CN108667490B - Channel state information feedback method and device - Google Patents

Channel state information feedback method and device Download PDF

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CN108667490B
CN108667490B CN201710202567.0A CN201710202567A CN108667490B CN 108667490 B CN108667490 B CN 108667490B CN 201710202567 A CN201710202567 A CN 201710202567A CN 108667490 B CN108667490 B CN 108667490B
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reference signal
precoding matrix
candidate
signal resource
transmission layer
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CN108667490A (en
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白文岭
吴凯
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China Academy of Telecommunications Technology CATT
Datang Mobile Communications Equipment Co Ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
    • H04B7/0621—Feedback content
    • H04B7/0626—Channel coefficients, e.g. channel state information [CSI]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
    • H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
    • H04L1/0026—Transmission of channel quality indication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals
    • H04L5/0057—Physical resource allocation for CQI

Abstract

The application discloses a channel state information feedback method and a channel state information feedback device, which are used for realizing the feedback of a beam forming weight of a reference signal resource. The method comprises the following steps: a terminal receives reference signals transmitted on S reference signal resources, wherein the S reference signal resources correspond to S beam forming weights one by one, and the reference signal transmitted on one reference signal resource uses the corresponding beam forming weight to carry out beam forming; wherein S is an integer greater than or equal to 1; the terminal determines respective corresponding metric values of the S reference signal resources according to the reference signals received on the S reference signal resources respectively; the terminal determines the fed back reference signal resources according to the respective corresponding metric values of the S reference signal resources; and the terminal feeds back the determined indication information of the reference signal resource to the base station.

Description

Channel state information feedback method and device
Technical Field
The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for feeding back channel state information.
Background
In a Long Term Evolution (LTE) communication system, a User Equipment (User Equipment, UE) measures Channel State Information (CSI) according to a reference signal sent by a base station, and feeds back the measured CSI Information to the base station, so that the base station performs downlink resource scheduling according to the CSI Information fed back by the UE, and allocates a required resource block and a Modulation and Coding Scheme (MCS), where the CSI Information includes a Rank Indicator (RI), a Channel Quality Indicator (CQI), and a Precoding Matrix Indicator (PMI).
In the R13 standard, the LTE communication system researches the Full-dimensional multiple-Input multiple-Output (FD-MIMO) characteristic, wherein a type of Channel State measurement pilot (CSI-RS) is introduced as a Beamformed (BF) pilot, which is called the CSI-RS of CLASS B. In a channel state information-reference signal (CSI-RS) scene of CLASS B, a base station can configure a plurality of CSI-RS resources for the same CSI process of User Equipment (UE), and the CSI-RS resources are shaped differently to compensate signal fading and distortion caused by factors such as space loss and multipath effect in a wireless propagation process and reduce interference. Therefore, the UE needs to feed back the optimal CSI-RS resource index to the base station when performing channel measurement, so as to provide a reference for selecting a suitable beamforming vector at the base station side.
Disclosure of Invention
The embodiment of the application provides a channel state information feedback method and a channel state information feedback device, which are used for realizing the feedback of a beam forming weight of a reference signal resource.
The embodiment of the application provides the following specific technical scheme:
in a first aspect, an embodiment of the present application provides a channel state information feedback method, including:
a terminal receives reference signals transmitted on S reference signal resources, wherein the S reference signal resources correspond to S beam forming weights one by one, and the reference signal transmitted on one reference signal resource uses the corresponding beam forming weight to carry out beam forming; wherein S is an integer greater than or equal to 1;
the terminal determines respective corresponding metric values of the S reference signal resources according to the reference signals received on the S reference signal resources respectively;
the terminal determines the fed back reference signal resources according to the respective corresponding metric values of the S reference signal resources;
and the terminal feeds back the determined indication information of the reference signal resource to the base station.
Optionally, the first reference signal resource is any one of the S reference signal resources; determining a metric value corresponding to the first reference signal resource, including:
determining a candidate precoding matrix set corresponding to each candidate transmission layer number according to each candidate transmission layer number in the candidate transmission layer number set corresponding to the first reference signal resource;
determining a first metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to each candidate transmission layer number;
and determining the metric value corresponding to the first reference signal resource according to the first metric value with the maximum value.
Optionally, before determining the metric value corresponding to the first reference signal resource, the method includes:
determining a first metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to the first candidate transmission layer number;
forming a subset of the candidate precoding matrix set by using the first N precoding matrices with first metric values arranged from large to small in the candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein N is greater than or equal to 1 and less than the number of precoding matrices in the candidate precoding matrix set;
and taking the subset as a candidate precoding matrix set corresponding to the first candidate transmission layer number of the S reference signal resources.
Optionally, determining a candidate precoding matrix set corresponding to the first candidate number of transmission layers, where the first candidate number of transmission layers is any one of the candidate number of transmission layers set corresponding to the first reference signal resource, includes:
and determining a first set or a subset of the first set as a candidate precoding matrix corresponding to the first candidate transmission layer number, wherein the first set comprises all available precoding matrices corresponding to the first candidate transmission layer number selected from a single-stage codebook or a double-stage codebook used by the terminal according to a codebook subset limiting parameter corresponding to the first reference signal resource.
Optionally, the subset of the first set is obtained according to the following manner:
selecting a pre-coding matrix in the first set to obtain a subset of the first set;
or selecting a plurality of precoding matrixes with discontinuous index values in the first set to obtain a subset of the first set;
or selecting a precoding matrix with a plurality of continuous index values in the first set to obtain a subset of the first set.
Optionally, determining a candidate precoding matrix set corresponding to the first candidate number of transmission layers, where the first candidate number of transmission layers is any one of the candidate number of transmission layers set corresponding to the first reference signal resource, includes:
determining a candidate precoding matrix set corresponding to the first candidate transmission layer number according to a first-stage precoding matrix set corresponding to the first candidate transmission layer number and a second-stage precoding matrix set corresponding to the first candidate transmission layer number; and calculating a candidate precoding matrix in the candidate precoding matrix set corresponding to the first candidate transmission layer number according to a precoding matrix in the first-stage precoding matrix set and a precoding matrix in the second-stage precoding matrix set.
Optionally, determining a candidate precoding matrix set corresponding to the first candidate number of transmission layers, where the first candidate number of transmission layers is any one of the candidate number of transmission layers set corresponding to the first reference signal resource, includes:
determining a second metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the first-level precoding matrix set corresponding to the first candidate transmission layer number;
forming a subset of the first-stage precoding matrix set by using the first M precoding matrices with second metric values arranged from large to small in the first-stage precoding matrix set corresponding to the first candidate transmission layer number, wherein M is greater than or equal to 1 and less than the number of precoding matrices in the first-stage precoding matrix;
and determining a candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein one candidate precoding matrix in the candidate precoding matrix set is obtained by calculation according to one precoding matrix in the subset and one precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number.
Optionally, the first reference signal resource is any one of the S reference signal resources; if the second-stage precoding matrix set corresponding to each candidate transmission layer number in the candidate transmission layer number set corresponding to the first reference signal resource only includes one precoding matrix, determining a metric value corresponding to the first reference signal resource, including:
determining a second metric value corresponding to each precoding matrix according to a reference signal received on the reference signal resource and each precoding matrix in a first-stage precoding matrix set corresponding to each candidate transmission layer number;
and determining the second metric value with the maximum value as the metric value corresponding to the first reference signal resource.
Optionally, before determining the metric value corresponding to the first reference signal resource, the method includes:
determining a first metric value corresponding to each precoding matrix according to a reference signal received on the first reference signal resource, each precoding matrix in a first-stage precoding matrix set corresponding to the first candidate transmission layer number and each precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number;
forming a subset of the first-level precoding matrix set by using precoding matrixes in the first-level precoding matrix set corresponding to first Q first metric values which are arranged from large to small, and forming a subset of the second-level precoding matrix set by using precoding matrixes in the second-level precoding matrix set corresponding to first Q first metric values which are arranged from large to small, wherein Q is more than or equal to 1 and less than the maximum value of the number of precoding matrixes in the first-level precoding matrix set and the number of precoding matrixes in the second-level precoding matrix set;
and taking the subset of the first-stage precoding matrix set as a first-stage precoding matrix set corresponding to a first candidate transmission layer number of the S reference signal resources, and taking the subset of the second-stage precoding matrix set as a second-stage precoding matrix set corresponding to the first candidate transmission layer number of the S reference signal resources.
Optionally, the candidate transmission layer number set corresponding to the first reference signal resource is the same as a second set or is a subset of the second set, where the second set includes all available transmission layer numbers determined according to the codebook subset restriction parameter corresponding to the first reference signal resource.
Optionally, the subset of the second set is obtained according to the following: selecting one transmission layer number in the second set to obtain a subset of the second set; or selecting a plurality of transmission layer numbers with discontinuous index values in the second set to obtain a subset of the second set; or, selecting the number of transmission layers with a plurality of continuous index values in the second set to obtain the subset of the second set.
Optionally, a first-stage precoding matrix set corresponding to the first candidate number of transmission layers is the same as or a subset of a third set, where the third set includes all available precoding matrices corresponding to the first candidate number of transmission layers of a region selected from a first-stage codebook used by the terminal according to a codebook subset restriction parameter corresponding to the first reference signal resource;
the second-stage precoding matrix set corresponding to the first candidate transmission layer number is the same as a fourth set or is a subset of the fourth set; the fourth set includes all available precoding matrices corresponding to the first candidate number of transmission layers selected from a second-level codebook used by the terminal according to the codebook subset restriction parameter corresponding to the first reference signal resource.
Optionally, the subset of the third set is obtained according to the following: selecting a pre-coding matrix in the third set to obtain a subset of the third set; or selecting a plurality of precoding matrixes with discontinuous index values in the third set to obtain a subset of the third set; or selecting a plurality of precoding matrixes with continuous index values in the third set to obtain a subset of the third set;
a subset of the fourth set is obtained according to the following: selecting a pre-coding matrix in the fourth set to obtain a subset of the fourth set; or selecting a plurality of precoding matrixes with discontinuous index values in the fourth set to obtain a subset of the fourth set; or selecting a precoding matrix with a plurality of continuous index values in the fourth set to obtain a subset of the fourth set.
Optionally, the first reference signal resource is any one of the S reference signal resources; determining a metric value for the first reference signal resource, comprising:
determining a channel matrix according to the reference signal received on the first reference signal resource;
and determining the energy of the reference signal received on the first reference signal resource according to the channel matrix, and taking the energy as a metric value corresponding to the first reference signal resource.
Optionally, the determining, by the terminal, the fed back reference signal resource according to the respective corresponding metric values of the S reference signal resources includes:
and the terminal determines the maximum value of the metric values corresponding to the S reference signal resources and determines the reference signal resource corresponding to the maximum value as the reference signal resource for feedback.
Optionally, the metric value includes throughput, channel capacity, mutual information sum, beam power gain, or a ratio of beam power gain to interference noise power gain.
In a second aspect, an embodiment of the present application provides a channel state information feedback apparatus, including:
a receiving module, configured to receive reference signals transmitted on S reference signal resources, where the S reference signal resources correspond to S beamforming weights one to one, and a reference signal transmitted on one reference signal resource performs beamforming using a corresponding beamforming weight; wherein S is an integer greater than or equal to 1;
a metric value determining module, configured to determine metric values corresponding to the S reference signal resources according to the reference signals received on the S reference signal resources, respectively;
a reference signal resource determining module, configured to determine a fed-back reference signal resource according to the respective corresponding metric values of the S reference signal resources;
and the feedback module is used for feeding back the determined indication information of the reference signal resource to the base station.
Optionally, the metric value determining module is specifically configured to: determining a candidate precoding matrix set corresponding to each candidate transmission layer number according to each candidate transmission layer number in a candidate transmission layer number set corresponding to a first reference signal resource; wherein the first reference signal resource is any one of the S reference signal resources;
determining a first metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to each candidate transmission layer number;
and determining the metric value corresponding to the first reference signal resource according to the first metric value with the maximum value.
Optionally, the metric value determining module is specifically configured to: determining a first set or a subset of the first set as a candidate precoding matrix corresponding to a first candidate transmission layer number, wherein the first candidate transmission layer number is any candidate transmission layer number in a candidate transmission layer number set corresponding to the first reference signal resource, and the first set comprises all available precoding matrices corresponding to the first candidate transmission layer number selected from a single-stage codebook or a double-stage codebook used by a terminal according to a codebook subset limiting parameter corresponding to the first reference signal resource.
Optionally, the metric value determining module is specifically configured to: determining a candidate precoding matrix set corresponding to a first candidate transmission layer number according to a first-stage precoding matrix set corresponding to the first candidate transmission layer number and a second-stage precoding matrix set corresponding to the first candidate transmission layer number; the first candidate transmission layer number is any one of the candidate transmission layer number sets corresponding to the first reference signal resource, and one candidate precoding matrix in the candidate precoding matrix set corresponding to the first candidate transmission layer number is calculated according to one precoding matrix in the first-stage precoding matrix set and one precoding matrix in the second-stage precoding matrix set.
Optionally, the metric value determining module is specifically configured to: determining a second metric value corresponding to each precoding matrix according to a reference signal received on a first reference signal resource and each precoding matrix in a first-stage precoding matrix set corresponding to a first candidate transmission layer number; wherein the first candidate number of transmission layers is any one of a set of candidate number of transmission layers corresponding to the first reference signal resource;
forming a subset of the first-stage precoding matrix set by using the first M precoding matrices with second metric values arranged from large to small in the first-stage precoding matrix set corresponding to the first candidate transmission layer number, wherein M is greater than or equal to 1 and less than the number of precoding matrices in the first-stage precoding matrix;
and determining a candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein one candidate precoding matrix in the candidate precoding matrix set is obtained by calculation according to one precoding matrix in the subset and one precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number.
Optionally, the metric value determining module is specifically configured to: if the second-stage precoding matrix set corresponding to each candidate transmission layer number in the candidate transmission layer number set corresponding to the first reference signal resource only comprises one precoding matrix, and the first reference signal resource is any one reference signal resource in the S reference signal resources, determining a second metric value corresponding to each precoding matrix according to a reference signal received on the reference signal resource and each precoding matrix in the first-stage precoding matrix set corresponding to each candidate transmission layer number;
and determining the second metric value with the maximum value as the metric value corresponding to the first reference signal resource.
Optionally, the candidate transmission layer number set corresponding to the first reference signal resource is the same as a second set or is a subset of the second set, where the second set includes all available transmission layer numbers determined according to the codebook subset restriction parameter corresponding to the first reference signal resource.
Optionally, the first-stage precoding matrix set corresponding to the first candidate number of transmission layers is the same as or a subset of a third set, where the third set includes all available precoding matrices corresponding to the first candidate number of transmission layers of a region selected from a first-stage codebook used by a terminal according to a codebook subset restriction parameter corresponding to the first reference signal resource;
the second-stage precoding matrix set corresponding to the first candidate transmission layer number is the same as a fourth set or is a subset of the fourth set; the fourth set includes all available precoding matrices corresponding to the first candidate number of transmission layers selected from a second-level codebook used by the terminal according to the codebook subset restriction parameter corresponding to the first reference signal resource.
Optionally, the metric value determining module is specifically configured to: determining a channel matrix according to a reference signal received on a first reference signal resource; wherein the first reference signal resource is any one of the S reference signal resources;
and determining the energy of the reference signal received on the first reference signal resource according to the channel matrix, and taking the energy as a metric value corresponding to the first reference signal resource.
Optionally, a maximum value of metric values corresponding to the S reference signal resources is determined, and the reference signal resource corresponding to the maximum value is determined as the reference signal resource for feedback.
Based on the above technical solution, in the embodiment of the present application, after receiving reference signals transmitted on S reference signal resources, a terminal determines metric values corresponding to the S reference signal resources according to the reference signals received on the S reference signal resources, determines a fed-back reference signal resource according to the respective metric values corresponding to the S reference signal resources, and feeds back indication information of the determined reference signal resource to a base station, where the S reference signal resources correspond to the S beamforming weights one to one, so that the base station can perform appropriate beamforming for a signal to be transmitted according to the indication information of the reference signal resource fed back by the terminal.
Drawings
Fig. 1 is a flowchart of a channel state information feedback method according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of a channel state information feedback apparatus according to an embodiment of the present disclosure;
fig. 3 is a schematic structural diagram of a terminal according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described in further detail with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The parameter representation methods used in the embodiments of the present application are first described below, and unless otherwise stated, the parameter representation methods appearing in the following embodiments are subject to the following descriptions:
s: representing the number of reference signal resources, S being an integer greater than or equal to 1;
s: s is more than or equal to 0 and less than or equal to S-1;
k: represents the number of subcarriers, and K is an integer greater than or equal to 1;
k: a sequence number indicating a subcarrier;
xk: represents the originating signal on subcarrier k, is a vector of r × 1;
r: represents the number of transmission layers (Rank), r being an integer greater than or equal to 1;
l: an index indicating the number of transmission layers;
i: an index representing a precoding matrix;
i1: an index representing a first level precoding matrix;
i2: index representing second-stage precoding matrix
Wr,i,k: when the number of transmission layers r is represented, the precoding matrix with index i corresponding to the k-th subcarrier is NtA matrix of x r;
Nt: representing the number of transmit antenna ports;
Nr: represents the number of receiving antennas;
γl,r,i,k: indicating the Signal to Interference and Noise Ratio (SINR) of the k-th subcarrier on the l-th layer when the number of transmission layers is r and the index of the precoding matrix is i;
Hk: represents Nr×NtThe estimated channel matrix of (2).
In the embodiment of the present application, s in the superscript of the parameter indicates a parameter corresponding to the s-th reference signal resource without specific statement.
The embodiments of the present application will be described in detail below with reference to the accompanying drawings.
In this embodiment of the application, the base station may be an evolved Node B (eNB or e-NodeB) in an LTE system or an evolved system thereof, a macro base station, a micro base station (also referred to as a "small base station"), a pico base station, an Access Point (AP) or a Transmission Point (TP), and the like, or may also be a base station in a future network, such as a base station in a 5G network. A Terminal may also be referred to as a User Equipment (UE), or may be referred to as Terminal, a Mobile Station (MS), a Mobile Terminal (RAN), and so on, and may communicate with one or more core networks via a Radio Access Network (RAN), for example, the Terminal may be a Mobile phone (or may be referred to as a "cellular" phone), a computer with a Mobile Terminal, and so on, and may also be a portable, pocket, handheld, computer-included, or vehicle-mounted Mobile device, which exchanges voice and/or data with the RAN. The terminal in the embodiment of the present application may also be a D2D (Device to Device) terminal or an M2M (Machine to Machine) terminal.
Fig. 1 shows a schematic flow chart of a method for determining the number of transmission layers according to an embodiment of the present application, where the flow may be implemented by a terminal, and includes the following steps:
step 101: the terminal receives reference signals transmitted on S reference signal resources, the S reference signal resources correspond to S beam forming weights one by one, the reference signals transmitted on one reference signal resource carry out beam forming by using the corresponding beam forming weight, wherein S is an integer larger than or equal to 1.
The S beamforming corresponding to the S reference signal resources may be in a horizontal dimension, a vertical dimension, or a horizontal-vertical two-dimensional dimension, and there is no limitation in the communication protocol. However, in practical applications, multiple CSI-RS resources of the same CSI process are usually shaped through different vertical dimensions. In addition, the number of ports of a plurality of CSI-RS resources of the same CSI process may be the same or different, and there is no limitation in the communication protocol. However, in practical applications, the number of ports of multiple CSI-RS resources of the same CSI process is generally the same.
Step 102: and the terminal determines the metric values corresponding to the S reference signal resources respectively according to the reference signals received on the S reference signal resources.
The metric corresponding to the reference signal resource includes throughput, channel capacity, mutual information sum, beam power gain, or a ratio of the beam power gain to interference noise power gain. The Mutual Information is related to a modulation scheme, and includes Bit Mutual Information (RBIR) generated based on each Received symbol, or Bit Mutual Information obtained by direct calculation, that is, Mean Mutual Information Per Bit (MMIB). The mutual information may be the mutual information under any modulation mode supported by the receiving end. Preferably, the mutual information is the mutual information in the modulation mode with the highest modulation order supported by the receiving end.
The terminal determines a metric value corresponding to a first reference signal resource through, but not limited to, the following two ways, where the first reference signal resource is any one of S reference signal resources:
determining a candidate precoding matrix set corresponding to each candidate transmission layer number according to each candidate transmission layer number in a candidate transmission layer number set corresponding to a first reference signal resource; determining a first metric value corresponding to each precoding matrix according to a reference signal received on a first reference signal resource and each precoding matrix in a precoding matrix set corresponding to each candidate transmission layer number; and determining the first metric value with the maximum value as the metric value corresponding to the first reference signal resource.
In a second mode, if only one precoding matrix is included in the set of second-stage precoding matrices corresponding to each candidate number of transmission layers in the set of candidate number of transmission layers corresponding to the first reference signal resource, determining a metric value corresponding to the first reference signal resource, including the following steps: determining a second metric value corresponding to each precoding matrix according to a reference signal received on the reference signal resource and each precoding matrix in a first-stage precoding matrix set corresponding to each candidate transmission layer number; and determining the second metric value with the maximum value as the metric value corresponding to the first reference signal resource. Wherein the second metric comprises a beam power gain, or a ratio of the beam power gain to an interference noise power gain.
Determining a channel matrix according to the reference signal received on the first reference signal resource;
and determining the energy of the reference signal received on the first reference signal resource according to the channel matrix, and taking the energy as a metric value corresponding to the first reference signal resource.
In a specific embodiment, the energy corresponding to the reference signal resource is represented by the following formula:
Figure GDA0002736884160000121
wherein the content of the first and second substances,
Figure GDA0002736884160000122
indicating a channel matrix corresponding to the s-th reference signal resource,
Figure GDA0002736884160000123
the square of the Frobenius norm of the matrix, i.e. the sum of the squares of all the elements in the matrix, is represented.
Step 103: and the terminal determines the fed back reference signal resources according to the respective corresponding metric values of the S reference signal resources.
Specifically, the terminal determines the maximum value of the metric values corresponding to the S reference signal resources, and determines the reference signal resource corresponding to the maximum value as the reference signal resource for feedback.
Step 104: and the terminal feeds back the indication information of the determined reference signal resource to the base station.
In a specific implementation manner, if the codebook subset restriction parameters corresponding to the S reference signal resources are the same, before performing step 102, the terminal determines a first metric value corresponding to each precoding matrix according to a reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to the first candidate transmission layer number; forming a subset of the candidate precoding matrix set by the first N precoding matrices with first metric values arranged from large to small in the candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein N is greater than or equal to 1 and less than the number of precoding matrices in the candidate precoding matrix set; and taking the subset as a candidate precoding matrix set corresponding to the first candidate transmission layer number of the S reference signal resources.
In another specific implementation manner, if the codebook subset restriction parameters corresponding to the S reference signal resources are the same and the codebook used by the terminal is a two-stage codebook, before performing step 102, the terminal determines, according to the reference signal received on the first reference signal resource, each precoding matrix in the first-stage precoding matrix set corresponding to the first candidate number of transmission layers, and each precoding matrix in the second-stage precoding matrix set corresponding to the first candidate number of transmission layers, a first metric value corresponding to each precoding matrix; forming a subset of the first-level precoding matrix set by using precoding matrixes in the first-level precoding matrix set corresponding to first Q first metric values which are arranged from large to small, and forming a subset of the second-level precoding matrix set by using precoding matrixes in the second-level precoding matrix set corresponding to first Q first metric values which are arranged from large to small, wherein Q is more than or equal to 1 and less than the maximum value of the number of precoding matrixes in the first-level precoding matrix set and the number of precoding matrixes in the second-level precoding matrix set; and taking the subset of the first-stage precoding matrix set as a first-stage precoding matrix set corresponding to a first candidate transmission layer number of the S reference signal resources, and taking the subset of the second-stage precoding matrix set as a second-stage precoding matrix set corresponding to the first candidate transmission layer number of the S reference signal resources.
In step 102, when the terminal determines the metric value corresponding to the first reference signal resource in the first mode, the candidate transmission layer number set corresponding to the first reference signal resource is the same as or a subset of the second set, where the second set includes all available transmission layer numbers determined according to the codebook subset restriction parameter corresponding to the first reference signal resource.
In particular, the subset of the second set is obtained according to the following way: selecting one transmission layer number in the second set to obtain a subset of the second set; or selecting a plurality of transmission layer numbers with discontinuous index values in a second set to obtain a subset of the second set; or, selecting the number of transmission layers with a plurality of continuous index values in the second set to obtain the subset of the second set.
In step 102, when the terminal determines the metric value corresponding to the first reference signal resource in the first mode, the candidate precoding matrix set corresponding to the first candidate transmission layer number may be determined by the following three methods, where the first candidate transmission layer number is any one candidate transmission layer number in the transmission layer number set corresponding to the first reference signal resource:
the method comprises the steps of determining a first set or a subset of the first set as candidate precoding matrixes corresponding to a first candidate transmission layer number, wherein the first set comprises all available precoding matrixes corresponding to the first candidate transmission layer number selected from a single-stage codebook or a double-stage codebook used by a terminal according to codebook subset limiting parameters corresponding to first reference signal resources.
Wherein the subset of the first set is obtained according to the following: selecting a pre-coding matrix in the first set to obtain a subset of the first set; or, in the second mode, selecting a plurality of precoding matrices with discontinuous index values in the first set to obtain a subset of the first set; or, in the third mode, a precoding matrix with a plurality of continuous index values in the first set is selected to obtain a subset of the first set. In implementation, the terminal determines the metric value of the first reference signal resource according to the subset of the first set, which can reduce the calculation amount of the reference signal resource for feedback determination.
And determining a candidate precoding matrix set corresponding to the first candidate transmission layer number according to a first-stage precoding matrix set corresponding to the first candidate transmission layer number and a second-stage precoding matrix set corresponding to the first candidate transmission layer number, wherein one candidate precoding matrix in the candidate precoding matrix set corresponding to the first candidate transmission layer number is obtained by calculation according to one precoding matrix in the first-stage precoding matrix set and one precoding matrix in the second-stage precoding matrix set.
The first-stage precoding matrix set corresponding to the first candidate transmission layer number is the same as or a subset of a third set, and the third set comprises all available precoding matrices corresponding to the first candidate transmission layer number selected from a first-stage codebook used by the terminal according to codebook subset limiting parameters corresponding to the first reference signal resource. And the second-stage precoding matrix set corresponding to the first candidate transmission layer number is the same as or is a subset of a fourth set, and the fourth set comprises all available precoding matrices corresponding to the first candidate transmission layer number selected from a second-stage codebook used by the terminal according to the codebook subset limiting parameter corresponding to the first reference signal resource. In an implementation, the terminal determines the metric value of the first reference signal resource according to the subset of the third set and/or the subset of the fourth set, so that the calculation amount for determining the reference signal resource for feedback can be reduced.
In particular, the subset of the third set is obtained according to the following way: selecting a pre-coding matrix in the third set to obtain a subset of the third set; or selecting a plurality of precoding matrixes with discontinuous index values in the third set to obtain a subset of the third set; or selecting a plurality of precoding matrixes with continuous index values in the third set to obtain a subset of the third set. The subset of the fourth set is obtained according to the following: selecting a pre-coding matrix in the fourth set to obtain a subset of the fourth set; or selecting a plurality of precoding matrixes with discontinuous index values in the fourth set to obtain a subset of the fourth set; or selecting a plurality of precoding matrixes with continuous index values in the fourth set to obtain a subset of the fourth set.
Determining a second metric value corresponding to each precoding matrix according to a reference signal received on a first reference signal resource and each precoding matrix in a first-stage precoding matrix set corresponding to a first candidate transmission layer number; forming a subset of the first-stage precoding matrix set by using the first M precoding matrices with second metric values arranged from large to small in the first-stage precoding matrix set corresponding to the first candidate transmission layer number, wherein M is more than or equal to 1 and less than the number of the precoding matrices in the first-stage precoding matrix; and determining a candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein one candidate precoding matrix in the candidate precoding matrix set is obtained by calculation according to one precoding matrix in the subset and one precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number. Wherein the second metric comprises a beam power gain, or a ratio of the beam power gain to an interference noise power gain.
Specifically, if the set of candidate transmission layer numbers corresponding to the S (0 ≦ S-1) th reference signal resource is set to be the same
Figure GDA0002736884160000151
When the number of transmission layers is r, i.e. RI is r, the corresponding set of candidate precoding matrices is
Figure GDA0002736884160000152
The terminal takes a set formed by all available transmission layer numbers determined by codebook subset limiting parameters corresponding to the s-th reference signal resource configured at the base station side as a candidate set
Figure GDA0002736884160000153
A set formed by all available precoding matrixes with RI-r determined according to codebook subset limiting parameters corresponding to the s-th reference signal resource configured at the base station side is used as a candidate set
Figure GDA0002736884160000161
Then it is determined
Figure GDA0002736884160000162
And
Figure GDA0002736884160000163
the method of (2) includes, but is not limited to, the following two ways:
the first method,
Figure GDA0002736884160000164
Is equal to
Figure GDA0002736884160000165
Figure GDA0002736884160000166
Equal to set
Figure GDA0002736884160000167
The second method,
Figure GDA0002736884160000168
Is a set
Figure GDA0002736884160000169
Is selected from the group consisting of (a) a subset of,
Figure GDA00027368841600001610
is a set
Figure GDA00027368841600001611
A subset of (a).
The codebook subset restriction parameters (for restricting the number of transmission layers and precoding matrices that can be used by the CSI-RS resource) of multiple CSI-RS resources of the same CSI process may be the same or different, and there is no restriction in the protocol. However, in practical applications, codebook subset restriction parameters of multiple CSI-RS resources of the same CSI process are generally the same.
In particular, the amount of the solvent to be used,
Figure GDA00027368841600001612
including but not limited to the following and combinations thereof:
first, for the s-th reference signal resource, the pair sets
Figure GDA00027368841600001613
Uniformly down-sampling to obtain
Figure GDA00027368841600001614
Will be
Figure GDA00027368841600001615
Is determined as
Figure GDA00027368841600001616
The formula is as follows:
Figure GDA00027368841600001617
wherein the content of the first and second substances,
Figure GDA00027368841600001618
a down-sampling factor for the number of transmission layers corresponding to the s-th reference signal resource takes a positive integer greater than or equal to 1,
Figure GDA00027368841600001619
is a set
Figure GDA00027368841600001620
Starting index of (2), value range
Figure GDA00027368841600001621
The values are integers.
Figure GDA00027368841600001622
The smaller the size, the higher the accuracy of the indication information of the reference signal resource fed back by the terminal, but the higher the complexity of determining the indication information of the reference signal resource fed back.
In practice, of S reference signal resources
Figure GDA00027368841600001623
Of S reference signal resources, which may be the same or different
Figure GDA00027368841600001624
May be the same or different.
Second, select the set for the s-th reference signal resource
Figure GDA00027368841600001625
The number of transmission layers with continuous index values
Figure GDA00027368841600001626
To obtain
Figure GDA00027368841600001627
Will be
Figure GDA00027368841600001628
Is determined as
Figure GDA00027368841600001629
The formula is as follows:
Figure GDA00027368841600001630
wherein the content of the first and second substances,
Figure GDA00027368841600001631
the number and value range of the available transmission layer number corresponding to the s-th reference signal resource
Figure GDA0002736884160000171
The value is an integer and the value is,
Figure GDA0002736884160000172
representation collection
Figure GDA0002736884160000173
The number of the elements in the Chinese character,
Figure GDA0002736884160000174
is composed of
Figure GDA0002736884160000175
Initial index of set, value range
Figure GDA0002736884160000176
The values are integers.
Figure GDA0002736884160000177
The larger the size, the higher the accuracy of the indication information of the reference signal resource fed back by the terminal, but the higher the complexity of determining the indication information of the reference signal resource fed back.
In practice, of S reference signal resources
Figure GDA0002736884160000178
Of S reference signal resources, which may be the same or different
Figure GDA0002736884160000179
May be the same or different.
In particular, the amount of the solvent to be used,
Figure GDA00027368841600001710
the subset is selected by the following methods and combinations thereof:
first, for the s-th reference signal resource, the pair sets
Figure GDA00027368841600001711
Uniformly down-sampling to obtain
Figure GDA00027368841600001712
Will be
Figure GDA00027368841600001713
As a subset of
Figure GDA00027368841600001714
The formula is as follows: .
Figure GDA00027368841600001715
Wherein the content of the first and second substances,
Figure GDA00027368841600001716
is a set
Figure GDA00027368841600001717
The down-sampling factor of (2) is a positive integer greater than or equal to 1,
Figure GDA00027368841600001718
is a set
Figure GDA00027368841600001719
Starting index of (2), value range
Figure GDA00027368841600001720
The values are integers.
Figure GDA00027368841600001721
The smaller the size, the higher the accuracy of the indication information of the reference signal resource fed back by the terminal, but the higher the complexity of determining the indication information of the reference signal resource fed back.
In practice, of S reference signal resources
Figure GDA00027368841600001722
Of S reference signal resources, which may be the same or different
Figure GDA00027368841600001723
May be the same or different.
Second, select the set for the s-th reference signal resource
Figure GDA00027368841600001724
A plurality of precoding matrix components with continuous index values
Figure GDA00027368841600001725
The formula is as follows:
Figure GDA00027368841600001726
wherein the content of the first and second substances,
Figure GDA00027368841600001727
is a set
Figure GDA00027368841600001728
The number of the middle pre-coding matrixes is within the range of
Figure GDA00027368841600001729
Is taken as an integer, wherein
Figure GDA00027368841600001730
Representation collection
Figure GDA00027368841600001731
The number of the elements in the Chinese character,
Figure GDA00027368841600001732
is a set
Figure GDA00027368841600001733
Has a value range of
Figure GDA0002736884160000181
The values are integers.
Figure GDA0002736884160000182
The larger the size, the higher the accuracy of the indication information of the reference signal resource fed back by the terminal, but the higher the complexity of determining the indication information of the reference signal resource fed back.
In practice, of S reference signal resources
Figure GDA0002736884160000183
Of S reference signal resources, which may be the same or different
Figure GDA0002736884160000184
May be the same or different.
In wireless communication systems, a dual-stage codebook is the product of a first-stage codebook and a second-stage codebook, i.e.
W＝W1W2
Wherein W represents a two-stage codebook, W1Representing a first-level codebook for quantizing channel bandwidth and long-term channel information, W2A second level codebook is represented for quantizing channel frequency selection and instantaneous channel information. Double stage if terminal is usedThe codebook is the product of a first-stage codebook and a second-stage codebook, and the double-stage codebook can be split for different transmission layers to obtain the first-stage codebook and the second-stage codebook. Therefore, if the codebook used by the terminal is a two-stage codebook, the candidate precoding matrix set composed of all available precoding matrices in the two-stage codebook that satisfy the codebook subset restriction parameter corresponding to the s-th reference signal resource configured on the base station side when RI is r can be selected
Figure GDA0002736884160000189
And selecting a subset to obtain a candidate precoding matrix set. Or the terminal splits the two-stage codebook into a first codebook and a second codebook, and performs subset selection on a set consisting of all available precoding matrices in the first-stage codebook, which satisfy codebook subset restriction parameters corresponding to the s-th reference signal resource configured on the base station side when RI is r, and a set consisting of all available precoding matrices in the second-stage codebook, which satisfy codebook subset restriction parameters corresponding to the s-th reference signal resource configured on the base station side when RI is r, to obtain a first-stage precoding matrix set
Figure GDA0002736884160000185
And a second level set of precoding matrices
Figure GDA0002736884160000186
The splitting of the dual-stage codebook is described below by taking an 8-antenna codebook (a result of multiplying the first-stage codebook by the second-stage codebook) in the LTE system as an example (the splitting is described by taking RI 1 and 2 as an example).
For the first level codebook W1Set of available precoding matrices
Figure GDA0002736884160000187
Figure GDA0002736884160000188
Wherein, X(k)∈{[b2kmod32b(2k+1)mod32b(2k+2)mod32b(2k+3)mod32]|k＝0,1,…,15}。
Let B be [ B ]0,b1…b31]Is a 4 × 32 matrix, each element in the matrix B
Figure GDA0002736884160000191
m＝0,1,2,3，n＝0,1,…,Nvec-1，Nvec＝32，NvecIndicating the number of beam directions involved. C1Optional number of (N)c1＝16。
The codebook has the characteristics that: two adjacent X(k)In which 2 column vectors are repeated, i.e. X(k)The last two column vectors of (2) and X(k+1)The first two column vectors of (a) are identical.
For the second level codebook W2Set of available precoding matrices C2：
When the RI is 1, the first signal is,
Figure GDA0002736884160000192
wherein
Figure GDA0002736884160000193
C2The selectable number of (2) is Nc2The number of the antenna is 16,
Figure GDA0002736884160000194
is a 4 x 1 column vector with 0 elements except the nth row element being 1. Is provided with C2The column vector index in (1) is nc2,1(nc2,1E 0,1,2,3), the column vector index in Y is nc2,2(nc2,2E.0, 1,2,3), then C2Index n of medium precoding matrixc2＝nc2,2×4+nc2,1。
C2Is to C1Is selected due to C1Two adjacent X(k)There are 2 column vectors that are identical, so when the number of transmission layers is 1, there are 128 types of redundancy in the joint codebook as a whole.
When the RI is 2, the first signal is,
Figure GDA0002736884160000195
wherein the content of the first and second substances,
Figure GDA0002736884160000196
Figure GDA0002736884160000197
is a 4X 1 column vector with 0 elements except the n-th row element being 1, C2The selectable number of (2) is Nc216. Is provided with C2The column vector index in (1) is nc2,1(nc2,1E 0,1), the index of the column vector in Y is nc2,2(nc2,2E.g. 0,1, 7), then C2Index n of medium precoding matrixc2＝nc2,2×2+nc2,1。
In practice, any one of them may be combined
Figure GDA0002736884160000198
And any one of the sets
Figure GDA0002736884160000199
In combination with the subset selection means.
In step 102, the metric value corresponding to the s-th reference signal resource is determined in the first manner, which may be implemented in the following specific manners:
in a first specific implementation manner, if the codebook used by the terminal is a single-stage codebook, the candidate transmission layer number set corresponding to the s-th reference signal resource is determined to be the candidate transmission layer number set according to the codebook subset limiting parameter of the CSI process configured at the base station side
Figure GDA00027368841600001910
When the number of transmission layers is r, i.e. RI is r, the corresponding set of candidate precoding matrices is
Figure GDA00027368841600001911
Wherein the content of the first and second substances,
Figure GDA00027368841600001912
and
Figure GDA00027368841600001913
is pre-configured in the terminal. The terminal determines the metric value of the s-th reference signal resource, comprising the following steps:
(1) for the s-th reference signal resource,
Figure GDA0002736884160000201
a first metric value T1 corresponding to each precoding matrix in the candidate precoding matrix set corresponding to each transmission layer number(s)As shown in the following formula:
Figure GDA0002736884160000202
wherein, I1l,r,i,kDetermined by SINR, I1l,r,i,k＝f1(γl,r,i,k) The first metric value includes throughput, channel capacity, or mutual information sum.
(2) Will be provided with
Figure GDA00027368841600002017
A first metric value T1 corresponding to each precoding matrix in the candidate precoding matrix set corresponding to each transmission layer number(s)Is determined as the metric value T of the s-th reference signal resource(s)I.e. by
Figure GDA0002736884160000203
Wherein the number of transmission layers
Figure GDA0002736884160000204
The index of the precoding matrix corresponding to the transmission layer number
Figure GDA0002736884160000205
The following conditions are satisfied:
Figure GDA0002736884160000206
in a second specific implementation manner, if the codebook used by the terminal is a dual-stage codebook, the candidate transmission layer number set corresponding to the s-th reference signal resource is determined to be the candidate transmission layer number set according to the codebook subset limiting parameter of the CSI process configured at the base station side
Figure GDA0002736884160000207
When the number of transmission layers is r, i.e. RI is r, the corresponding set of first-stage precoding matrices is
Figure GDA0002736884160000208
And the set of second-stage precoding matrices is
Figure GDA0002736884160000209
Wherein the content of the first and second substances,
Figure GDA00027368841600002010
and
Figure GDA00027368841600002011
is pre-configured in the terminal. The terminal determines the metric value of the s-th reference signal resource, comprising the following steps:
(1) determining
Figure GDA00027368841600002012
A first metric value T2 corresponding to each precoding matrix in the candidate precoding matrix set corresponding to each transmission layer number(s)As shown in the following formula:
Figure GDA00027368841600002013
wherein, when RI is r, one precoding matrix in the corresponding candidate precoding moment set is based on
Figure GDA00027368841600002014
A precoding matrix sum of
Figure GDA00027368841600002015
Is calculated from one of the precoding matrices in (1),
Figure GDA00027368841600002016
Figure GDA0002736884160000211
determined by SINR, i.e.
Figure GDA0002736884160000212
(2) Will be provided with
Figure GDA0002736884160000213
A first metric value T2 corresponding to each precoding matrix in the candidate precoding matrix set corresponding to each transmission layer number(s)Is determined as the metric value T of the s-th reference signal resource(s)I.e. by
Figure GDA0002736884160000214
Wherein the number of transmission layers
Figure GDA0002736884160000215
Index of the first-stage precoding matrix corresponding to the transmission layer number
Figure GDA0002736884160000216
And the index of the second-stage precoding matrix corresponding to the transmission layer number
Figure GDA0002736884160000217
The following conditions are satisfied:
Figure GDA0002736884160000218
in a third specific implementation manner, if the codebook used by the terminal is a dual-stage codebook, the s-th reference is determined according to the codebook subset limiting parameter of the CSI process configured at the base station sideThe candidate transmission layer number corresponding to the signal resource is set as
Figure GDA0002736884160000219
When the number of transmission layers is r, i.e. RI is r, the corresponding set of first-stage precoding matrix indexes is
Figure GDA00027368841600002110
And the set of second-stage precoding matrix indexes is
Figure GDA00027368841600002111
Wherein the content of the first and second substances,
Figure GDA00027368841600002112
and
Figure GDA00027368841600002113
is pre-configured in the terminal. The terminal determines the metric value of the s-th reference signal resource, comprising the following steps:
(1) determining
Figure GDA00027368841600002114
A second metric value I3 corresponding to each precoding matrix in the first set of precoding moments corresponding to each transmission layer number(s)As shown in the following formula:
Figure GDA00027368841600002115
wherein the content of the first and second substances,
Figure GDA00027368841600002116
a channel matrix corresponding to the s-th reference signal resource,
Figure GDA00027368841600002117
the first-stage precoding matrix set corresponding to the s-th reference signal resource when RI is r
Figure GDA00027368841600002118
Of precoding matrix, secondThe two metrics include the beam power gain, or the ratio of the beam power gain to the interference noise power gain.
(2) Front M to be arranged from large to smallrA second metric value I3(s)A set of corresponding first-level precoding matrices determined as a subset of the s-th set of candidate precoding matrices
Figure GDA00027368841600002119
Figure GDA00027368841600002120
(3) Determining
Figure GDA00027368841600002121
A first metric value T4 corresponding to each precoding matrix in the candidate precoding matrix set corresponding to each candidate transmission layer number(s)As shown in the following formula:
Figure GDA0002736884160000221
wherein, when RI is r, one precoding matrix in the corresponding candidate precoding moment set is based on
Figure GDA0002736884160000222
A precoding matrix sum of
Figure GDA0002736884160000223
Is calculated from one of the precoding matrices in (1),
Figure GDA0002736884160000224
Figure GDA0002736884160000225
determined by SINR, i.e.
Figure GDA0002736884160000226
(4) Will be provided with
Figure GDA0002736884160000227
A first metric value T4 corresponding to each precoding matrix in the candidate precoding matrix set corresponding to each candidate transmission layer number(s)Is determined as the metric value of the s-th reference signal resource as T(s)I.e. by
Figure GDA0002736884160000228
Wherein the number of transmission layers
Figure GDA0002736884160000229
Index of the first-stage precoding matrix corresponding to the transmission layer number
Figure GDA00027368841600002210
And index of second-level precoding matrix
Figure GDA00027368841600002211
The following conditions are satisfied:
Figure GDA00027368841600002212
in implementation, the terminal determines a channel matrix corresponding to a reference signal resource according to a received reference signal on the reference signal resource and a wireless transmission model
Figure GDA00027368841600002213
Specifically, the wireless communication transmission model is shown as follows:
yk＝HkWr,i,kxk+nk
wherein, ykTo receive a signal; hkIs a channel matrix; wr,i,kAs a precoding matrix, Wr,i,kThe code can be a pre-coding matrix in a single-stage codebook or a pre-coding matrix in a double-stage codebook, and when the code is a double-stage codeWhen it is used, i ═ i (i)1,i2)，i1Denotes an index of a precoding matrix in the first-level codebook, and i2An index representing a precoding matrix in the second-level codebook; x is the number ofkAs the originating signal, is a vector of r x 1, let E xkxk H]＝Ir，E[·]A desire to represent a matrix or vector; n iskIs NrX 1 independent identically distributed white Gaussian noise
Figure GDA00027368841600002214
Number and rank of selectable precoding matrices in codebook and number N of transmit antenna portstIn connection with, e.g., transmitting antenna port NtWhen the rank r is 1, the optional number of i is 16.
xkGenerating a transmission signal by inserting a Cyclic Prefix (CP) through Inverse Fast Fourier Transform (IFFT), the transmission signal passing through a multipath fading channel, removing the CP, and obtaining a receiving signal y through FFTk。
MMSE Signal-to-interference-and-noise ratio SINR gamma of the posterior takes a receiver adopting Minimum Mean Square Error (MMSE) algorithm as an examplel,r,i,kThe number of transmission layers, l, is given by:
Figure GDA0002736884160000231
wherein l is less than or equal to r.
In a specific embodiment, if the codebook used by the terminal is a dual-stage codebook, the candidate transmission layer number set corresponding to the s-th reference signal resource is a candidate transmission layer number set according to the codebook subset restriction parameter of the CSI process configured at the base station side
Figure GDA0002736884160000232
When the number of transmission layers is r, i.e. RI is r, the corresponding set of candidate first-stage precoding matrices is
Figure GDA0002736884160000233
And set of candidate second-stage precoding matrices as
Figure GDA0002736884160000234
Wherein the content of the first and second substances,
Figure GDA0002736884160000235
and
Figure GDA0002736884160000236
is pre-configured in the terminal. If it is
Figure GDA0002736884160000237
The method for determining the metric value of the s-th reference signal resource by the terminal comprises the following steps:
(1) determining
Figure GDA0002736884160000238
A second metric value I3 corresponding to each precoding matrix in the first set of precoding moments corresponding to each transmission layer number(s)As shown in the following formula:
Figure GDA0002736884160000239
wherein the content of the first and second substances,
Figure GDA00027368841600002310
a channel matrix corresponding to the s-th reference signal resource,
Figure GDA00027368841600002311
the first-stage precoding matrix set corresponding to the s-th reference signal resource when RI is r
Figure GDA00027368841600002312
The precoding matrix of (1).
(2) Will be provided with
Figure GDA00027368841600002313
A second metric value I3 corresponding to each precoding matrix in the first-stage precoding matrix set corresponding to each candidate transmission layer number(s)Is determined as the metric value of the s-th reference signal resource as T(s)I.e. by
Figure GDA00027368841600002314
Wherein the number of transmission layers
Figure GDA00027368841600002315
Index of the first-stage precoding matrix corresponding to the transmission layer number
Figure GDA00027368841600002316
The following conditions are satisfied:
Figure GDA00027368841600002317
in particular, the second metric value I3(s)Including the beam power gain, or the ratio of the beam power gain to the interference noise power gain, etc. First stage precoding matrix
Figure GDA0002736884160000241
Comprising one or more beams, when
Figure GDA0002736884160000242
When a plurality of beams is included, the beam is,
Figure GDA0002736884160000243
the beam power gain (or the ratio of the beam power gain to the interference noise power gain) of
Figure GDA0002736884160000244
The maximum value of the beam power gain (or the ratio of the beam power gain to the interference noise power gain) of all beams, or
Figure GDA0002736884160000245
The beam rate gain (or the ratio of the beam power gain to the interference noise power gain) of any one of the beams.
Wherein, for any reference signal resource, if the second metric value I3(s)Any one first-stage pre-coding matrix is the maximum value of the beam power gains of all the beams in the first-stage and coding matrixes
Figure GDA0002736884160000246
The second metric value of (2) is calculated as follows:
(1) computing an average channel correlation matrix
Figure GDA0002736884160000247
Figure GDA0002736884160000248
(2) Calculating a beam power gain Gm,n,r：
Figure GDA0002736884160000249
Wherein the content of the first and second substances,
Figure GDA00027368841600002410
first-level precoding matrix with index n when RI is r, and m represents
Figure GDA00027368841600002411
The index of the column vector of (a),
Figure GDA00027368841600002412
express get
Figure GDA00027368841600002413
The element of the m-th column of (c),
Figure GDA00027368841600002414
express get
Figure GDA00027368841600002415
1 to
Figure GDA00027368841600002416
1 st to 1 st of the row
Figure GDA00027368841600002417
The elements of the column are,
Figure GDA00027368841600002418
express get
Figure GDA00027368841600002419
To (1) a
Figure GDA00027368841600002420
To NtFirst of a line
Figure GDA00027368841600002421
To NtElements of a column;
(3) g is to bem,n,rThe maximum value of (a) is used as the first-stage precoding matrix corresponding to the s-th reference signal resource RI ═ r
Figure GDA00027368841600002422
Beam power gain of (a):
Figure GDA00027368841600002423
wherein N isX,colTo represent
Figure GDA0002736884160000251
The number of column vectors.
The following describes in detail the channel state information feedback method provided in the embodiments of the present application through three specific embodiments.
In the first embodiment, it is assumed that the CSI process has 3 CSI-RS resources, and each CSI process has 3 CSI-RS resourcesThe number of ports of the RS resource is 4, the terminal adopts a single-stage codebook, and the number of receiving antennas is 4. The Codebook subset restriction parameters of each CSI-RS resource are the same, and after the Codebook subset restriction parameters are analyzed and configured, all the Rank values and precoding matrices are available, and the precoding codebooks refer to Table 6.3.4.2.3-2 of 3GPP TS36.211 version c-50, wherein the Codebook is used for transmission on antenna ports {0,1,2,3} and for CSI reporting on antenna ports {0,1,2,3} or {15,16,17,18 }. Wherein the candidate transmission layer number set is composed of all available transmission layer numbers
Figure GDA0002736884160000252
Candidate precoding matrix set composed of indexes of all available precoding matrices
Figure GDA0002736884160000253
The terminal will
Figure GDA0002736884160000254
As a set of candidate transmission layer numbers for each CSI-RS resource
Figure GDA0002736884160000255
To pair
Figure GDA0002736884160000256
Carrying out uniform down-sampling to obtain a candidate precoding matrix set corresponding to each CSI-RS resource when RI is r
Figure GDA0002736884160000257
And will be
Figure GDA0002736884160000258
And
Figure GDA0002736884160000259
is pre-configured in the terminal.
Based on the application scenario, after the terminal receives the reference signals transmitted on the 3 CSI-RS resources, in step 102, the metric value T of each CSI-RS resource is determined in a first manner(s)Wherein, the firstA metric value
Figure GDA00027368841600002510
Is the channel capacity.
For the 0 th CSI-RS resource, when RI ═ r,
Figure GDA00027368841600002511
the calculation result of the channel capacity corresponding to the precoding matrix with the index i is shown in table 1, and it can be known from table 1 that: when RI is(0)＝1,PMI(0)When the channel capacity is 8, the channel capacity is the maximum, and the value is 42.52, namely, the metric value T corresponding to the 0 th CSI-RS resource(0)＝42.52。
TABLE 1 channel Capacity computation results for 0 th CSI-RS resource
Figure GDA00027368841600002512
Figure GDA0002736884160000261
For the 1 st CSI-RS resource, when RI ═ r,
Figure GDA0002736884160000262
the calculation result of the channel capacity corresponding to the precoding matrix with the index i is shown in table 2, and it can be known from table 2 that: when RI is(1)＝1,PMI(1)When the channel capacity is 4, the channel capacity is the maximum, and the value is 32.88, namely the metric value T corresponding to the 1 st CSI-RS resource(1)＝32.88。
TABLE 2 channel Capacity computation results for 1 st CSI-RS resource
Figure GDA0002736884160000263
For the 2 nd CSI-RS resource, when RI ═ r,
Figure GDA0002736884160000264
pre-coding with middle index iThe calculation results of the channel capacity corresponding to the code matrix are shown in table 3, and it can be seen from table 3 that: when RI is(2)＝0,PMI(2)When the channel capacity is 4, the channel capacity is maximum, and the value is 47.49, namely the metric value T corresponding to the 2 nd CSI-RS resource(2)＝47.49。
TABLE 3 channel capacity calculation results table for 2 nd CSI-RS resource
Figure GDA0002736884160000265
In step 103, the CSI-RS resource corresponding to the metric value with the largest value is determined as the CSI-RS resource to be fed back.
The metric value of each CSI-RS resource is shown in table 4, and the CSI-RS resource corresponding to the metric value with the largest value is the 2 nd CSI-RS resource, that is, the CRI is 2.
TABLE 4 measurement of CSI-RS resources
s 0 1 2
T(s) 42.52 32.88 47.49
In the second embodiment, it is assumed that the CSI process has 2 CSI-RS resources, the number of ports of each CSI-RS resource is 8, the terminal uses a dual-stage codebook, and the number of receiving antennas is 2. Each CSThe Codebook subset restriction parameters of the I-RS resources are the same, and after the Codebook subset restriction parameters are parsed and configured, all Rank values and precoding codebooks are available, which refer to Table 7.2.4-1 Codebook for 1-layer CSI reporting using ports 15to 22 and Table 7.2.4-2 Codebook for 2-layer CSI reporting using ports 15to 22 of 3GPP TS36.213 release b-40. Wherein the candidate transmission layer number set is composed of all available transmission layer numbers
Figure GDA0002736884160000271
Splitting a codebook given in a protocol to obtain a candidate precoding matrix set consisting of indexes of all available first-stage precoding matrices
Figure GDA0002736884160000272
Candidate precoding matrix set composed of indexes of all available second-stage precoding matrices
Figure GDA0002736884160000273
The terminal will
Figure GDA0002736884160000274
The number of transmission layers 1 in (1) is used as a candidate transmission layer number set corresponding to each CSI-RS resource
Figure GDA0002736884160000275
Will be provided with
Figure GDA0002736884160000276
A candidate first precoding matrix set corresponding to each CSI-RS resource when RI is r
Figure GDA0002736884160000277
Will be provided with
Figure GDA0002736884160000278
Taking the precoding matrix with the medium index of 0 as a candidate second precoding matrix set corresponding to each CSI-RS resource when RI is r
Figure GDA0002736884160000279
And will be
Figure GDA00027368841600002710
And
Figure GDA00027368841600002711
is pre-configured in the terminal.
Based on the application scenario, after the terminal receives the reference signals transmitted on the 2 CSI-RS resources, in step 102, the metric value T of each CSI-RS resource is determined in the second way(s)Wherein the second metric value
Figure GDA00027368841600002712
Is the beam power gain.
For the 0 th CSI-RS resource, when RI ═ r,
Figure GDA00027368841600002713
the calculation result of the beam power gain corresponding to the precoding matrix with the index i is shown in table 5, and it can be known from table 5 that: when RI is(0)＝1,PMI(0)When the value is (14,0), the beam power gain is maximum, and the value is 23.30, that is, the metric value T corresponding to the 0 th CSI-RS resource(0)＝23.30。
TABLE 5 calculation results of beam power gain corresponding to 0 th CSI-RS resource
Figure GDA0002736884160000281
For the 1 st CSI-RS resource, when RI ═ r,
Figure GDA0002736884160000282
the calculation result of the beam power gain corresponding to the precoding matrix with the index i is shown in table 6, and it can be known from table 6 that: when RI is(1)＝1,PMI(1)When the measured value is (14,0), the beam power gain is maximum, and the value is 27.96, that is, the measured value T corresponding to the 1 st CSI-RS resource(1)＝27.96。
TABLE 6 Beam Power gain calculation results for 1 st CSI-RS resource
Figure GDA0002736884160000283
Figure GDA0002736884160000291
In step 103, the CSI-RS resource corresponding to the metric value with the largest value is determined as the CSI-RS resource to be fed back.
The metric value of each CSI-RS resource is shown in table 7, and the CSI-RS resource corresponding to the metric value with the largest value is the 1 st CSI-RS resource, that is, the CRI is 1.
TABLE 7 resource metric values for CSI-RS resources
s 0 1
T(s) 23.30 27.96
In the third embodiment, it is assumed that the CSI process has 4 CSI-RS resources, the number of ports of each CSI-RS resource is 8, the terminal uses a dual-stage codebook, and the number of receiving antennas is 2.
Based on the application scenario, after the terminal receives the reference signals transmitted on the 2 CSI-RS resources, in step 102, the metric value T of each CSI-RS resource is determined in a third manner(s)Wherein the metric value of each CSI-RS resource
Figure GDA0002736884160000292
In step 103, the CSI-RS resource corresponding to the metric value with the largest value is determined as the CSI-RS resource to be fed back.
The metric value of each CSI-RS resource is shown in table 8, and the CSI-RS resource corresponding to the metric value with the largest value is the 3 rd CSI-RS resource, that is, the CRI is 3.
TABLE 8 resource metric values for CSI-RS resources
s 0 1 2 3
T(s) 33.30 47.96 57.88 69.77
Based on the same inventive concept, an embodiment of the present application further provides a device 200 for determining a number of transmission layers, as shown in fig. 2, for specific implementation of the device, reference may be made to the description of the method embodiment, and repeated descriptions are omitted, and the device mainly includes:
a receiving module 201, configured to receive reference signals transmitted on S reference signal resources, where the S reference signal resources correspond to S beamforming weights one to one, and a reference signal transmitted on one reference signal resource performs beamforming using a corresponding beamforming weight; wherein S is an integer greater than or equal to 1;
a metric value determining module 202, configured to determine metric values corresponding to the S reference signal resources according to the reference signals received on the S reference signal resources, respectively;
a reference signal resource determining module 203, configured to determine a fed-back reference signal resource according to the respective corresponding metric values of the S reference signal resources;
a feedback module 204, configured to feed back indication information of the determined reference signal resource to the base station.
Optionally, the metric value determining module 202 is specifically configured to: determining a candidate precoding matrix set corresponding to each candidate transmission layer number according to each candidate transmission layer number in a candidate transmission layer number set corresponding to a first reference signal resource; wherein the first reference signal resource is any one of the S reference signal resources; determining a first metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to each candidate transmission layer number; and determining the metric value corresponding to the first reference signal resource according to the first metric value with the maximum value.
Optionally, the metric value determining module 202 is specifically configured to: determining a first set or a subset of the first set as a candidate precoding matrix corresponding to a first candidate transmission layer number, wherein the first candidate transmission layer number is any candidate transmission layer number in a candidate transmission layer number set corresponding to the first reference signal resource, and the first set comprises all available precoding matrices corresponding to the first candidate transmission layer number selected from a single-stage codebook or a double-stage codebook used by a terminal according to a codebook subset limiting parameter corresponding to the first reference signal resource.
Optionally, the metric value determining module 202 is specifically configured to: determining a candidate precoding matrix set corresponding to a first candidate transmission layer number according to a first-stage precoding matrix set corresponding to the first candidate transmission layer number and a second-stage precoding matrix set corresponding to the first candidate transmission layer number; the first candidate transmission layer number is any one of the candidate transmission layer number sets corresponding to the first reference signal resource, and one candidate precoding matrix in the candidate precoding matrix set corresponding to the first candidate transmission layer number is calculated according to one precoding matrix in the first-stage precoding matrix set and one precoding matrix in the second-stage precoding matrix set.
Optionally, the metric value determining module 202 is specifically configured to: determining a second metric value corresponding to each precoding matrix according to a reference signal received on a first reference signal resource and each precoding matrix in a first-stage precoding matrix set corresponding to a first candidate transmission layer number; wherein the first candidate number of transmission layers is any one of a set of candidate number of transmission layers corresponding to the first reference signal resource; forming a subset of the first-stage precoding matrix set by using the first M precoding matrices with second metric values arranged from large to small in the first-stage precoding matrix set corresponding to the first candidate transmission layer number, wherein M is greater than or equal to 1 and less than the number of precoding matrices in the first-stage precoding matrix; and determining a candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein one candidate precoding matrix in the candidate precoding matrix set is obtained by calculation according to one precoding matrix in the subset and one precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number.
Optionally, the metric value determining module 202 is specifically configured to: if the second-stage precoding matrix set corresponding to each candidate transmission layer number in the candidate transmission layer number set corresponding to the first reference signal resource only comprises one precoding matrix, and the first reference signal resource is any one reference signal resource in the S reference signal resources, determining a second metric value corresponding to each precoding matrix according to a reference signal received on the reference signal resource and each precoding matrix in the first-stage precoding matrix set corresponding to each candidate transmission layer number; and determining the second metric value with the maximum value as the metric value corresponding to the first reference signal resource.
Optionally, the candidate transmission layer number set corresponding to the first reference signal resource is the same as a second set or is a subset of the second set, where the second set includes all available transmission layer numbers determined according to the codebook subset restriction parameter corresponding to the first reference signal resource.
Optionally, the first-stage precoding matrix set corresponding to the first candidate number of transmission layers is the same as or a subset of a third set, where the third set includes all available precoding matrices corresponding to the first candidate number of transmission layers of a region selected from a first-stage codebook used by a terminal according to a codebook subset restriction parameter corresponding to the first reference signal resource; the second-stage precoding matrix set corresponding to the first candidate transmission layer number is the same as a fourth set or is a subset of the fourth set; the fourth set includes all available precoding matrices corresponding to the first candidate number of transmission layers selected from a second-level codebook used by the terminal according to the codebook subset restriction parameter corresponding to the first reference signal resource.
Optionally, the metric value determining module 202 is specifically configured to: determining a channel matrix according to a reference signal received on a first reference signal resource; wherein the first reference signal resource is any one of the S reference signal resources; and determining the energy of the reference signal received on the first reference signal resource according to the channel matrix, and taking the energy as a metric value corresponding to the first reference signal resource.
Optionally, the reference signal resource determining module 203 is specifically configured to: and determining the maximum value of the metric values corresponding to the S reference signal resources, and determining the reference signal resource corresponding to the maximum value as the reference signal resource for feedback.
Based on the same inventive concept, embodiments of the present application further provide a terminal, and specific implementation of the terminal may refer to the description of the method embodiment, and repeated details are not described again, as shown in fig. 3, the terminal mainly includes:
the processor 301, configured to read the program in the memory 304, executes the following processes:
determining respective metric values corresponding to the S reference signal resources according to the reference signals received on the S reference signal resources respectively;
determining the fed-back reference signal resources according to the respective corresponding metric values of the S reference signal resources;
a transceiver 302 for receiving and transmitting data under the control of the processor 301, performing the following processes:
receiving reference signals transmitted on S reference signal resources, wherein the S reference signal resources correspond to the S beam forming weights one by one, and the reference signal transmitted on one reference signal resource uses the corresponding beam forming weight to carry out beam forming; wherein S is an integer greater than or equal to 1;
and feeding back indication information of the determined reference signal resource to the base station.
Optionally, the processor 301 is specifically configured to: determining a candidate precoding matrix set corresponding to each candidate transmission layer number according to each candidate transmission layer number in a candidate transmission layer number set corresponding to a first reference signal resource, wherein the first reference signal resource is any one reference signal resource in the S reference signal resources; determining a first metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to each candidate transmission layer number; and determining the first metric value with the maximum value as the metric value corresponding to the first reference signal resource.
Optionally, the processor 301 is specifically configured to: determining a first set or a subset of the first set as a candidate precoding matrix corresponding to a first candidate transmission layer number, wherein the first candidate transmission layer number is any candidate transmission layer number in a candidate transmission layer number set corresponding to the first reference signal resource, and the first set includes all available precoding matrices corresponding to the first candidate transmission layer number selected from a single-stage codebook or a double-stage codebook used by the terminal according to a codebook subset limiting parameter corresponding to the first reference signal resource.
Optionally, the processor 301 is specifically configured to: determining a first set or a subset of the first set as a candidate precoding matrix corresponding to the first candidate number of transmission layers, wherein the first set comprises all available precoding matrices corresponding to the first candidate number of transmission layers selected from a single-stage codebook or a double-stage codebook used by the terminal according to a codebook subset limiting parameter corresponding to the first reference signal resource
Optionally, the processor 301 is specifically configured to: determining a candidate precoding matrix set corresponding to the first candidate transmission layer number according to a first-stage precoding matrix set corresponding to the first candidate transmission layer number and a second-stage precoding matrix set corresponding to the first candidate transmission layer number; and calculating a candidate precoding matrix in the candidate precoding matrix set corresponding to the first candidate transmission layer number according to a precoding matrix in the first-stage precoding matrix set and a precoding matrix in the second-stage precoding matrix set.
Optionally, the processor 301 is specifically configured to: determining a second metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the first-level precoding matrix set corresponding to the first candidate transmission layer number; forming a subset of the first-stage precoding matrix set by using the first M precoding matrices with second metric values arranged from large to small in the first-stage precoding matrix set corresponding to the first candidate transmission layer number, wherein M is greater than or equal to 1 and less than the number of precoding matrices in the first-stage precoding matrix; and determining a candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein one candidate precoding matrix in the candidate precoding matrix set is obtained by calculation according to one precoding matrix in the subset and one precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number.
Optionally, the processor 301 is specifically configured to: if the second-stage precoding matrix set corresponding to each candidate transmission layer number in the candidate transmission layer number set corresponding to the first reference signal resource only comprises one precoding matrix, determining a second metric value corresponding to each precoding matrix according to a reference signal received on the reference signal resource and each precoding matrix in the first-stage precoding matrix set corresponding to each candidate transmission layer number, and determining the second metric value with the largest value as the metric value corresponding to the first reference signal resource.
Optionally, the candidate transmission layer number set corresponding to the first reference signal resource is the same as a second set or is a subset of the second set, where the second set includes all available transmission layer numbers determined according to the codebook subset restriction parameter corresponding to the first reference signal resource.
Optionally, a first-stage precoding matrix set corresponding to the first candidate number of transmission layers is the same as or a subset of a third set, where the third set includes all available precoding matrices corresponding to the first candidate number of transmission layers of a region selected from a first-stage codebook used by the terminal according to a codebook subset restriction parameter corresponding to the first reference signal resource; the second-stage precoding matrix set corresponding to the first candidate transmission layer number is the same as a fourth set or is a subset of the fourth set; the fourth set includes all available precoding matrices corresponding to the first candidate number of transmission layers selected from a second-level codebook used by the terminal according to the codebook subset restriction parameter corresponding to the first reference signal resource.
Optionally, the processor 301 is specifically configured to: and determining a channel matrix according to the reference signal received on the first reference signal resource, determining the energy of the reference signal received on the first reference signal resource according to the channel matrix, and taking the energy as a metric value corresponding to the first reference signal resource.
Optionally, the processor 301 is specifically configured to: and determining the maximum value of the metric values corresponding to the S reference signal resources, and determining the reference signal resource corresponding to the maximum value as the reference signal resource for feedback.
In FIG. 3, a bus architecture (represented by bus 300), bus 300 may include any number of interconnected buses and bridges, with bus 300 linking together various circuits including one or more processors, represented by general purpose processor 301, and memory, represented by memory 304. The bus 300 may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. A bus interface 303 provides an interface between the bus 300 and the transceiver 302. The transceiver 302 may be one element or may be multiple elements, such as multiple receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. For example: the transceiver 302 receives external data from other devices. The transceiver 302 is used for transmitting the data processed by the processor 301 to other devices. Depending on the nature of the computing system, a user interface 305, such as a keypad, display, speaker, microphone, joystick, may also be provided.
The processor 301 is responsible for managing the bus 300 and general processing, such as running a general-purpose operating system as described above. And memory 304 may be used to store data used by processor 301 in performing operations.
Alternatively, the processor 301 may be a CPU (central processing unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a CPLD (Complex Programmable Logic Device).
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims (24)

1. A method for feeding back channel state information, the method comprising:
a terminal receives reference signals transmitted on S reference signal resources, wherein the S reference signal resources correspond to S beam forming weights one by one, and the reference signal transmitted on one reference signal resource uses the corresponding beam forming weight to carry out beam forming; wherein S is an integer greater than or equal to 1;
the terminal determines respective corresponding metric values of the S reference signal resources according to the reference signals received on the S reference signal resources respectively;
the terminal determines the fed back reference signal resources according to the respective corresponding metric values of the S reference signal resources;
the terminal feeds back the determined indication information of the reference signal resource to the base station;
wherein the first reference signal resource is any one of the S reference signal resources; determining a metric value corresponding to the first reference signal resource, including:
determining a candidate precoding matrix set corresponding to each candidate transmission layer number according to each candidate transmission layer number in the candidate transmission layer number set corresponding to the first reference signal resource;
determining a first metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to each candidate transmission layer number;
and determining the metric value corresponding to the first reference signal resource according to the first metric value with the maximum value.
2. The method of claim 1, wherein the first candidate number of transmission layers is any one of a set of candidate numbers of transmission layers corresponding to a first reference signal resource, and wherein before determining the metric value corresponding to the first reference signal resource, the method comprises:
determining a first metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to the first candidate transmission layer number;
forming a subset of the candidate precoding matrix set by using the first N precoding matrices with first metric values arranged from large to small in the candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein N is greater than or equal to 1 and less than the number of precoding matrices in the candidate precoding matrix set;
and taking the subset as a candidate precoding matrix set corresponding to the first candidate transmission layer number of the S reference signal resources.
3. The method of claim 1 or 2, wherein the determining the candidate set of precoding matrices for which the first candidate number of transmission layers corresponds is for any one of the candidate set of number of transmission layers for which the first reference signal resource corresponds, and comprises:
and determining a first set or a subset of the first set as a candidate precoding matrix corresponding to the first candidate transmission layer number, wherein the first set comprises all available precoding matrices corresponding to the first candidate transmission layer number selected from a single-stage codebook or a double-stage codebook used by the terminal according to a codebook subset limiting parameter corresponding to the first reference signal resource.
4. The method of claim 3, wherein the subset of the first set is derived according to:
selecting a pre-coding matrix in the first set to obtain a subset of the first set;
or selecting a plurality of precoding matrixes with discontinuous index values in the first set to obtain a subset of the first set;
or selecting a precoding matrix with a plurality of continuous index values in the first set to obtain a subset of the first set.
5. The method of claim 1, wherein the determining the candidate set of precoding matrices for which the first candidate number of transmission layers corresponds is for any one of the candidate set of number of transmission layers for which the first reference signal resource corresponds, comprises:
determining a candidate precoding matrix set corresponding to the first candidate transmission layer number according to a first-stage precoding matrix set corresponding to the first candidate transmission layer number and a second-stage precoding matrix set corresponding to the first candidate transmission layer number; and calculating a candidate precoding matrix in the candidate precoding matrix set corresponding to the first candidate transmission layer number according to a precoding matrix in the first-stage precoding matrix set and a precoding matrix in the second-stage precoding matrix set.
6. The method of claim 1, wherein the determining the candidate set of precoding matrices for which the first candidate number of transmission layers corresponds is for any one of the candidate set of number of transmission layers for which the first reference signal resource corresponds, comprises:
determining a second metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the first-level precoding matrix set corresponding to the first candidate transmission layer number;
forming a subset of the first-stage precoding matrix set by using the first M precoding matrices with second metric values arranged from large to small in the first-stage precoding matrix set corresponding to the first candidate transmission layer number, wherein M is greater than or equal to 1 and less than the number of precoding matrices in the first-stage precoding matrix;
and determining a candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein one candidate precoding matrix in the candidate precoding matrix set is obtained by calculation according to one precoding matrix in the subset and one precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number.
7. The method of claim 1, wherein a first reference signal resource is any one of the S reference signal resources;
if the second-stage precoding matrix set corresponding to each candidate transmission layer number in the candidate transmission layer number set corresponding to the first reference signal resource only includes one precoding matrix, determining a metric value corresponding to the first reference signal resource, including:
determining a second metric value corresponding to each precoding matrix according to a reference signal received on the reference signal resource and each precoding matrix in a first-stage precoding matrix set corresponding to each candidate transmission layer number;
and determining the second metric value with the maximum value as the metric value corresponding to the first reference signal resource.
8. The method of any of claims 5-7, wherein the first candidate number of transmission layers is any one of a set of candidate numbers of transmission layers corresponding to a first reference signal resource, and before determining the metric value corresponding to the first reference signal resource, the method comprises:
determining a first metric value corresponding to each precoding matrix according to a reference signal received on the first reference signal resource, each precoding matrix in a first-stage precoding matrix set corresponding to the first candidate transmission layer number and each precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number;
forming a subset of the first-level precoding matrix set by using precoding matrixes in the first-level precoding matrix set corresponding to first Q first metric values which are arranged from large to small, and forming a subset of the second-level precoding matrix set by using precoding matrixes in the second-level precoding matrix set corresponding to first Q first metric values which are arranged from large to small, wherein Q is more than or equal to 1 and less than the maximum value of the number of precoding matrixes in the first-level precoding matrix set and the number of precoding matrixes in the second-level precoding matrix set;
and taking the subset of the first-stage precoding matrix set as a first-stage precoding matrix set corresponding to a first candidate transmission layer number of the S reference signal resources, and taking the subset of the second-stage precoding matrix set as a second-stage precoding matrix set corresponding to the first candidate transmission layer number of the S reference signal resources.
9. The method of any of claims 1,2 or 5-7, wherein the set of candidate transmission layer numbers corresponding to the first reference signal resource is the same as or a subset of a second set, and wherein the second set comprises all available transmission layer numbers determined according to the codebook subset restriction parameter corresponding to the first reference signal resource.
10. The method of claim 9, wherein the subset of the second set is derived according to:
selecting one transmission layer number in the second set to obtain a subset of the second set;
or selecting a plurality of transmission layer numbers with discontinuous index values in the second set to obtain a subset of the second set;
or, selecting the number of transmission layers with a plurality of continuous index values in the second set to obtain the subset of the second set.
11. The method according to any of claims 5-7, wherein the first set of level one precoding matrices corresponding to the first number of candidate transmission layers is the same as or a subset of a third set, wherein the third set comprises all available precoding matrices corresponding to the first number of candidate transmission layers of a region selected from a first level codebook used by the terminal according to a codebook subset restriction parameter corresponding to the first reference signal resource;
the second-stage precoding matrix set corresponding to the first candidate transmission layer number is the same as a fourth set or is a subset of the fourth set; the fourth set includes all available precoding matrices corresponding to the first candidate number of transmission layers selected from a second-level codebook used by the terminal according to the codebook subset restriction parameter corresponding to the first reference signal resource.
12. The method of claim 11, wherein the subset of the third set is derived according to:
selecting a pre-coding matrix in the third set to obtain a subset of the third set;
or selecting a plurality of precoding matrixes with discontinuous index values in the third set to obtain a subset of the third set;
or selecting a plurality of precoding matrixes with continuous index values in the third set to obtain a subset of the third set;
a subset of the fourth set is obtained according to the following:
selecting a pre-coding matrix in the fourth set to obtain a subset of the fourth set;
or selecting a plurality of precoding matrixes with discontinuous index values in the fourth set to obtain a subset of the fourth set;
or selecting a precoding matrix with a plurality of continuous index values in the fourth set to obtain a subset of the fourth set.
13. The method of claim 1, wherein a first reference signal resource is any one of the S reference signal resources;
determining a metric value for the first reference signal resource, comprising:
determining a channel matrix according to the reference signal received on the first reference signal resource;
and determining the energy of the reference signal received on the first reference signal resource according to the channel matrix, and taking the energy as a metric value corresponding to the first reference signal resource.
14. The method as claimed in any of claims 1-2, 5-7 or 13, wherein the terminal determines the fed back reference signal resource according to the respective corresponding metric values of the S reference signal resources, comprising:
and the terminal determines the maximum value of the metric values corresponding to the S reference signal resources and determines the reference signal resource corresponding to the maximum value as the reference signal resource for feedback.
15. The method of claim 1, wherein the metric value comprises a throughput, a channel capacity, a mutual information sum, a beam power gain, or a ratio of a beam power gain to an interference noise power gain.
16. A channel state information feedback apparatus, comprising:
a receiving module, configured to receive reference signals transmitted on S reference signal resources, where the S reference signal resources correspond to S beamforming weights one to one, and a reference signal transmitted on one reference signal resource performs beamforming using a corresponding beamforming weight; wherein S is an integer greater than or equal to 1;
a metric value determining module, configured to determine metric values corresponding to the S reference signal resources according to the reference signals received on the S reference signal resources, respectively;
a reference signal resource determining module, configured to determine a fed-back reference signal resource according to the respective corresponding metric values of the S reference signal resources;
a feedback module, configured to feed back indication information of the determined reference signal resource to a base station;
wherein the metric value determination module is specifically configured to:
determining a candidate precoding matrix set corresponding to each candidate transmission layer number according to each candidate transmission layer number in a candidate transmission layer number set corresponding to a first reference signal resource; wherein the first reference signal resource is any one of the S reference signal resources;
determining a first metric value corresponding to each precoding matrix according to the reference signal received on the first reference signal resource and each precoding matrix in the precoding matrix set corresponding to each candidate transmission layer number;
and determining the metric value corresponding to the first reference signal resource according to the first metric value with the maximum value.
17. The apparatus of claim 16, wherein the metric value determination module is specifically configured to:
and determining a first set or a subset of the first set as a candidate precoding matrix corresponding to a first candidate transmission layer number, wherein the first candidate transmission layer number is any candidate transmission layer number in a candidate transmission layer number set corresponding to the first reference signal resource, and the first set comprises all available precoding matrices corresponding to the first candidate transmission layer number selected from a single-stage codebook or a double-stage codebook used by a terminal according to a codebook subset limiting parameter corresponding to the first reference signal resource.
18. The apparatus of claim 16, wherein the metric value determination module is specifically configured to:
determining a candidate precoding matrix set corresponding to a first candidate transmission layer number according to a first-stage precoding matrix set corresponding to the first candidate transmission layer number and a second-stage precoding matrix set corresponding to the first candidate transmission layer number; the first candidate transmission layer number is any one of the candidate transmission layer number sets corresponding to the first reference signal resource, and one candidate precoding matrix in the candidate precoding matrix set corresponding to the first candidate transmission layer number is calculated according to one precoding matrix in the first-stage precoding matrix set and one precoding matrix in the second-stage precoding matrix set.
19. The apparatus of claim 16, wherein the metric value determination module is specifically configured to:
determining a second metric value corresponding to each precoding matrix according to a reference signal received on a first reference signal resource and each precoding matrix in a first-stage precoding matrix set corresponding to a first candidate transmission layer number; wherein the first candidate number of transmission layers is any one of a set of candidate number of transmission layers corresponding to the first reference signal resource;
forming a subset of the first-stage precoding matrix set by using the first M precoding matrices with second metric values arranged from large to small in the first-stage precoding matrix set corresponding to the first candidate transmission layer number, wherein M is greater than or equal to 1 and less than the number of precoding matrices in the first-stage precoding matrix;
and determining a candidate precoding matrix set corresponding to the first candidate transmission layer number, wherein one candidate precoding matrix in the candidate precoding matrix set is obtained by calculation according to one precoding matrix in the subset and one precoding matrix in a second-stage precoding matrix set corresponding to the first candidate transmission layer number.
20. The apparatus of claim 16, wherein the metric value determination module is specifically configured to:
if the second-stage precoding matrix set corresponding to each candidate transmission layer number in the candidate transmission layer number set corresponding to the first reference signal resource only comprises one precoding matrix, and the first reference signal resource is any one reference signal resource in the S reference signal resources, determining a second metric value corresponding to each precoding matrix according to a reference signal received on the reference signal resource and each precoding matrix in the first-stage precoding matrix set corresponding to each candidate transmission layer number;
and determining the second metric value with the maximum value as the metric value corresponding to the first reference signal resource.
21. The apparatus of any of claims 16-20, wherein the set of candidate transmission layer numbers corresponding to the first reference signal resource is the same as or a subset of a second set, and wherein the second set comprises all available transmission layer numbers determined according to the codebook subset restriction parameter corresponding to the first reference signal resource.
22. The apparatus according to any of claims 18-20, wherein the first set of level one precoding matrices corresponding to the first number of candidate transmission layers is the same as or a subset of a third set, where the third set includes all available precoding matrices corresponding to the first number of candidate transmission layers of a region selected from a first level codebook used by a terminal according to a codebook subset restriction parameter corresponding to the first reference signal resource;
the second-stage precoding matrix set corresponding to the first candidate transmission layer number is the same as a fourth set or is a subset of the fourth set; the fourth set includes all available precoding matrices corresponding to the first candidate number of transmission layers selected from a second-level codebook used by the terminal according to the codebook subset restriction parameter corresponding to the first reference signal resource.
23. The apparatus of claim 16, wherein the metric value determination module is specifically configured to:
determining a channel matrix according to a reference signal received on a first reference signal resource; wherein the first reference signal resource is any one of the S reference signal resources;
and determining the energy of the reference signal received on the first reference signal resource according to the channel matrix, and taking the energy as a metric value corresponding to the first reference signal resource.
24. The apparatus of any one of claims 16-20 or 23, wherein the reference signal resource determining module is specifically configured to:
and determining the maximum value of the metric values corresponding to the S reference signal resources, and determining the reference signal resource corresponding to the maximum value as the reference signal resource for feedback.
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