CN106301507B - A channel state information measurement feedback method - Google Patents

Abstract

The invention provides a channel state information measurement and feedback method. The base station sends CSI-RS through the N antenna elements corresponding to the N ports at M/N moments of each cycle, so that the user terminal feeds back to the base station when the N antenna elements obtained by the user terminal are sent to the channel matrix of the user terminal; Receive the N antenna elements fed back by the user terminal to the channel matrix of the user terminal, if the currently acquired channel matrix is the M/Nth channel matrix of the cycle, then the M/N channel matrices obtained in the cycle, according to The corresponding relationship between the N antenna ports and the N antenna elements at the M/N moments of the period, the channel matrices obtained in the period are combined, and used as the channel matrix from the M antenna elements to the user terminal in the period, using a limited number of The port realizes the transmission of multiple antenna elements, which can obtain channel state information of more antenna ports and save pilot overhead.

Description

A channel state information measurement feedback method

technical field

The invention relates to the field of communication technology, in particular to a channel state information measurement and feedback method.

Background technique

The introduction of active antennas makes 3D MIMO technology possible, that is, in addition to using multi-antennas for beamforming and spatial multiplexing in the horizontal dimension, multi-antennas can also be used for dynamic downtilt adjustment in the vertical dimension. The position in the vertical dimension, adjusts the beamforming direction in the vertical dimension.

To apply the 3D MIMO technology, in addition to measuring the Channel State Information Reference Signal (CSI-RS) in the horizontal dimension, it is also necessary to measure the CSI-RS in the vertical dimension. Since the horizontal dimension is to measure CSI-RS to obtain channel state information and feed it back to the base station, so as to complete various transmission schemes of multiple antennas, and the vertical dimension must be able to realize the direction adjustment of vertical beamforming, it is also necessary to measure the CSI of the vertical dimension -RS to obtain channel state information in the vertical dimension.

The system uses a large number of two-dimensional antenna arrays, and it is necessary to define a CSI-RS configuration with more than 8 antenna ports. As the number of antenna arrays increases, the number of CSI-RS transmission ports increases proportionally, although it can be considered that a simple extension to A CSI-RS larger than 8 ports will have a great impact on standardization, and will bring about a problem of high pilot overhead.

Contents of the invention

In view of this, the present application provides a channel state information measurement and feedback method to solve the problem of large pilot overhead.

In order to solve the problems of the technologies described above, the technical solution of the present application is achieved in the following way:

A CSI measurement feedback method, the method comprising:

The base station configures CSI-RS transmission information for M antenna elements, and the CSI-RS transmission information is: N antenna ports, and the N antennas corresponding to the N antenna ports at M/N moments in each cycle A while; wherein, N and M are integers greater than 0, and M/N is an integer;

The base station transmits CSI-RS through the N antenna elements corresponding to the N ports at M/N moments of each period, so that when the user terminal obtains N antenna elements to the channel matrix of the user terminal, it will be fed back to base station;

The base station receives the N antenna elements fed back by the user terminal to the channel matrix of the user terminal. If the currently acquired channel matrix is the M/Nth channel matrix of the cycle, the M/N channel matrices obtained in the cycle , according to the corresponding relationship between the N antenna ports and the N antenna elements at the M/N moments of the cycle, combining the channel matrices obtained in the cycle as the channel matrix from the M antenna elements to the user terminal in the cycle.

A CSI measurement feedback method, the method comprising:

The user terminal receives the CSI-RS transmission information configured by the base station sent by the base station, acquires and stores the CSI-RS transmission information; the CSI-RS transmission information is: N antenna ports, and the N antenna port N antenna elements corresponding to M/N moments in each period; where N and M are integers greater than 0, and M/N is an integer;

The user terminal receives the CSI-RS sent by the base station, and obtains a channel matrix from N antenna elements to the user terminal;

If the currently acquired channel matrix is the M/Nth channel matrix of the current period, according to the corresponding relationship between the stored N antenna ports and the N antenna elements at the M/N moments of the period, the channel acquired in this period The matrices are combined to serve as channel matrices from the M antenna elements in the period to the user terminal, and fed back to the base station.

It can be seen from the above technical solution that the base station in this application configures antenna ports less than the number of antenna elements, and each antenna port is mapped to different antenna elements at different times in a cycle, so as to use a limited number of ports to realize multiple antenna elements can obtain channel state information of more antenna ports and save pilot overhead.

Description of drawings

FIG. 1 is a schematic diagram of an antenna port corresponding to a horizontal antenna element in one cycle in an embodiment of the present application;

FIG. 2 is a schematic diagram of an antenna port corresponding to a longitudinal antenna element in one cycle in an embodiment of the present application;

FIG. 3 is a schematic flow chart of the CSI measurement feedback method in Embodiment 1 of the present application;

FIG. 4 is a schematic flowchart of a CSI measurement feedback method in Embodiment 2 of the present application.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below with reference to the accompanying drawings and examples.

An embodiment of the present application provides a CSI measurement feedback method. The base station configures antenna ports less than the number of antenna elements, and each antenna port is mapped to a different antenna element at different times in a cycle, so as to use a limited number of ports to achieve multiple The transmission of antenna elements can obtain channel state information of more antenna ports and save pilot overhead.

In this embodiment of the present application, the base station configures CSI-RS transmission information for M antenna elements, and the CSI-RS transmission information is: N antenna ports, and the M/N number of the N antenna ports in each period N antenna elements corresponding to the moment; wherein, N and M are integers greater than 0, and M/N is an integer.

In specific implementation, for example, for 16 antenna elements, 4 antenna ports can be used, for example, the 4 antenna ports are antenna port 1, antenna port 2, antenna port 3, and antenna port 4; the 16 antenna elements are respectively antenna elements 1. Antenna elements 2...Antenna elements 16, then it is necessary to send CSI-RS at 4 (16/4) moments in one cycle. The corresponding relationship between antenna elements and antenna ports in one cycle is: 4 at the first moment The antenna ports correspond to 4 different antenna elements. At the second moment, the 4 antenna ports correspond to 4 different antenna elements among the other 12 antenna elements. At the third moment, the 4 antenna ports correspond to 4 of the other 8 antenna elements. different antenna elements, the 4 antenna elements at the fourth moment correspond to 4 different antenna elements in the remaining 4 antenna elements.

It can be seen that each port corresponds to a different antenna element at four moments in one cycle, and corresponds to all antenna elements in one cycle.

This application provides the following correspondence between antenna ports and antenna elements:

The N is the number of M antenna elements arranged horizontally, or the number of antenna elements arranged vertically, that is, the N antenna elements corresponding to each moment are the number of horizontal antenna elements or the number of vertical antenna elements.

The relationship between the antenna port and the antenna elements will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , FIG. 1 is a schematic diagram of an antenna port corresponding to a horizontal antenna element in one cycle in an embodiment of the present application. Figure 1 takes 16 antenna elements and 4 antenna ports as an example. The dotted line antennas in FIG. 1 represent 4 antenna elements corresponding to 4 ports at the corresponding time. According to the corresponding relationship shown in FIG. 1 , CSI-RS is sent through each antenna element in one period.

Fig. 1 is only an example, as long as there are four antenna elements corresponding to the horizontal direction at each moment of the cycle, as the second moment can also correspond to the antenna element shown by the dotted line corresponding to the first moment, the third The time corresponds to the antenna element shown by the dotted line corresponding to the second time, the fourth time corresponds to the antenna element shown by the dotted line corresponding to the third time, and the first time corresponds to the antenna element shown by the dotted line corresponding to the fourth time Wait.

Referring to FIG. 2 , FIG. 2 is a schematic diagram of an antenna port corresponding to a longitudinal antenna element in one cycle in an embodiment of the present application. In Fig. 2, 32 antenna elements and 8 antenna ports are used as an example. The dotted line antennas in FIG. 2 represent 8 antenna elements corresponding to 8 ports. Through the corresponding relationship shown in FIG. 2 , each antenna element will send a CSI-RS in one period.

Fig. 1 is only an example, as long as there are 8 antenna elements corresponding to the vertical direction at each moment of the cycle, as the second moment can also correspond to the antenna element shown by the dotted line corresponding to the first moment, the third The time corresponds to the antenna element shown by the dotted line corresponding to the second time, the fourth time corresponds to the antenna element shown by the dotted line corresponding to the third time, and the first time corresponds to the antenna element shown by the dotted line corresponding to the fourth time Wait.

How the present application implements CSI-RS measurement feedback will be described in detail below with reference to the accompanying drawings.

Embodiment one

Referring to FIG. 3 , FIG. 3 is a schematic flowchart of a CSI measurement feedback method in Embodiment 1 of the present application. The specific steps are:

Step 301, the base station transmits CSI-RS through the N antenna elements corresponding to the N ports at M/N times of each cycle, so that when the user terminal obtains N antenna elements to the channel matrix of the user terminal, feedback to the base station.

Step 302, the base station receives the channel matrix from the N antenna elements to the user terminal fed back by the user terminal.

Step 303, if the currently obtained channel matrix is the M/Nth channel matrix of the cycle, the base station uses the M/N channel matrices obtained in the cycle according to the relationship between the N antenna ports at the M/N moments of the cycle The corresponding relationship of the N antenna elements, combining the channel matrices obtained in the period, is used as the channel matrix of the M antenna elements in the period to the user terminal.

When N is the number of antenna elements arranged horizontally by M antenna elements, the channel matrix from the N antenna elements to the user terminal is a Q×N dimensional matrix, and the channel matrix from the M antenna elements to the user terminal is (Q ×M/N)×N latitude matrix; wherein, Q is the number of antennas for the user terminal to receive the CSI-RS, and is an integer greater than 0;

When N is the number of antenna elements arranged vertically by M antenna elements, the channel matrix from the N antenna elements to the user terminal is an N×1 dimensional matrix, and the channel matrix from the M antenna elements to the user terminal is N× (Q×M/N) latitude matrix.

Taking FIG. 1 as an example, for one cycle, the base station transmits CSI-RSs at different times according to the corresponding relationship between antenna ports and antenna elements.

The user terminal receives the CSI-RS sent by the base station, and obtains the channel matrix from 4 antenna elements to the user terminal. When the user terminal uses 1 receiving antenna, at a moment in a cycle, the channel matrix obtained by the user terminal is 1 ×4 latitude matrix, and feed back the channel matrix obtained at each moment to the base station.

Suppose the channel matrix fed back by the channel at the first moment is a 1×4 dimensional matrix [H11 H12 H13 H14], the channel matrix fed back by the user terminal at the second moment is a 1×4 dimensional matrix [H21 H22 H23 H24], and the user terminal at the third moment The channel matrix fed back is a 1×4-dimensional matrix [H31 H32 H33 H34], and the channel matrix fed back by the user terminal at the fourth moment is a 1×4-dimensional matrix [H41 H42 H43 H44]. Correspondence The channel matrices at four moments are combined to obtain the channel matrix from the entire 16 antennas to the user terminal, as follows:

Embodiment two

Referring to FIG. 4 , FIG. 4 is a schematic flowchart of a CSI measurement feedback method in Embodiment 2 of the present application. The specific steps are:

Step 401, the user terminal receives the CSI-RS transmission information configured by the base station sent by the base station, acquires and stores the CSI-RS transmission information.

After the base station configures the CSI-RS transmission information, it notifies the user terminal, and the user terminal stores the received CSI-RS transmission information for combining the M antenna elements into the channel matrix of the user terminal.

Step 402, the user terminal receives the CSI-RS sent by the base station, and obtains a channel matrix from N antenna elements to the user terminal.

Step 403, if the currently acquired channel matrix is the M/Nth channel matrix of the current period, the user terminal will, according to the stored correspondence between the N antenna ports and the N antenna elements at the M/N moments of the period, set The channel matrices obtained in this period are combined, used as the channel matrix from the M antenna elements to the user terminal in this period, and fed back to the base station.

When N is the number of antenna elements arranged horizontally by M antenna elements, the channel matrix from the N antenna elements to the user terminal is a Q×N dimensional matrix, and the channel matrix from the M antenna elements to the user terminal is (Q ×M/N)×N latitude matrix; wherein, Q is the number of antennas for the user terminal to receive the CSI-RS;

When N is the number of antenna elements arranged vertically by M antenna elements, the channel matrix from the N antenna elements to the user terminal is an N×1 dimensional matrix, and the channel matrix from the M antenna elements to the user terminal is N× (Q×M/N) latitude matrix.

Taking FIG. 2 as an example, for one cycle, the base station transmits CSI-RSs at different times according to the corresponding relationship between antenna ports and antenna elements.

The user terminal receives the CSI-RS sent by the base station, and obtains the channel matrix from 8 antenna elements to the user terminal. When the user terminal uses 1 receiving antenna, at a moment in a period, the channel matrix obtained by the user terminal is 8 ×1 latitude matrix, after receiving the channel matrix at 4 moments in the current period, merge the channel matrix according to the corresponding relationship between the antenna port and the antenna element at each moment, and obtain the channel matrix from the 32 antenna elements to the user terminal in this period, and feedback to the base station.

Assume that the channel matrix fed back by the channel at the first moment is an 8×1 dimensional matrix [H11 H12 H13 H14 H15 H16H17 H18] ^T , and the channel matrix fed back by the user terminal at the second moment is an 8×1 dimensional matrix [H21 H22 H23 H24 H25 H26H27 H28 ] ^T , the channel matrix fed back by the user terminal at the third moment is an 8×1-dimensional matrix [H31 H32 H33 H34 H35 H36H37 H38] ^T , the channel matrix fed back by the user terminal at the fourth moment is an 8×1-dimensional matrix [H41 H42 H43 H44 H45 H46H47 H48] ^T , through the corresponding relationship between the antenna port and the antenna element at each time, the channel matrix at 4 time points can be combined to obtain the channel matrix from the entire 32 antennas to the user terminal, as follows:

It can be seen from the above two embodiments that the CSI-RS pilots are sent on different antenna elements at different times, and channel state information of more antenna ports can be obtained in combination, thereby achieving the purpose of saving pilot overhead. As shown in Figure 1, the channel matrix from 16 antenna elements to the user terminal is obtained through 4 ports; in body 2, the channel matrix from 32 antenna elements to the user terminal is obtained through 4 ports.

The channel matrix obtained by the base station contains a large amount of channel information. For example, for the 16 antenna arrays in Figure 1, a 4×4 channel matrix can be obtained in Figure 1, and the channel information of each row of the channel matrix, the channel information of each column, or The average channel information of the row or column is used for related processing such as codebook selection.

To sum up, this application configures antenna ports less than the number of antenna elements in the base station, and each antenna port is mapped to different antenna elements at different times in a cycle, so as to use a limited number of ports to realize the transmission of multiple antenna elements , can obtain channel state information of more antenna ports, and save pilot overhead.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (6)

1. a kind of channel state information CSI measures feedback method, which is characterized in that this method comprises:

Base station is directed to M antenna element, and configuration CSI- reference signal RS sends information, and the CSI-RS sends information are as follows: N number of day The M/N moment corresponding N number of antenna element of line end mouth and N number of antenna port in each period；Wherein, N and M are Integer greater than 0, and M/N is integer；

The base station sends CSI- by the corresponding N number of antenna element in the N number of port respectively at the M/N moment in each period RS feeds back to base station when making the every channel matrix for obtaining N number of antenna element to user terminal of user terminal；

The base station receives N number of antenna element of the user terminal feedback to the channel matrix of user terminal, if currently obtain Channel matrix is the M/N channel matrix in the period, then the M/N channel matrix obtained the period, according to N number of antenna end Mouth merges in the M/N moment in the period and the corresponding relationship of N number of antenna element, the channel matrix which is obtained, as Channel matrix of the M antenna element of the period to the user terminal.

2. the method according to claim 1, wherein the N is the transversely arranged antenna element of M antenna element Several or longitudinal arrangement antenna array subnumber.

3. the method according to claim 1, wherein

When N is the transversely arranged antenna array subnumber of M antenna element, the channel matrix of N number of antenna element to user terminal For Q × N-dimensional degree matrix, the channel matrix of the M antenna element to the user terminal is (Q × M/N) × N latitude matrix； Wherein, Q is the antenna number that user terminal receives CSI-RS, and is greater than 0 integer；

When the antenna array subnumber that N is M antenna element longitudinal arrangement, the channel matrix of N number of antenna element to user terminal For the dimensional matrix of N × 1, the channel matrix of the M antenna element to the user terminal is N × (Q × M/N) latitude matrix.

4. a kind of channel state information CSI measures feedback method, which is characterized in that this method comprises:

The CSI- reference signal RS that user terminal receives the base station configuration of base station transmission sends information, obtains the CSI- RS sends information and stores；The CSI-RS sends information are as follows: N number of antenna port and N number of antenna port are in each week The M/N moment of phase corresponding N number of antenna element；Wherein, N and M is the integer greater than 0, and M/N is integer；

The user terminal receive base station transmission CSI-RS, obtain N number of antenna element to this user terminal channel matrix；

If the channel matrix currently obtained is the M/N channel matrix of current period, existed according to N number of antenna port of storage The M/N moment in the period and the corresponding relationship of N number of antenna element, the channel matrix which is obtained merges, as this week M antenna element of phase and feeds back to base station to the channel matrix of this user terminal.

5. according to the method described in claim 4, it is characterized in that, the N is the transversely arranged antenna element of M antenna element Several or longitudinal arrangement antenna array subnumber.

6. according to the method described in claim 5, it is characterized in that,

When N is the transversely arranged antenna array subnumber of M antenna element, the channel matrix of N number of antenna element to user terminal For Q × N-dimensional degree matrix, the channel matrix of the M antenna element to the user terminal is (Q × M/N) × N latitude matrix； Wherein, Q is the antenna number that user terminal receives CSI-RS, and is greater than 0 integer；

When the antenna array subnumber that N is M antenna element longitudinal arrangement, the channel matrix of N number of antenna element to user terminal For the dimensional matrix of N × 1, the channel matrix of the M antenna element to the user terminal is N × (Q × M/N) latitude matrix.