WO2016106710A1

WO2016106710A1 - Precoding matrix indicator (pmi) feedback method and apparatus

Info

Publication number: WO2016106710A1
Application number: PCT/CN2014/095970
Authority: WO
Inventors: 吴强; 张雷鸣; 刘建琴; 刘江华
Original assignee: 华为技术有限公司
Priority date: 2014-12-31
Filing date: 2014-12-31
Publication date: 2016-07-07
Also published as: CN107113661A; CN107113661B

Abstract

By means of a PMI feedback method described in this embodiment, corresponding respective PMIs of different subcarriers can be integrated on the basis of the same PMI in some items of different subcarriers in different scenarios, so that a UE feeds back only once in a process of determining precoding matrices a common PMI that is used for indicating precoding matrices of different subcarriers, and a base station determines the precoding matrices of the subcarriers through the common PMI and non-common PMIs (a first PMI and a second PMI in this embodiment) in the different subcarriers; the UE sends to the base station the PMI that can be commonly used by the subcarriers and the non-common PMIs that cannot be commonly used by the subcarriers, wherein in a process of determining precoding matrices of two subcarriers, the total number of fed back PMIs is K, which is used for indicating Q precoding matrices in the two subcarriers, and the number K of the fed back PMIs is less than the number Q, thereby achieving the purpose of saving channel resources.

Description

Feedback method and device for precoding matrix indicating PMI

Background technique

Long Term Evolution (LTE) technology is a long-term evolution of the Universal Mobile Telecommunications System (UMTS) technology standard developed by the 3rd Generation Partnership Project (3GPP), LTE system. The introduction of key transmission technologies such as Multi-Input & Multi-Output (MIMO) has significantly increased spectral efficiency and data transmission rate.

By transmitting precoding techniques and receiving combining techniques, MIMO-based wireless communication systems can achieve diversity and array gain. A MIMO-based wireless communication system requires precoding processing of signals, and a signal transmission function based on precoding can be expressed as:

Where y is the received signal vector and H is the channel matrix.

Is a precoding matrix, s is the transmitted signal vector, n is the measurement noise, and the transmitted signal vector s is precoded at the transmitting end.

Perform precoding to obtain a precoded matrix

H is a channel characteristic matrix that reflects the characteristics of the current channel.

Right multiplied by the channel matrix H, got

It can be said that in the absence of noise, the signal after the channel number passes through the air interface, and then the superposition of the measurement noise n, the received signal vector y received at the receiving end can be determined.

Implementing optimal precoding usually requires the transmitter to obtain channel state information (CSI) in advance. The transmitter and receiver may be base station devices or terminal devices, respectively. In the downlink data transmission process, the transmitter may be a base station device, and the receiver may be a terminal device. A common method is that the terminal device quantizes the instantaneous CSI and reports it to the base station.

The CSI information reported by the terminal device includes a Rank Indicator (RI), a Precoding Matrix Indicator (PMI), and a Channel Quality Indicator (CQI) information, where the RI can be used to indicate data transmission. Number of transmission layers and precoding matrix used

PMI can be used to indicate the precoding matrix used for data transmission

In a multi-carrier system, signals can be transmitted on carriers in different frequency bands, due to different carrier correspondences. Different precoding matrices, the terminal needs to report PMI information under different carriers. In some cases, each carrier may include multiple PMIs that collectively indicate a precoding matrix used in the transmission of signals using the carrier. For example, the signal is transmitted on carrier 1 and carrier 2, the precoding matrix corresponding to carrier 1 is W1, and the precoding matrix corresponding to carrier 2 is W2; wherein PMI1 and PMI2 jointly indicate the W1, and PMI3 and PMI4 jointly indicate the W2. In this case, the UE is required to report PMI1, PMI2, PMI3, and PMI4. However, in the wireless transmission process, resources are very limited. Such a transmission method makes the PMI feedback amount large, and wastes the resources of the air interface.

Moreover, in some scenarios, the problem of wasted air resource is more serious.

For example, in some scenarios of 3D MIMO (3 Dimension MIMO), under one carrier, PMIs of two precoding matrices need to be fed back, respectively indicating a vertical direction precoding matrix and a horizontal direction precoding matrix. The horizontal direction is represented by a Kronecker Product of the vertical direction precoding matrix and the horizontal direction precoding matrix to represent the precoding matrix. The precoding matrix V ₁ can be expressed as follows:

among them,

Represents Kronecker Product. The size of the matrix V ₁ is determined by the number of rows and columns of the precoding matrix A in the vertical direction and the number of rows and columns of the precoding matrix B in the horizontal direction. Here, A may also be a horizontal direction precoding matrix, and correspondingly, B is a vertical direction precoding matrix.

In addition, in some other scenarios, the precoding matrix V ₂ in the codebook of each carrier may be represented as a dual codebook structure, and the long-term broadband characteristic matrix W ₁ represents the long-term/wideband characteristics of the channel; the short-term narrowband characteristic W ₂ represents the channel. Short-term/sub-band characteristics. In the feedback of the PMI, W ₁ and W ₂ are respectively indicated by different PMIs. The precoding matrix V ₂ can be expressed as follows:

V ₂ = W ₁ × W ₂

In the prior art, the base station determining a precoding matrix V ₁ (or a precoding matrix V ₂₎ in accordance with the feedback UE A, B corresponding to the PMI (or W _1, W ₂ corresponding PMI). As mentioned before, different carriers correspond to different precoding matrices. For each carrier, the number of PMIs fed back is the number of each precoding matrix above, for example, to determine the precoding matrix of carrier 1.

Need to feed back the PMI of A and the PMI of B, in order to determine the precoding matrix of carrier 2.

Need to feedback C's PMI and D's PMI, which greatly increases the number of feedback PMI, wasting the resources of the air interface.

Summary of the invention

The present invention provides a data transmission method to avoid wasting air interface resources while implementing PMI feedback.

In a first aspect, an embodiment of the present invention provides a precoding matrix indicating PMI feedback method, which is used in a wireless communication system with multi-carrier capability, where a user equipment UE in a wireless communication system uses a first subcarrier and a second The subcarriers are in communication with the network side device, the method comprising: the UE determining at least one common PMI, at least one first PMI, and at least one second PMI, wherein the at least one common PMI and the at least one first PMI a precoding matrix for indicating the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier; the UE is to the wireless communication A base station in the system transmits the at least one public PMI, the at least one first PMI, and the at least one second PMI.

In a first possible implementation manner of the first aspect, the precoding matrix of the first subcarrier is a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier a Kronecker product; the precoding matrix of the second subcarrier is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier; The common PMI is used to indicate a vertical direction precoding matrix of the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier; the first PMI is used to indicate the first a horizontal direction precoding matrix of one subcarrier; the second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.

In combination with the first possible implementation of the first aspect, in a second possible implementation manner,

The vertical precoding matrix of the first subcarrier indicated by the common PMI is:

Where N is a positive integer, k is an integer greater than or equal to 0 and less than or equal to N-1; m is the length of the precoding matrix W corresponding to the common PMI, and T represents the transposition of the matrix.

In a third possible implementation manner of the first aspect, the precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix of the first subcarrier and a short-term narrowband characteristic matrix; a precoding matrix of the second subcarrier is a product of a long-term broadband characteristic matrix of the second carrier and a short-term narrowband characteristic matrix; The PMI is used to indicate a long-term broadband characteristic matrix of the first sub-carrier; the common PMI is further used to indicate a long-term broadband characteristic matrix of the second sub-carrier; the first PMI is used to indicate the first sub-carrier a short-term narrowband characteristic matrix; the second PMI is used to indicate a short-term narrowband characteristic matrix of the second subcarrier.

With reference to the first aspect, or any one of the first to third possible implementation manners of the first aspect, in a fourth possible implementation, the method further includes: determining, by the UE, the first PMI compensation value δ, where The δ is used to indicate a precoding matrix of the first subcarrier together with the at least one common PMI and the at least one first PMI.

With reference to the fourth possible implementation manner of the first aspect, in a fifth possible implementation, the determining, by the UE, the first PMI compensation value δ includes: according to the second subcarrier precoding matrix and The first subcarrier precoding matrix determines the first PMI compensation value δ.

With reference to the fourth possible implementation manner of the first aspect, and any one possible implementation manner of the fifth possible implementation manner, in a sixth possible implementation manner, the UE sends the first PMI compensation value δ The method includes: transmitting, by using a physical uplink control channel PUCCH or a physical uplink shared channel PUSCH, the first PMI compensation value δ.

In a second aspect, an embodiment of the present invention provides a precoding matrix indicating PMI feedback method, which is used in a wireless communication system with multi-carrier capability, where a base station in a radio communication system uses a first subcarrier and a second subcarrier. Communicating with the user equipment UE, the method comprising: the base station receiving at least one public PMI, at least one first PMI and at least one second PMI, wherein the at least one common PMI and the at least one first PMI are used And a precoding matrix indicating the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier; and the base station is configured according to the at least one common PMI And determining, by the at least one first PMI, a precoding matrix of the first subcarrier, and determining a precoding matrix of the second subcarrier according to the at least one common PMI and the second PMI.

In a first possible implementation manner of the second aspect, the precoding matrix of the first subcarrier is a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier a Kronecker product; the precoding matrix of the second subcarrier is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier; The public PMI a vertical direction precoding matrix for indicating the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier; the first PMI is used to indicate the first subcarrier a horizontal direction precoding matrix; the second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner, the method includes: a vertical precoding matrix of the first subcarrier indicated by the common PMI is:

In a third possible implementation manner of the second aspect, the precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix of the first subcarrier and a short-term narrowband characteristic matrix; the second subcarrier a precoding matrix is a product of a long-term broadband characteristic matrix of the second carrier and a short-term narrowband characteristic matrix; the common PMI is used to indicate a long-term broadband characteristic matrix of the first subcarrier; and the common PMI is further used to indicate a long-term broadband characteristic matrix of the second subcarrier; the first PMI is used to indicate a short-term narrowband characteristic matrix of the first subcarrier; and the second PMI is used to indicate a short-term narrowband characteristic of the second subcarrier matrix.

With reference to the second aspect, or any one of the first to the third possible implementation manners of the second aspect, in a fourth possible implementation, the method further includes: receiving, by the base station, the first PMI compensation value δ sent by the UE, Determining, by the base station, a precoding matrix of the first subcarrier according to the δ and the at least one common PMI and the at least one first PMI.

With reference to the fourth possible implementation manner of the second aspect, in a fifth possible implementation manner, the receiving, by the base station, the first PMI compensation value δ includes: the base station by using a physical uplink control channel (PUCCH) or physical uplink sharing The channel PUSCH receives the first PMI compensation value δ.

In a third aspect, an embodiment of the present invention provides a precoding matrix indicating PMI feedback apparatus, which is used in a wireless communication system with multi-carrier capability, where a user equipment UE in the wireless communication system uses a first subcarrier and a second sub The carrier is in communication with the network side device, the UE includes: a determining unit, configured to determine at least one common PMI, at least one first PMI, and at least one second PMI, wherein the at least one common PMI and the at least one first a PMI is used to indicate a precoding matrix of the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier; And a sending unit, configured to send the at least one common PMI, the at least one first PMI, and the at least one second PMI to a base station in the wireless communication system.

In a first possible implementation manner of the third aspect, the precoding matrix of the first subcarrier is a vertical direction precoding matrix of the first subcarrier and a horizontal direction of the first subcarrier a Kronecker product of the coding matrix; the precoding matrix of the second subcarrier is a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier product;

The common PMI is used to indicate a vertical direction precoding matrix of the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier; the first PMI is used to indicate the first a horizontal direction precoding matrix of one subcarrier; the second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.

In combination with the first possible implementation manner of the third aspect, in a second possible implementation manner, the method includes:

In a third possible implementation manner of the third aspect, the precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix of the first subcarrier and a short-term narrowband characteristic matrix; The precoding matrix of the subcarrier is a product of a long-term broadband characteristic matrix of the second carrier and a short-term narrowband characteristic matrix; the common PMI is used to indicate a long-term broadband characteristic matrix of the first subcarrier; and the common PMI is further used And indicating a long-term broadband characteristic matrix of the second subcarrier; the first PMI is used to indicate a short-term narrowband characteristic matrix of the first subcarrier; and the second PMI is used to indicate a short-term of the second subcarrier Narrowband characteristic matrix.

With reference to the third aspect, or any one of the first to third possible implementation manners of the third aspect, in a fourth possible implementation, the determining unit is further configured to determine the first PMI compensation value. δ, the δ is used to determine a precoding matrix of the first subcarrier together with the at least one common PMI and the at least one first PMI; the sending unit is further configured to send the first PMI compensation value δ.

With reference to the fourth possible implementation manner of the third aspect, in a fifth possible implementation, the determining unit is further configured to determine the first subcarrier precoding matrix and the second subcarrier precoding matrix; Place Determining, by the determining unit, the at least one common PMI according to the first subcarrier precoding matrix; the determining unit determining the first PMI compensation value δ, comprising: according to the second subcarrier precoding matrix and the The first subcarrier precoding matrix determines the first PMI compensation value δ.

With reference to the fourth possible implementation manner of the third aspect, and any one possible implementation manner of the fifth possible implementation manner, in a sixth possible implementation manner, the sending unit sends the first PMI compensation value δ Specifically, the first PMI compensation value δ is sent by using a physical uplink control channel PUCCH or a physical uplink shared channel PUSCH.

In a fourth aspect, an embodiment of the present invention provides a precoding matrix indicating PMI feedback apparatus, which is used in a wireless communication system with multi-carrier capability, where a base station in the wireless communication system uses a first subcarrier and a second subcarrier. Communicating with the user equipment UE, the base station comprising: a receiving unit, configured to receive at least one public PMI, at least one first PMI, and at least one second PMI, wherein the at least one common PMI and the at least one first PMI a precoding matrix for indicating the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier; and a determining unit, configured to Determining, by the at least one common PMI and the at least one first PMI, a precoding matrix of the first subcarrier, and determining a precoding matrix of the second subcarrier according to the at least one common PMI and the second PMI.

In a first possible implementation manner of the fourth aspect, the precoding matrix of the first subcarrier is a vertical direction precoding matrix of the first subcarrier and a horizontal direction of the first subcarrier a Kronecker product of the coding matrix; the precoding matrix of the second subcarrier is a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier The common PMI is used to indicate a vertical direction precoding matrix of the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier; the first PMI is used to indicate a horizontal direction precoding matrix of the first subcarrier; the second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.

With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner, the method includes: a vertical precoding matrix of the first subcarrier indicated by the common PMI is:

Where N is a positive integer, k is an integer greater than or equal to 0 and less than or equal to N-1; m is the public The length of the precoding matrix W corresponding to the PMI, and T represents the transposition of the matrix.

In a third possible implementation manner of the fourth aspect, the precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix of the first subcarrier and a short-term narrowband characteristic matrix; The precoding matrix of the subcarrier is a product of a long-term broadband characteristic matrix of the second carrier and a short-term narrowband characteristic matrix; the common PMI is used to indicate a long-term broadband characteristic matrix of the first subcarrier; and the common PMI is further used And indicating a long-term broadband characteristic matrix of the second subcarrier; the first PMI is used to indicate a short-term narrowband characteristic matrix of the first subcarrier; and the second PMI is used to indicate a short-term of the second subcarrier Narrowband characteristic matrix.

With reference to the fourth aspect, or any one of the first to the third possible implementation manners of the fourth aspect, in a fourth possible implementation, the receiving unit is further configured to receive, by the UE, the first a PMI compensation value δ, which is used to determine a precoding matrix of the first subcarrier together with the at least one common PMI and the at least one first PMI.

With reference to the fourth possible implementation manner of the fourth aspect, in a fifth possible implementation, the receiving, by the receiving unit, the first PMI compensation value δ specifically includes: the receiving unit by using a physical uplink control channel, PUCCH, or physical The uplink shared channel PUSCH receives the first PMI compensation value δ.

Through the above solution, the present invention utilizes the characteristics that multiple carriers have the same or similar PMI values in a certain direction or certain characteristics in some cases, and combine multiple PMIs of the same or similar between different carriers into one common PMI for feedback. , reducing the number of PMIs that need feedback, thereby improving the resource utilization of air interfaces.

DRAWINGS

FIG. 1 is a flowchart of a UE side PMI feedback method according to an embodiment of the present invention;

FIG. 2 is a flowchart of still another feedback method of a UE-side PMI according to an embodiment of the present invention;

FIG. 3 is a flowchart of still another UE side PMI feedback method according to an embodiment of the present invention;

FIG. 4 is a flowchart of a method for feeding back a base station side PMI according to an embodiment of the present invention;

FIG. 5 is a flowchart of still another method for feeding back a base station side PMI according to an embodiment of the present invention;

FIG. 6 is a flowchart of still another method for feeding back a PMI on a base station according to an embodiment of the present disclosure;

FIG. 7 is a flowchart of still another feedback device of a UE-side PMI according to an embodiment of the present disclosure;

FIG. 8 is a flowchart of still another feedback device of a UE-side PMI according to an embodiment of the present disclosure;

FIG. 9 is a flowchart of still another feedback device of a UE-side PMI according to an embodiment of the present disclosure;

10 is a schematic structural diagram of a feedback apparatus for a base station side PMI according to an embodiment of the present disclosure;

FIG. 11 is a schematic structural diagram of a feedback apparatus for a base station side PMI according to an embodiment of the present disclosure;

FIG. 12 is a schematic structural diagram of a feedback apparatus for a base station side PMI according to an embodiment of the present disclosure;

FIG. 13 is a schematic structural diagram of a feedback device of a UE-side PMI according to an embodiment of the present disclosure;

FIG. 14 is a schematic structural diagram of a feedback apparatus for a base station side PMI according to an embodiment of the present disclosure;

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of the present invention.

It should be understood that the base station involved in the present invention may be, but not limited to, a Node B (Base station, BS), an Access Point, a Transmission Point (TP), and an Evolved Node B. eNB), relay, etc.; the user equipment UE involved in the present invention may be, but not limited to, a mobile station (MS), a relay, a mobile telephone, a handset. And portable equipment, mobile or non-mobile terminals.

1 is a schematic flowchart of a communication method according to an embodiment of the present invention, relating to a feedback method of a precoding matrix indicating PMI for a wireless communication system having multi-carrier capability, a user in the wireless communication system The device UE communicates with the base station using the first subcarrier and the second subcarrier.

Specifically include:

Step 101: The UE determines at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate the first subcarrier. a precoding matrix; the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier; wherein the common PMI, the first PMI, the second PMI It can be 2, 3 or more than 3 respectively.

It should be understood that the present invention does not limit the specific manner in which the UE determines the PMI, and the process of determining the PMI by the UE may be determined according to the reference signal measurement, and may be according to the measurement reference signal, respectively, from different dimensions. The retries are performed in the precoding sub-matrix, and the matrix with the best signal quality is selected.

Step 102: The UE sends the at least one public PMI, the at least one first PMI, and the at least one second PMI to a base station in the wireless communication system.

Hereinafter, the steps of determining at least one of the common PMI, the at least one first PMI, and the at least one second PMI in step 101 will be specifically described in the form of an example. For example, for the first subcarrier CA1, the UE needs to feed back 4 PMIs, which are respectively PMI 1/2/3/4, which are used to indicate the precoding matrix of the CA1; for the second subcarrier CA2, the UE needs feedback 4 The PMIs are PMI5/6/7/8, respectively, which are used to indicate the precoding matrix of the CA2. In an embodiment, PMI1, PMI2 may jointly indicate a sub-precoding matrix W _A1 under the CA1; PMI3, PMI4 may indicate another sub-precoding matrix W _B1 under CA1, and then by W _A1 , W _B1 and The determined operational relationship determines the CA1 precoding matrix W _A1B1 . PMI5, PMI6 may jointly indicate a sub-precoding matrix W _A2 under the CA2; PMI7, PMI8 may indicate another sub-precoding matrix W _B2 under CA2, and then determined by the W _A2 , W _B2 and the determined operational relationship CA1 precoding matrix W _A2B2 . The specific determination manner may be different, and the present invention is not limited, and may be determined in the form of calculating parameters of the precoding matrix. For example, the UE and/or the base station may calculate W _A1 according to two parameters of PMI1 and PMI2, or The UE and/or the base station may also store or predetermine a table, and may query the corresponding W _A1 according to PMI1 or PMI2, or PMI1/2/3/4 may be 4 parameters, PMI5/6/7. /8 can be 4 parameters, and the precoding matrix is directly calculated. It should be understood that the need to feed back 4 PMIs under one carrier is only an example, and in actual situations, other situations may occur. Each embodiment of the present application does not specifically refer to four PMIs. At least one PMI in the CA1 is the same as or similar to at least one PMI in the CA2 according to a certain channel condition or channel model. Then, the at least one PMI of CA1 and the at least one PMI of the CA2 may be determined as the common PMI. Wherein, the approximation here can be equivalent, for example, even if the two PMIs are different, the difference between the two PMIs is small, and finally the channel model of the CA1 precoding matrix and the CA2 precoding matrix can be obtained according to the respective calculations. Tolerance within the scope. For example, PMI1 and PMI5 correspond to each other. When certain conditions are met, it can be determined as public PMI _C1 ; PMI3 and PMI7 correspond to each other and can be determined as public PMI _C2 , namely:

PMI ₁ = PMI ₅ = PMI _C1

PMI ₃ = PMI ₇ = PMI _C2

Then, referring to step 102, the UE may feed back a common PMI: PMI _C1 , PMI _C2 ; and a first PMI: PMI2, PMI4; and a second PMI: PMI6, PMI8. The method of determining the common PMI is usually determined by the channel characteristics. For example, PMI1 and PMI5 are used to indicate certain matrix parameters, which are related in some scenarios (such as high-rise scenes or wide-area scenes). High, whose values are equal or the difference is negligible; or PMI1 and PMI5, in some scenarios, indicate a matrix set of the same type of matrix in the table, and other PMI2/PMI6 further indicate one of the matrix sets. The matrix (the matrix is an element in the matrix set), then, PMI1 and PMI5 can be determined as the common PMI ₁ in many identical scenarios; similarly, PMI3 and PMI7 can also adopt the above feedback method. Alternatively, the base station side may directly determine that the PMI _C1 and the PMI _C2 are common PMIs, and the PMI _C1 represents PMI1/PMI5, and the PMI _C2 represents PMI3/PMI7, and is sent to the UE.

The UE may preset a rule, or determine a common PMI, a first PMI, and a second PMI with the UE in a negotiated manner, or directly indicate a public PMI, a first PMI, or a first in a signaling or other signaling of the feedback PMI. The second PMI, the UE determines the public PMI, the first PMI, and the second PMI according to the indication or the preset rule. For example, in a high-rise scenario, the PMI ₁ and the PMI _{5 are} determined to be a public PMI, and the preset rule is also in the UE with which it interacts. This indication process can also come from other UEs or other network side devices.

It should be understood that, in step 101, the UE determines that the specific order of the at least one common PMI, the at least one first PMI, and the at least one second PMI may be different, and the present invention provides different implementation manners:

Embodiment 1, first determining the PMI of different carriers, and then determining the public PMI and the non-public PMI:

The UE may respectively determine a plurality of PMIs corresponding to the precoding matrix of the first subcarrier CA1, and multiple PMIs corresponding to the precoding matrix of the second subcarrier CA2, and corresponding to multiple PMIs and CA2 corresponding to the CA1. Determining, in the plurality of PMIs, the at least one common PMI that may be the public PMI, and the remaining PMIs that are not determined as the public PMI and corresponding to the CA1 as the at least one first PMI; the rest are not determined as the public PMI, and The PMI corresponding to CA2 is used as the second PMI.

Embodiment 2, directly determining a public PMI according to a scenario or other preset rules:

The UE may determine multiple PMIs corresponding to the precoding matrix of the first subcarrier CA1, and determine that at least one of them is a public PMI according to a channel situation, a usage scenario, or a preset rule, and other ones in the CA1 are not determined as public. The PMI of the PMI is the at least one first PMI; and the at least one second PMI corresponding to the second subcarrier CA2 precoding matrix is further determined. For example, the precoding matrix of CA1 is composed of a vertical direction precoding matrix and a horizontal direction precoding matrix. The precoding matrix of CA2 is also composed of a vertical direction precoding matrix and a horizontal direction precoding matrix, and needs to feed back the vertical direction of CA1 and CA2. The PMI of the coding matrix and the PMI of the horizontal direction precoding matrix, in certain scenarios, such as high-rise scenes, The vertical direction precoding matrix of CA1 and the vertical direction precoding matrix of CA2 may be determined as the common PMI. In the determining process of the UE, the PMI of the CA1 vertical direction precoding matrix may be determined to be a common PMI, and then the CA1 horizontal direction precoding matrix is determined to be the at least one first PMI, and the CA2 horizontal direction precoding matrix is determined to be the at least one Second PMI.

Embodiment 3, first determining the first PMI and the public PMI, and then determining the second PMI:

The UE may directly determine the at least one common PMI in the first subcarrier CA1 precoding matrix and the second subcarrier CA2 precoding matrix corresponding according to a preset rule or a usage scenario, and then determine the at least one first PMI and The at least one second PMI. For example, the precoding matrix of CA1 is composed of a precoding matrix in the vertical direction and the horizontal direction, and the CA2 precoding matrix is also composed of a precoding matrix in the vertical direction and the horizontal direction, and the PMI of the vertical precoding matrix of CA1 and CA2 needs to be fed back. The PMI of the horizontal direction precoding matrix. In a certain scenario, the PMI similarity of the precoding matrix in the vertical direction of CA1 and CA2 is high, and can be determined as the common PMI. In the determination process of the UE, the public PMI is directly determined, and this value may be preset for a certain situation or jointly determined according to CA1 and CA2. And determining that the CA1 horizontal direction precoding matrix is the at least one first PMI, and determining that the CA2 horizontal direction precoding matrix is the at least one second PMI.

It should be understood that the present invention is not limited to the specific implementation steps given in the above embodiments 1-3, and may be other specific embodiments for determining the at least one common PMI.

It should be understood that the present invention does not limit the specific method for determining the PMI corresponding to each precoding matrix, and may traverse from the precoding sub-matrices of different dimensions to select a matrix with the best signal quality. For example, the UE measures the CA1 optimal precoding matrices W1, W2 and CA2 optimal precoding matrices W3 and W4 based on CA1 and CA2, where W1, W2 can be determined from different codebooks, ie, precoding matrix sets, respectively. , W3, W4 can be determined from different codebooks, that is, precoding matrix sets.

In an embodiment, different RIs correspond to different PMI tables, and after the UE determines the value of the RI, the UE determines, from the plurality of PMI tables, a PMI table corresponding to the value of the RI, where the PMI table The correspondence between the PMI and the precoding matrix and/or the correspondence between the PMI and the precoding submatrix may be included. The PMI table may further include a relationship between the result measured by the UE according to the reference signal and a precoding matrix, and/or a relationship between the result measured by the UE according to the reference signal and the precoding sub-matrix. Then, according to at least one matrix in the PMI table, a PMI value corresponding to one CA is determined. Here, the process of determining the PMI value may traverse the signal quality corresponding to all the matrices in the determined PMI table to determine the most The optimal matrix is then determined by the PMI value corresponding to the optimal matrix, and the PMI value is the PMI value corresponding to the CA. In another embodiment, the PMI can be determined directly by determining a precoding matrix. The PMI table may be a specific table or a plurality of corresponding relationship sets stored in the UE.

It should be understood that the present invention does not limit the determining process of each PMI, and may be, but is not limited to, the result of negotiation between the UE and the base station, or the two parties predetermine a certain rule, or the UE directly determines, or the base station notifies the UE, or A specific determination method is determined according to the application scenario.

With the PMI feedback mode described in this embodiment, the PMI in some items between different subcarriers may be the same in different scenarios, and the different PMSCs are integrated corresponding to the respective PMIs, so that the UE is in a process of determining the precoding matrix. Only the common PMI is fed back once, and the common PMI is used to indicate the precoding matrix of different subcarriers, so that the base station passes the common PMI and the non-public PMI under different subcarriers (in this embodiment, the first PMI and the second PMI) The precoding matrix of each subcarrier is determined separately. In this embodiment, the UE sends, to the base station, a PMI that can be commonly used by each subcarrier and a non-public PMI that cannot be commonly used. In the process of determining two subcarrier precoding matrices at a time, the total number of PMIs fed back is K. It is used to indicate Q precoding matrices under two subcarriers, and the number of PMIs fed back is less than the number of Qs, so as to save channel resources. It should be understood that, in the public PMI of the present invention, the first PMI and the second PMI do not necessarily exist independently, and may be referred to as a common PMI, a first PMI, a second PMI, according to an embodiment of the present invention. You can reduce the number of common PMI fields that were originally fed back twice to save the number of bits.

It should be understood that, for different scenarios, the foregoing common PMI and non-public PMI may be determined according to specific scenario characteristics to save channel resources. In the following, the feedback method of the PMI indicated by the precoding matrix shown in FIG. 1 will be specifically introduced in different scenarios:

In an embodiment, for a 3D MIMO scenario or the like, the precoding matrix of the first subcarrier is a first precoding matrix W1 of the first subcarrier and a second precoding matrix of the first subcarrier. a Kronecker product of W2; PMI1 is one of the PMI of the W1 and the PMI of the W2; PMI2 is the other of the PMI of the W1 and the PMI of the W2; the second subcarrier a precoding matrix is a Kronecker product of a third precoding matrix W3 of the second subcarrier and a fourth precoding matrix W4 of the second subcarrier; the PMI1 is a PMI of the W3 and the One of the PMIs of W4; PMI3 is the other of the PMI of the W3 and the PMI of the W4. When W1 is a vertical direction precoding matrix of the first subcarrier, W2 is a horizontal direction precoding matrix of the first subcarrier; when W3 is the The vertical direction precoding matrix of the two subcarriers, and W4 is the horizontal direction precoding matrix of the second subcarrier.

Figure 2 illustrates a specific embodiment of the invention. The precoding matrix of the first subcarrier is a Kronecker product of a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier; the second subcarrier a precoding matrix is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier; the common PMI is used to indicate the first subcarrier a vertical direction precoding matrix; the common PMI is further configured to indicate a vertical direction precoding matrix of the second subcarrier; the first PMI is used to indicate a horizontal direction precoding matrix of the first subcarrier; The PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.

Specifically include:

Step 201: The user equipment UE determines at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI is used to indicate a vertical direction precoding matrix; the at least one first PMI is used to And indicating a first subcarrier horizontal direction precoding matrix; the at least one second PMI is used to indicate a second subcarrier horizontal direction precoding matrix.

Step 202: The UE sends the at least one common PMI, the at least one first PMI, and the at least one second PMI to a base station, where the at least one common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier, where the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier.

For 3D MIMO or the like, the antenna distribution can be regarded as being arranged in a vertical direction and in a horizontal direction. Therefore, the precoding matrix of the first subcarrier can be regarded as a vertical direction precoding matrix and a horizontal direction precoding matrix. The precoding matrix of the second subcarrier may be regarded as a vertical direction precoding matrix and a horizontal direction precoding matrix. For example, the precoding matrix of the first subcarrier is the first precoding matrix W1 of the first subcarrier and a Kronecker product of the second precoding matrix W2, when the precoding matrix of the second subcarrier is a Kronecker product of the third precoding matrix W3 and the fourth precoding matrix W4 of the second subcarrier, That is to say:

Wherein W _(CA1) is a precoding matrix of the first subcarrier, W _(CA2) is a precoding matrix of the second subcarrier, and W _{(CA1, 1)} is a first subcarrier vertical direction precoding matrix. , W _{(CA1, 2)} is the first subcarrier horizontal direction precoding matrix; W _{(CA2, 1)} is the second subcarrier vertical direction precoding matrix, and W _{(CA2, 2)} is the second subcarrier horizontal direction precoding matrix. Since the vertical direction expansion is much smaller than the horizontal expansion in the general scenario, the vertical direction is similar to the single-path channel, and the vertical channel can be determined as a single-path channel model. Further, the UE can be approximated or equivalent to the UE needs. Corresponding PMIs corresponding to the vertical direction precoding matrix of the different subcarriers are equal, corresponding to the PMI _{(CA1, 1)} indicating the first subcarrier vertical precoding matrix W _(CA1, ₁₎ and used for indicating The PMI _{(CA2, 1) of the} second subcarrier vertical precoding matrix W _(CA2, _{1) is} equal, namely:

PMI _(CA1,1) =PMI _(CA2,1) =PMI _C

In such a case, it may be determined that the PMI _C is the at least one common PMI. Correspondingly, determining that the PMI _{(CA1, 2)} used to indicate the first subcarrier horizontal direction precoding matrix W _(CA1, ₂₎ is the at least one first PMI; determining to indicate the second subcarrier The PMI _{(CA2, 2)} of the horizontal direction precoding matrix W _(CA2, ₂₎ is the at least one second PMI. Based on the above conditions, i.e. similar to a single-path channel in the vertical direction can be guaranteed at a transmission _PMI _C, PMI _(CA1,2), where _{PMI (CA2,2)} according to the PMI _C and _{PMI (CA1,2)} Indicating the W _(CA1) ; indicating the W _{(CA2, 2)} according to the PMI _C and PMI _(CA2, ₂₎ . The base station determines that PMI _C and the _{PMI (CA1,2)} the W _(CA1); determining the _{W (CA2,2)} based on the PMI _C and PMI _(CA2,2). The determining process here may be determined by the base station negotiation, or may be an indication of receiving the base station or other device or notifying the base station after determining by itself.

In an embodiment, the vertical precoding matrix and/or the horizontal precoding matrix of the first subcarrier indicated by the common PMI is:

According to the description of the above embodiment, when the precoding matrix of the first subcarrier can be decomposed into a vertical direction precoding matrix and a horizontal direction precoding matrix, the PMI indicates the vertical direction precoding matrix and The horizontal direction precoding matrix is characterized in that the angle expansion of the beam in the vertical direction is relatively small, and the UE transmits to the base station a PMI that can be commonly used for each subcarrier and a non-public PMI that cannot be commonly used, wherein two subcarriers are determined at one time. In the process of precoding the matrix, the total number of PMIs fed back is K, which is used to indicate Q precoding matrices under two subcarriers, and the number of PMIs fed back is smaller than the number of Qs, so as to save channel resources. It should be understood that if the position, channel characteristics or other conditions of the antenna change such that the angular spread of the horizontal beam is much smaller than the angular spread of the vertical direction, it can be determined that the horizontal channel is a model of an approximate single-path channel, which can be determined. The PMI indicating the first subcarrier horizontal direction precoding matrix is the at least one common PMI, and the PMI indicating the first subcarrier vertical direction precoding matrix is the at least one first PMI, and is used to indicate the second sub The PMI of the carrier vertical direction precoding matrix is the at least one second PMI. The specific steps and procedures are the same as those in the foregoing embodiment, and details are not described herein again.

It should be understood that the judgment about the channel model may be a condition determined by reaching a certain condition, which may be directly configured or calculated and determined according to the base station or the UE.

In one embodiment, such a PMI may also be determined to be a common PMI when the difference between PMIs in certain items of different subcarriers is less than a certain threshold in some cases. It should be understood that the present invention is not limited to the number of the stator carriers. As long as at least one PMI of each of the multiple subcarriers can be determined as the common PMI according to a preset rule or a certain condition, the channel resources can be saved by reducing the number of PMI feedbacks. the goal of.

In an embodiment, in the W1 and the W2, the precoding matrix corresponding to the first subcarrier of the common PMI is a vector, and/or:

In the W3 and the W4, the precoding matrix corresponding to the first subcarrier of the common PMI is a vector.

For example, the precoding matrix corresponding to the first subcarrier of the common PMI is:

Where N is a positive integer, k is an integer greater than or equal to 0 and less than or equal to N-1; m is the length of the precoding matrix W corresponding to the common PMI, and T represents the transposition of the matrix. It should be understood that the transposition here is merely for the convenience of representing the vector, and the vector may be an array during the calling of the implementation. Alternatively, the above formula may be stored in the system in the form of a matrix. It can be seen that W _p is a vector intercepted in the Fourier matrix. It should be understood that when the precoding matrix of the first subcarrier is not limited to the form shown by W _p , it may be from the following Fourier matrix. Intercept the vector obtained from different locations:

In another embodiment, a feedback method of another PMI is introduced. The method can be, but is not limited to, an antenna scene for 2D MIMO. The precoding matrix of the first subcarrier is a product of a first precoding matrix W ₅ and a second precoding matrix W ₆ of the first subcarrier; the common PMI is the PMI of the W ₅ and the a PMI W ₆ in; the first non PMI common to the other and said W PMI ₅ W PMI ₆ in; the precoding matrix to the second subcarrier of the first sub- a product of a first precoding matrix W ₇ and a second precoding matrix W ₈ of the carrier; the common PMI being one of the PMI of the W _{7 and} the PMI of the W ₈ ; the first non-public PMI is the W PMI ₇ W and the other PMI ₈ in. For example, the precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix (the W ₅ ) of the first subcarrier and a short-term narrowband characteristic matrix (the W ₆ ); the second subcarrier a precoding matrix is a product of a long-term broadband characteristic matrix (the W ₇ ) of the second carrier and a short-term narrowband characteristic matrix (the W ₈ );

The common PMI is used to indicate a long-term broadband characteristic matrix of the first sub-carrier; the common PMI is further used to indicate a long-term broadband characteristic matrix of the second sub-carrier;

The first PMI is used to indicate a short-term narrowband characteristic matrix of the first subcarrier;

The second PMI is used to indicate a short-term narrowband characteristic matrix of the second subcarrier.

In the following, a specific embodiment is given. In this embodiment, a composition method and a determination method of a codebook are specifically given. For some scenarios, the first subcarrier can be decomposed into the W5 and W6 of the product of the second subcarrier can be decomposed into the product of W and the W ₈ _7, wherein said W ₅ denotes a long-term/wideband characteristic of the first subcarrier precoding matrix; the W ₆ represents a short-term/narrowband characteristic of the first sub-carrier; and W ₇ represents a long-term of the second sub-carrier precoding matrix /Broadband characteristics; the W ₈ represents the short-term/narrowband characteristics of the second sub-carrier. That is to say:

W' _(CA1) = W ₅ × W ₆

W' _(CA2) = W ₇ × W ₈

Wherein W' _(CA1) is a precoding matrix of the first subcarrier; W' _(CA2) is a precoding matrix of the second subcarrier; below, first, a W' _(CA1) and a scheme are given relations between W ₅ to be a PMI _{(PMI. 5)} and the corresponding W ₆ PMI _{(PMI. 6),} the corresponding, W _'(CA2) to the corresponding _₇ PMI ₇ W and W ₈ corresponding to the PMI The relationship of ₈ can be the same. If there is a codebook set B is:

B=[b ₀ ,b ₁ ,...b ₃₁ ]

Where b ₀ , b ₁ ... b ₃₁ are column vectors, and the 1+m row 1+n column element B in B is _{1+m, 1+n} is:

It should be understood that, in this example, for convenience of describing each element therein, the codebook set B is in the form of a matrix, and the codebook set may also be a column in B, and form a set in the form of a vector.

The PMI ₅ for instructing the base station to select at least one from the codebook set and constituting the W _5, specifically, k = PMI _5, and a is an integer value in the range between 0-15, for Select (instruction) 4 columns from B to get X ^(k) :

X ^(k) = [b _2kmod32 b _{(2k+1) mod32} b _{(2k+2) mod32} b _{(2k+3) mod32} ]

Where mod is the modulo symbol.

Further obtaining the W ₅ = W ₅ ^(k) :

Constructing a codebook set C ₁ according to the W ₅ ^(k) :

C ₁ ={W ₁ ⁽⁰⁾ , W ₁ ⁽¹⁾ , W ₁ ⁽²⁾ ,...,W ₁ ⁽¹⁵⁾ }

The W ₅ ^(k) matrix characterizes the long-term broadband characteristics of the channel. On the other hand, another PMI (referred to as PMI ₆ for convenience of presentation) is used to instruct the base station to select at least one element from the codebook set C ₁ ( The codebook) and constitutes the W ₆ . For different RI, different configurations codebook set C _2. For example, when RI=1, the codebook set can be constructed in the following form:

Among them, Y∈{α ₁ , α ₂ , α ₃ , α ₄ }. α can be a vector with only 1 positions per column.

When RI=2, the codebook set can be constructed as follows:

Wherein, Y _1, Y ₂ in the order of (Y _1, Y ₂₎ may be any combination of α ₁ to α _4, it may also be in the form:

(Y ₁ , Y ₂ ) ∈ {(α ₁ , α ₁ ), (α ₂ , α ₂ ), (α ₃ , α ₃ ), (α ₄ , α ₄ ), (α ₁ , α ₂ ), ( α ₂ , α ₃ ), (α ₁ , α ₄ ), (α ₂ , α ₄ )}

When the RI = 1, according to the PMI _6, W ₆ is determined as an element from C _2,1; when the RI = 2, in accordance with PMI _6, an element is determined from C _{2, 2} as W _6.

Corresponding, the formula:

W' _(CA1) = W ₅ × W ₆

It can be said that the selection matrix W ₆ selects a superposition of certain columns from W ₅ to form a precoding matrix corresponding to the first subcarrier. The above W ₅ ^(k) includes a matrix of 4 beams, indicating long-term broadband channel characteristics, which can be shared by the first subcarrier and the second subcarrier, and therefore, one W ₅ can be shared for different subcarriers, and each sub- The carrier can separately feed back the PMI ₆ corresponding to the matrix W ₆ representing the short-term narrowband characteristics and the PMI ₈ corresponding to the matrix W ₈ representing the short-term narrowband characteristics. It should be understood that the specific numerical values in the above examples are only one example given for the purpose of the description, and may vary from antenna port, rank indication, or other parameters in a particular application. And the codebook and the selection manner are all exemplary descriptions, and the present invention claims a codebook in other forms and a manner of selecting a codebook.

The above W' _(CA1) = W ₅ × W ₆ and W' _(CA2) = W ₇ × W ₈ form, specifically applicable to 2D MIMO scenarios, the precoding matrix can be specifically determined by the long-term broadband characteristics of the signal and short-term The case of the product represented by the narrowband characteristic. Figure 3 shows the specific implementation steps when a precoding matrix can be shared due to the long-term broadband characteristics of its subcarriers.

Specifically, in step 301, the user equipment UE determines at least one public PMI, at least one first PMI, At least one second PMI, wherein the at least one common PMI is used to indicate a long-term broadband characteristic matrix; the at least one first PMI is used to indicate that a short-term narrowband characteristic matrix is embodied in the first sub-carrier; the at least one second The PMI is used to indicate that the short-term narrowband characteristic matrix is reflected in the second subcarrier.

Step 302: The UE sends the at least one common PMI, the at least one first PMI, and the at least one second PMI to a base station, where the at least one common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier, where the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier.

It should be understood that the present invention is not limited to the mutual integration between the various embodiments. In the specific determination of the order and specific manner of determining the PMI, the embodiments in FIGS. 2 and 3 may all be performed in the embodiment 1-3 shown in FIG. 1. , will not repeat them here.

For convenience of understanding, the present invention further provides a specific implementation method for specifically determining a PMI by using a lookup table, where the precoding matrix can be used by a first subcarrier precoding matrix and a second subcarrier precoding matrix. A scene constructed in the form of a product. It should be understood that the lookup table in the present invention may be to check a table stored in the UE or the base station, where the table includes a correspondence between the PMI and the matrix, and the table may be multiple in consideration of a specific application, so as to have Under different RI values or other parameters, the PMI and the specific precoding submatrix correspond to different tables. The UE acquires the information required in the table; or an array or a relationship, and is used to query the PMI value corresponding to the corresponding precoding matrix. It should be understood that the specific form of the table may be multiple, and may be a mapping relationship or a function relationship stored in the UE or the base station, which is not limited by the present invention. For convenience of description, the present embodiment is described in the form of a table. Determining, by the UE, a long-term broadband matrix corresponding to the first sub-carrier and the second sub-carrier, and determining a corresponding table in the corresponding rank, for example, the value of the rank indication is in the range of 1-4, and then determining that the corresponding needs are in Tables 1 to 4 Table (Table 1 corresponds to rank indication 1, Table 2 corresponds to rank indication 2, Table 3 corresponds to rank indication 3, and Table 4 corresponds to rank indication 4):

Table 1

Table 2

table 3

Table 4

Determining one of the tables 1-4 according to the RI, and determining, in the determined table, the long-term broadband characteristic matrix of the CA1 and the CA2 according to a specific use scenario, further determining according to the long-term broadband characteristic matrix The value of the common PMI(i ₁ ) is determined according to the short-term narrowband characteristic matrix of the CA1 and the PMI corresponding to the short-term narrowband characteristic matrix of the CA2, respectively, and the value of the first PMI(i ₂ ) corresponding to CA1 is determined. The value of the second PMI (i ₂ ') corresponding to the CA2 transmits a value of the terms i1, i2, i2' to the base station.

In the determined table, a specific manner of determining the values of the common PMI (i ₁ ) of the CA1 and the CA2 may be determined according to channel characteristics, and in Tables 1 to 4, PMI(i ₁ ) , PMI(i ₂ ) is used to determine

The value of m/n, since the characteristics determined by PMI(i ₁ ) correspond to the short-term narrow-band characteristics in the physical sense, the values may be the same in different CAs. Therefore, in this embodiment, the PMI of CA1 (i ₁ ) and P2(i ₁ ) of CA2 can be used as a public PMI.

In addition to using the PMI corresponding to the short-term narrow-band characteristic matrix as the common PMI, the PMI value of the long-term broadband characteristic matrix corresponding to the CA1 and the PMI value of the long-term broadband characteristic matrix corresponding to the CA2 may be respectively confirmed, and then selected from the PMI value. One out as the public PMI. It should be understood that if there are multiple CAs, such as CA1, CA2, and CA3, a common PMI can be determined. For example, the PMI corresponding to the short-term narrowband characteristic matrix of CA1, CA2, and CA3 can be used as a common PMI, and the UE only feedbacks. With 1 public PMI, the short-term narrow-band characteristic matrix of the three carriers can be indicated to achieve further resource saving. Of course, the present embodiment is also applicable to the long-term broadband characteristic and the vertical direction and horizontal direction precoding matrix, and details are not described herein again. Of course, multiple CAs can also have multiple public PMIs.

The embodiment shown in FIG. 3 may be shared with other subcarriers according to the long-term broadband characteristic matrix of the first subcarrier precoding matrix in the table, and the PMI corresponding to different subcarriers may be used as a common PMI to determine two precodings of different subcarriers. Sending the common PMI once in the case of a matrix, and transmitting, to the base station, a non-common PMI that cannot be commonly used by each subcarrier, to indicate four sub precoding matrices under two subcarriers (ie, the first subcarrier and the second subcarrier) The long-term broadband characteristic matrix and the short-term narrowband characteristic matrix respectively, and the number of PMIs fed back is smaller than the number of all four sub-precoding matrices that can be determined by the k PMIs, so as to save channel resources. It should be understood that the long-term broadband characteristic matrix according to the first subcarrier precoding matrix in the table may be shared with other subcarriers, and in other scenarios, the short-term narrowband characteristic matrix may be shared with other subcarriers. Corresponding to the determination manner in this embodiment, and details are not described herein again.

It should be understood that the embodiments of the present invention all determine the PMI under two subcarriers, and the present invention claims that when the number of subcarriers is more than two, the respective PMIs of the two subcarriers may be shared with other subcarriers. The PMI may be different from the PMI that is fed back by any one of the at least two subcarriers, and the PMI corresponding to the several subcarriers takes the form of separate feedback. For example, there are 3 subcarriers CA1, CA2, CA3, wherein although there are one or more common PMIs in CA1 and CA2, the UE cannot determine any PMI of CA3 and any PMI of CA2 and CA1. Given a public PMI, then the UE will separately feed back all PMIs of the CA3.

In the following, a further embodiment will be described in terms of a method of specifically determining a public PMI for the present invention. According to the embodiment shown in FIG. 1-3 above, when it is determined that a certain PMI _a of the first subcarrier is different from a certain PMI _{b of the} second subcarrier, but PMI _{a is} used as the PMI _{b of the} second subcarrier When the channel characteristic of the system is within a certain tolerance range or a certain condition is met, the PMI _a may be directly determined to be the common PMI; correspondingly, when the PMI _{a is} used as the PMI _b indicating the second subcarrier, When the channel characteristic of the system is within a certain tolerance range or a certain condition is met, the PMI _a may also be directly determined to be the common PMI; or when a PMI _{c is} used as the common of the first subcarrier and the second subcarrier. In the PMI, when the PMI _a and the PMI _b can be used, when the channel characteristics of the system can satisfy a certain condition, the PMI _c can be directly determined as the at least one common PMI. Optionally, the UE may determine the at least one common PMI, the at least one first PMI, the at least one second PMI, and a compensation value δ, wherein the at least one common PMI and the at least one first The PMI is configured to determine a precoding matrix of the first subcarrier; the at least one common PMI, the at least one second PMI, and the δ collectively indicate a precoding matrix of the second subcarrier, and send the to the base station At least one common PMI, the at least one first PMI, the at least one second PMI, and one compensation value δ. It should be understood that the PMI of the second subcarrier may also be determined as the at least one common PMI, and a compensation value δ′ is sent, according to the at least one common PMI, the δ′, and the at least one first PMI. a precoding matrix of the first subcarrier; determining a precoding matrix of the second subcarrier according to the at least one common PMI and the second PMI. Generally, the number of bits or resources occupied by δ is smaller than the number of bits or resources occupied by one PMI. In this case, the purpose of more accurately indicating the precoding matrix of the two subcarriers in the case of resource saving can be achieved.

Optionally, the UE determines and sends a first PMI compensation value δ ₁ and/or a second PMI compensation value δ ₂ , where the δ _{1 is} used together with the at least one common PMI and the at least one first PMI. Determining a precoding matrix of the first subcarrier; the δ _{2 is} configured to jointly determine a precoding matrix of the second subcarrier with the at least one common PMI and the at least one second PMI.

The above-mentioned UE determines and transmits the first PMI compensation value δ ₁ and/or the second PMI compensation value δ ₂ into three cases:

Situation 1:

The UE determines the δ ₁ and δ ₂ and transmits the δ ₁ and δ ₂ to the base station;

Case 2:

The UE determines the δ ₁ and sends the δ ₁ to the base station;

Case 3:

The UE determines the δ ₂ and transmits the δ ₂ to the base station.

It should be understood that the order of the δ ₁ and δ ₂ and the PMI that the UE needs to feed back is not limited, and may be sent simultaneously or sequentially. According to the different scenarios of the public PMI, the present invention provides three specific implementation manners:

Embodiment 4:

When the precoding matrix of the first subcarrier is a Kronecker product of the first precoding matrix W1 and the second precoding matrix W2 of the first subcarrier, the precoding matrix of the second subcarrier is the Under the scenario of the Kronecker product of the third precoding matrix W3 of the second subcarrier and the fourth precoding matrix W4:

Since the angular expansion in the vertical direction is much smaller than the angular expansion in the horizontal direction, the vertical direction approximates the single-path channel, and the vertical direction channel can be determined to be approximately a single-path channel model. As an example, in Embodiment 4, W _{(CA1) is} determined. ₁₎ Corresponding PMI _(CA1 _{, 1)} as one of the common PMIs, determining that the difference between the PMI _(CA1 _{, 1) and} the PMI _(CA2 _{, 1)} corresponding to the W _(CA2, ₁₎ can be used by δ _a OK. Determining that the PMI _(CA1, ₂₎ corresponding to W _(CA1, ₂₎ is the first PMI, and determining that the PMI _(CA2, ₂₎ corresponding to W _(CA2, ₂₎ is the second PMI, where the public PMI is The first PMI is used to determine (instruct) W _{(CA1, 1)} and the W _(CA1 , ₂₎ , respectively, the common PMI, the δ _a determines the W _{(CA2, 1)} , The second PMI describes W _(CA2 , ₂₎ to confirm the first subcarrier precoding matrix W _(CA1) , W _(CA2) . It should be understood that the method of determining the PMI _{(CA2, 1)} as the common PMI, the corresponding use δ _a ' and the common PMI indicating the W _(CA1) may be the same as the above method, and details are not described herein again.

Embodiment 5:

When the precoding matrix of the first subcarrier is a product of the first precoding matrix W5 and the second precoding matrix W6 of the first subcarrier; the precoding matrix of the second subcarrier is the first Under the scenario of the product of the first precoding matrix W7 and the second precoding matrix W8 of the subcarriers:

W' _(CA1) = W ₅ × W ₆

W' _(CA2) = W ₇ × W ₈

Represents CA1 long wideband channel characteristic matrix W5 can use the PMI ₅ indicates a matrix representing channel characteristics CA2 long wideband channel W7 can ₅ and a compensation value PMI δ _b indicates, as one example, is determined W5 corresponding PMI (PMI ₅₎ as The common PMI, the PMI (PMI ₆ ) corresponding to W6 is the first PMI, and the PMI (PMI ₈ ) corresponding to W8 is the second PMI. In one embodiment, the common PMI is used to determine (instruct) the W5, for determining the first PMI (indication) of the W6, the second PMI is used to indicate the W8, the common PMI and the δ _b for indicating the W7, W5 said W6 is used to determine the W' _(CA1) , the W7, and the W8 are used to determine the W'_(CA2); in another embodiment, the correspondence in the table 1-4 is determined according to the rank indication after the common PMI and the δ _b 'calculates; table, said correspondence table in common PMI i _1, the first table corresponding to the PMI i _2, the first subcarrier determining the precoding matrix W The obtained value corresponds to i ₁ in the table, i ₂ in the second PMI correspondence table, and the precoding matrix W ₂ corresponding to the second subcarrier is determined. It should be understood that the method of determining the PMI 7 as the common PMI is the same as the above embodiment, and details are not described herein again.

Embodiment 6:

According to the above embodiment, it is also possible to simultaneously give two compensation values, δ _c and δ _d . In this case, the δ _{c is} used to determine a precoding matrix of the first subcarrier together with the at least one common PMI and the at least one first PMI; the δ _{d is} used for the at least one The common PMI and the at least one second PMI jointly determine a precoding matrix of the second subcarrier.

It should be understood that when the compensation value compensation is involved, the base station and the UE may specify that the compensation value is not compensated for a certain feedback, and the compensation mode may be adopted by signaling or other convention.

It should be understood that the foregoing various embodiments for determining the compensation value are given the basis or sequence of the determination. The specific determination method is not limited in the present invention, and the determination manner of the compensation value may be different according to the number of allocated bits, for example, when public When the PMI is used to indicate that the error of the first subcarrier precoding matrix and the second subcarrier precoding matrix are not large (that is, can be within the tolerance range), one bit can be allocated, 0 represents no compensation, and 1 represents compensation. The compensation value may be predefined; in one embodiment, PMI _X and PMI _{Y are} used to indicate a first subcarrier precoding matrix, and PMI _Z and PMI _{W are} used to indicate a second subcarrier precoding matrix. When determining that the common PMI may be indicating the values of PMI _X and PMI _Z at the same time, that is, using the common PMI and PMI _Y (where PMI _{Y is} equivalent to the first PMI) indicating the precoding matrix of the first subcarrier; using the common PMI and PMI _Z (where PMI _{W is} equivalent to the second PMI) indicating a precoding matrix of the second subcarrier; when determining PMI _X = 7, it may be common with the first PMI (which may be PMI _Y in this embodiment) Indicates the first subcarrier precoding matrix. If the difference between the PMI _W and the PMI _X is not the same or the same, the PMI _W = 7 can be determined. In this case, as long as the UE determines δ=0 and sends δ, it can notify that no compensation is needed. However, if the system determines that the second subcarrier precoding matrix can be specified with PMI _W = 10 and the second PMI (which may be PMI _W in this embodiment), then the public PMI = 7 and the described The second PMI collectively indicates that the second subcarrier precoding matrix introduces a relatively large error. However, if the system preset compensation value δ=1 represents compensation 3, then 1 bit can accurately indicate that the base station side needs to recompensate 3 with a common PMI=7, and then determine the second subcarrier precoding matrix together with the second PMI. . It should be understood that, in this case, in some scenarios, if the compensation value δ=1 preset by the system represents compensation 2, the value indicated by the common PMI and the compensation value is 9 if it is within a certain tolerance range. , can also be accepted.

It should be understood that the above-described method of determining and transmitting the compensation value is merely an example, and within a logical range, the determination of the compensation value can be combined with any one of the embodiments for transmitting the compensation value, and other embodiments of the present invention.

The vertical direction precoding matrix or the long-term broadband characteristic precoding matrix of a certain subcarrier may be determined by using a single path characteristic of different subcarriers in the vertical direction or a long-term broadband characteristic of different subcarriers. A common PMI is further determined by a compensation value δ; a vertical direction precoding matrix or a long-term broadband characteristic precoding matrix of another subcarrier is indicated according to the δ and the common PMI. And indicating, according to the first PMI and the second PMI, a precoding matrix under the different subcarriers, thereby saving channel resources and improving indication precision.

4 is a schematic flowchart of a communication method according to an embodiment of the present invention, relating to a feedback method of a precoding matrix indicating PMI for a wireless communication system having multi-carrier capability, a base station in the wireless communication system The first subcarrier and the second subcarrier are used to communicate with the base station.

Specifically include:

Step 401: The base station receives at least one public PMI, at least one first PMI, and at least one second PMI.

Step 402: The base station determines, according to the at least one common PMI, the at least one first PMI, and the at least one second PMI, a precoding matrix of the first subcarrier and a precoding matrix of the second subcarrier, where the at least one a common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate the second subcarrier The precoding matrix of the wave.

Hereinafter, the steps of the receiving step in step 401 and the determining at least one of the common PMI, the at least one first PMI, and the at least one second PMI in step 401 will be specifically described in the form of an example. For example, for the first subcarrier CA1, the base station needs to determine that the four PMIs are respectively PMI1/2/3/4, and the four PMIs are used to indicate the precoding matrix of the CA1; for the second subcarrier CA2, the base station needs to determine 4 The PMIs are PMI5/6/7/8, respectively, which are used to indicate the precoding matrix of the CA2. In an embodiment, PMI1, PMI2 may jointly indicate a sub-precoding matrix W _A1 under the CA1; PMI3, PMI4 may indicate another sub-precoding matrix W _B1 under CA1, and then by W _A1 , W _B1 and The determined operational relationship determines the CA1 precoding matrix W _A1B1 . PMI5, PMI6 may jointly indicate a sub-precoding matrix W _A2 under the CA2; PMI7, PMI8 may indicate another sub-precoding matrix W _B2 under CA2, and then determined by the W _A2 , W _B2 and the determined operational relationship CA1 precoding matrix W _A2B2 . The specific determination manner may be different, and the present invention is not limited, and may be determined in the form of calculating parameters of the precoding matrix. For example, the UE and/or the base station may calculate W _A1 according to two parameters of PMI1 and PMI2, or The UE and/or the base station may also store or predetermine a table, and may query the corresponding W _A1 according to PMI1 or PMI2, or PMI1/2/3/4 may be 4 parameters, PMI5/6/7. /8 can be 4 parameters, and the precoding matrix is directly calculated. It should be understood that the need to feed back 4 PMIs under one carrier is only an example, and in actual situations, other situations may occur. Each embodiment of the present application does not specifically refer to four PMIs. At least one PMI in the CA1 is the same as or similar to at least one PMI in the CA2 according to a certain channel condition or channel model. Then, the at least one PMI of CA1 and the at least one PMI of the CA2 may be determined as the common PMI. Wherein, the approximation here is equivalent, for example, even if the two PMIs are different, the difference between the two PMIs is small, and the final base station according to the respective calculated CA1 precoding matrix and the channel model of the CA2 precoding matrix are Can be tolerated within the scope. For example, PMI1 and PMI5 correspond to each other. When certain conditions are met, it can be determined as public PMI _C1 ; PMI3 and PMI7 correspond to each other and can be determined as public PMI _C2 , namely:

PMI ₁ = PMI ₅ = PMI _C1

PMI ₃ = PMI ₇ = PMI _C2

Then, referring to step 401, the base station may receive a common PMI: PMI _C1 , PMI _C2 ; and a first PMI: PMI2, PMI4; and a second PMI: PMI6, PMI8. The method of determining the common PMI is usually determined by the channel characteristics. For example, PMI1 and PMI5 are used to indicate certain matrix parameters, which are related in some scenarios (such as high-rise scenes or wide-area scenes). High, whose values are equal or the difference is negligible; or PMI1 and PMI5, in some scenarios, indicate a matrix set of the same type of matrix in the table, and other PMI2/PMI6 further indicate one of the matrix sets. The matrix (which is an element in the matrix set), then PMI1 and PMI5 can be determined to be the common PMI ₁ in many identical scenarios; similarly, PMI3 and PMI7 can also use the above indication. Alternatively, the base station side may directly determine that the PMI _C1 and the PMI _C2 are common PMIs, and the PMI _C1 represents PMI1/PMI5, and the PMI _C2 represents PMI3/PMI7, and is sent to the UE.

The base station may preset a rule, or determine a common PMI, a first PMI, and a second PMI with the UE in a negotiated manner, or directly refer to the public PMI, the first PMI, or the other PMI in the signaling or other signaling of the feedback PMI. a second PMI, the base station determining the precoding matrix according to the indication. For example, in a high-rise scenario, the PMI ₁ and the PMI _{5 are} determined to be a public PMI, and the preset rule is also in the UE with which it interacts. This indication process can also come from other UEs or other network side devices.

It should be understood that, in the present invention, in step 402, the base station determines, according to the at least one common PMI, the at least one first PMI, and the at least one second PMI, a precoding matrix of the first subcarrier and a precoding of the second subcarrier. The specific process of the matrix may be that different RIs correspond to different PMI tables, and after the base station determines the value of the RI, the base station determines, from the plurality of PMI tables, a PMI table corresponding to the value of the RI, The PMI table may include a correspondence between a PMI and a precoding matrix and/or a correspondence between a PMI and a precoding submatrix. The precoding matrix of CA1 is determined according to the common PMI and the first PMI, or the precoding matrix corresponding to CA2 is determined by the common PMI and the second PMI. The PMI table may be a specific table or a plurality of corresponding relationship sets stored in the UE and/or the base station.

With the PMI receiving and determining manners in this embodiment, the PMIs in some items between different subcarriers may be the same in different scenarios, and different subcarriers are integrated corresponding to the respective PMIs, so that the base station performs a certain precoding. In the process of the matrix, only the common PMI is received once, and the common PMI is used to indicate the precoding matrix of different subcarriers, so that the base station passes the common PMI and the non-public PMI under different subcarriers (in this embodiment, the first PMI, The second PMI) determines the precoding matrix of each subcarrier, respectively. In this embodiment, the base station receives a PMI that can be commonly used by each subcarrier and a non-public PMI that cannot be commonly used. In the process of determining two subcarrier precoding matrices at a time, the total number of received PMIs is K, which is used to indicate Q precoding matrices under two subcarriers, and the number of PMIs fed back is less than the number of Qs, so as to save channel resources. It should be understood that the public PMI, the first PMI and the second PMI of the present invention It may not be independent, and may be referred to as a common PMI, a first PMI, and a second PMI according to different fields of the same message. According to an embodiment of the present invention, the public PMI field originally fed back twice may be reduced by one to save. The effect of the number of bits.

In an embodiment, for a 3D MIMO scenario or the like, the precoding matrix of the first subcarrier is a first precoding matrix W1 of the first subcarrier and a second precoding matrix of the first subcarrier. a Kronecker product of W2; PMI1 is one of the PMI of the W1 and the PMI of the W2; PMI2 is the other of the PMI of the W1 and the PMI of the W2; the second subcarrier a precoding matrix is a Kronecker product of a third precoding matrix W3 of the second subcarrier and a fourth precoding matrix W4 of the second subcarrier; the PMI1 is a PMI of the W3 and the One of the PMIs of W4; PMI3 is the other of the PMI of the W3 and the PMI of the W4. When W1 is a vertical direction precoding matrix of the first subcarrier, W2 is a horizontal direction precoding matrix of the first subcarrier; and when W3 is a vertical direction precoding matrix of the second subcarrier, W4 is When the horizontal direction precoding matrix of the second subcarrier is described.

Figure 5 shows a specific embodiment of the invention. The precoding matrix of the first subcarrier is a Kronecker product of a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier; the second subcarrier a precoding matrix is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier; the common PMI is used to indicate the first subcarrier a vertical direction precoding matrix; the common PMI is further configured to indicate a vertical direction precoding matrix of the second subcarrier; the first PMI is used to indicate a horizontal direction precoding matrix of the first subcarrier; The PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.

Specifically include:

Step 501: The base station receives at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI is used to indicate a vertical direction precoding matrix; and the at least one first PMI is used to indicate a subcarrier horizontal direction precoding matrix; the at least one second PMI is used to indicate a second subcarrier horizontal direction precoding matrix.

Step 502: The base station determines, according to the at least one common PMI, the at least one first PMI, and the at least one second PMI, a precoding matrix of the first subcarrier and a precoding matrix of the second subcarrier, where the at least one common PMI And the at least one first PMI is used to indicate a precoding matrix of the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate the second subcarrier Precoding matrix.

Where W _(CA1) is a precoding matrix of the first subcarrier, W _(CA2) is a precoding matrix of the second subcarrier, and W _{(CA1, 1)} is a first subcarrier vertical direction precoding matrix. , W _{(CA1, 2)} is the first subcarrier horizontal direction precoding matrix; W _{(CA2, 1)} is the second subcarrier vertical direction precoding matrix, and W _{(CA2, 2)} is the second subcarrier horizontal direction precoding matrix. Since the vertical direction expansion is much smaller than the horizontal expansion in the general scenario, the vertical direction is similar to the single-path channel, and the vertical channel can be determined as a single-path channel model. Further, the UE can be approximated or equivalent to the UE needs. Corresponding PMIs corresponding to the vertical direction precoding matrix of the different subcarriers are equal, corresponding to the PMI _{(CA1, 1)} indicating the first subcarrier vertical precoding matrix W _(CA1, ₁₎ and used for indicating The PMI _{(CA2, 1) of the} second subcarrier vertical precoding matrix W _(CA2, _{1) is} equal, namely:

PMI _(CA1,1) =PMI _(CA2,1) =PMI _C

In such a case, the base station may determine that the PMI _C of the UE is the at least one public PMI. Correspondingly, the base station may determine that the PMI _{(CA1, 2)} used to indicate the first subcarrier horizontal direction precoding matrix W _(CA1, ₂₎ is the at least one first PMI; and determine to indicate the second The PMI _{(CA2, 2)} of the subcarrier horizontal direction precoding matrix W _(CA2, ₂₎ is the at least one second PMI. Based on the above conditions, that is, approximating the single-path channel in the vertical direction, it can be ensured that according to the PMI _C and the PMI ₍ in the case of receiving the PMI _C , PMI _(CA1 , ₂₎ , PMI _{(CA2, 2)} sent by the UE _{( CA1, 2)} determines the W _(CA1) ; determines the W _{(CA2, 2)} according to the PMI _C and PMI _(CA2, ₂₎ . The base station determines that PMI _C and the _{PMI (CA1,2)} the W _(CA1); determining the _{W (CA2,2)} based on the PMI _C and PMI _(CA2,2). The determination here may also be determined by the receiving UE or other device, or both.

According to the description of the above embodiment, when the precoding matrix of the first subcarrier can be decomposed into a vertical direction precoding matrix and a horizontal direction precoding matrix, the PMI respectively indicates a vertical direction precoding matrix and a horizontal direction precoding matrix, and utilizes The angle expansion of the beam in the vertical direction is relatively small. The base station receives a PMI that the UE can use for each subcarrier and a non-public PMI that cannot be commonly used. The process of determining the precoding matrix of two subcarriers at a time is performed. The total number of PMIs fed back is K, which is used to indicate Q precoding matrices under two subcarriers, and the number of PMIs fed back is less than the number of Qs, so as to save channel resources. It should be understood that if the position, channel characteristics or other conditions of the antenna change such that the angular spread of the horizontal beam is much smaller than the angular spread of the vertical direction, it can be determined that the horizontal channel is a model of an approximate single-path channel, which can be determined. The PMI indicating the first subcarrier horizontal direction precoding matrix is the at least one common PMI, and the PMI indicating the first subcarrier vertical direction precoding matrix is the at least one first PMI, and is used to indicate the second sub The PMI of the carrier vertical direction precoding matrix is the at least one second PMI. The specific steps and procedures are the same as those in the foregoing embodiment, and details are not described herein again.

W' _(CA1) = W ₅ × W ₆

W' _(CA2) = W ₇ × W ₈

B=[b ₀ ,b ₁ ,...b ₃₁ ]

X ^(k) = [b _2kmod32 b _{(2k+1) mod32} b _{(2k+2) mod32} b _{(2k+3) mod32} ]

Where mod is the modulo symbol.

Further obtaining the W ₅ = W ₅ ^(k) :

Constructing a codebook set C ₁ according to the W ₅ ^(k) :

When RI=2, the codebook set can be constructed as follows:

Corresponding, the formula:

W' _(CA1) = W ₅ × W ₆

The above W' _(CA1) = W ₅ × W ₆ and W' _(CA2) = W ₇ × W ₈ form, specifically applicable to 2D MIMO scenarios, the precoding matrix can be specifically determined by the long-term broadband characteristics of the signal and short-term The case of the product represented by the narrowband characteristic. Figure 6 shows the specific implementation steps when a precoding matrix can be shared due to the long-term broadband characteristics of its subcarriers.

Specifically, in step 601, the base station receives at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI is used to indicate a long-term broadband characteristic matrix; the at least one first PMI is used by And indicating a short-term narrowband characteristic matrix in the first subcarrier; the at least one second PMI is used to indicate that the short-term narrowband characteristic matrix is reflected in the second subcarrier.

Step 602: The base station determines, according to the at least one common PMI, the at least one first PMI, and the at least one second PMI, a precoding matrix of a first subcarrier and a precoding matrix of a second subcarrier, where the at least one a common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate precoding of the second subcarrier matrix.

For convenience of understanding, the present invention further provides a specific implementation method for specifically determining a PMI by using a lookup table, where the precoding matrix can be used by a first subcarrier precoding matrix and a second subcarrier precoding matrix. A scene constructed in the form of a product. It should be understood that the lookup table in the present invention may be to check a table stored in the UE or the base station, where the table includes a correspondence between the PMI and the matrix, and the table may be multiple in consideration of a specific application, so as to have Under different RI values or other parameters, the PMI and the specific precoding submatrix correspond to different tables. The base station acquires the information required in the table; or an array or relationship for querying the precoding matrix corresponding to the corresponding PMI value. It should be understood that the specific form of the table may be multiple, and may be a mapping relationship or a function relationship stored in the UE or the base station, which is not limited by the present invention. For convenience of description, the present embodiment is described in the form of a table. Determining, by the base station, the first subcarrier and the second subcarrier according to the PMI Long-term broadband matrix, the corresponding table is determined in the corresponding rank, for example, the value of the rank indication ranges from 1-4, then the corresponding table is determined in Table 1 to Table 4 (Table 1 corresponds to rank indication 1, Table 2 Corresponding rank indication 2, Table 3 corresponding rank indication 3, Table 4 corresponding rank indication 4):

Table 1

Table 2

table 3

Table 4

Determining one of the tables 1-4 according to the RI, after the base station receives the public PMI (i1), the first PMI (i2), and the second PMI (i2'), and then in the determined table, according to Determining, by a specific usage scenario, a long-term broadband characteristic precoding matrix corresponding to the value of the common PMI (i ₁ ) of the CA1 and the CA2, and determining a short-term narrowband characteristic of the CA1 according to the first PMI and the second PMI A matrix and a short-term narrow-band characteristic matrix of the CA2.

It should be understood that if there are multiple CAs, such as CA1, CA2, and CA3, a common PMI can also be received. For example, the PMI corresponding to the short-term narrowband characteristic matrix of CA1, CA2, and CA3 can be used as a public PMI, and the public PMI is fed back once. The short-term narrowband characteristic matrix of the three carriers may be indicated, and the base station receives the public PMI fed back by the UE to achieve further resource saving. Of course, the present embodiment is also applicable to the long-term broadband characteristic and the vertical direction and horizontal direction precoding matrix, and details are not described herein again. Of course, multiple CAs can also have multiple public PMIs.

In the embodiment shown in FIG. 6, the long-term broadband characteristic matrix of the first subcarrier precoding matrix in the table may be shared with other subcarriers, and the PMI corresponding to different subcarriers may be used as a common PMI, and the base station determines different subcarriers. The common PMI is received once in the case of two precoding matrices, and the base station receives a non-common PMI that is not commonly used by each subcarrier transmitted by the UE, and is used to indicate four sub precoding matrices (ie, the first subcarrier) under two subcarriers. The long-term broadband characteristic matrix and the short-term narrowband characteristic matrix of the carrier and the second sub-carrier respectively, and the number of received PMIs is smaller than the number of all four sub-precoding matrices that can be determined by the k PMIs to save channel resources. purpose. It should be understood that the long-term broadband characteristic matrix according to the first subcarrier precoding matrix in the table may be shared with other subcarriers, and in other scenarios, the short-term narrowband characteristic matrix may be shared with other subcarriers. Corresponding to the determination manner in this embodiment, and details are not described herein again.

It should be understood that the embodiments of the present invention both determine a precoding matrix under two subcarriers, and the present invention claims that when there are more than two subcarriers, the respective PMIs of the two subcarriers may be associated with other sub-carriers. The PMI shared by the carrier may be different. The sub-carrier may also have a plurality of sub-carriers different from the PMI fed back by any one of the at least two sub-carriers, and the PMI corresponding to the several sub-carriers adopts separate feedback. form. For example, there are 3 subcarriers CA1, CA2, CA3, wherein, although one or more common PMIs exist in CA1 and CA2, but all PMIs of CA3 cannot be associated with any PMI of CA1 or CA2 as a common PMI, then the base station will be based on All PMIs of the CA3 are individually fed back to determine the precoding matrix.

In the following, a further embodiment will be described in terms of a method of specifically determining a public PMI for the present invention. According to the embodiment shown in FIG. 4-6 above, when it is determined that a certain PMI _a of the first subcarrier is different from a certain PMI _{b of the} second subcarrier, but PMI _{a is} used as the PMI _{b of the} second subcarrier When the channel characteristic of the system is within a certain tolerance range or a certain condition is met, the base station may directly determine that the common PMI is PMI _a ; correspondingly, when PMI _{a is} used as the PMI _b indicating the second subcarrier When the channel characteristic of the system is within a certain tolerance range or a certain condition is met, the PMI _a may be directly determined to be the common PMI; or when one PMI _{c is} used as the first subcarrier and the second subcarrier. When the public PMI is used as the PMI _a and the PMI _b , when the channel characteristics of the system can satisfy a certain condition, the PMI _c can be directly determined as the at least one common PMI. The above process may be determined at the UE or the base station. Optionally, the base station may determine the at least one common PMI, the at least one first PMI, the at least one second PMI, and a compensation value δ, wherein the at least one common PMI and the at least one a first PMI is used to determine a precoding matrix of the first subcarrier; the at least one common PMI, the at least one second PMI, and the δ collectively indicate a precoding matrix of the second subcarrier, the base station receiving the The UE transmits the at least one common PMI, the at least one first PMI, the at least one second PMI, and a compensation value δ. It should be understood that the PMI of the second subcarrier may also be determined as the at least one common PMI, and a compensation value δ′ is received, which is determined according to the at least one common PMI, the δ′, and the at least one first PMI. a precoding matrix of the first subcarrier; determining a precoding matrix of the second subcarrier according to the at least one common PMI and the second PMI. In general, the number of bits or resources occupied by δ may be, but is not limited to, less than the number of bits or resources occupied by one PMI. In this case, the purpose of more accurately indicating the precoding matrix of the two subcarriers in the case of resource saving can be achieved.

Optionally, the base station receives the first PMI compensation value δ ₁ and/or a second PMI compensation value δ ₂ , where the δ _{1 is} used together with the at least one common PMI and the at least one first PMI. Determining a precoding matrix of the first subcarrier; the δ _{2 is} configured to jointly determine a precoding matrix of the second subcarrier with the at least one common PMI and the at least one second PMI.

The above-mentioned base station determines or receives the first PMI compensation value δ ₁ and/or the second PMI compensation value δ ₂ into three cases:

Situation 1:

The base station or UE determines the δ ₁ and δ ₂ , and the base station receives the δ ₁ and δ ₂ ;

Case 2:

The base station or the UE determines the δ ₁ , and the base station receives the δ ₁ ;

Case 3:

The base station or UE determines the δ ₂ , and the base station receives the δ ₂ .

It should be understood that the order of the δ ₁ and δ ₂ and the PMI that the base station needs to receive is not limited, and may be received simultaneously or sequentially. According to the different scenarios of the public PMI, the present invention provides three specific implementation manners:

Embodiment 7:

Embodiment 8:

When the precoding matrix of the first subcarrier is a product of the first precoding matrix W5 and the second precoding matrix W6 of the first subcarrier; the precoding matrix of the second subcarrier is the first Subcarrier number Under the scene of the product of a precoding matrix W7 and a second precoding matrix W8:

W' _(CA1) = W ₅ × W ₆

W' _(CA2) = W ₇ × W ₈

Embodiment 9:

It should be understood that the foregoing various embodiments for determining the compensation value are given the basis or sequence of the determination. The specific determination method is not limited in the present invention, and the determination manner of the compensation value may be different according to the number of allocated bits, for example, when public When the PMI is used to indicate that the error of the first subcarrier precoding matrix and the second subcarrier precoding matrix are not large (that is, can be within the tolerance range), one bit can be allocated, 0 represents no compensation, and 1 represents compensation. The compensation value may be predefined; in one embodiment, PMI _X and PMI _{Y are} used to indicate a first subcarrier precoding matrix, and PMI _Z and PMI _{W are} used to indicate a second subcarrier precoding matrix. When it is determined that the common PMI may be a value indicating both PMI _X and PMI _Z , that is, a common PMI and PMI _Y (where PMI _{Y is} equivalent to the first PMI) indicating a precoding matrix of the first subcarrier; a common PMI and a PMI _Z (here PMI _{W is} equivalent to the second PMI) indicating a precoding matrix of the second subcarrier; when determining PMI _X = 7, it may be jointly indicated with the first PMI (which may be PMI _Y in this embodiment) The first subcarrier precoding matrix, if the difference between the PMI _W and the PMI _X is not the same or the same, the PMI _W = 7 can be determined. In this case, as long as the base station receives δ=0, it can be determined that no compensation is needed; The system determines that when the PMI _W = 10 and the second PMI (which may be PMI _W in this embodiment) collectively indicate that the second subcarrier precoding matrix is accurate, then the common PMI = 7 and the second PMI are used together. Indicating that the second subcarrier precoding matrix introduces a relatively large error, the system herein may be the base station, the UE, or other network device notifying the base station. However, if the system preset compensation value δ=1 represents compensation 3, then 1 bit can accurately indicate that the base station or the UE side needs to recompensate 3 with a common PMI=7, and then determine the second subcarrier pre-determination together with the second PMI. Encoding matrix. It should be understood that, in this case, in some scenarios, if the compensation value δ=1 preset by the system represents compensation 2, the value indicated by the common PMI and the compensation value is 9 if it is within a certain tolerance range. , can also be accepted.

It should be understood that the above-described method of determining or receiving the compensation value is merely an example, and within a logical range, the determination or reception of the compensation value may be combined with any one of the embodiments for transmitting the compensation value, and other embodiments of the present invention.

The vertical direction precoding matrix or the long-term broadband characteristic precoding matrix of a certain subcarrier may be received under different channel models by using the single-path characteristic of the vertical direction of different subcarriers or the long-term broadband characteristics of different subcarriers. The common PMI further receives a compensation value δ; and determines a vertical direction precoding matrix or a long-term broadband characteristic precoding matrix of another subcarrier according to the δ and the common PMI. Determining a precoding matrix under the different subcarriers according to the first PMI and the second PMI, thereby saving channel resources and improving indication precision.

FIG. 7 is a schematic structural diagram of a communication device according to an embodiment of the present invention. A user equipment UE is involved in a precoding matrix indicating feedback of a PMI for a multi-carrier capable wireless communication system, the UE communicating with a base station using a first subcarrier and a second subcarrier. Specifically include:

a determining unit 701, configured to determine at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate the first child a precoding matrix of carriers; the at least one common PMI and the at least one second PMI And a precoding matrix for indicating the second subcarrier; wherein the common PMI, the first PMI, and the second PMI may be 2, 3, or more than 3, respectively. The specific functions in step 101 can be implemented.

It should be understood that the present invention does not limit the specific manner in which the determining unit determines the PMI, and the determining unit determines that the process of the PMI may be determined according to the reference signal measurement, and may be precoding from different dimensions according to the measurement reference signal. Traverse in the submatrix to select the matrix with the best signal quality. The measurement process here can be performed by a receiving unit 703 for receiving a reference signal, and a measuring unit for measuring the reference signal, and the measuring unit can also be integrated in the determining unit.

For a specific implementation manner, a specific illustrated example may be performed by referring to the step of determining at least one of the common PMI, the at least one first PMI, and the at least one second PMI in step 101.

The determining unit may determine that the specific order of the at least one common PMI, the at least one first PMI, and the at least one second PMI may be different, and may refer to the specific implementation manner 1 in the embodiment shown in FIG. Mode 2, Embodiment 3, It should be understood that the present invention is not limited to the specific implementation steps given in Embodiments 1-3 above, and may be other specific implementation manners for determining the at least one common PMI. Referring to the embodiment shown in FIG. 1, different RIs correspond to the determination manners of different PMI tables.

It should be understood that the present invention does not limit the determining process of each PMI, and may be, but is not limited to, the result of negotiation between the UE and the base station, or the two parties predetermine a certain rule, or directly determined by the UE, or through the receiving unit. Receive a notification from the base station or determine a specific determination method according to the application scenario.

The sending unit 702 is configured to send the at least one common PMI, the at least one first PMI, and the at least one second PMI to a base station in the wireless communication system. The specific functions in step 102 can be implemented.

The UE device that is fed back by the PMI described in this embodiment may use the same PMI in some items between different sub-carriers in different scenarios, and integrate different sub-carriers to correspond to respective PMIs, so that the UE is in a certain pre-determination. In the process of coding the matrix, only the common PMI is fed back. The common PMI is used to indicate the precoding matrix of different subcarriers, so that the base station passes the common PMI and the non-public PMI under different subcarriers (the first PMI in this embodiment). And a second PMI) respectively determining a precoding matrix of each subcarrier. In this embodiment, the sending unit of the UE sends, to the base station, a PMI that can be commonly used by each subcarrier and a non-public PMI that cannot be commonly used, where the feedback is performed in the process of determining two subcarrier precoding matrices at a time. The total number of PMIs is K, indicating Q precoding matrices under two subcarriers, and feedback The number K of PMIs is smaller than the number of Qs in order to save channel resources. It should be understood that the common PMI, the first PMI and the second PMI of the embodiments of the present invention do not necessarily exist independently, and may be referred to as a common PMI, a first PMI, and a second PMI according to different fields of the same message. In an embodiment, the common PMI field originally fed back twice can be reduced by one to achieve the effect of saving the number of bits.

It should be understood that, for different scenarios, the determining unit may determine the public PMI and the non-public PMI according to specific scenario characteristics to save channel resources. In the following, the UE device that indicates the feedback of the PMI in the precoding matrix shown in FIG. 7 will be specifically introduced in different scenarios:

FIG. 8 is a schematic structural diagram of a communication device according to an embodiment of the present invention. The precoding matrix of the first subcarrier is a Kronecker product of a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier; the second subcarrier a precoding matrix is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier; the common PMI is used to indicate the first subcarrier a vertical direction precoding matrix; the common PMI is further configured to indicate a vertical direction precoding matrix of the second subcarrier; the first PMI is used to indicate a horizontal direction precoding matrix of the first subcarrier; The PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.

Specifically include:

a determining unit 801, configured to determine at least one common PMI, at least one first PMI, and at least one second PMI, wherein the at least one common PMI is used to indicate a vertical direction precoding matrix; the at least one first PMI is used to And indicating a first subcarrier horizontal direction precoding matrix; the at least one second PMI is used to indicate a second subcarrier horizontal direction precoding matrix.

The sending unit 802 is configured to send, to the base station, the at least one common PMI, the at least one first PMI, and the at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier, where the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier.

For 3D MIMO or the like, the antenna distribution can be regarded as being arranged in a vertical direction and in a horizontal direction. Therefore, the precoding matrix of the first subcarrier can be regarded as a vertical direction precoding matrix and a horizontal direction precoding matrix. The precoding matrix of the second subcarrier may be regarded as a vertical direction precoding matrix and a horizontal direction precoding matrix. For example, the precoding matrix of the first subcarrier is the first precoding matrix W1 of the first subcarrier and The Kronecker product of the second precoding matrix W2, the precoding matrix of the second subcarrier When the Kroneck product of the third precoding matrix W3 and the fourth precoding matrix W4 of the second subcarrier is satisfied, it satisfies:

Where W _(CA1) is a precoding matrix of the first subcarrier, W _(CA2) is a precoding matrix of the second subcarrier, and W _{(CA1, 1)} is a first subcarrier vertical direction precoding matrix. , W _{(CA1, 2)} is the first subcarrier horizontal direction precoding matrix; W _{(CA2, 1)} is the second subcarrier vertical direction precoding matrix, and W _{(CA2, 2)} is the second subcarrier horizontal direction precoding matrix. In the general scenario, the angular expansion in the vertical direction is much smaller than the angular expansion in the horizontal direction, so the vertical direction approximates the single-path channel, and the determining unit may determine that the vertical direction channel is a single-path channel model, and further, may approximate or The PMI corresponding to the vertical direction precoding matrix is equal to the different subcarriers that the UE needs to feed back. Corresponding to the embodiment, the PMI _{(CA1, 1)} indicating the vertical precoding matrix W _{(CA1, 1)} of the first subcarrier is used _. It is equal to the PMI _{(CA2, 1)} used to indicate the second subcarrier vertical direction precoding matrix W _(CA2, ₁₎ , namely:

PMI _(CA1,1) =PMI _(CA2,1) =PMI _C

In such a case, the determining unit may determine that the PMI _C is the at least one common PMI. Correspondingly, the determining unit determines a PMI _{(CA1, 2)} for indicating the first subcarrier horizontal direction precoding matrix W _(CA1, ₂₎ as the at least one first PMI; The PMI _{(CA2, 2)} indicating the second subcarrier horizontal direction precoding matrix W _(CA2, ₂₎ is the at least one second PMI. Based on the above conditions, i.e. similar to a single-path channel in the vertical direction can be guaranteed at a transmission _PMI _C, PMI _(CA1,2), where _{PMI (CA2,2)} according to the PMI _C and _{PMI (CA1,2)} Indicating the W _(CA1) ; indicating the W _{(CA2, 2)} according to the PMI _C and PMI _(CA2, ₂₎ . The base station determines that PMI _C and the _{PMI (CA1,2)} the W _(CA1); determining the _{W (CA2,2)} based on the PMI _C and PMI _(CA2,2). The determining process here may be determined by the base station negotiation, or may be an indication of receiving the base station or other device or notifying the base station after determining by itself.

According to the description of the above embodiment, when the precoding matrix of the first subcarrier can be decomposed into a vertical direction precoding matrix and a horizontal direction precoding matrix, the PMI indicates the vertical direction precoding matrix and The horizontal direction precoding matrix utilizes a feature that the angle expansion of the beam in the vertical direction is relatively small, and the transmitting unit transmits, to the base station, a PMI that can be commonly used for each subcarrier and a non-public PMI that cannot be commonly used, where is determined once. In the process of two subcarrier precoding matrices, the total number of PMIs fed back is K, which is used to indicate Q precoding matrices under two subcarriers, and the number of PMIs fed back is smaller than the number of Qs to save channel resources. purpose. It should be understood that if the position, channel characteristics or other conditions of the antenna change such that the angular spread of the horizontal beam is much smaller than the angular spread of the vertical direction, the horizontal channel can be determined as a model of an approximate single-path channel, the determination The unit may determine that the PMI for indicating the first subcarrier horizontal direction precoding matrix is the at least one common PMI, and indicate that the PMI of the first subcarrier vertical direction precoding matrix is the at least one first PMI, where The PMI indicating the second subcarrier vertical direction precoding matrix is the at least one second PMI. The specific steps and procedures are the same as those in the foregoing embodiment, and details are not described herein again.

It should be understood that the judgment about the channel model may be a condition that the determining unit determines by reaching a certain condition, and may be directly configured or calculated and determined according to the base station or the UE.

In one embodiment, the determining unit may also determine such a PMI as a common PMI when the difference between the PMIs in certain items of different subcarriers is less than a certain threshold in some cases. It should be understood that the present invention is not limited to the number of the stator carriers. As long as at least one PMI of each of the multiple subcarriers can be determined as the common PMI according to a preset rule or a certain condition, the channel resources can be saved by reducing the number of PMI feedbacks. the goal of.

In another embodiment, a feedback device for another PMI is described. The apparatus may be, but is not limited to, an antenna scenario for 2D MIMO: a precoding matrix of the first subcarrier is a product of a first precoding matrix W ₅ and a second precoding matrix W ₆ of the first subcarrier; the common PMI is the W PMI ₅ and the W PMI ₆ of one; of the first non-common PMI to the other and said W PMI ₅ W PMI ₆ in; the a precoding matrix of the second subcarrier is a product of a first precoding matrix W ₇ and a second precoding matrix W ₈ of the first subcarrier; the common PMI is a PMI of the W ₇ and the W ₈ one of the PMI; the first non-common PMI is the other of the W PMI ₇ and the W PMI ₈ in. For example, the precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix (the W ₅ ) of the first subcarrier and a short-term narrowband characteristic matrix (the W ₆ ); the second subcarrier a precoding matrix is a product of a long-term broadband characteristic matrix (the W ₇ ) of the second carrier and a short-term narrowband characteristic matrix (the W ₈ );

W' _(CA1) = W ₅ × W ₆

W' _(CA2) = W ₇ × W ₈

B=[b ₀ ,b ₁ ,...b ₃₁ ]

X ^(k) = [b _2kmod32 b _{(2k+1) mod32} b _{(2k+2) mod32} b _{(2k+3) mod32} ]

Where mod is the modulo symbol.

Further obtaining the W ₅ = W ₅ ^(k) :

Constructing a codebook set C ₁ according to the W ₅ ^(k) :

When RI=2, the codebook set can be constructed as follows:

Corresponding, the formula:

W' _(CA1) = W ₅ × W ₆

a determining unit 901, configured to determine at least one public PMI, at least one first PMI, at least one a second PMI, wherein the at least one common PMI is used to indicate a long-term broadband characteristic matrix; the at least one first PMI is used to indicate a short-term narrowband characteristic matrix in the first sub-carrier; and the at least one second PMI is used A short-term narrowband characteristic matrix is embodied in the second subcarrier.

The sending unit 902 is configured to send, to the base station, the at least one common PMI, the at least one first PMI, the at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier, where the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier.

It should be understood that the present invention is not limited to the mutual integration between the various embodiments, and the specific determining unit determines the order and specific determination manner of the PMI, and the embodiments in FIGS. 8 and 9 can all be implemented as shown in FIG. Executed 1-3, and will not be described here.

For convenience of understanding, the present invention further provides a specific implementation manner in which the determining unit specifically determines a PMI by using a lookup table, where the precoding matrix can be used by the first subcarrier precoding matrix and the second sub A scenario in which a carrier precoding matrix is formed in the form of a product. It should be understood that the lookup table in the present invention may be to check a table stored in the UE or the base station, where the table includes a correspondence between the PMI and the matrix, and the table may be multiple in consideration of a specific application, so as to have Under different RI values or other parameters, the PMI and the specific precoding submatrix correspond to different tables. The determining unit acquires information required in the table; or an array or a relationship, and is used to query a PMI value corresponding to the corresponding precoding matrix. It should be understood that the specific form of the table may be multiple, and may be a mapping relationship or a function relationship stored in the UE or the base station, which is not limited by the present invention. For convenience of description, the present embodiment is described in the form of a table. The determining unit determines a long-term broadband matrix corresponding to the first sub-carrier and the second sub-carrier, and determines a corresponding table in the corresponding rank, for example, the value of the rank indication ranges from 1 to 4, then the determining unit is in Table 1. It is determined in Table 4 that the corresponding table is required (Table 1 corresponding rank indication 1, Table 2 corresponding rank indication 2, Table 3 corresponding rank indication 3, Table 4 corresponding rank indication 4):

Table 1

Table 2

table 3

Table 4

Determining, by the determining unit, one of the tables 1-4 according to the RI, and determining, in the determined table, a long-term broadband characteristic matrix of the CA1 and the CA2 according to a specific usage scenario, further according to the long-term broadband matrix determining characteristic values of the common PMI (i _1), according to the characteristics of the narrowband CA1 short CA2 matrix and the short-term characteristic matrix corresponding to the PMI narrow band, respectively, to determine the CA1 corresponding to a first PMI (i ₂ The value of the second PMI (i ₂ ') corresponding to the CA2 is transmitted to the base station for the values of i1, i2, i2'.

The determining unit determines, in the determined table, a specific manner of determining the value of the common PMI (i ₁ ) of the CA1 and the CA2, which may be determined according to channel characteristics, in Table 1 - Table 4, PMI (i ₁ ), PMI(i ₂ ) is used to determine

The determining unit may separately confirm the PMI value of the long-term broadband characteristic matrix corresponding to the CA1 and the PMI value of the long-term broadband characteristic matrix corresponding to the CA2, respectively, except that the PMI corresponding to the short-term narrow-band characteristic matrix is used as the common PMI. And select one of them as the public PMI. It should be understood that if there are multiple CAs, such as CA1, CA2, and CA3, a common PMI can be determined. For example, the PMI corresponding to the short-term narrowband characteristic matrix of CA1, CA2, and CA3 can be used as a common PMI, and the UE only feedbacks. With 1 public PMI, the short-term narrow-band characteristic matrix of the three carriers can be indicated to achieve further resource saving. Of course, the present embodiment is also applicable to the long-term broadband characteristic and the vertical direction and horizontal direction precoding matrix, and details are not described herein again. Of course, multiple CAs can also have multiple public PMIs.

In the embodiment shown in FIG. 9, the determining unit may be shared with other subcarriers according to the long-term broadband characteristic matrix of the first subcarrier precoding matrix in the table, and the PMI corresponding to different subcarriers may be determined as the common PMI in the determining unit. In the case of two precoding matrices of different subcarriers, the common PMI is sent by the transmitting unit once, and the transmitting unit sends a non-public PMI that cannot be commonly used by each subcarrier to the base station, to indicate two subcarriers. The following four sub-precoding matrices (ie, the long-term broadband characteristic matrix and the short-term narrow-band characteristic matrix of the first subcarrier and the second subcarrier, respectively), and the number of PMIs fed back is smaller than all four subpredetermined by the k PMIs. The number of coding matrices is used to save channel resources. It should be understood that the long-term broadband characteristic matrix according to the first subcarrier precoding matrix in the table may be shared with other subcarriers, and in other scenarios, the short-term narrowband characteristic matrix may be shared with other subcarriers. Corresponding to the determination manner in this embodiment, and details are not described herein again.

It should be understood that the embodiments of the present invention are all that the determining unit determines the PMI under two subcarriers, and the present invention claims that when the number of subcarriers is more than two, the respective PMIs of the two subcarriers may be a PMI that is shared with other subcarriers, and a plurality of subcarriers may be different from a PMI that is fed back by any one of the at least two subcarriers, and the sending unit sends a PMI corresponding to the several subcarriers. The form of separate feedback. For example, there are 3 subcarriers CA1, CA2, CA3, wherein although CA1 and CA2 have one or more common PMIs, the UE cannot place any of CA3 The PMI and any one of CA2 and CA1 are determined to be a common PMI, then the UE will separately feed back all PMIs of the CA3.

In the following, a further embodiment will be described in terms of a method of specifically determining a public PMI for the present invention. According to the embodiment shown in FIG. 7-9 above, when the determining unit determines that a certain PMI _a of the first subcarrier is different from a certain PMI _{b of the} second subcarrier, but uses PMI _a as the second subcarrier. The PMI _b , when the channel characteristic of the system is within a certain tolerance range or a certain condition is met, the determining unit may directly determine that the PMI _a is the public PMI; correspondingly, when the PMI _{a is} used as the indication When the PMI _{b of the} two subcarriers is within a certain tolerance range or a certain condition is met, the determining unit may directly determine that the PMI _a is the public PMI; or when using a PMI _c When the common PMI of the first subcarrier and the second subcarrier is used as the PMI _a and the PMI _b , when the channel characteristics of the system can satisfy a certain condition, the determining unit may directly determine The PMI _c acts as the at least one public PMI. Optionally, the determining unit may determine the at least one common PMI, the at least one first PMI, the at least one second PMI, and a compensation value δ, wherein the at least one common PMI and the at least a first PMI is used to determine a precoding matrix of the first subcarrier; the at least one common PMI, the at least one second PMI, and the δ collectively indicate a precoding matrix of the second subcarrier, and are sent by the The unit transmits the at least one common PMI, the at least one first PMI, the at least one second PMI, and a compensation value δ to the base station. It should be understood that the determining unit may also determine a PMI of the second subcarrier as the at least one common PMI, and the sending unit is further configured to send a compensation value δ′ according to the at least one common PMI. ???, the at least one first PMI determines a precoding matrix of the first subcarrier; and determines a precoding matrix of the second subcarrier according to the at least one common PMI and the second PMI. Generally, the number of bits or resources occupied by δ is smaller than the number of bits or resources occupied by one PMI. In this case, the purpose of more accurately indicating the precoding matrix of the two subcarriers in the case of resource saving can be achieved.

Optionally, the determining unit determines and sends a first PMI compensation value δ ₁ and/or a second PMI compensation value δ ₂ , and the δ _{1 is} used for the at least one common PMI, the at least one first PMI Determining a precoding matrix of the first subcarrier jointly; the δ _{2 is} used to determine a precoding matrix of the second subcarrier together with the at least one common PMI and the at least one second PMI.

The above determining unit determines and transmits the first PMI compensation value δ ₁ and/or the second PMI compensation value δ ₂ can be classified into three cases:

Situation 1:

The determining unit is configured to determine the δ ₁ and δ ₂ , and the sending unit is configured to send the δ ₁ and δ ₂ to the base station;

Case 2:

The determining unit is configured to determine the δ ₁ , and the sending unit is configured to send the δ ₁ to the base station;

Case 3:

The determining unit is configured to determine the δ ₂ , and the sending unit is configured to send the δ ₂ to the base station.

Embodiment 10:

Since the angular expansion in the vertical direction is much smaller than the angular expansion in the horizontal direction, the vertical direction approximates the single-path channel, and the determining unit may determine that the vertical direction channel is approximately a single-path channel model. As an example, in Embodiment 4, The determining unit determines a PMI _(CA1, ₁₎ corresponding to W _(CA1, ₁₎ as one of the common PMIs, and the determining unit determines that the PMI _{(CA1, 1)} and the W _{(CA2, 1)} correspond to The difference in PMI _(CA2,1) can be determined by δ _a . The determining unit determines that the PMI _(CA1, ₂₎ corresponding to W _(CA1, ₂₎ is the first PMI, and the determining unit determines that the PMI _(CA2, ₂₎ corresponding to W _(CA2, ₂₎ is the second PMI, where the common PMI, the first PMI are respectively used to determine (instruct) W _{(CA1, 1)} and the W _(CA1 , ₂₎ , the common PMI, the δ _a determines the W _{(CA2, 1)} , the second PMI describes W _(CA2 , ₂₎ to confirm the first subcarrier precoding matrix W _(CA1) , W _(CA2) . It should be understood that the determining unit determines the PMI _{(CA2, 1)} as the common PMI, and the corresponding method of using the δ _a ' and the common PMI to indicate the W _(CA1) may be the same as the above method, and details are not described herein again.

Embodiment 11:

W' _(CA1) = W ₅ × W ₆

W' _(CA2) = W ₇ × W ₈

It represents a matrix W5 long channel characteristics wideband channel CA1 can PMI ₅ indicates, denotes a matrix CA2 long channel characteristics wideband channel W7 can values PMI ₅ and a compensating δ _b indicates, as one example, the determination unit for determining W5 corresponding a PMI (PMI ₅ ) is the PMI (PMI ₆ ) is the first PMI, and the determining unit is configured to determine that the PMI (PMI ₈ ) corresponding to the W8 is the second PMI, in one embodiment, the common PMI for indicating the W5, the first PMI for indicating the W6, the second PMI is used to indicate the W8, the common PMI and with the δ _b Instructing the W7, the W5, W6 are used to determine the W' _(CA1) , the W7, and the W8 are used to determine the W'_(CA2); in another embodiment, the determining unit For determining a correspondence table in the table 1-4 according to the rank indication, the common PMI correspondence table i ₁ , the first PMI correspondence table i ₂ , determining a precoding matrix corresponding to the first subcarrier W is; table corresponding to the value of the common PMI and obtained after the δ _b 'calculates the i _1, the second table corresponding to the PMI i _2, determining a second Carrier corresponding precoding matrix W _2. It should be understood that the method of determining the PMI 7 as the common PMI is the same as the above embodiment, and details are not described herein again.

Embodiment 12:

It should be understood that when it comes to the case of compensation value compensation, it may be provided that the compensation value is not compensated for at a certain feedback. Signaling may be sent by a transmitting unit, or a receiving unit for receiving signaling, or other mode that does not employ compensation.

It should be understood that the foregoing embodiments for determining the compensation value by the determining unit provide the basis or the sequence determined by the determining unit, and the specific determining method is not limited by the present invention, and the determining manner of the compensation value may be determined according to the The number of bits is different, for example, when the common PMI is used to indicate that the errors of the first subcarrier precoding matrix and the second subcarrier precoding matrix are not large (ie, can be within tolerance), one bit can be allocated. 0 represents no compensation, 1 represents compensation, and specific compensation values may be predefined; in one embodiment, PMI _X and PMI _{Y are} used to indicate a first subcarrier precoding matrix, and PMI _Z and PMI _{W are} used to indicate a second subcarrier. Precoding matrix. When the determining unit determines that the common PMI may be a value indicating PMI _X and PMI _Z at the same time, that is, using a common PMI and PMI _Y (where PMI _{Y is} equivalent to the first PMI) indicating a precoding matrix of the first subcarrier; a common PMI and a PMI _Z (where PMI _{W is} equivalent to the second PMI) indicating a precoding matrix of the second subcarrier; when determining PMI _X = 7, may be associated with the first PMI (in this embodiment may be PMI _Y ) jointly indicates the first subcarrier precoding matrix. If the difference between the PMI _W and the PMI _X is not the same or the same, the PMI _W =7 can be determined. In this case, the determining unit determines that δ=0 and The transmission δ can be notified that no compensation is needed; however, if the determining unit or system determines that the second subcarrier precoding matrix is jointly indicated by PMI _W = 10 and the second PMI (which may be PMI _W in this embodiment) Then, using the common PMI=7 and the second PMI together to indicate the second subcarrier precoding matrix brings a relatively large error. However, if the compensation value δ=1 preset by the determining unit or system represents compensation 3, then 1 bit can accurately indicate that the base station side needs to recompensate 3 with a common PMI=7, and then jointly determine the second with the second PMI. Subcarrier precoding matrix. It should be understood that, in this case, in some scenarios, if the compensation value δ=1 preset by the determining unit or system represents compensation 2, the value indicated by the common PMI and the compensation value is 9 if some Within the scope of tolerance, it is equally acceptable.

It should be understood that the determining unit determines the compensation value, and the method for the sending unit to send the compensation value is only an example. In the logical range, the determination of the compensation value may be performed with any one of the implementation methods for transmitting the compensation value, and Other embodiments of the invention are combined.

The single-path characteristic in the vertical direction of different subcarriers, or the long-term broadband characteristics of different subcarriers are similar, and the determining unit may determine a vertical direction precoding matrix or a long-term broadband characteristic of a certain subcarrier under different channel models. The coding matrix is the common PMI, and the determining unit further determines a compensation value δ; and indicates a vertical direction precoding matrix or a long-term broadband characteristic precoding matrix of another subcarrier according to the δ and the common PMI. According to the first PMI and the second PMI, the sending unit indicates a precoding matrix under the different subcarriers, thereby saving channel resources and improving indication precision.

FIG. 10 is a schematic structural diagram of a communication device according to an embodiment of the present invention. A base station is involved in a precoding matrix indicating feedback of a PMI for a multi-carrier capable wireless communication system, the base station communicating with the UE using a first subcarrier and a second subcarrier. Specifically include:

Specifically include:

The receiving unit 1001 is configured to receive at least one public PMI, at least one first PMI, and at least one second PMI;

a determining unit 1002, configured to determine, according to the at least one common PMI, the at least one first PMI, and the at least one second PMI, a precoding matrix of the first subcarrier and a precoding matrix of the second subcarrier; wherein the at least one a common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate precoding of the second subcarrier matrix.

Hereinafter, the steps of determining, by the determining unit, at least one of the common PMI, the at least one first PMI, and the at least one second PMI will be specifically described in the form of an example. For example, for the first subcarrier CA1, the determining unit needs to determine that the four PMIs are respectively PMI1/2/3/4, and the four PMIs are used to indicate the precoding matrix of the CA1; for the second subcarrier CA2, The determining unit needs to determine that the four PMIs are respectively PMI5/6/7/8, and the four PMIs are used to indicate the precoding matrix of the CA2. In an embodiment, PMI1 and PMI2 may jointly indicate one sub-precoding matrix W _A1 under the CA1; PMI3 and PMI4 may indicate another sub-precoding matrix W _B1 under CA1, and the determining unit is further determined by the W _A1 , W _B1 and the determined operational relationship determine the CA1 precoding matrix W _A1B1 . PMI5, PMI6 may jointly indicate a sub-precoding matrix W _A2 under the CA2; PMI7, PMI8 may indicate another sub-precoding matrix W _B2 under CA2, and then determined by the W _A2 , W _B2 and the determined operational relationship CA1 precoding matrix W _A2B2 . The specific determination manner may be different, and the present invention is not limited, and may be determined in the form of calculating parameters of the precoding matrix. For example, the UE and/or the determining unit may calculate W _A1 according to two parameters of PMI1 and PMI2. Alternatively, the UE and/or the determining unit may store or predetermine a table, and the determining unit may query the corresponding W _A1 according to PMI1, PMI2, or PMI1/2/3/4 may be 4 parameters. The PMI 5/6/7/8 may be 4 parameters, and the determining unit directly calculates the precoding matrix. It should be understood that the need to feed back 4 PMIs under one carrier is only an example, and in actual situations, other situations may occur. Each embodiment of the present application does not specifically refer to four PMIs. At least one PMI in the CA1 is the same as or similar to at least one PMI in the CA2 according to a certain channel condition or channel model. Then, the at least one PMI of CA1 and the at least one PMI of the CA2 may be determined as the common PMI. Wherein, the approximation here is equivalent, for example, even if the two PMIs are different, the difference between the two PMIs is small, and the final base station according to the respective calculated CA1 precoding matrix and the channel model of the CA2 precoding matrix are Can be tolerated within the scope. For example, PMI1 and PMI5 correspond to each other. When certain conditions are met, it can be determined as public PMI _C1 ; PMI3 and PMI7 correspond to each other and can be determined as public PMI _C2 , namely:

PMI ₁ = PMI ₅ = PMI _C1

PMI ₃ = PMI ₇ = PMI _C2

Then, referring to step 401, the receiving unit may receive a common PMI: PMI _C1 , PMI _C2 ; and a first PMI: PMI2, PMI4; and a second PMI: PMI6, PMI8. The method of determining the common PMI is usually determined by the channel characteristics. For example, PMI1 and PMI5 are used to indicate certain matrix parameters, which are related in some scenarios (such as high-rise scenes or wide-area scenes). High, whose values are equal or the difference is negligible; or PMI1 and PMI5, in some scenarios, indicate a matrix set of the same type of matrix in the table, and other PMI2/PMI6 further indicate one of the matrix sets. The matrix (which is an element in the matrix set), then PMI1 and PMI5 can be determined to be the common PMI ₁ in many identical scenarios; similarly, PMI3 and PMI7 can also use the above indication. Alternatively, the base station side may directly determine that the PMI _C1 and the PMI _C2 are common PMIs, and the PMI _C1 represents PMI1/PMI5, and the PMI _C2 represents PMI3/PMI7, and is sent to the UE.

The determining unit may preset a rule, or determine a public PMI, a first PMI, a second PMI by means of a sending unit or a receiving unit to negotiate with a UE or other network device, or may be that the receiving unit directly receives a feedback PMI. The signaling or other signaling refers to the common PMI, the first PMI, and the second PMI, and the determining unit determines the precoding matrix according to the indication. For example, in a high-rise scenario, the PMI ₁ and the PMI _{5 are} determined to be a public PMI, and the preset rule is also in the UE with which it interacts. This indication process can also come from other UEs or other network side devices.

It should be understood that the present invention is not limited to step 402, and the determining unit determines a precoding matrix and a second subcarrier of the first subcarrier according to the at least one common PMI, the at least one first PMI, and the at least one second PMI. The specific process of the precoding matrix may be that different RIs correspond to different PMI tables, and after the determining unit determines the value of the RI, the determining unit determines the RI from the plurality of PMI tables. The value corresponds to the PMI table, and the PMI table may include a correspondence between the PMI and the precoding matrix and/or a correspondence between the PMI and the precoding submatrix. The determining unit determines a precoding matrix of CA1 according to the common PMI and the first PMI, or determines a precoding matrix corresponding to CA2 by the common PMI and the second PMI. The PMI table may be a specific table or a plurality of corresponding relationship sets stored in the memory.

In the PMI receiving and determining manner described in this embodiment, the PMI in some items between different subcarriers may be the same in different scenarios, and different subcarriers are integrated corresponding to the respective PMIs, so that the receiving unit is in one The common PMI is received only once in the process of determining the precoding matrix, and the common PMI is used to indicate the precoding matrix of different subcarriers, so that the determining unit passes the common PMI and the non-public PMI under different subcarriers (this embodiment) The first PMI and the second PMI) respectively determine a precoding matrix of each subcarrier. In this embodiment, the receiving unit receives a PMI that can be commonly used by each subcarrier and a non-public PMI that cannot be commonly used, where the receiving unit is in the process of determining the two subcarrier precoding matrices at one time. The total number of received PMIs is K, which is used to indicate Q precoding matrices under two subcarriers, and the number of PMIs fed back is less than the number of Qs, so as to save channel resources. It should be understood that, in the public PMI of the present invention, the first PMI and the second PMI do not necessarily exist independently, and may be referred to as a common PMI, a first PMI, a second PMI, according to an embodiment of the present invention. You can reduce the number of common PMI fields that were originally fed back twice to save the number of bits.

11 is a schematic structural diagram of a communication device according to an embodiment of the present invention. A base station is involved in a precoding matrix indicating feedback of a PMI for a multi-carrier capable wireless communication system, the base station communicating with a UE using a first subcarrier and a second subcarrier. The precoding matrix of the first subcarrier is a Kronecker product of a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier; the second subcarrier a precoding matrix is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier; the common PMI a vertical direction precoding matrix for indicating the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier; the first PMI is used to indicate the first subcarrier a horizontal direction precoding matrix; the second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.

Specifically include:

The receiving unit 1101 is configured to receive at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI is used to indicate a vertical direction precoding matrix; the at least one first PMI is used to And indicating a first subcarrier horizontal direction precoding matrix; the at least one second PMI is used to indicate a second subcarrier horizontal direction precoding matrix.

a determining unit 1102, configured to determine, according to the at least one common PMI, the at least one first PMI, and the at least one second PMI, a precoding matrix of the first subcarrier and a precoding matrix of the second subcarrier; wherein the at least one a common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate precoding of the second subcarrier matrix.

PMI _(CA1,1) =PMI _(CA2,1) =PMI _C

In such a case, the determining unit may determine that the PMI _C of the UE is the at least one public PMI. Correspondingly, the determining unit may determine that the PMI _{(CA1, 2)} used to indicate the first subcarrier horizontal direction precoding matrix W _(CA1, ₂₎ is the at least one first PMI; The PMI _{(CA2, 2)} of the second subcarrier horizontal direction precoding matrix W _(CA2, ₂₎ is the at least one second PMI. Based on the above conditions, that is, approximating the single-path channel in the vertical direction, it can be ensured that, when the receiving unit receives the PMI _C , PMI _(CA1 , ₂₎ , and PMI _{(CA2, 2)} sent by the UE, according to the PMI _C And PMI _{(CA1, 2)} determines the W _(CA1) ; the W _{(CA2, 2) is} determined according to the PMI _C and PMI _(CA2, ₂₎ . The base station determines that PMI _C and the _{PMI (CA1,2)} the W _(CA1); determining the _{W (CA2,2)} based on the PMI _C and PMI _(CA2,2). The determination here may also be determined by the receiving UE or other device, or both.

According to the description of the above embodiment, when the precoding matrix of the first subcarrier can be decomposed into a vertical direction precoding matrix and a horizontal direction precoding matrix, the PMI can respectively indicate a vertical direction precoding matrix and horizontal direction precoding. a matrix that utilizes a relatively small angular spread of a beam in a vertical direction thereof, the receiving unit receiving a PMI that the UE transmits a common sub-carrier and a non-public PMI that cannot be commonly used, wherein the determining unit determines at one time In the process of two subcarrier precoding matrices, the total number of PMIs fed back is K, which is used to indicate Q precoding matrices under two subcarriers, and the number of PMIs fed back is smaller than the number of Qs to save channel resources. purpose. It should be understood that if the position, channel characteristics or other conditions of the antenna change such that the angular spread of the horizontal beam is much smaller than the angular spread of the vertical direction, it can be determined that the horizontal channel is a model of an approximate single-path channel, which can be determined. The PMI indicating the first subcarrier horizontal direction precoding matrix is the at least one common PMI, and the PMI indicating the first subcarrier vertical direction precoding matrix is the at least one first PMI, and is used to indicate the second sub The PMI of the carrier vertical direction precoding matrix is the at least one second PMI. The specific steps and procedures are the same as those in the foregoing embodiment, and details are not described herein again.

It should be understood that the judgment about the channel model may be a condition determined by reaching a certain condition, It may be directly configured or calculated and determined according to the determining unit or UE.

In another embodiment, a feedback device for another PMI is described. The method can be, but is not limited to, an antenna scene for 2D MIMO. The precoding matrix of the first subcarrier is a product of a first precoding matrix W ₅ and a second precoding matrix W ₆ of the first subcarrier; the common PMI is the PMI of the W ₅ and the a PMI W ₆ in; the first non PMI common to the other and said W PMI ₅ W PMI ₆ in; the precoding matrix to the second subcarrier of the first sub- a product of a first precoding matrix W ₇ and a second precoding matrix W ₈ of the carrier; the common PMI being one of the PMI of the W _{7 and} the PMI of the W ₈ ; the first non-public PMI is the W PMI ₇ W and the other PMI ₈ in. For example, the precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix (the W ₅ ) of the first subcarrier and a short-term narrowband characteristic matrix (the W ₆ ); the second subcarrier a precoding matrix is a product of a long-term broadband characteristic matrix (the W ₇ ) of the second carrier and a short-term narrowband characteristic matrix (the W ₈ );

W' _(CA1) = W ₅ × W ₆

W' _(CA2) = W ₇ × W ₈

B=[b ₀ ,b ₁ ,...b ₃₁ ]

X ^(k) = [b _2kmod32 b _{(2k+1) mod32} b _{(2k+2) mod32} b _{(2k+3) mod32} ]

Where mod is the modulo symbol.

Further obtaining the W ₅ = W ₅ ^(k) :

Constructing a codebook set C ₁ according to the W ₅ ^(k) :

When RI=2, the codebook set can be constructed as follows:

Corresponding, the formula:

W' _(CA1) = W ₅ × W ₆

The above W' _(CA1) = W ₅ × W ₆ and W' _(CA2) = W ₇ × W ₈ form, specifically applicable to 2D MIMO scenarios, the precoding matrix can be specifically determined by the long-term broadband characteristics of the signal and short-term The case of the product represented by the narrowband characteristic. Fig. 12 shows an implementation step of a base station apparatus when a precoding matrix can be shared due to the long-term broadband characteristics of its subcarriers.

The receiving unit 1201 is configured to receive at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI is used to indicate that a long-term broadband characteristic matrix is embodied; the at least one first PMI is used to Indicates that a short-term narrowband characteristic matrix is embodied in the first subcarrier; and the at least one second PMI is used to indicate that the short-term narrowband characteristic matrix is embodied in the second subcarrier.

a determining unit 1201, configured to determine, according to the at least one common PMI, the at least one first PMI, and the at least one second PMI, a precoding matrix of the first subcarrier and a precoding matrix of the second subcarrier; wherein the at least one a common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate precoding of the second subcarrier matrix.

For convenience of understanding, the present invention further provides a specific implementation method for specifically determining a PMI by using a lookup table, where the precoding matrix can be used by a first subcarrier precoding matrix and a second subcarrier precoding matrix. A scene constructed in the form of a product. It should be understood that, in the look-up table in the present invention, the determining unit may check a table stored in a UE or a base station, where the table includes a correspondence between a PMI and a matrix, and To a specific application, the table may be multiple, so that the PMI and the specific precoding submatrix correspond to different tables under different RI values or other parameters. The determining unit may determine or obtain information required in the table by using the receiving unit; or an array or a relationship for querying a precoding matrix corresponding to the corresponding PMI value. It should be understood that the specific form of the table may be multiple, and may be a mapping relationship or a function relationship stored in the UE or the base station memory, which is not limited by the present invention. For convenience of description, the present embodiment is described in the form of a table. The determining unit determines, according to the PMI, a long-term broadband matrix corresponding to the first sub-carrier and the second sub-carrier, and determines a corresponding table in the corresponding rank, for example, the value of the rank indication ranges from 1 to 4, then, in Table 1 to Table 4 determines the corresponding table to be required (Table 1 corresponds to rank indication 1, Table 2 corresponds to rank indication 2, Table 3 corresponds to rank indication 3, and Table 4 corresponds to rank indication 4):

Table 1

Table 2

table 3

Table 4

Determining one of the tables 1-4 according to the RI, after the receiving unit receives the public PMI (i1), the first PMI (i2), and the second PMI (i2'), the determining unit is further determined in the determining The long-term broadband characteristic precoding matrix corresponding to the value of the common PMI (i ₁ ) of the CA1 and the CA2 is determined according to a specific usage scenario, and is determined according to the first PMI and the second PMI. A short-term narrowband characteristic matrix of CA1 and a short-term narrowband characteristic matrix of the CA2.

It should be understood that if there are multiple CAs, such as CA1, CA2, and CA3, the receiving unit can also receive a common PMI. For example, the PMI corresponding to the short-term narrowband characteristic matrix of CA1, CA2, and CA3 can be used as a common PMI. The public PMI can be used to indicate the short-term narrow-band characteristic matrix of the three carriers, and the base station receives the public PMI fed back by the UE to achieve further resource saving. Of course, the present embodiment is also applicable to the long-term broadband characteristic and the vertical direction and horizontal direction precoding matrix, and details are not described herein again. Of course, multiple CAs can also have multiple public PMIs.

The embodiment shown in FIG. 12 may be shared with other subcarriers according to the long-term broadband characteristic matrix of the first subcarrier precoding matrix in the table. The PMI corresponding to different subcarriers may serve as a common PMI, and the determining unit determines different subcarriers. The common PMI is received once in the case of two precoding matrices, and the receiving unit receives a non-common PMI that is not commonly used by each subcarrier transmitted by the UE, and is used to indicate four sub precoding matrices under two subcarriers (ie, a long-term broadband characteristic matrix and a short-term narrowband characteristic matrix of a subcarrier and a second subcarrier, respectively, and the number of received PMIs is smaller than the number of all four subprecoding matrices that the k PMI can determine to save the channel The purpose of the resource. It should be understood that the determining unit described herein According to the long-term broadband characteristic matrix of the first subcarrier precoding matrix in the table, the matrix may be shared with other subcarriers. In other scenarios, the short-term narrowband characteristic matrix may be shared with other subcarriers, which is the same as in the embodiment. The determination method is corresponding and will not be described here.

It should be understood that the embodiments of the present invention both determine a precoding matrix under two subcarriers, and the present invention claims that when there are more than two subcarriers, the respective PMIs of the two subcarriers may be associated with other sub-carriers. The PMI shared by the carrier may be different from the PMI that is fed back by any one of the at least two subcarriers, and the PMI corresponding to the plurality of subcarriers adopts a form of separate feedback. For example, there are three subcarriers CA1, CA2, CA3, wherein, although one or more common PMIs exist for CA1 and CA2, but all PMIs of CA3 cannot be associated with any PMI of CA1 or CA2 as a common PMI, then the determination The unit will determine the precoding matrix from all PMIs that individually feed back the CA3.

In the following, a further embodiment will be described in terms of a method of specifically determining a public PMI for the present invention. According to the embodiment shown in the above FIGS. 10-12, when it is determined that a certain PMI _a of the first subcarrier is different from a certain PMI _{b of the} second subcarrier, but PMI _{a is} used as the PMI _{b of the} second subcarrier When the channel characteristic of the system is within a certain tolerance range or a certain condition is met, the base station may directly determine that the common PMI is PMI _a ; correspondingly, when PMI _{a is} used as the PMI _b indicating the second subcarrier When the channel characteristic of the system is within a certain tolerance range or a certain condition is met, the PMI _a may be directly determined to be the common PMI; or when one PMI _{c is} used as the first subcarrier and the second subcarrier. When the public PMI is used as the PMI _a and the PMI _b , when the channel characteristics of the system can satisfy a certain condition, the PMI _c can be directly determined as the at least one common PMI. The above process may be determined at the determining unit of the UE or the base station. Optionally, the receiving unit may receive the at least one common PMI, the at least one first PMI, the at least one second PMI, and a compensation value δ, wherein the at least one common PMI and the at least a first PMI is used to determine a precoding matrix of the first subcarrier; the at least one common PMI, the at least one second PMI, and the δ collectively indicate a precoding matrix of the second subcarrier, and the receiving unit receives The UE sends the at least one common PMI, the at least one first PMI, the at least one second PMI, and a compensation value δ. It should be understood that the determining unit may also determine, by the receiving unit, the PMI of the second subcarrier as the at least one common PMI, and receive a compensation value δ′, the determining unit according to the at least one public a PMI, the δ′, the at least one first PMI determining a precoding matrix of the first subcarrier; determining a precoding matrix of the second subcarrier according to the at least one common PMI and the second PMI . In general, the number of bits or resources occupied by δ may be, but is not limited to, less than the number of bits or resources occupied by one PMI. In this case, the purpose of more accurately indicating the precoding matrix of the two subcarriers in the case of resource saving can be achieved.

Optionally, the receiving unit receives the first PMI compensation value δ ₁ and/or a second PMI compensation value δ ₂ , and the δ _{1 is} used for the at least one common PMI, the at least one first PMI Determining a precoding matrix of the first subcarrier jointly; the δ _{2 is} used to determine a precoding matrix of the second subcarrier together with the at least one common PMI and the at least one second PMI.

The determining unit determining and the receiving unit receiving the first PMI compensation value δ ₁ and/or the second PMI compensation value δ _{2 are} classified into three cases:

Situation 1:

The determining unit or UE determines the δ ₁ and δ ₂ , and the receiving unit receives the δ ₁ and δ ₂ ;

Case 2:

The determining unit or UE determines the δ ₁ , and the receiving unit receives the δ ₁ ;

Case 3:

The determining unit or UE determines the δ ₂ , and the receiving unit receives the δ ₂ .

It should be understood that the order in which the receiving unit receives the δ ₁ and δ ₂ and the PMI that the receiving unit needs to receive is not limited, and may be received simultaneously or sequentially. After the determining unit determines the δ ₁ and/or δ ₂ , the δ ₁ and/or δ _{2 may be} transmitted to the UE by one transmitting unit, or the δ ₁ and/or may be received by a receiving unit. δ ₂ . According to the different scenarios of the public PMI, the present invention provides three specific implementation manners:

Embodiment 13:

Since the angular expansion in the vertical direction is much smaller than the angular expansion in the horizontal direction, the vertical direction approximates the single-path channel, and the determining unit may determine that the vertical direction channel is approximately a single-path channel model. As an example, in Embodiment 4, Determining a PMI _(CA1, ₁₎ corresponding to W _(CA1, ₁₎ as one of the common PMIs, the determining unit determining the PMI _{(CA1, 1)} and the PMI _(CA2, corresponding to the W _(CA2, ₁₎ _, The difference of ₁₎ can be determined by δ _a . Determining that the PMI _(CA1, ₂₎ corresponding to W _(CA1, ₂₎ is the first PMI, and determining that the PMI _(CA2, ₂₎ corresponding to W _(CA2, ₂₎ is the second PMI, where the public PMI is The first PMI is used to determine (instruct) W _{(CA1, 1)} and the W _(CA1 , ₂₎ , respectively, the common PMI, the δ _a determines the W _{(CA2, 1)} , The second PMI describes W _(CA2 , ₂₎ such that the determining unit confirms the first subcarrier precoding matrix W _(CA1) , W _(CA2) . It should be understood that the method of determining the PMI _{(CA2, 1)} as the common PMI, the corresponding use δ _a ' and the common PMI indicating the W _(CA1) may be the same as the above method, and details are not described herein again.

Embodiment 14:

W' _(CA1) = W ₅ × W ₆

W' _(CA2) = W ₇ × W ₈

Represents CA1 long wideband channel characteristic matrix W5 can use the PMI ₅ indicates a matrix representing channel characteristics CA2 long wideband channel W7 can ₅ and a compensation value PMI δ _b indicates, as one example, is determined W5 corresponding PMI (PMI ₅₎ as The common PMI, the PMI (PMI ₆ ) corresponding to W6 is the first PMI, and the PMI (PMI ₈ ) corresponding to W8 is the second PMI. In one embodiment, the common PMI is used to determine (instruct) the W5, for determining the first PMI (indication) of the W6, the second PMI is used to indicate the W8, the common PMI and the δ _b for indicating the W7, W5 said , W6 is used to determine the W′ _(CA1) , the W7, and the W8 are used to determine the W′ _(CA2) ; in another embodiment, the determining unit determines the table 1 according to the rank indication. 4 in the correspondence table, said correspondence table PMI common to i _1, a first table corresponding to the PMI i _2, the first sub-carrier determining unit determines the precoding matrix W is; and the common PMI The value obtained by the operation of δ _b ' corresponds to i ₁ in the table, and the second PMI corresponds to i ₂ in the table, and the determining unit determines that the second subcarrier corresponds to Precoding matrix W ₂ . It should be understood that the method of determining the PMI 7 as the common PMI is the same as the above embodiment, and details are not described herein again.

Embodiment 15:

According to the above embodiment, two compensation values, δ _c and δ _d , can also be given simultaneously by the determining unit or the UE. In this case, the δ _{c is} used to determine a precoding matrix of the first subcarrier together with the at least one common PMI and the at least one first PMI; the δ _{d is} used for the at least one The common PMI, the at least one second PMI jointly determines a precoding matrix of the second subcarrier.

It should be understood that the foregoing various embodiments for determining the compensation value are given the basis or sequence of the determination. The specific determination method is not limited in the present invention, and the determination manner of the compensation value may be different according to the number of allocated bits, for example, when public When the PMI is used to indicate that the error of the first subcarrier precoding matrix and the second subcarrier precoding matrix are not large (that is, can be within the tolerance range), one bit can be allocated, 0 represents no compensation, and 1 represents compensation. The compensation value may be predefined; in one embodiment, PMI _X and PMI _{Y are} used to indicate a first subcarrier precoding matrix, and PMI _Z and PMI _{W are} used to indicate a second subcarrier precoding matrix. When the determining unit determines that the common PMI may be indicating the values of PMI _X and PMI _Z at the same time, that is, using a common PMI and PMI _Y (where PMI _{Y is} equivalent to the first PMI) indicating a precoding matrix of the first subcarrier; PMI and PMI _Z (where PMI _{W is} equivalent to the second PMI) indicating a precoding matrix of the second subcarrier; when the determining unit determines PMI _X = 7, may be associated with the first PMI (in this implementation) The example may be PMI _Y ) jointly indicating the first subcarrier precoding matrix. If the difference between the PMI _W and the PMI _X is not the same or the same, the PMI _W = 7 may be determined, in which case the base station receives δ=0. It can be determined that no compensation is needed; however, if the system determines that the second subcarrier precoding matrix can be specified with PMI _W = 10 and the second PMI (which may be PMI _W in this embodiment), then the public PMI = 7 and the second PMI jointly indicate that the second subcarrier precoding matrix brings a relatively large error, and the system herein may be the base station, the UE, or other network device notifying the base station. However, if the system preset compensation value δ=1 represents compensation 3, then 1 bit can accurately indicate that the base station or the UE side needs to recompensate 3 with a common PMI=7, and then determine the second subcarrier pre-determination together with the second PMI. Encoding matrix. It should be understood that, in this case, in some scenarios, if the compensation value δ=1 preset by the system represents compensation 2, the value indicated by the common PMI and the compensation value is 9 if it is within a certain tolerance range. , can also be accepted.

It should be understood that the method for determining or receiving the compensation value by the determining unit is merely an example, and within the scope of the logic, the determination or reception of the compensation value may be combined with any one of the embodiments for transmitting the compensation value, and other embodiments of the present invention. Combine.

The base station apparatus utilizes a single-path characteristic of a vertical direction of different subcarriers or a long period of different subcarriers The broadband characteristics are similar, and the receiving unit may receive a vertical direction precoding matrix or a long-term broadband characteristic precoding matrix of a certain subcarrier as the common PMI under different channel models, and then receive a compensation value δ; the determining unit A vertical direction precoding matrix or a long term broadband characteristic precoding matrix of another subcarrier is determined according to the delta and the common PMI. Determining a precoding matrix under the different subcarriers according to the first PMI and the second PMI, thereby saving channel resources and improving indication precision.

FIG. 13 is a schematic structural diagram of a communication device according to an embodiment of the present invention. A user equipment UE is involved in a precoding matrix indicating feedback of a PMI for a multi-carrier capable wireless communication system, the UE communicating with a base station using a first subcarrier and a second subcarrier. Specifically include:

The processor 1301 is configured to determine at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate the first subcarrier a precoding matrix; the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier; wherein the common PMI, the first PMI, the second PMI It can be 2, 3 or more than 3 respectively. The specific functions in step 101 can be implemented. In addition, the determining unit in FIG. 7, FIG. 8, and FIG. 9 can also be implemented in the form of the processor.

The transmitter 1302 is configured to send the at least one common PMI, the at least one first PMI, and the at least one second PMI to a base station in the wireless communication system. The specific function in step 102 can be implemented. In addition, the transmitting unit in FIG. 7, FIG. 8, and FIG. 9 can also be implemented in the form of the transmitter.

In an embodiment, when the processor 1301 determines the specific manner of determining the at least one common PMI, the at least one first PMI, and the at least one second PMI, the two sides may determine the common PMI according to a rule. The at least one first PMI and the at least one second PMI are required to receive an indication sent by the base station or negotiate with the base station, and the UE further includes a receiver 1303, configured to receive the first message sent by the base station, where the processing is performed. And determining, according to the first message, the at least one common PMI, the at least one first PMI, and the at least one second PMI. In another embodiment, after the processor determines the determining the at least one common PMI, the at least one first PMI, and the at least one second PMI, the transmitter 1302 is further configured to send the second message. Furthermore, in addition, the receiving unit in FIGS. 7, 8, and 9 can also be implemented in the form of the receiver.

In one embodiment, the UE includes a memory 1304 for storing messages or signaling, codebooks or determining rules

FIG. 14 is a schematic structural diagram of a communication device according to an embodiment of the present invention. Involving a precoding moment A base station indicating feedback of PMI for a wireless communication system having multi-carrier capability, the base station communicating with the UE using the first subcarrier and the second subcarrier. Specifically include:

The receiver 1401 is configured to receive at least one common PMI, at least one first PMI, and at least one second PMI. The receiving unit in FIG. 10, FIG. 11, and FIG. 12 may also be implemented in the form of the processor.

The processor 1402 is configured to determine, according to the at least one common PMI, the at least one first PMI, and the at least one second PMI, a precoding matrix of the first subcarrier and a precoding matrix of the second subcarrier, where the at least one a common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier; the at least one common PMI and the at least one second PMI are used to indicate precoding of the second subcarrier matrix. The determining unit in FIG. 10, FIG. 11, and FIG. 12 may be a processing unit, or may be implemented in the form of the processor.

In an embodiment, when the processor 1401 determines the specific manner of determining the at least one common PMI, the at least one first PMI, and the at least one second PMI, the public may be determined according to a rule on both sides. When the PMI, the at least one first PMI, and the at least one second PMI are required to send an indication to the UE or negotiate with the UE, the base station further includes a transmitter 1403, configured to determine, according to the first message, the processor After the at least one common PMI, the at least one first PMI, and the at least one second PMI, send a first message to the UE to instruct the UE to determine the at least one public PMI, the at least one first PMI according to the first message. And at least one second PMI. In another embodiment, the receiver receives a second message sent by another network side device, and the processor determines the at least one public PMI, the at least one first PMI, and the at least one second according to the second message. PMI. The transmitter 1403 is further configured to send a second message. Furthermore, the receiving unit in Figures 10, 11 and 12 can also be implemented in the form of a receiver.

In one embodiment, the base station includes a memory 1404 for storing messages or signaling, codebooks or determining rules

The transmitter 1302 involved in FIG. 13 may be an antenna, or a wireless transmitter, and the receiver 1303 may be an antenna, or a wireless receiver, and the transmitter and the receiver may be the same antenna or a wireless transceiver.

The transmitter 1403 involved in FIG. 14 may be an antenna, or a wireless transmitter. The receiver 1401 may be an antenna, or a wireless receiver, and the transmitter and the receiver may be the same antenna or a wireless transceiver.

The processor of FIG. 13 and/or FIG. 14 may be a general-purpose processor, such as a general-purpose central processing unit (CPU), a network processor (NP Processor, NP), a microprocessor, etc., or may be an application-specific integrated circuit. (application-specific integrated circuit, ASIC), or one or more integrated circuits for controlling the execution of the program of the present invention. It can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. It is also possible for multiple processors to perform different functions.

The memory involved in FIG. 13 and/or FIG. 14 stores a program for executing the technical solution of the present invention, and may also store an operating system and other applications. In particular, the program can include program code, the program code including computer operating instructions. More specifically, the memory may be a read-only memory (ROM), other types of static storage devices that can store static information and instructions, random access memory (RAM), and storable information. And other types of dynamic storage devices, disk storage, and so on. It can also be a different memory storage.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented in hardware, firmware implementation, or a combination thereof. When implemented in software, the functions described above may be stored in or transmitted as one or more instructions or code on a computer readable medium. Computer readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another. A storage medium may be any available media that can be accessed by a computer. By way of example and not limitation, computer readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage media or other magnetic storage device, or can be used for carrying or storing in the form of an instruction or data structure. The desired program code and any other medium that can be accessed by the computer. Also. Any connection may suitably be a computer readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable , fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, wireless, and microwave are included in the fixing of the associated media. As used in the present invention, a disk and a disc include a compact disc (CD), a laser disc, a compact disc, a digital versatile disc (DVD), a floppy disk, and a Blu-ray disc, wherein the disc is usually magnetically copied, and the disc is The laser is used to optically replicate the data. Combinations of the above should also be included within the scope of the computer readable media.

In summary, the above description is only a preferred embodiment of the technical solution of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

A precoding matrix indicating PMI feedback method, characterized in that it is used in a wireless communication system having multi-carrier capability, wherein a user equipment UE in the wireless communication system uses a first subcarrier and a second subcarrier and a network side device Communication, the method includes:

Determining, by the UE, at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier The at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier;

The UE transmits the at least one public PMI, the at least one first PMI, and the at least one second PMI to a base station in the wireless communication system.
The method of claim 1 wherein

The precoding matrix of the first subcarrier is a Kronecker product of a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier; the second subcarrier The precoding matrix is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier;

The common PMI is used to indicate a vertical direction precoding matrix of the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier;

The first PMI is used to indicate a horizontal direction precoding matrix of the first subcarrier;

The second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.
The method of claim 2 wherein

The vertical precoding matrix of the first subcarrier indicated by the common PMI is:

Where N is a positive integer, k is an integer greater than or equal to 0 and less than or equal to N-1; m is the length of the precoding matrix W corresponding to the common PMI, and T represents the transposition of the matrix.
The method of claim 1 wherein

The precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix of the first subcarrier and a short-term narrowband characteristic matrix; and a precoding matrix of the second subcarrier is a long-term broadband of the second carrier The product of the property matrix and the short-term narrow-band property matrix;

The common PMI is used to indicate a long-term broadband characteristic matrix of the first sub-carrier; the common PMI is further used to indicate a long-term broadband characteristic matrix of the second sub-carrier;

The first PMI is used to indicate a short-term narrowband characteristic matrix of the first subcarrier;

The second PMI is used to indicate a short-term narrowband characteristic matrix of the second subcarrier.
The method of any of claims 1-4, further comprising:

The UE determines and transmits a first PMI compensation value δ, which is used to indicate a precoding matrix of the first subcarrier together with the at least one common PMI and the at least one first PMI.
The method of claim 5 wherein:

The UE determines the first PMI compensation value δ, including:

Determining the first PMI compensation value δ according to the second subcarrier precoding matrix and the first subcarrier precoding matrix.
The method according to claim 5 or 6, wherein the sending, by the UE, the first PMI compensation value δ comprises:

The first PMI compensation value δ is transmitted through a physical uplink control channel PUCCH or a physical uplink shared channel PUSCH.
A precoding matrix indicating PMI feedback method, characterized in that, for a wireless communication system having multi-carrier capability, a base station in the wireless communication system communicates with a user equipment UE by using a first subcarrier and a second subcarrier, The method includes:

The base station receives at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate a precoding matrix of the first subcarrier. The at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier;

Determining, by the base station, a precoding matrix of the first subcarrier according to the at least one common PMI and the at least one first PMI, and determining precoding of the second subcarrier according to the at least one common PMI and the second PMI matrix.
The method of claim 8 wherein

The precoding matrix of the first subcarrier is a Kronecker product of a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier; the second subcarrier Precoding The matrix is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier;

The common PMI is used to indicate a vertical direction precoding matrix of the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier;

The first PMI is used to indicate a horizontal direction precoding matrix of the first subcarrier;

The second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.
The method of claim 9 comprising:

The vertical precoding matrix of the first subcarrier indicated by the common PMI is:

Where N is a positive integer, k is an integer greater than or equal to 0 and less than or equal to N-1; m is the length of the precoding matrix W corresponding to the common PMI, and T represents the transposition of the matrix.
The method of claim 8 wherein

The precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix of the first subcarrier and a short-term narrowband characteristic matrix; and a precoding matrix of the second subcarrier is a long-term broadband characteristic of the second carrier The product of the matrix and the short-term narrow-band characteristic matrix;

The common PMI is used to indicate a long-term broadband characteristic matrix of the first sub-carrier; the common PMI is further used to indicate a long-term broadband characteristic matrix of the second sub-carrier;

The first PMI is used to indicate a short-term narrowband characteristic matrix of the first subcarrier;

The second PMI is used to indicate a short-term narrowband characteristic matrix of the second subcarrier.
The method of any of claims 8-11, further comprising:

Receiving, by the base station, a first PMI compensation value δ sent by the UE,

Determining, by the base station, a precoding matrix of the first subcarrier according to the δ and the at least one common PMI and the at least one first PMI.
The method according to claim 12, wherein the receiving, by the base station, the first PMI compensation value δ comprises:

The base station receives the first PMI compensation value δ through a physical uplink control channel PUCCH or a physical uplink shared channel PUSCH.
A precoding matrix indicating PMI feedback device characterized by being used for multi-carrier capability a line communication system, where the user equipment UE in the wireless communication system communicates with the network side device by using the first subcarrier and the second subcarrier, where the UE includes:

a determining unit, configured to determine at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate a preset of the first subcarrier An encoding matrix; the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier;

And a sending unit, configured to send the at least one common PMI, the at least one first PMI, and the at least one second PMI to a base station in the wireless communication system.
The UE according to claim 14, comprising:

The precoding matrix of the first subcarrier is a Kronecker product of a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier; the second subcarrier The precoding matrix is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier;

The common PMI is used to indicate a vertical direction precoding matrix of the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier;

The first PMI is used to indicate a horizontal direction precoding matrix of the first subcarrier;

The second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.
The UE according to claim 15, comprising:

The vertical precoding matrix of the first subcarrier indicated by the common PMI is:

Where N is a positive integer, k is an integer greater than or equal to 0 and less than or equal to N-1; m is the length of the precoding matrix W corresponding to the common PMI, and T represents the transposition of the matrix.
The UE according to claim 14, comprising:

The precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix of the first subcarrier and a short-term narrowband characteristic matrix; and a precoding matrix of the second subcarrier is a long-term broadband characteristic of the second carrier The product of the matrix and the short-term narrow-band characteristic matrix;

The common PMI is used to indicate a long-term broadband characteristic matrix of the first sub-carrier; the common PMI is further used to indicate a long-term broadband characteristic matrix of the second sub-carrier;

The first PMI is used to indicate a short-term narrowband characteristic matrix of the first subcarrier;

The second PMI is used to indicate a short-term narrowband characteristic matrix of the second subcarrier.
The UE according to any one of claims 14-17, characterized in that:

The determining unit is further configured to determine a first PMI compensation value δ, where the δ is used to determine a precoding matrix of the first subcarrier together with the at least one common PMI and the at least one first PMI;

The sending unit is further configured to send the first PMI compensation value δ.
The UE according to claim 18, wherein the determining unit is further configured to determine the first subcarrier precoding matrix and the second subcarrier precoding matrix; the determining unit is according to the first a subcarrier precoding matrix determining the at least one common PMI;

The determining unit determines the first PMI compensation value δ, including:

Determining the first PMI compensation value δ according to the second subcarrier precoding matrix and the first subcarrier precoding matrix.
The UE according to claim 18 or 19, wherein the sending, by the sending unit, the first PMI compensation value δ specifically includes:

The first PMI compensation value δ is transmitted through a physical uplink control channel PUCCH or a physical uplink shared channel PUSCH.
A precoding matrix indicating PMI feedback device, characterized by being used in a wireless communication system having multi-carrier capability, wherein a base station in the wireless communication system communicates with a user equipment UE by using a first subcarrier and a second subcarrier, The base station includes:

a receiving unit, configured to receive at least one common PMI, at least one first PMI, and at least one second PMI, where the at least one common PMI and the at least one first PMI are used to indicate a pre- An encoding matrix; the at least one common PMI and the at least one second PMI are used to indicate a precoding matrix of the second subcarrier;

a determining unit, configured to determine a precoding matrix of the first subcarrier according to the at least one common PMI and the at least one first PMI, and determine a second subcarrier according to the at least one common PMI and the second PMI Precoding matrix.
The base station according to claim 21, comprising:

The precoding matrix of the first subcarrier is a Kronecker product of a vertical direction precoding matrix of the first subcarrier and a horizontal direction precoding matrix of the first subcarrier; the second subcarrier Precoding The matrix is a Kronecker product of a vertical direction precoding matrix of the second subcarrier and a horizontal direction precoding matrix of the second subcarrier;

The common PMI is used to indicate a vertical direction precoding matrix of the first subcarrier; the common PMI is further used to indicate a vertical direction precoding matrix of the second subcarrier;

The first PMI is used to indicate a horizontal direction precoding matrix of the first subcarrier;

The second PMI is used to indicate a horizontal direction precoding matrix of the second subcarrier.
The base station according to claim 22, comprising:

The vertical precoding matrix of the first subcarrier indicated by the common PMI is:

Where N is a positive integer, k is an integer greater than or equal to 0 and less than or equal to N-1; m is the length of the precoding matrix W corresponding to the common PMI, and T represents the transposition of the matrix.
The base station according to claim 21, comprising:

The precoding matrix of the first subcarrier is a product of a long-term broadband characteristic matrix of the first subcarrier and a short-term narrowband characteristic matrix; and a precoding matrix of the second subcarrier is a long-term broadband characteristic of the second carrier The product of the matrix and the short-term narrow-band characteristic matrix;

The common PMI is used to indicate a long-term broadband characteristic matrix of the first sub-carrier; the common PMI is further used to indicate a long-term broadband characteristic matrix of the second sub-carrier;

The first PMI is used to indicate a short-term narrowband characteristic matrix of the first subcarrier;

The second PMI is used to indicate a short-term narrowband characteristic matrix of the second subcarrier.
A base station according to any one of claims 21-24, characterized in that:

The receiving unit is further configured to receive a first PMI compensation value δ sent by the UE, where the δ is used to determine a precoding matrix of the first subcarrier together with the at least one common PMI and the at least one first PMI. .
The base station according to claim 25, wherein the receiving, by the receiving unit, the first PMI compensation value δ specifically includes:

The receiving unit receives the first PMI compensation value δ through a physical uplink control channel PUCCH or a physical uplink shared channel PUSCH.