WO2011075978A1

WO2011075978A1 - Method and system for switching between beam forming and mimo beam forming

Info

Publication number: WO2011075978A1
Application number: PCT/CN2010/073461
Authority: WO
Inventors: 肖华华; 朱登魁; 鲁照华; 刘锟; 张万帅; 陈刚
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-12-22
Filing date: 2010-06-02
Publication date: 2011-06-30
Also published as: CN102104406B; CN102104406A

Abstract

A method and system for switching between beam forming and multiple input multiple output(MIMO) beam forming are disclosed in the invention. The method includes that: during the decision period, a data transmission mode, which is adapted to the current receiving end, is selected from multiple antenna data transmission modes based on a switching algorithm, wherein the multiple antenna transmission modes include beam forming and MIMO beam forming; the selected data transmitting mode is used to transmit data. The invention maximizes the performance of the system.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to communication or otherwise, and relates to a beam forming (Beam Forming, BF for short) and a multi-input multi-input A method and system for switching Multiple Input Multiple Output Beam Forming (MIMO + BF for short). Background technique

BF is based on the principle of adaptive antenna. The antenna array is used to weight each antenna unit by advanced signal processing algorithms to make the array align with the useful signal direction in real time, and form a zero point in the interference direction to suppress the interference signal. The signal-to-noise ratio improves system performance and increases system coverage. 1 is a schematic diagram of a BF transmitting end according to the related art. As shown in FIG. 1, after a channel is encoded and modulated, it is multiplied by a weight Wi on a corresponding antenna, where i=l, 2, ... , Tx, Tx is the actual physical antenna of the transmitting end. After beamforming, multiple antennas are equivalent to a virtual antenna. MIMO is a communication system in which a plurality of antennas are respectively disposed at a transmitting end and a receiving end, and is mainly divided into two types. When there are multiple antennas on the transmitting end or the receiving end, and the data sets sent by the respective transmitting antennas are the same, the receiving end combines the signals obtained by multiple branches to improve the reliability of the link. We will classify this type of MIMO. Technology is called spatial diversity. In addition, when multiple antennas exist at the same time on the transmitting end and the receiving end, since the MIMO channel is equivalent to multiple parallel channels, multiple data streams can be simultaneously transmitted in parallel, and the data transmission rate is improved. Technology is called spatial multiplexing. MIMO + BF is a technology that combines the advantages of both MIMO and beamforming. It divides the antenna at the transmitting end into multiple sub-arrays. Each sub-array is beamformed to form a beam, which is equivalent to a virtual antenna. The virtual antennas between the multiple sub-arrays constitute a MIMO system. It can suppress the interference signal like beamforming, and can improve the reliability or transmission rate of the link like MIMO. 2 is a schematic diagram of a MIMO + BF transmitting end according to the related art, and a schematic diagram of a transmitting end of a MIMO beamforming is shown in FIG. 2. The system divides the antenna into n sub-arrays, each of which contains a Tx root physical antenna. Of course, the sub-array can contain a different number of physical antennas. Each sub-array performs beamforming processing to form a beam, that is, a virtual antenna. A plurality of virtual antennas form a MIMO system. However, sometimes there is a case where the equivalent channel correlation between the virtual antennas is high, and the signal of one virtual antenna may flood the signal of another virtual antenna, and thus is not suitable for MIMO. At this time, all physical antennas do one beam to transmit data, which can improve the signal-to-noise ratio. Therefore, there is currently no solution to the BF and MIMO + BF adaptive switching problem. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a method and system for switching BF and MIMO + BF to at least solve the above problems. According to an aspect of the present invention, a method for switching beamforming and MIMO beamforming is provided, including: selecting, during a decision period, a data transmission mode suitable for a current receiving end from a multi-antenna data transmission mode according to a handover algorithm, Wherein, the multi-antenna transmission mode includes beamforming and MIMO beamforming; and the data is transmitted using the selected data transmission mode. Preferably, the handover algorithm comprises: Step 1: Initializing a previous channel correlation matrix R _Pre , the period of the handover decision is a T frame; Step 2, calculating, according to the time sequence of the frame, the current receiving end is used in the frame structure for calculation Channel correlation matrix on the carrier set of the channel correlation matrix: R id n , where N represents the number of carriers included in the set of carriers, is the channel coefficient matrix of the first subcarrier in the set of carriers, and x, 3⁄4c are respectively sent The number of transmitting antennas at the terminal and the receiving end, the superscript ^ is the conjugate transposition of the matrix; in step 3, the previous channel correlation matrix is updated to ^ _δ = λΚ^+(1-;σ;^, which is constant and 0≤ ≤1 Step 4, repeat steps 2 to 3 until the end of the cycle; Step 5, calculate the correlation constant of the previous channel correlation matrix: 3⁄4 = /(R _Pre ), where / is the processing function for the correlation matrix R _Pre . , obtain H _73⁄4 (t) by at least one of the following methods: The uplink channel coefficient, where the uplink channel includes at least one of the following: a data channel for transmitting the uplink service by the receiving end, an uplink feedback channel for the receiving end to feed back information to the transmitting end, a channel corresponding to the Sounding signal sent by the receiving end to the transmitting end, and receiving The pilot channel included in the data sent by the transmitting end to the transmitting end; the receiving end feeds back the channel coefficient corresponding to the receiving end to the transmitting end through the uplink feedback channel. Preferably, / includes one of the following: f(R _Pre ) = -^ , muscle J = H,

HR

u = n ), where is the maximum eigenvalue and the minimum eigenvalue of the matrix R _Pre , respectively, and tr(R _Pre ) represents the trace of the matrix R _Pre . Preferably, selecting a data transmission mode suitable for the current receiving end according to the switching algorithm comprises: selecting a data transmission mode suitable for the current receiving end according to the relationship between the threshold value Tr and the configured threshold value. Preferably, selecting a data transmission mode suitable for the current receiving end according to the relationship with the configured threshold value Tr includes: if ≤ Tr , and the receiving end previously uses the beamforming data transmission mode, the receiving end continues to use beamforming; If ≤ 7 and the receiving end uses the data transmission mode of MIMO beamforming before, the receiving end switches to beamforming; if 3⁄4 > 7 and the receiving end uses beamforming data transmission mode before, the receiving end switches to MIMO beamforming; if i > Tr , and the receiving end previously used MIMO beamforming data transmission mode, the receiving end continues to use MIMO beamforming. According to another aspect of the present invention, a beamforming and multiple input multiple output MIMO beamforming switching system is provided, including: a mode decision module, configured to determine, according to a handover algorithm, a transmit mode suitable for use by a receiving end as a beam Shape or MIMO beamforming; a MIMO beamforming transmitting module, configured to perform MIMO encoding on the data, and multiply the MIMO encoded data by a weight component of the corresponding antenna; and transmit a beam shaping module, The data is multiplied by the weight component of the corresponding antenna, and then sent; the switching module is configured to use the beamforming transmitting module or the MIMO beamforming transmitting module to send data according to the decision result of the mode determining module. Preferably, the handover algorithm comprises: Step 1: Initializing a previous channel correlation matrix R _Pre , the period of the handover decision is a T frame; Step 2, in the period of time, according to the time sequence of the frame, calculating the current receiving end in the frame structure Channel correlation matrix on the set of carriers for calculating the channel correlation matrix:

R

Where N represents the number of carriers included in the set of carriers, Is the channel coefficient matrix of the first subcarrier in the carrier set, x, 3⁄4c are the number of transmitting antennas at the transmitting end and the receiving end, respectively, and the superscript ^ is a conjugate transposition for the matrix; Step 3, the previous channel correlation matrix is updated to ^ _δ = λΚ^+(1-;σ;^, is constant and 0≤ ≤1; Step 4, repeat steps 2 to 3 until the end of the cycle; Step 5, calculate the correlation constant of the previous channel correlation matrix: 3i = / (R _Pre ) , where / is the processing function for the correlation matrix R _Pre .

Preferably, / includes one of the following: RR _Pre )= -^ , f(R _Pre )= ^{ H ^pre ,

Among the HR muscles, d) UR _Pre ) are the maximum eigenvalue and the minimum eigenvalue of the matrix R _Pre , respectively, and tr(R _Pre ) represents the trace of the matrix R _Pre . Preferably, the mode decision module comprises: a first mode decision sub-module, configured to continue to use beamforming in the case of ≤7, and using the beamforming data transmission mode before the receiving end; the second mode decision a submodule, configured to determine that the receiving end switches to beamforming in the case of a data transmission mode using MIMO beamforming before the receiving end, and the third mode decision submodule is used at > 7 and In the case where the receiving end uses the beamforming data transmission mode before, the decision receiving end switches to MIMO beamforming; the fourth mode decision sub-module is used to use MIMO beamforming data before i>Tr, and the receiving end In the case of the transmit mode, the decision terminal continues to use MIMO beamforming. Through the invention, the technology with good performance in BF or MIMO + BF is selected according to the channel condition of the system to transmit data, which solves the problem that the system cannot achieve BF and MIMO + BF adaptive switching, thereby maximizing the performance of the system. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a schematic diagram of a BF transmitting end according to the related art; FIG. 2 is a schematic diagram of a MIMO + BF transmitting end according to the related art; 3 is a flowchart of a switching method of BF and MIMO + BF according to an embodiment of the present invention; FIG. 4 is a structural block diagram of a switching system of BF and MIMO + BF according to an embodiment of the present invention; A preferred block diagram of a switching system for BF and MIMO + BF according to an embodiment of the present invention; FIG. 6 is a detailed flowchart of a method for switching BF and MIMO + BF according to an 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. According to an embodiment of the present invention, a handover method of BF and MIMO + BF is provided for a wireless communication system including a transmitting end and a receiving end. The transmitting end in the embodiment of the present invention is a device for transmitting data or information, such as a macro base station, a micro base station, etc.; the receiving end is a type of terminal for receiving data or information, such as a mobile station, a handheld device, or a data card. . The various embodiments of the present invention are described below as being implemented on the basis of the wireless communication system. FIG. 3 is a flowchart of a method for switching BF and MIMO + BF according to an embodiment of the present invention. As shown in FIG. 3, the method includes the following steps: step S302 to step 4: S302: In the decision period, Selecting a data transmission mode suitable for the current receiving end from the predetermined multi-antenna data transmission mode according to the handover algorithm, wherein the predetermined multi-antenna data transmission mode includes: BF and MIMO + BF. Step S304, transmitting data using the selected data transmission mode. In the related art, beamforming and MIMO beamforming cannot be adaptively switched. In the embodiment of the present invention, the handover algorithm can be used for the decision of the multi-antenna transmission mode. Adaptive switching of beamforming and MIMO beamforming can be achieved by selecting a data transmission mode suitable for beamforming of the current receiving end or a data transmission mode of MIMO beamforming. Specifically, in the decision period, the wireless communication system selects a data transmission mode suitable for the current receiving end from the two multi-antenna data transmission modes according to the handover algorithm; and the transmitting end in the wireless communication system uses the corresponding result according to the selected result. Transmission mode for transmitting data, here are two more days The line transmission mode includes beamforming and MIMO beamforming, and the handover algorithm is performed by a mode decision module in the wireless communication system. The handover algorithm of the wireless communication system mode decision module in step S302 includes the following steps: Step 1: Initialize a previous channel correlation matrix R _Pre , and the period of the handover decision is a T frame. Step 2: Calculate, in the period T, the channel correlation matrix on the carrier set used by the current receiving end to calculate the channel correlation matrix in the frame structure according to the time sequence of the frame:

Where N is the number of carriers included in the set of carriers, is the channel coefficient matrix of the first subcarrier in the set of carriers, 73⁄4, R is the number of transmitting antennas at the transmitting end and the receiving end respectively, and the superscript ^ is for the matrix Conjugate transposition. The _{H3⁄4 3⁄4} (k) is obtained by at least one of the following manners: Mode 1: The transmitting end measures the uplink channel coefficient corresponding to the receiving end, where the uplink channel includes at least one of the following: the receiving end transmits the data channel of the uplink service, and receives The uplink feedback channel that feeds back information to the transmitting end, the channel corresponding to the Sounding signal sent by the receiving end to the transmitting end, and the pilot channel included in the data sent by the receiving end to the transmitting end. Manner 2: The receiving end feeds back the channel coefficient corresponding to the receiving end to the transmitting end through the uplink feedback channel. Step 3, the previous channel correlation matrix is updated to

, is constant and

0 < 7 < 1 Step 4, repeat steps 2 to 3 until the end of period T. Step 5: Calculate the correlation constant of the previous channel correlation matrix: 3i = f(R _Pre ) where / is the processing function for the correlation matrix R.

Preferably, / includes one of the following: f(R _Pre )

f( _e ) = H ) , where is the maximum eigenvalue and the minimum eigenvalue of the matrix R _Pre , respectively, and tr(R _Pre ) represents the trace of the matrix R _Pre . Then, selecting a data transmission mode suitable for the current receiving end according to the switching algorithm includes: selecting a data transmission mode suitable for the current receiving end according to a relationship between the threshold and the configured threshold value Tr, specifically: if ≤ 7 , and the receiving end is before the judgment With BF technology, the receiver continues to use BF. If ≤7, and the receiver uses MIMO + BF technology before the decision, the receiver switches to

BF. If > 7 and the receiver uses BF technology before the decision, the receiver switches to MIMO + BF. If 3⁄4 > Tr and the receiver uses MIMO + BF technology before the decision, the receiver continues to use MIMO + BF. Through this embodiment, a method for beamforming and MIMO beamforming adaptive switching is provided, which can realize adaptive switching of beamforming and MIMO beamforming, thereby effectively combining the two and maximizing the system. Performance. According to an embodiment of the present invention, a switching system of BF and MIMO + BF is provided, which can be used to implement the above-described switching method of BF and MIMO + BF. 4 is a structural block diagram of a switching system of BF and MIMO + BF according to an embodiment of the present invention. As shown in FIG. 4, the system includes: a mode decision module 2, a switching module 4, a MIMO + BF transmitting module 6, and a BF. Transmitting module 8, the above structure will be described in detail below. Mode decision module 2: for transmitting, according to the handover algorithm, the transmission mode most suitable for use by the decision receiving end is BF or MIMO + BF; the switching module 4: is connected to the mode decision module 2, and is used for the result of the mode decision module 2, Deciding to use BF sending module 8 or MIMO + BF sending module 6 to transmit data; MIMO + BF transmitting module 6: connected to switching module 4 for MIMO encoding data, and multiplying MIMO encoded data by corresponding antenna After the weight component is transmitted, the BF transmitting module 8 is connected to the switching module 4, and is configured to multiply the data by the weight component of the corresponding antenna and then transmit the data. The switching algorithm includes: Step 1: Initialize the previous channel correlation matrix R _Pre , and the period of the handover decision is a T frame. Step 2: Calculate, according to the time sequence of the frame, the current receiver in the frame structure for calculating the channel correlation matrix in the frame structure. Channel correlation matrix:

R , where N represents the number of carriers included in the set of carriers,

H _3⁄473⁄4 ( ) is a channel coefficient matrix of the A-th subcarrier in the carrier set, Jx, R are the number of transmitting antennas at the transmitting end and the receiving end, respectively, and the superscript ^ is a conjugate transposition for the matrix; Step 3, the previous channel The correlation matrix is updated to R^z R^+Cl-z^R , which is constant and 0 ≤ p ≤ l; Step 4, repeat step 4 to 2 to 4 to 3 until the end of the cycle; Step 5, calculate the previous channel correlation matrix Correlation constant: 3i = /(R _Pre ), where / is a processing function for the matrix R, preferably, / includes one of the following: J\R _pre , ,

U = K muscle J = 丽丽 (R _P J, where U^ _re ), UR _Pre ) is the maximum eigenvalue of the matrix R _Pre and the most 'j, eigenvalue, R _Pre ) respectively represent the trace of the matrix R _Pre . The mode decision module 2 includes: a first mode decision sub-module, configured to determine that the receiving end continues to use beamforming when ≤7 and the beam-formed data transmission mode is used before the receiving end. The second mode decision sub-module is configured to determine that the receiving end switches to beamforming in the case of ≤ 7 and the data transmission mode of the MIMO beamforming is used before the receiving end. The third mode decision sub-module is configured to determine that the receiving end switches to MIMO beamforming in the case of > 7 and the beamforming data transmission mode is used before the receiving end. The fourth mode decision sub-module is used to determine the receiving end to continue to use MIMO beamforming in the case of > 7 and the data transmission mode of the MIMO beamforming is used before the receiving end. Through the above embodiments, the problem of beamforming and MIMO beamforming adaptive switching is solved, and the performance of the wireless communication system is improved. The above system will be described below in conjunction with practical applications. 5 is a block diagram showing a preferred structure of a switching system of BF and MIMO + BF according to an embodiment of the present invention. As shown in FIG. 5, on the one hand, a source is channel-coded, modulated, and enters a switching module, and on the other hand, a channel coefficient is obtained. The channel information of the matrix is input to the mode decision module, and the mode decision module notifies the handover module of the decision result, and the handover module selects the MIMO + BF transmission module or the BF transmission module to transmit the data. 6 is a detailed flowchart of a method for switching BF and MIMO + BF according to an embodiment of the present invention, and a preferred embodiment of the present invention will be described below with reference to FIG. Embodiment 1 This embodiment is an embodiment in which the processing according to the channel correlation matrix R _pre is f(R _pre ) = ^A mU .

HRpre ) Suppose there are M receivers on the service under one sender, the set is represented as Ω, and the receiver is denoted as Μ, . The set of MIMO + BF receivers is denoted as Ω and initialized to an empty set, ie

Ω _ΜΜΟ+ΒΡ = { } ₀ The set of BF receivers is denoted as Q _SF and initialized to the full set, ie Ω _Β = Ω. The period of configuration switching is frame. If it is the first frame of access, the previous channel correlation matrix R _{Pre is} configured as an all-zero matrix, otherwise it is initialized to the value calculated in the previous decision. In the period ,, each receiving end 发送, . , 1, 2, . . . , Μ under the transmitting end performs the following processing, as shown in the flow of FIG. 6, until all the receiving ends are traversed.

(1) Calculate the channel correlation matrix on the set of carriers used by the current receiving end in the frame structure for calculating the channel-related matrix in the period 根据 according to the time sequence of the frame:

R , where ^ denotes the number of carriers included on the set of carriers,

A matrix of channel coefficients of the first subcarrier in the set of carriers, obtained by at least one of the following methods: Manner 1: The transmitting end measures the uplink channel coefficient corresponding to the receiving end, where the uplink channel includes a data channel for transmitting the uplink service by the receiving end, or an uplink feedback channel for the receiving end to feed back information to the transmitting end or a Sounding signal sent by the receiving end to the transmitting end. The corresponding channel or the pilot channel included in the data that the receiving end wants to send by the transmitting end. Manner 2: The receiving end feeds back the channel coefficient corresponding to the receiving end to the transmitting end through the uplink feedback channel. Where Tx and Rx are the number of transmitting antennas at the transmitting end and the receiving end, respectively, and the superscript H is a conjugate transposition for the matrix.

(2) The previous channel correlation matrix is updated to R _Pre = pR _Pre + (lp)R , which is constant and 0 ≤ ≤1. (3) Repeat (1) ~ (2) until the end of the period.

(4) Calculate the correlation constant of the previous channel correlation matrix: ^H = ^mm( D, where _mn (R _Pre ) is the minimum eigenvalue of the matrix R _pre , triR _Pre ) represents the trace of the matrix R _Pre .

(5) For the receiving end, .

, make the following mode selection:

(A) If Μ,. in the ΜΙΜΟ + BF receiver set Ω and ≤ 7 , then the receiver is removed from the MIMO + BF set and added to the BF set Q _BF .

(B) If Μ,. is in the BF receiving set Q _SF and 3⁄4 ≤ 7, the receiving end continues to remain in the BF set Q _SF .

(C) If Μ,. in the ΜΙΜΟ + BF receiver set Ω and > 7 , then the receiver continues to remain at the MIMO + BF receiver set Ω (D) if ^M ' is at the BF receiver set Ω _且 and >7, then the receiver is from BF Remove from the set and add it to the MIMO + BF set Ω. The transmitting end sends data according to the set of the receiving end. If the receiving end is in the BF set, the BF sending module is selected to transmit the data in the BF mode; if the receiving end is in the MIMO + BF set, the MIMO is selected. + BF Transmit Module, which sends data out in MIMO + BF mode. Then, the sender enters the next decision cycle. Embodiment 2 This embodiment is an embodiment in which the processing according to the channel correlation matrix R _pre is f (R _pr J ).

Suppose there are M receivers on the service under one sender, the set is represented as Ω, and the receiver is marked as Μ, . The set of MIMO + BF receivers is Ω, and the initial 4 匕 is an empty set, ie M _MO+BF = { } . The set of BF receivers is denoted as Q _SF and initialized to the full set, ie Ω _Β = Ω. The period of configuration switching is frame. If it is the first frame of access, the previous channel correlation matrix R _{Pre is} configured as an all-zero matrix, otherwise it is initialized to the value calculated in the previous decision. In the period ,, each receiving end 发送, . , 1, 2, .. ·, 发送 under the transmitting end performs the following processing, as shown in the flow of Fig. 6, until all the receiving ends are traversed.

(1) Calculate the channel correlation matrix on the carrier set used by the current receiving end to calculate the channel correlation matrix in the frame structure in the period τ according to the time sequence of the frame: R

Here, N represents the number of carriers included in the carrier set, and is a channel coefficient matrix of the first subcarrier in the carrier set, which is obtained by at least one of the following manners: Mode 1: The transmitting end measures the uplink channel coefficient corresponding to the receiving end. The uplink channel includes a data channel for transmitting the uplink service by the receiving end, or an uplink feedback channel for the receiving end to feed back information to the transmitting end, or a channel corresponding to the Sounding signal sent by the receiving end to the transmitting end, or a receiving end The pilot channel included in the data sent by the sender. Manner 2: The receiving end feeds back the channel coefficient corresponding to the receiving end to the transmitting end through the uplink feedback channel. Where Tx and Rx are the number of transmitting antennas at the transmitting end and the receiving end, respectively, and the superscript H is a conjugate transposition for the matrix. (2) The previous channel correlation matrix is updated to R _Pre = pR _Pre + (1 - )R , which is constant and 0 ≤ ? ≤ 1.

(3) Repeat (1) ~ (2) until the end of period T.

(4) Calculate the correlation constant of the correlation matrix: = ( ), where UR _Pre ), i _mn (R _Pre ) are the maximum eigenvalue and the minimum eigenvalue of the matrix R _Pre , respectively.

(5) For the receiving end, ζ' = 1, 2, ···, , make the following mode selection: ( A ) If Μ,. in the MIMO + BF receiver set Ω _{ΜΜ σ + κ?} and ≤ 7 The receiver is removed from the MIMO + BF set and is forced into the BF set Ω _。.

( Β ) If w,. is in the BF receiver set Q _BF and ≤ 7 , then the receiver continues to remain in the BF set Q _SF .

(C) If Μ,. in the MIMO + BF receiver set Ω _{ΜΜ σ + Β / 且} and > Tr, then the receiver continues to remain at the MIMO + BF receiver set Ω

(D) If Μ,. is in the BF receiver set Ω _ΒΙΓ and > 7 , then the receiver is removed from the BF set and added to the MIMO + BF set Ω. The transmitting end sends data according to the set of the receiving end. If the receiving end is in the BF set, the BF sending module is selected to transmit the data in the BF mode; if the receiving end is in the MIMO + BF set, the MIMO is selected. + BF send module, the data is in MIMO + BF mode Send it out. Then, the sender enters the next decision cycle. Embodiment 3 This embodiment is an embodiment in which the processing of the channel correlation matrix R _Pre R is f (R _Pre , = _mn (R _Pre ). Suppose that there are M receiving ends of a service under the transmitting end, and the set thereof is expressed as Ω. The receiving end is recorded as Μ, .. where ΜΙΜΟ + BF receiver set is recorded as Ω, initialized to an empty set, ie

Ω _ΜΜΟ+ΒΡ ={ } ₀ The set of BF receivers is denoted as Q _SF and initialized to the full set, ie Ω _Β = Ω. The period of configuration switching is frame. If it is the first frame of access, the previous channel correlation matrix R _{Pre is} configured as an all-zero matrix, otherwise it is initialized to the value calculated in the previous decision. During the period, each receiving end 发送, . , 1, 2, .., Μ under the transmitting end performs the following processing, as shown in the flow of Fig. 6, until all the receiving ends are traversed.

R

Here, N represents the number of carriers included in the set of carriers, and H _73⁄4 (t) is a matrix of channel coefficients of the first subcarrier in the set of carriers, obtained by at least one of the following manners: Mode 1: transmitting measurement end Corresponding uplink channel coefficient, wherein the uplink channel includes a data channel for transmitting the uplink service by the receiving end, or an uplink feedback channel for the receiving end to feed back information to the transmitting end, or a channel corresponding to the Sounding signal sent by the receiving end to the transmitting end, or the receiving end wants The pilot channel included in the data sent by the sender. Manner 2: The receiving end feeds back the channel coefficient corresponding to the receiving end to the transmitting end through the uplink feedback channel. Where Tx and Rx are the number of transmitting antennas at the transmitting end and the receiving end, respectively, and the superscript H is a conjugate transposition for the matrix. (2) The previous channel correlation matrix is updated to

, is constant and 0 ≤ ≤1.

(3) Repeat (1) ~ (2) until the end of period T.

(4) Calculate the correlation constant of the previous channel correlation matrix: = UR _Pre ), where l _mn (R _Pre ) is the minimum eigenvalue of the matrix R _Pre respectively.

(5) For the receiving end, .

, make the following mode selection:

(A) if Μ ,. MIMO + BF at the receiving end and the set Ω ≤ 7, then the receiving end of the MIMO + BF is deleted from the set, ^ ¹ and opening to its force BF collection.

(Β) If Μ,. is in the BF receiving set Q _SF and 3⁄4 ≤ 7, the receiving end continues to remain in the BF set Q _SF .

(C) If Μ,. in the MIMO + BF receiver set Ω _{ΜΜσ+3⁄4?} and > Tr, then the receiver continues to remain at the MIMO + BF receiver set Ω

(D) If Μ, in the BF receiver set Q _SF and > 7 , the receiver is removed from the BF set and added to the MIMO + BF set Ω. The transmitting end sends data according to the set of the receiving end. If the receiving end is in the BF set, the BF sending module is selected to transmit the data in the BF mode; if the receiving end is in the MIMO + BF set, the MIMO is selected. + BF Transmit Module, which sends data out in MIMO + BF mode. Then, the sender enters the next decision cycle. Through the above embodiments of the present invention, it is possible to flexibly select technologies with better performance in beamforming and MIMO beamforming according to the characteristics of the system to transmit data, thereby maximizing the system. Performance. 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 beamforming and multiple input multiple output MIMO beamforming switching method, comprising:

During the decision period, a data transmission mode suitable for the current receiving end is selected from the predetermined multi-antenna data transmission mode according to the handover algorithm, wherein the multi-antenna transmission mode includes beamforming and MIMO beamforming;

Transfer data using the selected data transmission mode.

2. The method according to claim 1, wherein the switching algorithm comprises:

Step 1: Initialize the previous channel correlation matrix R _Pre , and the period of the handover decision is a T frame. Step 2: In the period, the current receiving end is used to calculate the channel correlation matrix in the frame structure according to the time sequence of the frame. Channel correlation matrix on the set of carriers:

Wherein, N represents the number of carriers included in the specific carrier set, H _J3⁄4 (where is the channel coefficient matrix of the first subcarrier in the carrier set, Tx, Rx are the number of transmitting antennas at the transmitting end and the receiving end, respectively, and the superscript H The conjugate transpose is performed on the matrix; Step 3, the previous channel correlation matrix is updated to R _Pre = pR _Pre + (l - p)R , which is a constant JL 0 ≤ ≤ l; Step 4, repeat step 4 gather 2 ~ Step 4 gathers 3 until the end of the cycle;

Step 5: Calculate a correlation constant of the previous channel correlation matrix: 3i = /(R _Pre ) , where f is a processing function for the previous channel correlation matrix R _Pre .

3. The method according to claim 2, wherein the ^^W is obtained by at least one of:

The transmitting end measures the channel coefficient of the uplink channel corresponding to the receiving end, where the uplink channel includes at least one of the following: a data channel for transmitting the uplink service by the receiving end, an uplink feedback channel for the receiving end to feed back information to the transmitting end, and a receiving end for transmitting a channel corresponding to the Sounding signal sent by the terminal, and a pilot channel included in the data sent by the receiving end to the transmitting end;

The receiving end feeds back the channel coefficient corresponding to the receiving end to the transmitting end through the uplink feedback channel. The method according to claim 2, characterized in that / comprises one of the following: muscle ^λ : Β, /d) = K muscle j = d where, respectively, a matrix maximum eigenvalue and a minimum eigenvalue, representing a matrix R _Pre Traces. The method according to claim 2, wherein selecting a data transmission mode suitable for the current receiving end according to the switching algorithm comprises:

According to the relationship with the configured threshold value Tr, the data transmission mode applicable to the current receiving end is selected. The method according to claim 5, wherein selecting a data transmission mode suitable for the current receiving end according to the relationship with the configured threshold value 7 comprises:

If < Tr , and the receiving end previously uses the beamforming data transmission mode, the receiving end continues to use beamforming;

If < Tr , and the receiving end previously uses the data transmission mode of MIMO beamforming, the receiving end switches to beamforming;

If > Tr and the receiving end previously uses the beamforming data transmission mode, the receiving end switches to MIMO beamforming;

If > Tr and the receiving end previously used the data transmission mode of MIMO beamforming, the receiving end continues to use MIMO beamforming. A beamforming and multiple input multiple output MIMO beamforming switching system, comprising:

a mode decision module, configured to determine, according to a handover algorithm, a transmit mode suitable for use by the receiving end to form the beam or the MIMO beam;

a MIMO beamforming transmitting module, configured to perform MIMO encoding on the data, and multiply the MIMO encoded data by a weight component of the corresponding antenna;

a beamforming transmitting module, configured to perform multiplication by multiplying data by a weight component of the corresponding antenna;

And a switching module, configured to determine, according to the decision result of the mode decision module, to use the beamforming transmitting module or the MIMO beamforming transmitting module to send data.

The system according to claim 7, wherein the switching algorithm comprises: Step 1: Initializing a previous channel correlation matrix R _Pre , the period of the handover decision is a T frame; Step 2, in the period, According to the time sequence of the frame, the channel correlation matrix of the current receiving end on the carrier set of the frame correlation matrix is calculated:

R

Wherein, N represents the number of carriers included in the specific carrier set, H _J3⁄4 is a channel coefficient matrix of the first subcarrier in the specific carrier set, and rx, 3⁄4c are the number of transmitting antennas at the transmitting end and the receiving end respectively, and the superscript ^ Is to conjugate transpose the matrix;

Step 3: The previous channel correlation matrix is updated to R _Pre = pR _Pre + (\-p)R, which is a constant JL0 ≤ ≤ l; Step 4, repeat step 4 to 2 to 4 to 3 until the end of the period;

Step 5: Calculate a correlation constant of the previous channel correlation matrix: 3i = /(R _Pre ), where f is a processing function for the previous channel correlation matrix R _Pre .

9. The system of claim 8 wherein / comprises one of the following:

/d)„ ;), /(D = K, muscle J = d where, respectively, the maximum eigenvalue and the minimum eigenvalue of the matrix, representing the trace of the matrix R _Pre .

10. The system according to claim 8, wherein the mode decision module comprises: a first mode decision sub-module, configured to use a beamforming data transmission mode before ≤ 7 and before the receiving end Determining that the receiving end continues to use beamforming;

a second mode decision sub-module, configured to: when the data transmission mode of MIMO beamforming is used before the receiving end, determine that the receiving end switches to beamforming; and the third mode determining sub-module is used In the case where > 7 and the data transmission mode of the beamforming is used before the receiving end, the receiving end is determined to switch to MIMO beamforming; The fourth mode decision sub-module is configured to determine that the receiving end continues to use MIMO beamforming in the case of > Tr, and the data transmission mode of the MIMO beamforming is used before the receiving end.