity corresponding to the non-zero singular value The vector is used as the channel characteristic data; or the base station obtains the corresponding channel matrix by using the uplink measurement pilot signal sent by the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode.

H, obtaining an autocorrelation matrix ^^ through the above-mentioned channel matrix H, performing eigenvalue decomposition, and obtaining a feature vector corresponding to the non-zero eigenvalue as the channel characteristic data. Preferably, after selecting the two user equipments corresponding to the maximum distance, the method further includes: if it is determined that the distance between the two selected user equipments is less than a threshold, the base station and the user with the highest priority among the foregoing SU scheduling modes. Data is transmitted between devices using resources blocks to be scheduled. Preferably, the step of selecting a user equipment suitable for the multi-user MU scheduling mode from the user equipment includes: calculating an average value of CQIs of each sub-band of each of the user equipments; when the average value is greater than a threshold, The user equipment corresponding to the average value is suitable for the above MU scheduling mode. User equipment. The following is explained in detail by various embodiments. Referring to the flowchart of the second embodiment shown in FIG. 3, the method includes:

S21: Determine, according to the user feedback CQI parameter, the MU scheduling user set, and the SU scheduling user set. The CQI information fed back by the user or other similar information representing the channel quality, such as the packet loss rate, the bit error rate, the load of the channel, etc., the division of the scheduling set for all users, determining the multi-user MU scheduling user set Q, single The user SU schedules the user set P. When determining the scheduling mode of each user equipment, the following methods may be used: For example, when one sector of the base station BS has a total of N users to be scheduled, ^UU N, each household feeds back the sub-band information of all κ sub-bands: Includes: Channel quality information

CQI ₂ CQI _K , precoding codebook index, PMI2 ΡΜΙκ , _B S obtains historical scheduling information ^λι , ^λ2 ... ^{λΛί of} M users and scheduling information of resource blocks to be scheduled before scheduling. First, calculate the broadband CQI information of one user: _C ~QBuCQI-CQI, where C^/

¹ 2 N i is the average of the K Subband subband CQIs of the user. Compare C^/ / ₂ ... ^ with the set threshold ί3⁄4/ ^. The size of _ω , when greater than the threshold, determines that the user is suitable for the MU scheduling mode; when less than the threshold, determines that the user is suitable for the SU scheduling mode, thereby determining the SU scheduling user set and the MU scheduling user set Q User, ie

Ρ = {U _s Us2- . Usr}, Q = {U _mh Una...Urr^.

S22: Scheduling the resource block loop to find the next scheduled resource block. S23: Prioritize the users in the SU scheduling set and the MU scheduling set on the current scheduling resource block according to the user feedback CQI and the historical scheduling information, so that the users with the highest priority among the two sets are the primary users of the respective sets. . For all currently selected scheduled resource blocks, calculate all user priorities in the SU scheduling set. Level, find the highest priority u _Sk , let _έ be the primary user of the P set and the priority is pijJ _Sk ); calculate the priority of all users in the MU scheduling set Q, find the highest priority, and let U _mk be The primary user of the Q set with a priority of p( J _mk ). There are many algorithms that can be used to calculate a user's priority, for example: Using a proportional fair algorithm, ie using the following formula: r _k (t)

Where, the user k is the current priority, indicating the current channel quality of the user, ^(t) = F(\ _k (t - \)) , which is the weighted average of the historical scheduling capacity of the user _k updated after each scheduling. , that is, the weighted average of all the scheduling capacities before t-1 times. t is the scheduling number. S24: Determine whether the priority of the primary user of the MU set is greater than the priority of the primary user of the SU set. If it is greater, S25 is performed; if it is less, S26 is performed. Compare the priority with ^Umk . If ^P(Umk ) > ^{P(U k} ), then ^Umk is the current scheduled user, and step S25 is performed; otherwise, ^ is the current scheduled user, step S26 is performed, and the resource block is used to schedule the SU mode set. user. S26: Using the data of the user with the highest priority among the resource block SU mode set, go to the step

S30.

S25: According to the PMI fed back by the user, seek a suitable pairing user of the primary user in the MU scheduling user set. In the MU scheduling mode, the channel feature parameters of each user equipment in the MU scheduling mode need to be obtained: the corresponding channel characteristic parameters, such as the channel subspace right singular vector F, can be found through the PMI fed back by the user; in addition, the user can also receive the user. In the manner of reciprocity feedback, the transmitted uplink measurement pilot signal is a dish ding symbol. The base station obtains the coefficients of the channel matrix H by measuring the received dish ding symbol, and performs singular value decomposition on the channel matrix H (SVD, Singular vector Decomposition ) Decomposes to obtain a right singular vector corresponding to a non-zero singular value to obtain channel characteristic data. The self-covariance matrix HH can also be obtained through the channel matrix H, and eigenvalue decomposition can be performed to obtain a feature vector corresponding to the non-zero eigenvalue as the channel feature data. The paired users that are suitable for the primary user are determined by the channel characteristic parameters, and the PMI information or other information representing the spatial characteristics of the channel is fed back according to the user, such as indexing by PMI, by calculating the channel matrix, and the like. Calculate channel space characteristic information of each user and primary user except the primary user in the MU scheduling set Q: f F _mk , F _m ,

Find the maximum value f(F _mk , F _m] ) = max(f(F _mi ,F lf(F _mt , 1⁄2 ₂ )■■■/ (F _mi ,F _nin )) (may also be the minimum value, according to /(·) depends on the algorithm), where " represents the user's channel space feature information, such as the right singular vector F. For / (·) can usually be calculated by a defined subspace (vector) distance, you can use The following way: Example ^ mouth: string huge away

1/2

[M F1 F2 IF"

Where, ^ is the input channel space feature vector, II'IIF represents the F norm, F ^h represents the conjugate symmetric matrix of the matrix F, M is the set constant, ^d ^rd represents the chord distance; or, the projection is two Number distance d proiiF

Where ^ and ^ ² are the input channel space eigenvectors, ΙΙ'Ι^ denotes the F norm, F ^H denotes the conjugate symmetric matrix of the matrix F, A _mm 04) denotes the non-zero minimum singular value of the matrix A, and d denotes Shadow two norm distance, or Frobenius-Study distance

= arccos|detCF^F ₂ )|etc., where det(^) represents the determinant of matrix A. Preferably, the chord distance based on the PMI feedback is used as a basis for determining whether the user channel is orthogonal or close to orthogonal. The larger the chord distance, the closer the two user channel subspaces are to the orthogonal, which is more advantageous for pairing. The definition of the chord distance is:

Where C _u represents the chord distance of the user ui and U2, where ^ and ^ are the input channel space feature vectors, and are column vectors. Ll'l denotes the F norm and F denotes the conjugate symmetric matrix of the matrix F. After the execution of step S25, step S27 is performed.

S27: Determine whether the channel characteristic information between the two users meets the requirement of the MU scheduling mode. Preferably, if yes, go to S28; otherwise, go to S29. According to the comparison of the maximum value f F _mt , F _mj ) and the set threshold or calculate the reference value f _threshoM , if f F _mk , F _m ≥ f _threshold (greater than or less than the threshold according to the (·) algorithm) , indicating that the two users meet the requirements of the MU mode, continue to execute S28, otherwise execute S29.

S28: The two selected users are scheduled by the MU mode, and the process goes to step S30. During the scheduling process, the selected two users are scheduled using the MU scheduling mode.

S29, determining whether the user determined in S25 is the last user in the MU set, if not, deleting the user from the MU set, and returning to S25; otherwise, scheduling the primary user with the highest priority in the SU mode, preferably , you can perform the same steps as S26, and then go to S30. If the resource block can schedule more than two users, that is, the orthogonality of the channel characteristics of any two of the multiple users meets the threshold requirement, the resource block can be used to schedule each user. S30: Update the resource block information to be scheduled, and update the scheduling information of the user. After each execution of the scheduling, the resource block information to be scheduled needs to be executed, that is, the remaining schedulable resources are counted; and the scheduling information of the history of the scheduled users is updated.

S31: Scheduling resource block loop. The resource blocks to be scheduled are arranged to find the resource block to be scheduled next time.

S32: Output the scheduling result, and save the scheduling information. After the local scheduling ends, the information of the scheduling is updated and saved, which is convenient for subsequent resource blocks to be used. The above embodiment describes the flow of the method of the present invention in detail. For the present invention, various situations may be present in the application process, which will be described in detail below through various embodiments. Referring to the flowchart of the third embodiment shown in FIG. 4, the method includes:

S41: Determine, according to the user feedback CQI parameter, the MU scheduling user set, and the SU scheduling user set. According to the CQI information fed back by the user or other similar information representing the channel quality, such as the packet loss rate, the bit error rate, the load of the channel, etc., the scheduling set of all users is divided, and the multi-user MU scheduling user set Q, single is determined. The user SU scheduling user set P can determine the scheduling mode of each user equipment in the following manner: For example, when one sector of the base station BS has a total of N users to be scheduled, ^UU N, each household feeds back all K children. Subband information of the band: includes: channel quality information ^^ι CQI ₂ CQI _K , precoding codebook index, PMI2 ΡΜΙκ, _B S obtains historical scheduling information ^λι , ^λ2 ... ^λΛί and Scheduled resource block scheduling information.

CQ CQI CQI φ ΐ First, calculate the CQI information of the scorpion's scorpion: ^ ¹ , ² . . . w , where; is the average of the K subband subband CQI of the user. Comparing, ... ^CQI N and setting the threshold ^Q ¹ threshold size, when greater than the threshold, determining that the user is suitable for the MU scheduling mode; when less than the threshold, determining that the user is suitable for the SU scheduling mode, Thereby determining the SU scheduling user set P and the MU scheduling user set Q, ie

P = {U _s Us2- . Usr} , Q = {U _mh Una...Urr^. S42: Scheduling the resource block loop to find the next scheduled resource block.

S43: prior to the user feedback CQI and the historical scheduling information, prioritize the users in the SU scheduling set and the MU scheduling set on the current scheduling resource block, so that the users with the highest priority among the two sets are respectively the respective sets. Primary user. For the currently selected resource block scheduling, calculating all users set P SU scheduling priority, to identify the highest priority ^{of Usk,} so ^έ p is the primary user and set priority ^{p (XJsk);} calculated MU The priority of all users in the set Q is scheduled, and the highest priority ^ ^{έ is found} , so that ^Umk is the primary user of the Q set and the priority is ^{P( )} . There are many algorithms that can be used to calculate the user's priority, for example: Using the proportional fair algorithm (pro=portional fair), ie using the following formula:

^k ) where, represents the current priority of user k, indicating the current channel quality of the user, ^k(t) = F(X _k (t - l)) , which is the historical schedule of user _k updated after each scheduling The weighted average of the capacity, that is, the weighted average of all the scheduled capacity before t-1 times. t is the scheduling number.

S44: Determine that the MU set primary user priority is greater than or equal to the SU set primary user priority. Compare the priority of U _Sk with 17}^, compare iH _P (U ) ≥ P(U _Sk ), and let U be the current user.

S45: Determine that the channel characteristic information between the two users meets the requirement of the MU scheduling mode. The chord distance based on PMI feedback is used as the basis for judging whether the user channel is orthogonal or close to orthogonal. The larger the chord distance, the closer the two user channel subspaces are to the orthogonal, which is more advantageous for pairing. The definition of the chord distance is:

Where L _u represents the chord distance of the user ui and U2, and ^F1 and ^F 2 are the precoding vectors corresponding to the precoding index (PMI) fed back by the users U1 and U2, respectively, and are column vectors. According to the comparison of the maximum values ^f , ^{F, Fmj} ) and the set threshold or calculate the reference value ^f threshold, if f(F _mt , F _{mj ≥} f _threshold (greater than or less than the threshold according to the / (·) algorithm ), the two users meet the requirements of the MU mode. S46: The two users selected by the MU mode are scheduled. During the scheduling process, the selected two users are scheduled by the MU scheduling mode.

S47: Update the resource block information to be scheduled, and update the scheduling information of the user. After each execution of the scheduling, the resource block information to be scheduled needs to be executed, that is, the remaining schedulable resources are counted; and the scheduling information of the history of the scheduled users is updated. S48: Scheduling resource block loops. The resource blocks to be scheduled are arranged to find the resource block to be scheduled next time.

S49: Output the scheduling result, and save the scheduling information. After the local scheduling ends, the information of the current scheduling is updated and saved, which is convenient for subsequent resource block scheduling. The third embodiment above illustrates the process of scheduling users in the MU mode after priority discrimination. In this process, if the user in the MU scheduling mode has a lower priority than the user in the SU scheduling mode, or MU If the user in the scheduling mode cannot meet the requirements, the resource block to be scheduled is used for the user with the highest priority in the SU mode. The following is explained by the fourth embodiment. Referring to the flowchart of FIG. 5, the method includes:

S51: Determine, according to the user feedback CQI parameter, the MU scheduling user set, and the SU scheduling user set. According to the CQI information fed back by the user or other similar information representing the channel quality, such as the packet loss rate, the bit error rate, the load of the channel, etc., the scheduling set of all users is divided, and the multi-user MU scheduling user set Q, single is determined. The user SU schedules the user set P. When determining the scheduling mode of each user equipment, the following methods may be used: For example, when a sector of the base station BS has a total of N users to be scheduled, ^UU N, each household feeds back subband information of all K subbands: The method includes: channel quality information ^^ι CQI ₂ CQI _K , precoding codebook index, PMI2 ΡΜΙκ, _B S obtains historical scheduling information ^λι , ^λ2 ... ^{λΛί of the} M users and scheduling information of the resource block to be scheduled before scheduling .

^山,] ^ _λ ^ . , , ^ CQ CQI CQI φ ΐ First, calculate the CQI information of the corpse of the corpse: ^ ¹ , ² . . . w , where; K subband subband CQI of the user average value.

Compare, ^CQ ... ^CQI N with the set threshold CQ ¹ th _res h. The size of the _ld is greater than the threshold, determining that the user is suitable for the MU scheduling mode; when less than the threshold, determining that the user is suitable for the SU scheduling mode, thereby determining the SU scheduling user set P and the MU scheduling user set Q User, ie

P = {U _s Us2- . Usr} , Q = {U _mh Una...Urr^.

S52: Scheduling the resource block loop to find the next scheduled resource block.

S53: prior to the user feedback CQI and the historical scheduling information, prioritize the users in the SU scheduling set and the MU scheduling set on the current scheduling resource block, so that the users with the highest priority among the two sets are respectively the respective sets. Primary user. For the currently selected resource block scheduling, scheduling set SU calculated for all users in Ρ priority, to identify the highest priority ^{of Usk,} so ^έ p is the primary user and set priority ^{p (JJsk);} Calculate the priority of all users in the MU scheduling set Q, and find the highest priority " ^f , let" ^mk be the primary user of the Q set and the priority is ^P() . There are many algorithms that can be used to calculate a user's priority, for example: Using a proportional fair algorithm, ie using the following formula: r _k (t)

Where, the user k is the current priority, indicating the current channel quality of the user, ^(t) = F(\ _k (t - \)) , which is the weighted average of the historical scheduling capacity of the user _k updated after each scheduling. , that is, the weighted average of all the scheduling capacities before t-1 times. t is the scheduling number.

S54: Determine that the MU set primary user priority is less than the SU set primary user priority. Compare the priority of _{3⁄4 έ} with u and compare p(U ) < p{U _Sk ) to make _{3⁄4 当前} the current scheduled user.

S55 : Call the user with the highest priority in the SU mode. The user with the highest priority in the SU mode is called with the resource block to be called.

S56: Update the resource block information to be scheduled, and update the scheduling information of the user. After each execution of the scheduling, the resource block information to be scheduled needs to be executed, that is, the remaining schedulable resources are counted; and the scheduling information of the history of the scheduled users is updated.

S57: Scheduling resource block loop. The resource blocks to be scheduled are arranged to find the resource block to be scheduled next time. S58: Output the scheduling result, and save the scheduling information. After the local scheduling ends, the information of the current scheduling is updated and saved, which is convenient for subsequent resource block scheduling. In this embodiment, the scheduled resource block can be selected according to the priority of the user, in the following In the fifth embodiment, when the priority of the MU scheduling mode is high, but the threshold requirement is not met, the resource block to be scheduled may also be used for the user with the highest priority among the SU modes. Referring to the schematic diagram shown in FIG. 6, the following steps are included;

S61: Determine, according to the user feedback CQI parameter, the MU scheduling user set, and the SU scheduling user set. According to the CQI information fed back by the user or other similar information representing the channel quality, such as the packet loss rate, the bit error rate, the load of the channel, etc., the scheduling set of all users is divided, and the multi-user MU scheduling user set Q, single is determined. The user SU schedules the user set P. When determining the scheduling mode of each user equipment, the following methods may be used: For example, when a sector of the base station BS has a total of N users to be scheduled, ^UU N, each household feeds back subband information of all K subbands: The method includes: channel quality information ^^ι CQI ₂ CQI _K , precoding codebook index, PMI2 ΡΜΙκ, _B S obtains historical scheduling information ^λι , ^{λ λΝ of} M users and scheduling information of resource blocks to be scheduled before scheduling.

COI

First, calculate the broadband CQI information of one user: the average value of the CQI for the subband of the user.

Compare ^ ¹ , ^ ² . . . N with the set threshold CQ ¹ _thresh . The size of the _ld is greater than the threshold, determining that the user is suitable for the MU scheduling mode; when less than the threshold, determining that the user is suitable for the SU scheduling mode, thereby determining the SU scheduling user set P and the MU scheduling user set Q User, ie

P = {U _sh Us2- . Usr} , Q = {U _mh Una...Urr^.

S62: Scheduling the resource block loop to find the next scheduled resource block.

S63: prior to the user feedback CQI and the historical scheduling information, prioritize the users in the SU scheduling set and the MU scheduling set on the current scheduling resource block, so that the users with the highest priority among the two sets are respectively the respective sets. Primary user. Calculate all user priorities in the SU scheduling set P for the currently selected scheduled resource block Level, find the highest priority, let "the primary user of the P set and the priority is "*"; calculate the priority of all users in the MU scheduling set Q, find the highest priority ^ ^έ , make ^Umk Q The primary user of the collection has a priority of ^{P( )} . There are many algorithms that can be used to calculate the user's priority, for example: Using the proportional fair algorithm, ie using the following formula: r _k (t)

In the formula, it represents the current priority of user k, indicating the current channel quality of the user, X _k (t) = F(\ _k (t - \)), which is the weighting of the historical scheduling capacity of user k updated after each scheduling. On average, all of the scheduled capacity before t-1 is weighted averaged. t is the scheduling number.

S64: Determine that the priority of the primary user of the MU set is greater than or equal to the priority of the primary user of the SU set. Compare the priority of ^Usk and ^Umk , compare ≥ and let ^ be the current scheduled user.

S65: Determine that the channel characteristic information between the two users does not meet the requirement of the MU scheduling mode. The projection two norm distance based on PMI feedback is used as the basis for judging whether the user channel is orthogonal or close to orthogonal. The larger the chord distance, the closer the two user channel subspaces are to the orthogonal, which is more advantageous for pairing. The definition of the projection two norm distance is:

According to the comparison of the maximum value ^mj and the set threshold value or the calculation of the reference value ^f threshold n" ^{, Fmj} < f threshold , it indicates that the two users do not meet the requirements of the MU mode.

S66: Call the user with the highest priority in the SU mode. The user with the highest priority in the SU mode is called with the resource block to be called. S67: Update the resource block information to be scheduled, and update the scheduling information of the user. After each execution of the scheduling, the resource block information to be scheduled needs to be executed, that is, the remaining schedulable resources are counted; and the scheduling information of the history of the scheduled users is updated.

S68: Scheduling resource block loop. The resource blocks to be scheduled are arranged to find the resource block to be scheduled next time.

S69: Output the scheduling result, and save the scheduling information. After the local scheduling ends, the information of the current scheduling is updated and saved, which is convenient for subsequent resource block scheduling. In each of the above embodiments, in the process of selecting a user to be scheduled, it is assumed that a certain sector of the BS has a total of N users to be scheduled, and ² ... ^ the i-th user only feeds back the sub-bands for the optimal M sub-bands. Information: ^CQI , ^CQI ^ . . . ^CQI w , PMI , PMh PMh _M , BS Obtain N user history scheduling information ^λι , ^λ2 ... ^λΛί and resource block scheduling information before scheduling. When scheduling a resource block, if the base station finds that there is no feedback information from any user on its subband. At this time, only one user is randomly selected from the SU scheduling set to be scheduled on this resource block to complete the scheduling. Various embodiments of the present invention have been described in detail above, and the method of the present invention can be integrated into a wireless transceiver, such as a base station controller, in the form of various device modules. A preferred apparatus embodiment 6 of the present invention is shown below. Referring to the schematic diagram shown in FIG. 7, a base station includes the following units: a mode determining unit 71, a selecting unit 72, a channel comparing unit 73, a device determining unit 74, and a transmitting unit. 75. The mode determining unit 71 is configured to select a user equipment that is suitable for the multi-user MU scheduling mode from the plurality of user equipments, and use the unselected user equipment of the multiple user equipments as the single-user SU scheduling mode. a user equipment; the selecting unit 72 is configured to select a user equipment with the highest priority as the primary user equipment in the MU scheduling mode, and select the user equipment in the SU scheduling mode in the user equipment in the MU scheduling mode. The user equipment with the highest priority is used as the primary user of the SU scheduling mode. The channel comparison unit 73 is configured to compare the priorities of the two selected primary user equipments; the priority of the primary user equipment selected by the device determining unit 74 in the MU scheduling mode is not low. Determining whether the user equipment other than the primary user equipment of the MU scheduling mode exists in the user equipment that is suitable for the MU scheduling mode, when the priority of the primary user equipment is selected in the SU scheduling mode. The channel characteristics between the primary user equipments of the MU scheduling mode are closest to the orthogonal user equipment; the transmission unit 75 is configured to: when there is a user equipment whose channel characteristics are closest to the orthogonal between the primary user equipments of the MU scheduling mode And using the resource block to be scheduled to transmit data between the user equipments with the highest priority among the user equipments that are the most orthogonal to the channel characteristics. In the preferred embodiment, by selecting a primary user equipment in a suitable MU scheduling mode and a user equipment for communicating with the primary user equipment that meets the conditions, the base station can utilize a resource block to be orthogonal to the channel characteristics. Data is transmitted between user equipments, thereby achieving reasonable scheduling of resource blocks. Preferably, the resource block may be various wireless parameters such as bandwidth, symbols, frequency points, time slots, sub-bands, sub-carriers, PRUs, and the like. Preferably, the device determining unit 74 includes: a sorting module, configured to perform priority ordering on user equipments other than the primary user equipment in the MU scheduling mode of the user equipment that is suitable for the MU scheduling mode; Determining whether the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode is the same as the one according to the priority from high to low or low to high. The channel characteristics between the primary user equipments of the MU scheduling mode are closest to the orthogonal user equipment. Preferably, if the user equipment in the MU scheduling mode is the user equipment other than the primary user equipment in the MU scheduling mode, the channel characteristics between the user equipments in the MU scheduling mode and the primary user equipment in the MU scheduling mode are not orthogonal to each other. The user equipment, the transmission unit 75 is further configured to use the resource block to be scheduled to transmit data between the user equipment with the highest priority in the SU scheduling mode. Preferably, after comparing the priorities of the two selected primary user equipments, the method further includes: when the priority of the primary user equipment selected in the MU scheduling mode is lower than the priority of the primary user equipment selected in the foregoing SU scheduling mode. The transmission unit 75 is also used for the SU scheduling mode described above. Data is transmitted between the highest priority user equipments using the resource blocks to be scheduled. Preferably, the selecting unit 72 selects the user equipment with the highest priority as the primary user equipment of the MU scheduling mode in the user equipment of the MU scheduling mode, and selects the user equipment with the highest priority among the user equipments in the SU scheduling mode. The step of the primary user equipment in the SU scheduling mode includes: calculating, by using a proportional fairness formula, a priority of each user equipment in the MU scheduling mode and a priority of each user equipment in the foregoing SU scheduling mode; in the foregoing MU scheduling mode The user equipment with the highest priority is selected, and the user equipment with the highest priority is selected in the foregoing SU scheduling mode; wherein the above proportional fairness formula includes:

In the formula, the current priority of the user equipment k is represented, indicating the current channel quality CQI of the user equipment k; the weighted average of the historical scheduling capacity of the user equipment k before the current scheduling; t is the sequence number of each scheduling. Preferably, the channel comparison unit 73 includes: a feature data operation unit, configured to obtain channel feature data of the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode; And a cross-analysis unit, configured to calculate, by using the obtained channel characteristic data of each user equipment, channel characteristic data of the primary user equipment in the MU scheduling mode, to obtain respective chord distances, projection two norm distances, Or a Ferrobinius distance; a sorting unit, configured to sort the respective distances according to the operation from large to small, and select two user equipments corresponding to the largest value of the largest distance. Preferably, the channel comparison unit 73 obtains channel characteristic data of the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode by using one of the following steps: the base station obtains the foregoing suitable MU scheduling mode. The encoded codebook index PMI information fed back by the user equipment other than the primary user equipment in the user equipment, the base station calculates corresponding channel characteristic data by using each PMI information; the base station is removed by the user equipment suitable for the MU scheduling mode. The uplink measurement pilot signal sent by the user equipment other than the primary user equipment in the MU scheduling mode obtains a corresponding channel response coefficient matrix H, and performs singular value decomposition on the channel coefficient matrix H to obtain a right corresponding to the non-zero singular value. The singular vector is used as the channel characteristic data; or the base station obtains the corresponding channel moment by using the uplink measurement pilot signal sent by the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode. The array H obtains an auto-covariance matrix H through the above-mentioned channel matrix H, performs eigenvalue decomposition, and obtains a feature vector corresponding to the non-zero eigenvalue as the channel characteristic data. Preferably, after the two user equipments corresponding to the maximum value are selected, the method further includes: if it is determined that the distance between the two selected user equipments is less than a threshold, the transmission unit 75 and the SU scheduling mode have the highest priority. The user equipment uses the resource block to be scheduled to transmit data. Preferably, the mode determining unit 71 selects a user equipment suitable for the multi-user MU scheduling mode from the user equipment by: calculating an average value of CQIs of each sub-band of each of the user equipments; when the average value is greater than a threshold, The user equipment corresponding to the average value is used as a user equipment suitable for the MU scheduling mode described above. Preferably, the foregoing base station is used for resource scheduling of multiple input and multiple outputs. The structure of each unit in a base station of the present invention is described in detail above. For the present invention, not only this form, but also other structures may be used to implement the method of the present invention. The base station in the embodiment of the present invention may be implemented. The method flow in each of the above embodiments is not described here. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present invention are intended to be included within the scope of the present invention.

Claims

A multi-input and multi-output resource scheduling method, comprising:

The base station selects a user equipment suitable for the multi-user MU scheduling mode from the plurality of user equipments, and uses the unselected user equipments of the plurality of user equipments as the single-user SU scheduling mode user equipment;

The base station selects the user equipment with the highest priority as the primary user equipment in the MU scheduling mode, and selects the user equipment with the highest priority among the user equipments in the SU scheduling mode as the user equipment in the MU scheduling mode. a primary user equipment of the SU scheduling mode;

Comparing priorities of the selected two primary user equipments;

When the priority of the primary user equipment selected in the MU scheduling mode is not lower than the priority of the primary user equipment selected in the SU scheduling mode, the base station determines that the user equipment is suitable for the MU scheduling mode. Whether there is a user equipment that is closest to the channel feature between the user equipments of the MU scheduling mode except the primary user equipment of the MU scheduling mode;

If present, the base station transmits data using the resource block to be scheduled between the user equipments with the highest priority among the user equipments whose channel characteristics are closest to each other.

The method according to claim 1, wherein the base station determines whether the user equipment other than the primary user equipment of the MU scheduling mode exists in the user equipment suitable for the MU scheduling mode The steps of the channel characteristics of the primary user equipment in the MU scheduling mode that are closest to the orthogonal user equipment include:

Prioritizing the user equipments other than the user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode;

Determining whether the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode is in the scheduling mode with the MU according to the priority from high to low or low to high The channel characteristics between the primary user equipments are closest to the orthogonal user equipment. The method according to claim 1 or 2, wherein, if the user equipment in the MU scheduling mode is not in the user equipment other than the primary user equipment in the MU scheduling mode, the MU scheduling mode does not exist. The channel characteristics of the primary user equipment are the closest to the orthogonal user equipment, and also include:

The base station uses the resource block to be scheduled to transmit data between the user equipment with the highest priority in the SU scheduling mode. The method according to claim 1, wherein after comparing the priorities of the selected two primary user devices, the method further includes:

When the priority of the primary user equipment selected in the MU scheduling mode is lower than the priority of the primary user equipment selected in the SU scheduling mode, the base station and the SU scheduling mode have the highest priority. The user equipment uses the resource block to be scheduled to transmit data. The method according to claim 1, wherein the base station selects the user equipment with the highest priority as the primary user equipment of the MU scheduling mode, and schedules the SU in the user equipment in the MU scheduling mode. The step of selecting the user equipment with the highest priority among the user equipments of the mode as the primary user equipment of the SU scheduling mode includes:

Calculating, by using a proportional fairness formula, a priority of each user equipment in the MU scheduling mode and a priority of each user equipment in the SU scheduling mode;

Selecting the user equipment with the highest priority in the MU scheduling mode, and selecting the user equipment with the highest priority in the SU scheduling mode;

Wherein, the proportional fairness formula includes:

Where A(t) represents the current priority of the user equipment k, (0 represents the current channel quality CQI of the user equipment k; is the weighted average of the historical scheduling capacity of the user equipment k prior to the current scheduling; t is each time The sequence number of the schedule.

The method of claim 1, wherein the step of determining whether there is a user equipment that is closest to the channel characteristics of the primary user equipment in the MU scheduling mode comprises:

Obtaining, by the base station, channel feature data of the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment that is suitable for the MU scheduling mode;

Performing, by using the obtained channel characteristic data of each user equipment, channel characteristic data of the primary user equipment in the MU scheduling mode, respectively, obtaining respective chord distances, projection two norm distances, or Ferro Niños Distance

The distances calculated according to the above are sorted from large to small, and the two user equipments corresponding to the distance with the largest value are selected.

The method of claim 6, wherein the step of obtaining the channel feature data of the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode is at least The base station includes: the base station obtains coded codebook index PMI information fed back by the user equipment other than the primary user equipment in the user equipment that is suitable for the MU scheduling mode, where the base station uses each PMI information to calculate corresponding Channel characteristic data;

Obtaining, by the base station, an uplink measurement pilot signal sent by a user equipment other than the primary user equipment of the MU scheduling mode in the user equipment that is suitable for the MU scheduling mode, and obtaining a corresponding channel response coefficient matrix H, by using the The channel coefficient matrix H performs singular value decomposition to obtain a right singular vector corresponding to the non-zero singular value as the channel characteristic data; or the base station passes the user equipment suitable for the MU scheduling mode except the MU scheduling mode. An uplink measurement pilot signal sent by a user equipment other than the user equipment, obtains a corresponding channel matrix H, obtains an auto-covariance matrix Η ^Η通过 through the channel matrix H, performs eigenvalue decomposition, and obtains a feature corresponding to the non-zero eigenvalue A vector as the channel characteristic data.

The method according to claim 6, wherein after selecting the two user equipments corresponding to the distance with the largest value, the method further includes:

If it is determined that the distance between the two selected user equipments is less than a threshold, the base station and the user equipment with the highest priority in the SU scheduling mode use the resource blocks to be scheduled to transmit data.

The method according to claim 1, wherein the step of selecting a user equipment suitable for the multi-user MU scheduling mode from the user equipment comprises:

Calculating an average value of CQIs of each sub-band of each of the user equipments;

When the average value is greater than the threshold, the user equipment corresponding to the average value is used as the user equipment suitable for the MU scheduling mode.

A base station, comprising: a mode determining unit, a selecting unit, a channel comparing unit, a device determining unit, and a transmitting unit, where

The mode determining unit is configured to select a user equipment that is suitable for the multi-user MU scheduling mode from the plurality of user equipments, and use the unselected user equipment of the multiple user equipments as the user equipment of the single-user SU scheduling mode. ;

The selecting unit is configured to select, as the primary user equipment of the MU scheduling mode, the user equipment with the highest priority among the user equipments in the MU scheduling mode, and select the highest priority among the user equipments in the SU scheduling mode. User equipment as the primary user equipment of the SU scheduling mode;

The channel comparison unit is configured to compare the priorities of the two selected primary user equipments; the device determining unit is configured to: the priority of the primary user equipment selected in the MU scheduling mode is not lower than Determining whether there is a scheduling with the MU in the user equipment other than the primary user equipment in the MU scheduling mode of the user equipment that is suitable for the MU scheduling mode, when the priority of the primary user equipment is selected in the SU scheduling mode. The channel characteristics of the primary user equipment in the mode are closest to the orthogonal user equipment;

The transmitting unit is configured to: when there is a user equipment whose channel feature is closest to the orthogonality between the primary user equipments of the MU scheduling mode, the user with the highest priority among the user equipments that are closest to the channel characteristics Data is transmitted between devices using resources blocks to be scheduled.

The base station according to claim 10, wherein the device determining unit comprises: a sorting module, configured to: in the user equipment suitable for the MU scheduling mode, other than the primary user equipment in the MU scheduling mode User equipment for prioritization;

a determining module, configured to judge, in order of priority from high to low or low to high, whether the user equipment other than the primary user equipment of the MU scheduling mode in the user equipment suitable for the MU scheduling mode is The channel characteristics between the primary user equipments of the MU scheduling mode are closest to the orthogonal user equipment.

The base station according to claim 11, wherein if the user equipment other than the primary user equipment of the MU scheduling mode is not present in the user equipment suitable for the MU scheduling mode, the MU scheduling mode does not exist. The channel characteristics of the primary user equipment are the closest to the orthogonal user equipment, and the transmission unit is further configured to use the resource block to be scheduled to transmit data between the user equipment with the highest priority in the SU scheduling mode.

The base station according to claim 10, wherein the channel comparison unit comprises: a feature data operation unit, configured to obtain a primary user device of the user equipment suitable for the MU scheduling mode except the MU scheduling mode Channel characteristic data of the user equipment; the orthogonal analysis unit is configured to calculate, by using the obtained channel characteristic data of each user equipment, channel characteristic data of the primary user equipment in the MU scheduling mode, respectively, to obtain corresponding Each chord distance, projected two-norm distance, or Ferrobinius distance;

The sorting unit is configured to sort the respective distances according to the operation from large to small, and select two user equipments corresponding to the distance with the largest value.