WO2017000258A1 - 一种获取信道状态信息的方法、装置 - Google Patents

一种获取信道状态信息的方法、装置 Download PDF

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Publication number
WO2017000258A1
WO2017000258A1 PCT/CN2015/082954 CN2015082954W WO2017000258A1 WO 2017000258 A1 WO2017000258 A1 WO 2017000258A1 CN 2015082954 W CN2015082954 W CN 2015082954W WO 2017000258 A1 WO2017000258 A1 WO 2017000258A1
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Prior art keywords
channel
user equipment
subspace
base station
dimension
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PCT/CN2015/082954
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English (en)
French (fr)
Inventor
吴晔
刘瑾
毕晓艳
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华为技术有限公司
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Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to PCT/CN2015/082954 priority Critical patent/WO2017000258A1/zh
Priority to EP15896789.3A priority patent/EP3301841A4/en
Priority to CN201580080703.2A priority patent/CN107615695B/zh
Publication of WO2017000258A1 publication Critical patent/WO2017000258A1/zh
Priority to US15/858,969 priority patent/US10447369B2/en

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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
    • H04B7/0413—MIMO systems
    • H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
    • 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
    • H04B7/06—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
    • H04B7/0636—Feedback format
    • H04B7/0639—Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/0202—Channel estimation
    • H04L25/0224—Channel estimation using sounding signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W24/00—Supervisory, monitoring or testing arrangements
    • H04W24/10—Scheduling measurement reports ; Arrangements for measurement reports
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W72/00—Local resource management
    • H04W72/20—Control channels or signalling for resource management
    • H04W72/21—Control channels or signalling for resource management in the uplink direction of a wireless link, i.e. towards the network

Definitions

  • the present invention relates to the field of communications technologies, and in particular, to a method and apparatus for acquiring channel state information.
  • LTE Long Term Evolution
  • LTE-A 3GPP Long Term Evolution-Advanced
  • MIMO Multi-input Multi-output
  • the relevant channel state information (English: Channel State Information; CSI) must be acquired by the data transmitting end (for example, a base station) to obtain accurate precoding. :precode).
  • CSI Channel State Information
  • the data transmitting end for example, a base station
  • precode the data transmitting end
  • LTE/LTE-A there are two methods for obtaining CSI in the general data transmitting end:
  • the data transmitting end transmits the pilot of the downlink measurement CSI.
  • the receiving end (for example, the UE) measures the pilot to obtain the CSI, and the UE performs the feedback CSI.
  • the CSI of the feedback is generally a quantized CSI, and the LTE is a precoding matrix indicator (English: Precoding Matrix Indicator; PMI for short).
  • PMI Precoding Matrix Indicator
  • the rank guide (English: Rank Index; referred to as: RI), the data transmitting end uses the CSI to pre-code and transmit the data.
  • the data receiving end transmits the pilot of the uplink measurement CSI, for example, the sounding reference signal (English: Sounding Reference Signal; SRS) in the LTE/LTE-A, and is uplinked by the data transmitting end.
  • the data transmitting end considers the uplink channel measurement, that is, the downlink channel according to the channel dissimilarity (generally requires necessary reciprocity parameter correction), and then pre-codes the data according to the CSI.
  • the key to the acquisition of CSI in existing MIMO is to acquire the complete real-time CSI (the so-called complete refers to the channel information of all data transmitting antennas) at one time to obtain the channel with the most accurate channel, wherein the CSI is only required to acquire the first-level reference signal ( English: Reference Signal; referred to as: RS).
  • the specific primary RS can be divided into the following two forms of implementation:
  • the pilot of the downlink measurement CSI is first transmitted by the data transmitting end, for example, the CSI-RS or the cell-specific reference signal in the LTE/LTE-A (English: Cell-specific Reference Signal; CRS), the data receiving end measures the pilot acquisition CSI (for example, a precoding matrix in LTE/LTE-A), and performs quantization, and the data receiving end feeds the quantized CSI to the transmitting and receiving end, and the transmitting end uses the CSI.
  • the data is precoded and sent. This solution is applicable to FDD and TDD.
  • Implementation 2 As shown in FIG. 2, the data receiving end transmits an uplink measurement CSI pilot, such as SRS in LTE/LTE-A, and the data transmitting end measures the pilot to acquire CSI, for example, in LTE/LTE-A.
  • the precoding matrix is further precoded and transmitted according to the CSI. This program is suitable for TDD.
  • the uplink pilot overhead is proportional to the number of UEs to be served, and the uplink CSI feedback amount is also proportional to the number of antennas at the data transmitting end.
  • the pilot overhead and the amount of uplink CSI feedback can be controlled.
  • the number of antennas is large (the number of UEs available for scheduling increases)
  • the uplink and downlink pilot overhead and the uplink CSI feedback amount will occupy a large amount of time-frequency resources, causing the time-frequency resources available for data transmission to be compressed, and the system throughput will be greatly affected.
  • the prior art needs to process a square matrix whose dimensions are the number of antennas at the data transmitting end, which poses an unprecedented challenge to the baseband processing capability of the data transmitting end. Whether it is CSI feedback using downlink measurement or CSI for uplink measurement, the number of antennas at the transmitting end is more likely to cause excessive problem of excessive pilot overhead for acquiring CSI and excessive calculation of channel information.
  • the embodiment of the invention provides a method and a device for acquiring channel state information, which can reduce the pilot overhead and computational complexity of acquiring channel state information.
  • an embodiment of the present invention provides a method for acquiring channel state information, including:
  • the base station sends one or more downlink signaling to the user equipment, where the one or more downlink signaling indicates that the user equipment feeds back channel dimension information;
  • the channel dimension information includes an effective dimension of a channel subspace of a statistical channel between the base station and the user equipment, and an effective dimension of the channel subspace is smaller than a reference signal port number used to measure channel state information;
  • the base station receives the channel dimension information fed back by the user equipment.
  • the channel dimension information further includes a subspace index in an effective dimension of the channel subspace
  • the subspace index has a one-to-one correspondence with the quantization precoding of the feature vector of the channel subspace.
  • the quantization precoding of the feature vector of the channel subspace corresponding to the subspace index includes the statistical channel Part of the energy.
  • the first downlink signaling indicates that the user equipment feeds back an effective dimension of the channel subspace
  • the sending, by the base station, the multiple downlink signaling to the user equipment further includes: sending, by the base station, the second downlink signaling to the user equipment;
  • the second downlink signaling indicates that the user equipment feeds back a subspace index, where the second downlink signaling carries a channel determined by the base station according to an effective dimension of the channel subspace fed back by the user equipment.
  • the effective dimension of the subspace
  • the base station Receiving, by the base station, the channel dimension information that is fed back by the user equipment, that the base station receives a subspace index in an effective dimension of a channel subspace determined by the base station that is fed back by the user equipment.
  • the user equipment is a user equipment to be scheduled.
  • the third downlink signaling indicates that the user equipment feeds back an effective dimension of the channel subspace, and a subspace index in an effective dimension of the channel subspace;
  • the receiving, by the base station, the channel dimension information that is fed back by the user equipment includes: receiving, by the base station, a valid dimension of a channel subspace fed back by the user equipment, and a subspace index in an effective dimension of the channel subspace.
  • the method further includes:
  • the base station sends a fourth downlink signaling to the user equipment, where the fourth downlink signaling indicates that the user equipment feeds back a subspace index in an effective dimension of a channel subspace determined by the base station;
  • the base station receives the subspace index in the effective dimension of the channel subspace determined by the base station and fed back by the user equipment.
  • the one or more downlink signalings indicating that the user equipment feeds back channel dimension information, that the one or more downlink signalings indicate that the user equipment periodically feeds back channel dimension information;
  • the period of the feedback is indicated by the one or more downlink signaling or pre-agreed.
  • the one or more downlink signalings indicating that the user equipment feeds back channel dimension information, that the one or more downlink signalings indicate that the user equipment feeds back channel dimension information at one time;
  • the base station Receiving, by the base station, the channel dimension information fed back by the user equipment, the base station receiving the channel dimension information that is fed back by the user equipment at one time.
  • the embodiment of the present invention provides a method for feeding back channel state information, including:
  • the user equipment receives one or more downlink signalings from the base station, where the one or more downlink signalings indicate that the user equipment feeds back channel dimension information;
  • the channel dimension information includes an effective dimension of a channel subspace of a statistical channel between the base station and the user equipment, and an effective dimension of the channel subspace is smaller than a reference signal port number used to measure channel state information;
  • the user equipment feeds back the channel dimension information to the base station.
  • the channel dimension information further includes a subspace index in an effective dimension of the channel subspace
  • the subspace index has a one-to-one correspondence with the quantization precoding of the feature vector of the channel subspace.
  • the quantized precoding of the feature vector of the channel subspace corresponding to the subspace index includes the energy of the portion of the statistical channel.
  • the method further includes: the user equipment The space is statistically measured to obtain an effective dimension of the channel subspace.
  • an embodiment of the present invention provides an apparatus for acquiring channel state information, including:
  • a sending module configured to send, by the base station, one or more downlink signalings to the user equipment, where the one or more downlink signalings indicate that the user equipment feeds back channel dimension information;
  • the channel dimension information includes an effective dimension of a channel subspace of a statistical channel between the base station and the user equipment, and an effective dimension of the channel subspace is smaller than a reference signal port number used to measure channel state information;
  • a receiving module configured to receive, by the base station, the channel dimension information that is fed back by the user equipment.
  • the channel dimension information further includes a subspace index in an effective dimension of the channel subspace
  • the subspace index has a one-to-one correspondence with the quantization precoding of the feature vector of the channel subspace.
  • the quantization precoding of the feature vector of the channel subspace corresponding to the subspace index includes the statistical channel Part of the energy.
  • the first downlink signaling indicates that the user equipment feeds back an effective dimension of the channel subspace
  • the sending, by the base station, the multiple downlink signaling to the user equipment further includes: sending, by the base station, the second downlink signaling to the user equipment;
  • the second downlink signaling indicates that the user equipment feeds back a subspace index, where the second downlink signaling carries a channel determined by the base station according to an effective dimension of the channel subspace fed back by the user equipment.
  • the effective dimension of the subspace
  • the base station Receiving, by the base station, the channel dimension information that is fed back by the user equipment, that the base station receives a subspace index in an effective dimension of a channel subspace determined by the base station that is fed back by the user equipment.
  • the user equipment is a user equipment to be scheduled.
  • the third downlink signaling indicates that the user equipment feeds back an effective dimension of the channel subspace, and a subspace index in an effective dimension of the channel subspace;
  • the receiving, by the base station, the channel dimension information that is fed back by the user equipment includes: receiving, by the base station, a valid dimension of a channel subspace fed back by the user equipment, and a subspace index in an effective dimension of the channel subspace.
  • the device further includes:
  • a determining module configured to determine, by the base station, an effective dimension of the channel subspace according to the effective dimension and the subspace index of the channel subspace fed back by the user equipment;
  • the sending module is further configured to send, by the base station, fourth downlink signaling to the user equipment, where the fourth downlink signaling indicates that the user equipment feeds back a subspace under an effective dimension of a channel subspace determined by the base station. index;
  • the receiving module is further configured to receive, by the base station, a subspace index in an effective dimension of a channel subspace determined by the base station that is fed back by the user equipment.
  • the one or more downlink signalings indicating that the user equipment feeds back channel dimension information, that the one or more downlink signalings indicate that the user equipment periodically feeds back channel dimension information;
  • the period of the feedback is indicated by the one or more downlink signaling or pre-agreed.
  • the one or more downlink signalings indicating that the user equipment feeds back channel dimension information, that the one or more downlink signalings indicate that the user equipment feeds back channel dimension information at one time;
  • the base station Receiving, by the base station, the channel dimension information fed back by the user equipment, the base station receiving the channel dimension information that is fed back by the user equipment at one time.
  • an embodiment of the present invention provides an apparatus for feeding back channel state information, including:
  • a receiving module configured to receive, by the user equipment, one or more downlink signalings from the base station, where the one or more downlink signalings indicate that the user equipment feeds back channel dimension information;
  • the channel dimension information includes an effective dimension of a channel subspace of a statistical channel between the base station and the user equipment, and an effective dimension of the channel subspace is smaller than a reference signal port number used to measure channel state information;
  • a feedback module configured to feed back, by the user equipment, the channel dimension information to the base station.
  • the channel dimension information further includes a subspace index in an effective dimension of the channel subspace
  • the subspace index has a one-to-one correspondence with the quantization precoding of the feature vector of the channel subspace.
  • the quantized precoding of the feature vector of the channel subspace corresponding to the subspace index includes the energy of the portion of the statistical channel.
  • the device further includes:
  • a measurement module configured to perform statistical measurement on the channel subspace by the user equipment, to obtain an effective dimension of the channel subspace.
  • the embodiment of the present invention allows the user equipment to feed back the dimension information (or channel dimension information) of the valid statistical channel for use by the base station, where the channel dimension information may include the effective dimension and the subspace index of the channel subspace, and the effective dimension of the channel subspace. Less than the number of reference signal ports used to measure channel state information. Since the effective dimension of the channel subspace is smaller than the number of reference channel ports for the user to measure channel state information, the spatial stream required for feedback channel state information is reduced relative to the prior art, thereby reducing the pilot overhead of acquiring channel state information. And computational complexity.
  • FIG. 1 is an implementation manner of CSI acquisition in the prior art
  • Embodiment 3 is a method for acquiring and feeding back channel state information according to Embodiment 1 of the present invention.
  • Embodiment 4 is a method for acquiring and feeding back channel state information according to Embodiment 2 of the present invention.
  • FIG. 5 is a schematic diagram of a method for acquiring and feeding back channel state information according to Embodiment 3 of the present invention.
  • Embodiment 6 is a method for acquiring and feeding back channel state information according to Embodiment 2 of the present invention.
  • Figure 8 is another data effect diagram of system performance versus ideal system performance of the present invention.
  • Figure 9 is another data rendering of the system performance versus the ideal system performance of the present invention.
  • Figure 10 is another data effect diagram comparing the performance of the system of the present invention with the performance of an ideal system
  • Figure 11 is another data effect diagram of system performance versus ideal system performance of the present invention.
  • FIG. 12 is an apparatus for acquiring channel state information according to an embodiment of the present invention.
  • FIG. 13 is an apparatus for feeding back channel state information according to an embodiment of the present invention.
  • FIG. 14 is an apparatus for acquiring or feeding back channel state information according to an embodiment of the present invention.
  • the user equipment (UE, User Equipment) in the embodiment of the present invention may also be referred to as a mobile terminal (Mobile Terminal), a mobile user equipment, etc., and may be connected to one or more via a radio access network (for example, RAN, Radio Access Network).
  • the plurality of core networks communicate, and the user equipment can be a mobile terminal, such as a mobile phone (or "cellular" phone) and a computer with a mobile terminal, for example, can be portable, pocket-sized, handheld, built-in or on-board Mobile devices that exchange language and/or data with a wireless access network.
  • Base station (English Base Station; BS for short), which may be a base station (BTS, Base Transceiver Station) in GSM or CDMA, a base station (NodeB) in WCDMA, or an evolved base station (eNB or LTE) in LTE.
  • BTS Base Transceiver Station
  • NodeB base station
  • eNB evolved base station
  • LTE evolved base station
  • the base station in the e-NodeB, evolutional Node B) or the future evolved PLMN (Public Land Mobile Network) communication system (referred to as "5G network”) is not limited in the present invention.
  • 5G network Public Land Mobile Network
  • channel state information refers to channel characteristics in a communication link.
  • the CSI describes the effects of the signal being transmitted by the transmitter through the channel to the receiver, such as scattering, fading, and attenuation of energy over distance. This information allows us to adapt the transmission to the environment we are in, enabling high bit rates and reliable communication in multi-antenna systems.
  • the user equipment (English: User equipment; abbreviated as: UE) feeds back the dimension information (or channel dimension information) of the valid statistical channel for use by the base station, where the channel dimension information may be used.
  • the effective dimension S and the subspace index (English: Subspace Index; short: SI) of the channel subspace are included, and S is less than or equal to the number of reference signal ports used for measuring channel state information.
  • the channel dimension information can be understood as a specific CSI, and the The pilot overhead required for the channel dimension information is approximately proportional to S, and the pilot overhead for obtaining CSI in the prior art is roughly proportional to the product of the number of transmit antennas and the rank (English: Rank), and the former is much smaller than the latter. Thereby, the pilot overhead for acquiring channel state information can be saved.
  • the dimension of the precoding matrix indicated by the SI under S is S
  • the dimension of the precoding matrix in the prior art is the transmission.
  • the product of the number of antennas and the Rank which is much smaller than the latter, because the calculation of the acquisition state information involves a large number of calculations of the precoding matrix, and the computational complexity of the matrix decreases as the dimension of the matrix decreases, thereby implementing the present invention.
  • the example can also effectively reduce the computational complexity of acquiring channel state information.
  • the channel corresponding to the channel subspace is broadband, and it needs to be characterized by a subspace index obtained by two or more channel measurements of the UE (English: Subspace Index; short: SI). Specifically, more than two channel measurements are
  • the channel in the embodiment of the present invention may be referred to as a statistical channel; then the channel subspace R is as follows:
  • H is the statistical channel
  • H H is the Hermitian matrix of H
  • E( ⁇ ) is the expectation of matrix
  • R can be obtained by alpha filtering on the time domain or average multiple statistics on the frequency domain.
  • ⁇ 1 ⁇ 2 ... ⁇ M is an eigenvalue of the channel subspace
  • M is a reference signal port number for measuring channel state information
  • the quantization precoding of the feature vector of the channel subspace can be obtained.
  • S is equivalent to the number of effective eigenvalues of the channel subspace; when the number of effective eigenvalues of the channel subspace is S, it indicates that the quantized precoding of the eigenvector corresponding to the S eigenvalues includes part of the energy of the channel (for example, 90% of the energy, in this case, is equivalent to containing most of the channel state information) or can meet the actual needs; in particular, the eigenvalue of the channel subspace can be satisfied by ⁇ 1 ⁇ by transform (for example, matrix transformation) ⁇ 2 ⁇ ... ⁇ S >> ⁇ S+1 ⁇ ... ⁇ M , that is, the first S feature values can be made effective eigenvalues; at this time, S is called the effective dimension of the channel subspace (specifically, S is equivalent to a channel subspace precoding matrix Dimensions), wherein the effective dimension of the channel subspace is less than or equal to the number of reference
  • the base station may use the periodic mode to indicate that the UE periodically feeds back the channel dimension information by using the downlink signaling. Further, when the base station requests the UE to stop feeding back the information through the downlink signaling, the UE stops the feedback.
  • the base station may use a trigger (English: trigger) mode to actively send signaling, and request the UE to feed back channel dimension information.
  • This mode can be aperiodic and triggered according to actual needs.
  • the feedback of the channel dimension information is one-time or signaling-triggered.
  • the periodic mode needs to additionally indicate the period of the feedback to the UE, and the period may be pre-agreed or carried in the indication information. In this case, the period may be changed by the indication information carrying the period information. Size to meet actual needs or parameter requirements.
  • Embodiment 1 Cycle Mode 1
  • FIG. 3 is a schematic diagram of a method for acquiring and feeding back channel state information according to Embodiment 1 of the present invention, as shown in FIG. 3:
  • Step 301 The BS sends the first downlink signaling to the UE, where the first downlink signaling indicates that the UE periodically feeds back the S determined by the UE.
  • Step 302 The UE performs statistical measurement on the channel subspace to obtain S.
  • Step 303 The UE periodically feeds back S to the BS.
  • Step 304 The BS determines the UE to be scheduled; or the BS determines the user equipment set, and the UEs in the user equipment set are all UEs to be scheduled.
  • Step 305 The BS sends the second downlink signaling to the UE to be scheduled, where the second downlink signaling indicates that the UE to be scheduled periodically feeds back the SI, and further, the second downlink signaling carries the S determined by the BS.
  • the S fed back by the UE determines an S that satisfies the channel condition or the actual requirement.
  • the S determined by the BS may be the same as or different from the S determined by the UE.
  • the SI fed back by the UE is the precoding of the channel subspace.
  • the dimension is the SI at the S determined by the BS (or the SI under the S determined by the BS).
  • the second downlink signaling may carry the S determined by the plurality of BSs, that is, the second downlink signaling indicates that the UE to be scheduled feeds back a plurality of SIs in the S determined by the plurality of BSs. Further, the S can be determined for the plurality of BSs.
  • the row is encoded or given an index, so that only the encoded codeword or index needs to be sent to the UE to be scheduled.
  • Step 306 The UE performs channel subspace measurement of the statistical channel, and obtains the SI under the S determined by the BS.
  • Step 307 The UE periodically feeds back the SI to the BS.
  • Step 308 The BS sends a signaling to notify the UE to be scheduled to stop feeding SI when the UE does not need to feed back the SI. Further, the BS may also send signaling to instruct the UE to stop the effective dimension S of the feedback channel subspace, and may also agree to stop feedback.
  • the period of the periodic feedback may be pre-agreed, or may be dynamically specified in the first downlink signaling by using an interval (English: index); the first downlink signaling and the first The two downlink signaling may be user-specific (English: UE-specific) or may be cell-specific (English: cell-specific).
  • Embodiment 2 Cycle Mode 2
  • FIG. 4 is a method for acquiring and feeding back channel state information according to Embodiment 2 of the present invention, as shown in FIG. 4:
  • Step 401 The BS sends the first downlink signaling to the UE, where the first downlink signaling indicates that the UE periodically feeds back the SI under S and S.
  • Step 402 The UE performs statistical measurement on the channel subspace to obtain an SI under S and S.
  • Step 403 The UE periodically feeds back the SI under S and S to the BS.
  • the step 404 the BS sends the second downlink signaling to the UE, where the second downlink signaling indicates that the UE periodically feeds back the SI, and further, the second downlink signaling carries the S determined by the BS.
  • S and SI determine an S that satisfies the channel condition or actual needs, and the S determined by the BS may be the same as or different from the S determined by the UE; in this case, the SI fed back by the UE is the precoding of the channel subspace.
  • the dimension is the SI at the S determined by the BS (or the SI under the S determined by the BS).
  • the second downlink signaling may carry the S determined by the plurality of BSs, that is, the second downlink signaling indicates that the UE to be scheduled feeds back a plurality of SIs in the S determined by the plurality of BSs.
  • the S determined by the plurality of BSs may be encoded or given an index, so that only the coded codeword or index needs to be sent to the UE to be scheduled.
  • step 405 the UE performs channel subspace measurement of the statistical channel, and obtains the SI under the S determined by the BS;
  • step 406 the UE periodically feeds back the SI to the BS;
  • the BS sends signaling to the UE to stop the UE to stop feedback S and SI when the UE does not need to perform feedback S and SI.
  • the period of the periodic feedback may be pre-agreed, or may be dynamically specified in the first downlink signaling by using an interval (English: index); the first downlink signaling and the first The two downlink signaling may be user-specific (English: UE-specific) or may be cell-specific (English: cell-specific).
  • the BS may directly use the S and the SI that are fed back by the UE as the obtained channel state information.
  • the BS may determine the channel and the SI according to the S and SI that are first fed back by the UE.
  • the sub-space matching S may then send the second downlink signaling, instructing the UE to periodically feed back the SI under the S determined by the BS, and if the S feedback in the step S403 is the same as the S determined by the BS, the second downlink information
  • the command may also not indicate that the UE periodically feeds back the SI, but only informs the S determined by the BS.
  • Embodiment 3 Trigger Mode 1
  • FIG. 5 is a schematic diagram of a method for acquiring and feeding back channel state information according to Embodiment 3 of the present invention, as shown in FIG. 5:
  • the steps of the first embodiment and the first embodiment are basically the same, except that the BS no longer indicates that the UE periodically feeds back the S or the SI, so that the UE does not periodically feed back S or SI, but the signaling is performed once or below. Feedback for triggering.
  • Step 501 The BS sends the first downlink signaling to the UE, where the first downlink signaling indicates that the UE feeds back the S determined by the UE.
  • Step 502 The UE performs statistical measurement on the channel subspace to obtain S.
  • Step 503 The UE feeds back S to the BS;
  • Step 504 The BS determines the UE to be scheduled; or the BS determines the user equipment set, and the UEs in the user equipment set are all UEs to be scheduled.
  • Step 505 The BS sends the second downlink signaling to the UE to be scheduled, where the second downlink signaling indicates that the UE to be scheduled feeds back the SI, and further, the second downlink signaling carries the S determined by the BS.
  • S determines an S that satisfies the channel condition or the actual requirement.
  • the S determined by the BS may be the same as or different from the S determined by the UE.
  • the SI fed back by the UE is the precoding dimension of the channel subspace.
  • the SI at the S determined by the BS (or the SI under the S determined by the BS).
  • the second downlink signaling may carry the S determined by the plurality of BSs, that is, the second downlink signaling indicates the number of UE feedbacks to be scheduled.
  • the S determined by the plurality of BSs may be encoded or given an index, so that only the coded codeword or index needs to be sent to the UE to be scheduled.
  • Step 506 The UE performs channel subspace measurement of the statistical channel, and obtains the SI under the S determined by the BS.
  • Step 507 The UE feeds back the SI to the BS.
  • the feedback mode of the embodiment may be aperiodic, one-time or may be triggered by the first downlink signaling; the first downlink signaling and the second downlink signaling may be user-specific. (English: UE-specific), or cell-specific.
  • Embodiment 4 Trigger Mode 2
  • FIG. 6 is a schematic diagram of a method for acquiring and feeding back channel state information according to Embodiment 2 of the present invention, as shown in FIG.
  • the steps in this embodiment and the second embodiment are basically the same, except that the BS does not instruct the UE to periodically feed back S or SI, so that the UE does not periodically feed back S or SI, but instead performs signaling at one time or below. Feedback for triggering.
  • Step 601 The BS sends the first downlink signaling to the UE, where the first downlink signaling indicates that the UE feeds back the S of the S and the S.
  • the feedback mode of the embodiment may be aperiodic or one-time.
  • the first downlink signaling may be triggered by the first downlink signaling; the first downlink signaling may be user-specific (English: UE-specific) or may be cell-specific (English: cell-specific).
  • Step 602 The UE performs statistical measurement on the channel subspace to obtain an SI under S and S.
  • Step 603 The UE feeds back the SI under S and S to the BS.
  • the step 604 the BS sends the second downlink signaling to the UE, where the second downlink signaling indicates that the UE feeds back the SI, and further, the second downlink signaling carries the S determined by the BS.
  • the SI determines an S that satisfies the channel condition or the actual requirement.
  • the S determined by the BS may be the same as or different from the S determined by the UE.
  • the SI fed back by the UE is the precoding dimension of the channel subspace.
  • the SI at the S determined by the BS (or the SI under the S determined by the BS).
  • the second downlink signaling may carry the S determined by the plurality of BSs, that is, the second downlink signaling indicates that the UE to be scheduled feeds back a plurality of SIs in the S determined by the plurality of BSs.
  • the S determined by the plurality of BSs may be encoded or given an index, so that only the coded codeword or index needs to be sent to the UE to be scheduled.
  • step 605 the UE performs channel subspace measurement of the statistical channel, and obtains the SI under the S determined by the BS;
  • step 606 the UE feeds back the SI to the BS;
  • the feedback mode of the embodiment may be aperiodic, one-time or may be triggered by the first downlink signaling; the first downlink signaling and the second downlink signaling may be user-specific. (English: UE-specific), or cell-specific.
  • the BS may directly use the S and SI fed back by the UE as the acquired channel state information.
  • the BS may determine the channel and the SI more accurately according to the S and SI that are first fed back by the UE.
  • the sub-space matching S may then send the second downlink signaling, indicating that the UE feeds back the SI under the S determined by the BS, and if the S feedback in the step S603 is the same as the S determined by the BS, the second downlink signaling is also
  • the UE may not be instructed to periodically feed back the SI, but only the S determined by the BS.
  • the periodic feedback S or the periodic feedback SI (for example, steps 303 and 307) is not limited to before or after the other steps are performed, because the periodicity of the feedback may be longer, so the duration may be longer.
  • the UE may also feed back S after steps 304, 305 (ie, step 303 is still being performed). Second, indicating that the feedback S or SI is stopped does not necessarily need to be performed, so step 308 is optional.
  • the BS may send the first downlink signaling to one or more UEs (which may be all UEs in the cell, or may be a group of UEs), but in the step of determining the UE to be scheduled (for example, In step 304), the BS determines the UE to be scheduled in the one or more UEs, and then the BS sends the second downlink signaling to the determined UE to be scheduled, where the UE to be scheduled includes at most the one or more UEs. All UEs.
  • the BS notifies the UE to feed back the SI corresponding to the channel subspace precoding matrix of the S dimension, instead of arbitrarily feedback, by using the S determined by the BS in the sent signaling, thereby reducing the feedback overhead, and the BS indicates the to be scheduled.
  • the UE performs feedback of the SI without requiring feedback from all UEs, which also reduces the overhead of feedback.
  • the base station After the base station obtains the effective dimensions S of the channel subspace and the SI under the S, the base station can use the information to perform precoding, beamforming, etc., and can also use the information to reduce the channel information acquisition. For example, the dimensionality reduction precoding is performed to reduce the pilot overhead and computational complexity of the next channel measurement.
  • the base station obtains the SIs corresponding to the effective dimensions S and S of the channel subspace of the user, because the effective dimension of the channel subspace is smaller (or much smaller) than the number of reference signal ports used to measure the channel state information, which is equivalent to Obtained the channel subspace after dimensionality reduction;
  • the base station schedules the user equipment, determines the user equipment set that participates in the multiple input multiple output, and performs the next-level channel state information measurement on the user equipment in the user equipment set, and obtains the real-time channel state information of the reduced channel subspace;
  • the base station processes the downlink data and the user-specific demodulation reference signal by two-stage precoding, and then sends the data to the user equipment in the user equipment set.
  • the two-stage precoding includes the first level pre-corresponding to the channel subspace channel state information.
  • the second level precoding corresponding to the real time channel state information is encoded.
  • the embodiment of the present invention can be applied to a system in which a MU-MIM O is applied in a downlink, when there are many users to be scheduled and users participating in MU-MIMO (typically, in a large-scale antenna array system but not limited to the system) .
  • the channel reduction in the embodiment of the present invention effectively reduces the overhead of acquiring CSI.
  • the overhead savings include (compared with the first-level RS scheme of the LTE in the prior art and the effect of the scheme of the present invention):
  • the primary RS scheme of LTE averages the density at each transmit antenna time frequency to be x REs/ms/15 kHz, and the total density of RSs of the M transmit antennas is M*x REs/ms/15 kHz;
  • the downlink RS overhead in the embodiment of the present invention is composed of two parts of the two-stage RS: the primary-level RS only needs to obtain the channel subspace that changes slowly in time and frequency, and the density in the time and frequency domain can be reduced (for example, The time density may be 1/4 or less of the LTE primary RS density, and the density of the LTE primary RS 1/2 is considered in the frequency), and the density of the general M transmitting antennas may be controlled to be M*x/8REs/ms/15 kHz;
  • Uplink feedback overhead (applicable to FDD/TDD, assuming each downlink subband performs a feedback):
  • the prior art scheme requires an RS UE feedback for all the T 1 of the pending scheduled, provided that number density
  • the total RE number time density occupied by the UE to be scheduled is T 1 *y REs/ms/downstream subband;
  • the UEs in the T 2 scheduling UE sets need to be fed back. If the number of REs to be scheduled for each UE to be scheduled is maintained consistent with the LTE primary RS solution, the UEs in the T 2 scheduling UE sets are occupied.
  • uplink RS overhead (only for TDD)
  • the prior art scheme requires an RS RS UE performs uplink transmission for all T 1 of the pending scheduled, the average scheduled to be occupied by the UE transmits an RS RE number density on the time frequency z REs / ms / 15kHz, the overall density of the RS is scheduled UE pending T 1 is T 1 * z REs / ms / 15kHz;
  • the uplink RS overhead of the embodiment of the present invention is composed of two parts of the two-stage RS: the primary RS only needs to obtain the channel subspace that changes slowly in time and frequency, and the density in the time and frequency domain can be reduced (such as time).
  • the density may be less than 1/4 of the LTE primary RS density, and the density of the LTE primary RS 1/2 is considered in the frequency.
  • the RS density of the T 1 to -be-scheduled UEs may be controlled to be T 1 *z/8REs/ms.
  • the secondary RS needs to support the change of the real-time channel, and the average density on the UE time frequency in each scheduling set is also z REs/ms/15 kHz, so the T 2 scheduling UEs in the UE set are secondary
  • the update speed of the first-level precoding is slow, which is not the main bottleneck for solving the computational complexity. Therefore, the SVD obtained when acquiring the second precoding is the computational complexity of the main DL CSI acquisition.
  • FIG. 7 is a data rendering diagram comparing the performance of the system of the present invention with the performance of an ideal system as shown in FIG. 7. Under the transmission period of changing the primary RS, the performance of the system of the present invention is always small from the ideal system performance;
  • FIG. 8 Another data rendering diagram of the system performance of the present invention as compared with the ideal system performance as shown in FIG. 8 shows that the performance of the system of the present invention is always small from the ideal system performance under the dimension of changing the dimensionality reduction;
  • FIG. 9 Another data rendering diagram of the performance of the system of the present invention as compared with the ideal system performance as shown in FIG. 9 shows that the performance of the system of the present invention is small at a low speed and the performance of the ideal system is small in the case of changing the mobility of the UE, but the medium and high speed The difference between the performance of the system and the ideal system is large (that is, the performance loss of the system of the present invention is large at medium and high speeds), so the present invention is mainly applicable to low-speed scenes;
  • FIG. 11 Another data rendering diagram comparing the performance of the system of the present invention with the ideal system performance as shown in FIG. 11 shows that the performance of the system of the present invention always differs from the ideal system performance when the number of transmitting antennas at the data transmitting end (the number of antennas is greater than or equal to 64) is changed. Very small
  • the channel subspace channel state information after the dimension reduction is obtained through the measurement of the primary channel state information, and the secondary channel state information is measured for the user equipment in the user equipment set, and the reduced real-time channel state is obtained.
  • the information is processed by the two-stage pre-coding after the downlink data and the user-specific demodulation reference signal are processed, and the uplink and downlink are solved when the number of antennas of the data transmitting end is large in the prior art.
  • the technical problem of large pilot overhead and large amount of uplink CSI feedback so that the system has more time-frequency resources for data transmission, effectively increasing the system's swallowing.
  • channel reduction can solve the high complexity problem of the system baseband processing in the prior art and reduce the need for baseband processing capability.
  • the embodiment of the present invention further provides an apparatus for acquiring channel state information, as shown in FIG. 12, including:
  • the sending module 1201 is configured to send, by the base station, one or more downlink signalings to the user equipment, where the one or more downlink signalings indicate that the user equipment feeds back channel dimension information;
  • the channel dimension information includes an effective dimension of a channel subspace of a statistical channel between the base station and the user equipment, and an effective dimension of the channel subspace is smaller than a reference signal port number used for measuring channel state information;
  • the receiving module 1202 is configured to receive, by the base station, channel dimension information fed back by the user equipment.
  • the channel dimension information further includes a subspace index under the effective dimension of the channel subspace; the subspace index has a one-to-one correspondence with the quantization precoding of the feature vector of the channel subspace.
  • the quantization precoding of the feature vector of the channel subspace corresponding to the subspace index includes the energy of the portion of the statistical channel.
  • the base station sends a downlink signaling to the user equipment, where the base station sends the third downlink signaling to the user equipment.
  • the third downlink signaling indicates a valid dimension of the user equipment feedback channel subspace, and a subspace index under the effective dimension of the channel subspace;
  • the channel dimension information that the base station receives the feedback from the user equipment includes the effective dimension of the channel subspace fed back by the receiving device, and the subspace index in the effective dimension of the subspace.
  • the device further includes:
  • the determining module 1203 is configured to determine, by the base station, an effective dimension of the channel subspace according to the effective dimension and the subspace index of the channel subspace fed back by the user equipment;
  • the sending module 1201 is further configured to: the base station sends a fourth downlink signaling to the user equipment, where the fourth downlink signaling indicates that the user equipment feeds back the subspace index in the effective dimension of the channel subspace determined by the base station;
  • the receiving module 1202 is further configured to: receive, by the base station, a subspace index in an effective dimension of the channel subspace determined by the base station that is fed back by the user equipment.
  • the apparatus for acquiring channel state information provided by the embodiment of the present invention may be used on a network element node device or a base station.
  • the embodiment of the present invention further provides an apparatus for feeding back channel state information, as shown in FIG.
  • the receiving module 1301 is configured to receive, by the user equipment, one or more downlink signalings from the base station, where the one or more downlink signalings indicate that the user equipment feeds back channel dimension information;
  • the channel dimension information includes an effective dimension of a channel subspace of a statistical channel between the base station and the user equipment, and an effective dimension of the channel subspace is smaller than a reference signal port number used for measuring channel state information;
  • the feedback module 1302 is configured to feed back, by the user equipment, channel dimension information to the base station.
  • the channel dimension information further includes a subspace index under the effective dimension of the channel subspace; the subspace index has a one-to-one correspondence with the quantization precoding of the feature vector of the channel subspace.
  • the quantization precoding of the feature vector of the channel subspace corresponding to the subspace index includes the energy of the portion of the statistical channel.
  • the apparatus further includes: a measurement module 1303, configured to perform statistical measurement on the channel subspace by the user equipment, to obtain an effective dimension of the channel subspace.
  • a measurement module 1303 configured to perform statistical measurement on the channel subspace by the user equipment, to obtain an effective dimension of the channel subspace.
  • the device for feeding back channel state information provided by the embodiment of the present invention can be used on a network element node device or a user equipment.
  • the embodiment of the present invention further provides a processing device, as shown in FIG. 14, comprising: a processor 1401, a memory 1402, a transmitter 1403, and a bus 1404, wherein the processor 1401, the memory 1402, and the transmitter 1403 are connected by the bus 1404 for data.
  • the transmission 1402 is configured to store data processed by the processor 1401;
  • the bus 1404 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Etc., here is not limited.
  • the bus 1404 can be divided into an address bus, a data bus, and a control bus. Wait. For ease of representation, only one thick line is shown in Figure 14, but it does not mean that there is only one bus or one type of bus. among them:
  • the memory 1402 is configured to store data or executable program code, where the program code includes computer operating instructions, specifically: an operating system, an application, and the like.
  • the memory 1402 may include a high speed RAM memory and may also include a non-volatile memory such as at least one disk memory.
  • the processor 1401 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more configured to implement the embodiments of the present invention. integrated circuit.
  • CPU central processing unit
  • ASIC application specific integrated circuit
  • the processor 1401 is configured to implement the method for acquiring channel state information in the foregoing embodiment by executing the program code in the memory 1402.
  • the processor 1401 can also be used to implement the feedback channel state in the foregoing embodiment by executing the program code in the memory 1402.
  • Method of information including some technical features, such as: effective dimension of channel subspace, subspace index, statistical channel // periodic feedback, one-time feedback, etc., and some technical features involved in the method embodiment of the present invention Similar or corresponding, this embodiment will not repeat the description. The specific process will not be repeated.
  • the size of the serial numbers of the above processes does not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic, and should not be implemented by the present invention.
  • the implementation of the examples constitutes any limitation.
  • the disclosed apparatus and method can be In other ways.
  • the device embodiments described above are merely illustrative.
  • the division of the unit is only a logical function division.
  • there may be another division manner for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed.
  • the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, or an electrical, mechanical or other form of connection.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the embodiments of the present invention.
  • each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.
  • the above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. Specifically, it can be implemented by means of software and necessary general hardware.
  • the general hardware includes a general-purpose integrated circuit, a general-purpose CPU (English: Central Processing Unit, Chinese: central processing unit), and a general-purpose digital signal processor (English: Digital Signal Processor) , referred to as: DSP), Field Programmable Gate Array (English: Field Programming Gate Array, referred to as: FPGA), Programmable Logical Device (English: Programmable Logical Device, PLD for short), general-purpose memory, general-purpose components, etc. It can be realized by dedicated hardware including an application specific integrated circuit (ASIC), a dedicated CPU, a dedicated memory, a dedicated component, and the like.
  • ASIC application specific integrated circuit
  • the integrated unit if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium.
  • the technical solution of the present invention contributes in essence or to the prior art, or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium.
  • a number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention.
  • the foregoing storage medium includes: a U disk, a mobile hard disk, a read only memory (English: Read Only Memory, abbreviated as ROM), a random access memory (English: Random Access Memory, abbreviated as RAM), A variety of media that can store program code, such as a disk or an optical disk.
  • ROM Read Only Memory
  • RAM Random Access Memory
  • Software or instructions can also be transferred over a transmission medium.
  • a transmission medium For example, if you use coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL: DSL) or wireless technology (such as infrared, radio and microwave) to transfer software from websites, servers or other remote sources.
  • coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies are included in the definition of the transmission medium.

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Abstract

本发明实施例提出了一种获取信道状态信息的方法，包括：基站向用户设备发送一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；所述基站接收所述用户设备反馈的所述信道维度信息。由于信道子空间的有效维度小于用户测量信道状态信息的参考信道端口数，则需要用于反馈信道状态信息的空间流相对于现有技术会减小，从而降低了获取信道状态信息的导频开销和计算复杂度。

Description

一种获取信道状态信息的方法、装置 技术领域
本发明涉及通信技术领域，具体涉及一种获取信道状态信息的方法、装置。
背景技术
在3GPP长期演进(英文：Long Term Evolution；简称：LTE)以及3GPP后续长期演进(英文：Long Term Evolution-Advanced；简称：LTE-A)中，随着数据发射端的天线数量在不断地快速增长，需要服务的用户设备(英文：User equipment；简称：UE)数量，即待调度UE的数量也在快速增长。天线数量的增长可以提供更高的空间自由度，这为下行空间复用多个数据流，例如：多输入多输出(英文：Multi-input Multi-output；简称：MIMO)，包括单用户多输入多输出和多用户多输入多输出，创造了有利条件。
为了获取大规模天线所能提供的高空间自由度，相关的信道状态信息(英文：Channel State Information；简称：CSI)必须被数据发射端(例如：基站)获取，以获取精确的预编码(英文：precode)。在进行MIMO时，现有技术(例如：LTE/LTE-A)中，一般数据发射端有两种方法获取CSI：
一种是在时分双工(英文：Time Division Duplexing；简称：TDD)或频分双工(英文：Frequency Division Duplexing；简称：FDD)情况下，数据发射端发送下行测量CSI的导频，由数据接收端(例如：UE)测量该导频获取CSI，UE再进行反馈CSI，其中，反馈的CSI一般为量化的CSI，在LTE中为预编码矩阵索引(英文：Precoding Matrix Indicator；简称：PMI)和秩指引(英文：Rank Index；简称：RI)，数据发射端使用该CSI对数据进行预编码并发送。另一种是在TDD情况下，数据接收端发送上行测量CSI的导频，例如：LTE/LTE-A中的探测参考信号(英文：Sounding Reference Signal；简称：SRS)，由数据发射端进行上行信道CSI测量，数据发射端依据信道互异性认为上行信道测量即下行信道(一般需要必要的互异性参数修正)，再根据该CSI对数据进行预编码发送。
现有MIMO的CSI获取的关键在于一次性快速获取完整实时的CSI(所谓完整是指所有数据发射端天线的信道信息)，以获得尽可能准确的信道，其中，获取CSI只要一级参考信号(英文：Reference Signal；简称：RS)。具体一级RS可以分为以下两种实现形式：
实现方式1：如图1所示，首先由数据发射端发送下行测量CSI的导频，例如LTE/LTE-A中的CSI-RS或者小区专用参考信号(英文：Cell-specific Reference Signal；简称：CRS)，数据接收端测量该导频获取CSI(例如在LTE/LTE-A中为预编码矩阵)，并进行量化，数据接收端把量化后的CSI反馈给收发射端，发射端使用该CSI对数据进行预编码并发送。该方案适用于FDD与TDD。
实现方式2：如图2所示，数据接收端发射上行测量CSI的导频，例如LTE/LTE-A中的SRS，数据发射端测量该导频获取CSI，例如在LTE/LTE-A中为预编码矩阵，再根据该CSI对数据进行预编码发送。该方案适用于TDD。
由于下行的导频开销量与数据发射端的天线数成正比，上行的导频开销量又与待服务UE数量呈正比，上行的CSI反馈量也与数据发射端的天线数成正比，在数据发射端天线数不是很多时(例如LTE/LTE-A的4/8天线)，导频开销以及上行的CSI反馈量可以得到控制，然而当天线数量较多时(可供调度的UE数量也会随之增加)，上下行的导频开销与上行CSI的反馈量就会占用大量时频资源，造成可供数据传输的时频资源被压缩，系统吞吐量就会受到很大影响。
现有技术需要对维度为数据发射端天线数的方阵进行处理，这对数据发射端的基带处理能力提出了前所未有的挑战。无论是采用下行测量进行的CSI反馈，或者进行上行测量CSI，发射端天线数较多情况下都较容易造成获取CSI的导频开销过大的问题以及获取信道信息计算量过大的问题。
发明内容
本发明实施例提出了一种获取信道状态信息的方法、装置，能够降低了获取信道状态信息的导频开销和计算复杂度。
第一方面，本发明实施例提出了一种获取信道状态信息的方法，包括：
基站向用户设备发送一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；
其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
所述基站接收所述用户设备反馈的所述信道维度信息。
结合第一方面，在第一方面的第一种可能的实现方式中，所述信道维度信息还包括所述信道子空间的有效维度下的子空间索引；
所述子空间索引与信道子空间的特征向量的量化预编码一一对应。
结合第一方面的第一种可能的实现方式，在第一方面的第二种可能的实现方式中，所述子空间索引对应的信道子空间的特征向量的量化预编码包含所述统计信道的部分的能量。
结合第一方面或第一方面的第一种或第二种可能的实现方式，在第一方面的第三种可能的实现方式中，
基站向用户设备发送多个下行信令包括所述基站向所述用户设备发送第一下行信令；
其中，所述第一下行信令指示所述用户设备反馈所述信道子空间的有效维度；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的所述信道子空间的有效维度；
所述基站向用户设备发送多个下行信令还包括所述基站向所述用户设备发送第二下行信令；
其中，所述第二下行信令指示所述用户设备反馈子空间索引，其中，所述第二下行信令携带所述基站根据所述用户设备反馈的所述信道子空间的有效维度确定的信道子空间的有效维度；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的所述基站确定的信道子空间的有效维度下的子空间索引。
结合第一方面的第三种可能的实现方式，在第一方面的第四种可能的实现方式中，所述用户设备为待调度的用户设备。
结合第一方面或第一方面的第一种或第二种可能的实现方式，在第一方面的第五种可能的实现方式中，
基站向用户设备发送一个下行信令包括所述基站向所述用户设备发送第三下行信令；
其中，所述第三下行信令指示所述用户设备反馈所述信道子空间的有效维度，以及所述信道子空间的有效维度下的子空间索引；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的信道子空间的有效维度，以及所述信道子空间的有效维度下的子空间索引。
结合第一方面的第五种可能的实现方式，在第一方面的第六种可能的实现方式中，所述方法还包括：
所述基站根据所述用户设备反馈的所述信道子空间的有效维度和子空间索引确定信道子空间的有效维度；
所述基站向所述用户设备发送第四下行信令，所述第四下行信令指示所述用户设备反馈所述基站确定的信道子空间的有效维度下的子空间索引；
所述基站接收所述用户设备反馈的所述基站确定的信道子空间的有效维度下的子空间索引。
结合第一方面或第一方面的第一种至第六种任一项可能的实现方式，在第一方面的第七种可能的实现方式中，
所述一个或多个下行信令指示所述用户设备反馈信道维度信息包括所述一个或多个下行信令指示所述用户设备周期性地反馈信道维度信息；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备周期性地反馈的所述信道维度信息；
其中，反馈的周期是通过所述一个或多个下行信令指示的或预先约定的。
结合第一方面或第一方面的第一种至第六种任一项可能的实现方式，在第一方面的第八种可能的实现方式中，
所述一个或多个下行信令指示所述用户设备反馈信道维度信息包括所述一个或多个下行信令指示所述用户设备一次性地反馈信道维度信息；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备一次性地反馈的所述信道维度信息。
第二方面，本发明实施例提出了一种反馈信道状态信息的方法，包括：
用户设备从基站接收一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；
其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
所述用户设备向所述基站反馈所述信道维度信息。
结合第二方面，在第二方面的第一种可能的实现方式中，
所述信道维度信息还包括所述信道子空间的有效维度下的子空间索引；
所述子空间索引与信道子空间的特征向量的量化预编码一一对应。
结合第二方面的第一种可能的实现方式，在第二方面的第二种可能的实现方式中，
所述子空间索引对应的信道子空间的特征向量的量化预编码包含所述统计信道的部分的能量。
结合第二方面或第二方面的第一种或第二种可能的实现方式，在第二方面的第三种可能的实现方式中，所述方法还包括：所述用户设备对所述信道子空间进行统计测量，得到所述信道子空间的有效维度。
第三方面，本发明实施例提出了一种获取信道状态信息的装置，包括：
发送模块，用于基站向用户设备发送一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；
其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
接收模块，用于所述基站接收所述用户设备反馈的所述信道维度信息。
结合第三方面，在第三方面的第一种可能的实现方式中，所述信道维度信息还包括所述信道子空间的有效维度下的子空间索引；
所述子空间索引与信道子空间的特征向量的量化预编码一一对应。
结合第三方面的第一种可能的实现方式，在第三方面的第二种可能的实现方式中，所述子空间索引对应的信道子空间的特征向量的量化预编码包含所述统计信道的部分的能量。
结合第三方面或第三方面的第一种或第二种可能的实现方式，在第三方面的第三种可能的实现方式中，
基站向用户设备发送多个下行信令包括所述基站向所述用户设备发送第一下行信令；
其中，所述第一下行信令指示所述用户设备反馈所述信道子空间的有效维度；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的所述信道子空间的有效维度；
所述基站向用户设备发送多个下行信令还包括所述基站向所述用户设备发送第二下行信令；
其中，所述第二下行信令指示所述用户设备反馈子空间索引，其中，所述第二下行信令携带所述基站根据所述用户设备反馈的所述信道子空间的有效维度确定的信道子空间的有效维度；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的所述基站确定的信道子空间的有效维度下的子空间索引。
结合第三方面的第三种可能的实现方式，在第三方面的第四种可能的实现方式中，所述用户设备为待调度的用户设备。
结合第三方面或第三方面的第一种或第二种可能的实现方式，在第三方面的第五种可能的实现方式中，
基站向用户设备发送一个下行信令包括所述基站向所述用户设备发送第三下行信令；
其中，所述第三下行信令指示所述用户设备反馈所述信道子空间的有效维度，以及所述信道子空间的有效维度下的子空间索引；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的信道子空间的有效维度，以及所述信道子空间的有效维度下的子空间索引。
结合第三方面的第五种可能的实现方式，在第三方面的第六种可能的实现方式中，所述装置还包括：
确定模块，用于所述基站根据所述用户设备反馈的所述信道子空间的有效维度和子空间索引确定信道子空间的有效维度；
所述发送模块还用于所述基站向所述用户设备发送第四下行信令，所述第四下行信令指示所述用户设备反馈所述基站确定的信道子空间的有效维度下的子空间索引；
所述接收模块还用于所述基站接收所述用户设备反馈的所述基站确定的信道子空间的有效维度下的子空间索引。
结合第三方面或第三方面的第一种至第六种任一项可能的实现方式，在第三方面的第七种可能的实现方式中，
所述一个或多个下行信令指示所述用户设备反馈信道维度信息包括所述一个或多个下行信令指示所述用户设备周期性地反馈信道维度信息；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备周期性地反馈的所述信道维度信息；
其中，反馈的周期是通过所述一个或多个下行信令指示的或预先约定的。
结合第三方面或第三方面的第一种至第六种任一项可能的实现方式，在第三方面的第八种可能的实现方式中，
所述一个或多个下行信令指示所述用户设备反馈信道维度信息包括所述一个或多个下行信令指示所述用户设备一次性地反馈信道维度信息；
所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备一次性地反馈的所述信道维度信息。
第四方面，本发明实施例提出了一种反馈信道状态信息的装置，包括：
接收模块，用于用户设备从基站接收一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；
其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
反馈模块，用于所述用户设备向所述基站反馈所述信道维度信息。
结合第四方面，在第四方面的第一种可能的实现方式中，
所述信道维度信息还包括所述信道子空间的有效维度下的子空间索引；
所述子空间索引与信道子空间的特征向量的量化预编码一一对应。
结合第四方面的第一种可能的实现方式，在第四方面的第二种可能的实现方式中，
所述子空间索引对应的信道子空间的特征向量的量化预编码包含所述统计信道的部分的能量。
结合第四方面或第四方面的第一种或第二种可能的实现方式，在第四方面的第三种可能的实现方式中，所述装置还包括：
测量模块，用于所述用户设备对所述信道子空间进行统计测量，得到所述信道子空间的有效维度。
本发明实施例让用户设备反馈其有效的统计信道的维度信息(或信道维度信息)供基站进行使用，其中，信道维度信息可以包括信道子空间的有效维度和子空间索引，信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数。由于信道子空间的有效维度小于用户测量信道状态信息的参考信道端口数，则需要用于反馈信道状态信息的空间流相对于现有技术会减小，从而降低了获取信道状态信息的导频开销和计算复杂度。
附图说明
为了更清楚地说明本发明实施例中的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为现有技术的CSI获取的一种实现方式；
图2为现有技术的CSI获取的另一种实现方式；
图3为本发明实施例一提供的获取及反馈信道状态信息的方法；
图4为本发明实施例二提供的获取及反馈信道状态信息的方法；
图5为本发明实施例三提供的获取及反馈信道状态信息的方法；
图6为本发明实施例二提供的获取及反馈信道状态信息的方法；
图7为本发明系统性能与理想系统性能对比的数据效果图；
图8为本发明系统性能与理想系统性能对比的另一数据效果图；
图9为本发明系统性能与理想系统性能对比的另一数据效果图；
图10为本发明系统性能与理想系统性能对比的另一数据效果图；
图11为本发明系统性能与理想系统性能对比的另一数据效果图；
图12为本发明实施例提供的一种获取信道状态信息的装置；
图13为本发明实施例提供的一种反馈信道状态信息的装置；
图14为本发明实施例提供的一种获取或反馈信道状态信息的设备。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
本发明实施例中的用户设备(UE，User Equipment)，也可称之为移动终端(Mobile Terminal)、移动用户设备等，可以经无线接入网(例如，RAN，Radio Access Network)与一个或多个核心网进行通信，用户设备可以是移动终端，如移动电话(或称为“蜂窝”电话)和具有移动终端的计算机，例如，可以是便携式、袖珍式、手持式、计算机内置的或者车载的移动装置，它们与无线接入网交换语言和/或数据。
基站(英文Base Station；简称：BS)，可以是GSM或CDMA中的基站(BTS，Base Transceiver Station)，也可以是WCDMA中的基站(NodeB)，还可以是LTE中的演进型基站(eNB或e-NodeB，evolutional Node B)或未来演进的PLMN(Public Land Mobile Network，公共陆地移动网络)通信系统(简称“5G网络”)中的基站，本发明并不限定。
在无线通信中，信道状态信息(CSI)指的是通信链路中的信道特性。CSI描述信号由发射机经过信道到达接收机受到的影响，如散射、衰落，以及能量随距离的衰减。这些信息使得我们能将传输适应通到的环境，进而在多天线系统中达成高的比特率与可靠的通信。
本发明实施例在常规获取信道状态信息前让用户设备(英文：User equipment；简称：UE)反馈其有效的统计信道的维度信息(或信道维度信息)供基站进行使用，其中，信道维度信息可以包括信道子空间的有效维度S和子空间索引(英文：Subspace Index；简称：SI)，S小于等于用于测量信道状态信息的参考信号端口数。该信道维度信息可以理解为一种特定的CSI，获取该 信道维度信息所需的导频开销大致与S成正比，而现有技术中获取CSI的导频开销大致与发射天线数和秩(英文：Rank)之积成正比，而前者远小于后者，从而可以节省获取信道状态信息的导频开销。
具体地，在基站天线数较多的应用场景下，通过获取统计信道的信道维度信息，S下SI所指示的预编码矩阵的维度就是S，而现有技术中的预编码矩阵的维度是发射天线数和Rank之积，而前者远小于后者，因为获取状态信息的计算大量涉及预编码矩阵的计算，而矩阵的计算复杂度是随着矩阵的维度降低而减小的，从而本发明实施例也可以有效地减小获取信道状态信息的计算复杂度。
关于信道子空间以及信道子空间的有效维度：
一般而言，信道子空间对应的信道是宽带的，它需要UE的两次以上信道测量得到的子空间索引(英文：Subspace Index；简称：SI)来表征，具体地，两次以上信道测量是对信道的统计测量，此时，可以将本发明实施例中的信道称为统计信道；则信道子空间R如下：
R＝E(HHH)
其中，H为统计信道，HH为H的埃尔米特矩阵(英文：Hermitian matrix)，E(·)为求矩阵·的期望。其中，R可以通过时域上的alpha滤波或频域上的平均多次统计得到。
对R进行特征值分解(英文：Eigen Value Decomposition；简称：EVD)或奇异值分解(英文：Singular Value Decomposition；简称：SVD)，可以得到：
R＝E(HHH)＝UΛUH＝(u1 u2 … uM)diag(λ1 λ2 … λM)(u1 u2 … uM)H
其中，λ1 λ2 … λM为信道子空间的特征值，M为用于测量信道状态信息的参考信号端口数。
进一步地，根据分解的结果，可以得到信道子空间的特征向量的量化预编码
Figure PCTCN2015082954-appb-000001
其中，S相当于信道子空间的有效特征值个数；信道子空间的有效特征值个数为S个时，表明其中S个特征值对应的特征向量的量化预编码包含该信道的部分能量(例如90％的能量，此时，也就相当于包含了大部分的信道状态信息)或可以满足实际需求；具体地，可以通过变换(例如矩阵变换)使得信道子空间的特征值满足λ1≥λ2≥…λS＞＞λS+1≥…≥λM，也就是说，可以使得前S个特征值为有效特征值；此时，S称为信道子空间的有效维度(具 体地，S相当于是信道子空间预编码矩阵
Figure PCTCN2015082954-appb-000002
的维度)，其中，信道子空间的有效维度小于等于用于测量信道状态信息的参考信号端口数(一般地，也可以说，信道子空间的有效维度小于等于发射天线端口数)。
关于反馈信道维度信息的方式：
可选地，基站可以采用周期模式，通过下行信令指示UE周期性地反馈信道维度信息，进一步地，当基站通过下行信令要求UE停止反馈此信息时，UE停止反馈。
可选地，基站可以采用触发(英文：trigger)模式，主动发送信令，要求UE反馈信道维度信息。该模式可以是非周期的，根据实际需要触发。这种情况下，信道维度信息的反馈是一次性的或者是信令触发的。
相比于触发模式，周期模式要额外向UE指明反馈的周期，该周期可以是预先约定的，也可以是携带在指示信息中的，此时，可以通过携带该周期信息的指示信息改变周期的大小，以满足实际需要或参数要求。
实施例一：周期模式1
图3为本发明实施例一提供的获取及反馈信道状态信息的方法，如图3所示：
步骤301：BS向UE发送第一下行信令，其中，第一下行信令指示UE周期性地反馈UE确定的S；
步骤302：UE对信道子空间进行统计测量，得到S；
步骤303：UE向BS周期性地反馈S；
步骤304：BS确定待调度的UE；或者，BS确定用户设备集，该用户设备集里的UE都是待调度的UE。
步骤305：BS向待调度的UE发送第二下行信令，其中，第二下行信令指示待调度的UE周期性地反馈SI，进一步地，第二下行信令携带BS确定的S(BS根据UE反馈的S确定出一个满足信道条件或实际需要的S，BS确定的S可以和UE确定的S相同，也可以不同)；在这种情况下，UE反馈的SI是信道子空间的预编码的维度为BS确定的S时的SI(或者称作BS确定的S下的SI)。进一步地，第二下行信令可以携带数个BS确定的S，也就相当于第二下行信令指示待调度的UE反馈数个BS确定的S下的数个SI。进一步地，可以对该数个BS确定的S进 行编码或给定索引，从而只需将该编码后的码字或索引向待调度的UE发送即可。
步骤306：UE进行统计信道的信道子空间测量，得到BS确定的S下的SI；
步骤307：UE向BS周期性地反馈SI；
步骤308：BS在不需要UE反馈SI时发送信令指示待调度的UE停止反馈SI；进一步地，BS也可以发送信令指示UE停止反馈信道子空间的有效维度S，也可以约定停止反馈。
可选地，该周期反馈的周期可以是预先约定的，也可以在第一下行信令中通过间隔(英文：interval)的索引(英文：index)动态规定；第一下行信令和第二下行信令可以是用户专用的(英文：UE-specific)，也可以是小区专用的(英文：cell-specific)。
实施例二：周期模式2
图4为本发明实施例二提供的获取及反馈信道状态信息的方法，如图4所示：
步骤401：BS向UE发送第一下行信令，其中，第一下行信令指示UE周期性地反馈S以及S下的SI；
步骤402：UE对信道子空间进行统计测量，得到S和S下的SI；
步骤403：UE向BS周期性地反馈S以及S下的SI；
可选地，步骤404：BS向UE发送第二下行信令，其中，第二下行信令指示UE周期性地反馈SI，进一步地，第二下行信令携带BS确定的S(BS根据UE反馈的S以及SI确定出一个满足信道条件或实际需要的S，BS确定的S可以和UE确定的S相同，也可以不同)；在这种情况下，UE反馈的SI是信道子空间的预编码的维度为BS确定的S时的SI(或者称作BS确定的S下的SI)。进一步地，第二下行信令可以携带数个BS确定的S，也就相当于第二下行信令指示待调度的UE反馈数个BS确定的S下的数个SI。进一步地，可以对该数个BS确定的S进行编码或给定索引，从而只需将该编码后的码字或索引向待调度的UE发送即可。
可选地，步骤405：UE进行统计信道的信道子空间测量，得到BS确定的S下的SI；
可选地，步骤406：UE向BS周期性地反馈SI；
可选地，步骤407：BS在不需要UE进行反馈S和SI时，向UE发送信令指示UE停止反馈S和SI。
可选地，该周期反馈的周期可以是预先约定的，也可以在第一下行信令中通过间隔(英文：interval)的索引(英文：index)动态规定；第一下行信令和第二下行信令可以是用户专用的(英文：UE-specific)，也可以是小区专用的(英文：cell-specific)。
在本发明实施例二中，BS可以直接将UE反馈的S和SI作为获取到的信道状态信息；可选地，BS也可以根据UE首先反馈的S和SI可以更准确的确定出与该信道子空间相匹配的S，然后可以发送第二下行信令，指示UE周期性反馈BS确定的S下的SI，若改UE在步骤403中反馈的S和BS确定的S相同，第二下行信令也可以不指示UE周期性反馈SI，而只通知其BS所确定的S。
实施例三：触发模式1
图5为本发明实施例三提供的获取及反馈信道状态信息的方法，如图5所示：
本实施例和实施例一的步骤基本相同，只是BS不再指示UE周期性地反馈S或SI，从而，UE也不再周期性地反馈S或SI，而是一次性地或以下行信令为触发地反馈。
步骤501：BS向UE发送第一下行信令，其中，第一下行信令指示UE反馈UE确定的S；
步骤502：UE对信道子空间进行统计测量，得到S；
步骤503：UE向BS反馈S；
步骤504：BS确定待调度的UE；或者，BS确定用户设备集，该用户设备集里的UE都是待调度的UE。
步骤505：BS向待调度的UE发送第二下行信令，其中，第二下行信令指示待调度的UE反馈SI，进一步地，第二下行信令携带BS确定的S(BS根据UE反馈的S确定出一个满足信道条件或实际需要的S，BS确定的S可以和UE确定的S相同，也可以不同)；在这种情况下，UE反馈的SI是信道子空间的预编码的维度为BS确定的S时的SI(或者称作BS确定的S下的SI)。进一步地，第二下行信令可以携带数个BS确定的S，也就相当于第二下行信令指示待调度的UE反馈数 个BS确定的S下的数个SI。进一步地，可以对该数个BS确定的S进行编码或给定索引，从而只需将该编码后的码字或索引向待调度的UE发送即可。
步骤506：UE进行统计信道的信道子空间测量，得到BS确定的S下的SI；
步骤507：UE向BS反馈SI；
可选地，本实施例的反馈方式可以是非周期的、一次性的或者可以是以该第一下行信令为触发的；第一下行信令和第二下行信令可以是用户专用的(英文：UE-specific)，也可以是小区专用的(英文：cell-specific)。
实施例四：触发模式2
图6为本发明实施例二提供的获取及反馈信道状态信息的方法，如图6所示：
本实施例和实施例二的步骤基本相同，只是BS不再指示UE周期性地反馈S或SI，从而，UE也不再周期性地反馈S或SI，而是一次性地或以下行信令为触发地反馈。
步骤601：BS向UE发送第一下行信令，其中，第一下行信令指示UE反馈S以及S下的SI；可选地，本实施例的反馈方式可以是非周期的、一次性的或者可以是以该第一下行信令为触发的；第一下行信令可以是用户专用的(英文：UE-specific)，也可以是小区专用的(英文：cell-specific)。
步骤602：UE对信道子空间进行统计测量，得到S和S下的SI；
步骤603：UE向BS反馈S以及S下的SI；
可选地，步骤604：BS向UE发送第二下行信令，其中，第二下行信令指示UE反馈SI，进一步地，第二下行信令携带BS确定的S(BS根据UE反馈的S以及SI确定出一个满足信道条件或实际需要的S，BS确定的S可以和UE确定的S相同，也可以不同)；在这种情况下，UE反馈的SI是信道子空间的预编码的维度为BS确定的S时的SI(或者称作BS确定的S下的SI)。进一步地，第二下行信令可以携带数个BS确定的S，也就相当于第二下行信令指示待调度的UE反馈数个BS确定的S下的数个SI。进一步地，可以对该数个BS确定的S进行编码或给定索引，从而只需将该编码后的码字或索引向待调度的UE发送即可。
可选地，步骤605：UE进行统计信道的信道子空间测量，得到BS确定的S下的SI；
可选地，步骤606：UE向BS反馈SI；
可选地，本实施例的反馈方式可以是非周期的、一次性的或者可以是以该第一下行信令为触发的；第一下行信令和第二下行信令可以是用户专用的(英文：UE-specific)，也可以是小区专用的(英文：cell-specific)。
在本发明实施例四中，BS可以直接将UE反馈的S和SI作为获取到的信道状态信息；可选地，BS也可以根据UE首先反馈的S和SI可以更准确的确定出与该信道子空间相匹配的S，然后可以发送第二下行信令，指示UE反馈BS确定的S下的SI，若改UE在步骤603中反馈的S和BS确定的S相同，第二下行信令也可以不指示UE周期性反馈SI，而只通知其BS所确定的S。
本发明实施例中，周期性反馈S或周期性反馈SI(例如步骤303、307)并不限定其执行要再其他步骤之前或之后，因为反馈时周期性的，其持续时间可能较长，所以可能在例如步骤304、305之后UE还会反馈S(即还在执行步骤303)。其次，指示停止反馈S或SI并不一定需要执行，所以步骤308是可选地。另外，本发明实施例中BS可以向一个或多个UE(可以是小区中的所有UE，也可以是一组UE)发送第一下行信令，而在确定待调度的UE的步骤(例如步骤304)中，BS在该一个或多个UE中确定待调度的UE，然后BS向确定出的待调度的UE发送第二下行信令，待调度的UE最多包括该一个或多个UE中的所有UE。
BS通过在发送的信令中携带BS确定的S来通知UE反馈维度为S的信道子空间预编码矩阵对应的SI，而不是随意反馈，从而降低反馈开销，同时，BS指示的是待调度的UE进行SI的反馈，而无需所有UE都进行反馈，这也降低了反馈的开销。
通过上述实施例的方法，基站获得信道子空间的有效维度S和S下的SI后，基站可以利用这些信息进行预编码、波束赋形等，还可以利用这些信息来实现降低信道信息获取量，例如，进行降维预编码，以减少下一步进行信道测量的导频开销及计算复杂度。
具体地，基站获得用户的信道子空间的有效维度S和S对应的SI，因为信道子空间的有效维度小于(或远小于)用于测量信道状态信息的参考信号端口数，这也就相当于获得了降维后的信道子空间；
基站调度用户设备，确定参与多输入多输出的用户设备集合，并针对用户设备集合中的用户设备进行下一级信道状态信息测量，获取降维后的信道子空间的实时信道状态信息；
基站将下行数据和用户专用的解调参考信号通过两级预编码进行处理后，发送给用户设备集合中的用户设备；其中，两级预编码包括信道子空间信道状态信息对应的第一级预编码和实时信道状态信息对应的第二级预编码。
本发明实施例可以应用于下行应用MU-MIM O的系统中，当待调度用户与参与MU-MIMO的用户都很多的情况下(典型的如在大规模天线阵列系统但不局限于该系统)。
通过本发明提供的方法，可以大大节省系统开销，具体地：
假设发射天线数为M，待调度UE数为T1，调度UE集合中的UE数为T2，UE的天线数为N，通过本发明实施例中的信道降维有效降低了获取CSI的开销，开销节省包括(对比现有技术中LTE的一级RS方案与本发明方案体现效果)：
a、下行的RS开销(适用FDD/TDD)：
现有技术中LTE的一级RS方案平均每个发射天线时间频率上的密度为x REs/ms/15kHz，则M个发射天线的RS的总的密度为M*x REs/ms/15kHz；
而本发明实施例中的下行RS开销由两级RS两部份组成：一级RS只需要获得时间与频率上均缓慢变化的信道子空间，则时间与频域上的密度都可以降低(如时间密度可以为LTE一级RS密度的1/4以下，频率上考虑LTE一级RS 1/2的密度)，则一般M个发射天线的密度可控制为M*x/8REs/ms/15kHz；二级RS的需要支持反馈实时信道的变化，则平均每个空间维度时间频率上的密度也为x REs/ms/15kHz，降维维度S一般＝M/4，因此S维空间天线的密度为最多为M*x/4REs/ms/15kHz；
因此，在下行RS开销上，本发明方案相比现有技术中LTE的一级RS方案节省1-(M*x/4+M*x/8)/M*x＝62.5％的RE开销。
b、上行的反馈开销(适用FDD/TDD，假设每个下行子带进行一次反馈)：
现有技术中LTE的一级RS方案需要针对所有的T1个待调度UE进行反馈，假设每个待调度UE的反馈占用RE数的时间密度为y REs/ms/下行子带， 则T1个待调度UE占用的总的RE数时间密度为T1*y REs/ms/下行子带；
而本发明实施例只需要针对T2个调度UE集合中的UE进行反馈，假设每个待调度UE反馈占用RE数维持与LTE一级RS方案一致，则T2个调度UE集合中的UE占用的总的RE数时间密度为T2*y REs/ms/下行子带。即使在保守情况下，T2/T1<＝1/4；
因此，在上行反馈开销上，本发明方案相比现有技术中LTE的一级RS方案节省1-T2*y/(T1*y)＝75％的RE开销。
c、上行的RS开销(只适用TDD)
现有技术中LTE的一级RS方案需要针对所有的T1个待调度UE进行上行RS发送，平均每个待调度UE发送RS占用的RE数时间频率上的密度为z REs/ms/15kHz，则T1个待调度UE的RS总的密度为T1*z REs/ms/15kHz；
而本发明实施例的上行RS开销由两级RS两部份组成：一级RS只需要获得时间与频率上均缓慢变化的信道子空间，则时间与频域上的密度都可以降低(如时间密度可以为LTE一级RS密度的1/4以下，频率上考虑LTE一级RS 1/2的密度)，则一般T1个待调度UE的RS密度可控制为T1*z/8REs/ms/15kHz；二级RS的需要支持获取实时信道的变化，则平均每个调度集合中UE时间频率上的密度也为z REs/ms/15kHz，因此T2个调度UE集合中的UE的二级RS密度为最多为T2*z/4REs/ms/15kHz，即使在保守情况下，T2/T1<＝1/4；
因此，在上行RS开销上，本发明方案相比现有技术中LTE的一级RS方案节省1-(T2*z+T1*z/8)/(T1*z)＝62.5％的RE开销。
还可理解的是，经过本发明实施例的信道降维后，在获取二级预编码时的计算复杂度以3次方的速度降低，如256天线降维到32维，可以降低计算复杂度8^3＝512倍，相应的处理时延也随之降低512倍，具体如下表所示：
Figure PCTCN2015082954-appb-000003
其中，一级预编码的更新速度很慢，不是解决计算复杂度的主要瓶颈，因此获取二级预编码时的SVD为主要DL CSI获取的计算复杂度，上述表中当降到32维时，计算结果是27*32^3*6*100*3*1e3/5＝320Gflops，其中27*32^3是每个子带的SVD复杂度，6为复数相乘所需要的实数乘加数，100为子带数(100MHz系统带宽)，3扇区，1e3/5为一秒内获取二级CSI的次数。
需要说明的是，从系统性能看，本发明实施例的性能与理性系统性能的差距很小，下面以MU-MIMO为例，结合图7至图11示出的本发明系统性能与理想系统性能对比的数据效果图，从误码率SER与信噪比SNR(dB)来进行说明：
如图7示出的本发明系统性能与理想系统性能对比的数据效果图，在改变一级RS的发送周期下，本发明系统性能始终与理想系统性能的差距很小；
如图8示出的本发明系统性能与理想系统性能对比的另一数据效果图，在改变降维的维度下，本发明系统性能始终与理想系统性能的差距很小；
如图9示出的本发明系统性能与理想系统性能对比的另一数据效果图，在改变UE移动性的情况下，本发明系统性能在低速下与理想系统性能的差距很小，但中高速下与理想系统性能的差距较大(即在中高速下本发明系统性能损失较大)，因此本发明主要适用于低速场景；
如图10示出的本发明系统性能与理想系统性能对比的另一数据效果图，在改变数据发送端与数据接收端的相关性的情况下，本发明系统性能始终与理想系统性能的差距很小；
如图11示出的本发明系统性能与理想系统性能对比的另一数据效果图，在改变数据发送端的发射天线数目(天线数大于等于64)下，本发明系统性能始终与理想系统性能的差距很小；
通过实施本发明实施例，通过一级信道状态信息测量，获取降维后的信道子空间信道状态信息，针对该用户设备集合中的用户设备进行二级信道状态信息测量，获取降维实时信道状态信息，将下行数据和用户专用的解调参考信号通过两级预编码进行处理后发送，解决了现有技术中当数据发射端天线数较多(待服务UE数也较多)时，上下行导频开销大，上行CSI反馈量大的技术问题，从而使系统有更多的时频资源可以进行数据的传输，有效增大了系统的吞 吐量；另外，通过信道降维可以解决现有技术中系统基带处理的高复杂度问题，降低基带处理能力的需求。
相应于上面的方法实施例，本发明实施例还提供一种获取信道状态信息的装置，参见图12所示：包括：
发送模块1201，用于基站向用户设备发送一个或多个下行信令，其中，一个或多个下行信令指示用户设备反馈信道维度信息；
其中，信道维度信息包括基站和用户设备之间的统计信道的信道子空间的有效维度，信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
接收模块1202，用于基站接收用户设备反馈的信道维度信息。
其中，信道维度信息还包括信道子空间的有效维度下的子空间索引；子空间索引与信道子空间的特征向量的量化预编码一一对应。
进一步地，子空间索引对应的信道子空间的特征向量的量化预编码包含统计信道的部分的能量。
可选地，基站向用户设备发送一个下行信令包括基站向用户设备发送第三下行信令；
其中，第三下行信令指示用户设备反馈信道子空间的有效维度，以及信道子空间的有效维度下的子空间索引；
基站接收用户设备反馈的信道维度信息包括接收设备反馈的信道子空间的有效维度，以及子空间的有效维度下的子空间索引。
进一步地，该装置还包括：
确定模块1203，用于基站根据用户设备反馈的信道子空间的有效维度和子空间索引确定信道子空间的有效维度；
发送模块1201还用于基站向用户设备发送第四下行信令，第四下行信令指示用户设备反馈基站确定的信道子空间的有效维度下的子空间索引；
接收模块1202还用于基站接收用户设备反馈的基站确定的信道子空间的有效维度下的子空间索引。
其中涉及到的一些技术特征，例如：信道子空间的有效维度、子空间索引、统计信道//周期性反馈、一次性反馈等，和本发明方法实施例涉及到的一些技 术特征类似或对应，本实施例不再进行重复说明。
本发明实施例提供的获取信道状态信息的装置可用于网元节点设备或基站上。
相应于上面的方法实施例，本发明实施例还提供一种反馈信道状态信息的装置，参见图13所示：包括：
接收模块1301，用于用户设备从基站接收一个或多个下行信令，一个或多个下行信令指示用户设备反馈信道维度信息；
其中，信道维度信息包括基站和用户设备之间的统计信道的信道子空间的有效维度，信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
反馈模块1302，用于用户设备向基站反馈信道维度信息。
其中，信道维度信息还包括信道子空间的有效维度下的子空间索引；子空间索引与信道子空间的特征向量的量化预编码一一对应。
进一步地，子空间索引对应的信道子空间的特征向量的量化预编码包含统计信道的部分的能量。
可选地，该装置还包括：测量模块1303，用于用户设备对信道子空间进行统计测量，得到信道子空间的有效维度。
其中涉及到的一些技术特征，例如：信道子空间的有效维度、子空间索引、统计信道//周期性反馈、一次性反馈等，和本发明方法实施例涉及到的一些技术特征类似或对应，本实施例不再进行重复说明。
本发明实施例提供的反馈信道状态信息的装置可用于网元节点设备或用户设备上。
本发明实施例还提供一种处理设备，参照图14所示，包括：处理器1401、存储器1402、发射机1403及总线1404，其中处理器1401、存储器1402、发射机1403通过总线1404连接进行数据传输，存储器1402用于存储处理器1401处理的数据；
该总线1404可以是工业标准体系结构(Industry Standard Architecture，简称为ISA)总线、外部设备互连(Peripheral Component，简称为PCI)总线或扩展工业标准体系结构(Extended Industry Standard Architecture，简称为EISA)总线等，此处并不限定。该总线1404可以分为地址总线、数据总线、控制总线 等。为便于表示，图14中仅用一条粗线表示，但并不表示仅有一根总线或一种类型的总线。其中：
存储器1402用于存储数据或可执行程序代码，其中程序代码包括计算机操作指令，具体可以为：操作系统、应用程序等。存储器1402可能包含高速RAM存储器，也可能还包括非易失性存储器(non-volatile memory)，例如至少一个磁盘存储器。
处理器1401可能是一个中央处理器(Central Processing Unit，简称为CPU)，或者是特定集成电路(Application Specific Integrated Circuit，简称为ASIC)，或者是被配置成实施本发明实施例的一个或多个集成电路。
处理器1401用于通过执行存储器1402中的程序代码实现上述实施例中的获取信道状态信息的方法，处理器1401也可以用于通过执行存储器1402中的程序代码实现上述实施例中的反馈信道状态信息的方法，其中涉及到的一些技术特征，例如：信道子空间的有效维度、子空间索引、统计信道//周期性反馈、一次性反馈等，和本发明方法实施例涉及到的一些技术特征类似或对应，本实施例不再进行重复说明。具体过程也不再赘述。
应理解地，在本发明的各种实施例中，上述各过程的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本发明实施例的实施过程构成任何限定。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、计算机软件或者二者的结合来实现，为了清楚地说明硬件和软件的可互换性，在上述说明中已经按照功能一般性地描述了各示例的组成及步骤。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本发明的范围。
所属领域的技术人员可以清楚地了解到，为了描述的方便和简洁，上述描述的系统、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的装置和方法，可 以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个系统，或一些特征可以忽略，或不执行。另外，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口、装置或单元的间接耦合或通信连接，也可以是电的，机械的或其它的形式连接。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本发明实施例方案的目的。
另外，在本发明各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以是两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件功能单元的形式实现。具体的，可以借助软件加必需的通用硬件的方式来实现，通用硬件包括通用集成电路、通用CPU(英文：Central Processing Unit，中文：中央处理器)、通用数字信号处理器(英文：Digital Signal Processor，简称：DSP)、现场可编程门阵列(英文：Field Programming Gate Array，简称：FPGA)、可编程逻辑器件(英文：Programmable Logical Device，简称：PLD)、通用存储器、通用元器件等，当然也可以通过专用硬件包括专用集成电路(英文：Application Specific Integrated Circuit，简称ASIC)、专用CPU、专用存储器、专用元器件等来实现。
所述集成的单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本发明的技术方案本质上或者说对现有技术做出贡献的部分，或者该技术方案的全部或部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本发明各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(英文：Read Only Memory，简称为ROM)、随机存取存储器(英文：Random Access Memory，简称为RAM)、 磁碟或者光盘等各种可以存储程序代码的介质。
软件或指令还可以通过传输介质来传输。例如，如果使用同轴电缆、光纤光缆、双绞线、数字用户线(英文：Digital Subscriber Line,简称：DSL)或者无线技术(如红外线、无线电和微波)从网站、服务器或其它远程源传输软件，那么同轴电缆、光纤光缆、双绞线、DSL或者无线技术(如红外线、无线电和微波))包括在传输介质的定义中。
以上所述，仅为本发明的具体实施方式，但本发明的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本发明揭露的技术范围内，可轻易想到各种等效的修改或替换，这些修改或替换都应涵盖在本发明的保护范围之内。因此，本发明的保护范围应以权利要求的保护范围为准。

Claims (26)

  1. 一种获取信道状态信息的方法，其特征在于，包括：
    基站向用户设备发送一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；
    其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
    所述基站接收所述用户设备反馈的所述信道维度信息。
  2. 根据权利要求1所述的方法，其特征在于，
    所述信道维度信息还包括所述信道子空间的有效维度下的子空间索引；
    所述子空间索引与信道子空间的特征向量的量化预编码一一对应。
  3. 根据权利要求2所述的方法，其特征在于，
    所述子空间索引对应的信道子空间的特征向量的量化预编码包含所述统计信道的部分的能量。
  4. 根据权利要求1-3任一项所述的方法，其特征在于，
    基站向用户设备发送多个下行信令包括所述基站向所述用户设备发送第一下行信令；
    其中，所述第一下行信令指示所述用户设备反馈所述信道子空间的有效维度；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的所述信道子空间的有效维度；
    所述基站向用户设备发送多个下行信令还包括所述基站向所述用户设备发送第二下行信令；
    其中，所述第二下行信令指示所述用户设备反馈子空间索引，其中，所述第二下行信令携带所述基站根据所述用户设备反馈的所述信道子空间的有效维度确定的信道子空间的有效维度；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的所述基站确定的信道子空间的有效维度下的子空间索引。
  5. 根据权利要求4所述的方法，其特征在于，
    所述用户设备为待调度的用户设备。
  6. 根据权利要求1-3任一项所述的方法，其特征在于，
    基站向用户设备发送一个下行信令包括所述基站向所述用户设备发送第三下行信令；
    其中，所述第三下行信令指示所述用户设备反馈所述信道子空间的有效维度，以及所述信道子空间的有效维度下的子空间索引；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的信道子空间的有效维度，以及所述信道子空间的有效维度下的子空间索引。
  7. 根据权利要求6所述的方法，其特征在于，所述方法还包括：
    所述基站根据所述用户设备反馈的所述信道子空间的有效维度和子空间索引确定信道子空间的有效维度；
    所述基站向所述用户设备发送第四下行信令，所述第四下行信令指示所述用户设备反馈所述基站确定的信道子空间的有效维度下的子空间索引；
    所述基站接收所述用户设备反馈的所述基站确定的信道子空间的有效维度下的子空间索引。
  8. 根据权利要求1-7任一项所述的方法，其特征在于，
    所述一个或多个下行信令指示所述用户设备反馈信道维度信息包括所述一个或多个下行信令指示所述用户设备周期性地反馈信道维度信息；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备周期性地反馈的所述信道维度信息；
    其中，反馈的周期是通过所述一个或多个下行信令指示的或预先约定的。
  9. 根据权利要求1-7任一项所述的方法，其特征在于，
    所述一个或多个下行信令指示所述用户设备反馈信道维度信息包括所述一个或多个下行信令指示所述用户设备一次性地反馈信道维度信息；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备一次性地反馈的所述信道维度信息。
  10. 一种反馈信道状态信息的方法，其特征在于，包括：
    用户设备从基站接收一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；
    其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的 信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
    所述用户设备向所述基站反馈所述信道维度信息。
  11. 根据权利要求10所述的方法，其特征在于，
    所述信道维度信息还包括所述信道子空间的有效维度下的子空间索引；
    所述子空间索引与信道子空间的特征向量的量化预编码一一对应。
  12. 根据权利要求11所述的方法，其特征在于，
    所述子空间索引对应的信道子空间的特征向量的量化预编码包含所述统计信道的部分的能量。
  13. 根据权利要求10-12任一项所述的方法，其特征在于，所述方法还包括：
    所述用户设备对所述信道子空间进行统计测量，得到所述信道子空间的有效维度。
  14. 一种获取信道状态信息的装置，其特征在于，包括：
    发送模块，用于基站向用户设备发送一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；
    其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
    接收模块，用于所述基站接收所述用户设备反馈的所述信道维度信息。
  15. 根据权利要求14所述的装置，其特征在于，
    所述信道维度信息还包括所述信道子空间的有效维度下的子空间索引；
    所述子空间索引与信道子空间的特征向量的量化预编码一一对应。
  16. 根据权利要求15所述的装置，其特征在于，
    所述子空间索引对应的信道子空间的特征向量的量化预编码包含所述统计信道的部分的能量。
  17. 根据权利要求14-16任一项所述的装置，其特征在于，
    基站向用户设备发送多个下行信令包括所述基站向所述用户设备发送第一下行信令；
    其中，所述第一下行信令指示所述用户设备反馈所述信道子空间的有效维 度；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的所述信道子空间的有效维度；
    所述基站向用户设备发送多个下行信令还包括所述基站向所述用户设备发送第二下行信令；
    其中，所述第二下行信令指示所述用户设备反馈子空间索引，其中，所述第二下行信令携带所述基站根据所述用户设备反馈的所述信道子空间的有效维度确定的信道子空间的有效维度；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的所述基站确定的信道子空间的有效维度下的子空间索引。
  18. 根据权利要求17所述的装置，其特征在于，
    所述用户设备为待调度的用户设备。
  19. 根据权利要求14-16任一项所述的装置，其特征在于，
    基站向用户设备发送一个下行信令包括所述基站向所述用户设备发送第三下行信令；
    其中，所述第三下行信令指示所述用户设备反馈所述信道子空间的有效维度，以及所述信道子空间的有效维度下的子空间索引；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备反馈的信道子空间的有效维度，以及所述信道子空间的有效维度下的子空间索引。
  20. 根据权利要求19所述的装置，其特征在于，所述装置还包括：
    确定模块，用于所述基站根据所述用户设备反馈的所述信道子空间的有效维度和子空间索引确定信道子空间的有效维度；
    所述发送模块还用于所述基站向所述用户设备发送第四下行信令，所述第四下行信令指示所述用户设备反馈所述基站确定的信道子空间的有效维度下的子空间索引；
    所述接收模块还用于所述基站接收所述用户设备反馈的所述基站确定的信道子空间的有效维度下的子空间索引。
  21. 根据权利要求14-20任一项所述的装置，其特征在于，
    所述一个或多个下行信令指示所述用户设备反馈信道维度信息包括所述 一个或多个下行信令指示所述用户设备周期性地反馈信道维度信息；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备周期性地反馈的所述信道维度信息；
    其中，反馈的周期是通过所述一个或多个下行信令指示的或预先约定的。
  22. 根据权利要求14-20任一项所述的装置，其特征在于，
    所述一个或多个下行信令指示所述用户设备反馈信道维度信息包括所述一个或多个下行信令指示所述用户设备一次性地反馈信道维度信息；
    所述基站接收所述用户设备反馈的所述信道维度信息包括所述基站接收所述用户设备一次性地反馈的所述信道维度信息。
  23. 一种反馈信道状态信息的装置，其特征在于，包括：
    接收模块，用于用户设备从基站接收一个或多个下行信令，所述一个或多个下行信令指示所述用户设备反馈信道维度信息；
    其中，所述信道维度信息包括所述基站和所述用户设备之间的统计信道的信道子空间的有效维度，所述信道子空间的有效维度小于用于测量信道状态信息的参考信号端口数；
    反馈模块，用于所述用户设备向所述基站反馈所述信道维度信息。
  24. 根据权利要求23所述的装置，其特征在于，
    所述信道维度信息还包括所述信道子空间的有效维度下的子空间索引；
    所述子空间索引与信道子空间的特征向量的量化预编码一一对应。
  25. 根据权利要求24所述的装置，其特征在于，
    所述子空间索引对应的信道子空间的特征向量的量化预编码包含所述统计信道的部分的能量。
  26. 根据权利要求23-25任一项所述的装置，其特征在于，所述装置还包括：
    测量模块，用于所述用户设备对所述信道子空间进行统计测量，得到所述信道子空间的有效维度。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110168949A (zh) * 2017-01-26 2019-08-23 华为技术有限公司 用于反馈信道状态信息的方法、终端设备和网络设备

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018204273A1 (en) 2017-05-05 2018-11-08 Intel Corporation Management of mimo communication systems
EP4075682A4 (en) * 2020-01-14 2022-12-07 Huawei Technologies Co., Ltd. CHANNEL MEASUREMENT METHOD AND APPARATUS

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102468916A (zh) * 2010-11-16 2012-05-23 华为技术有限公司 信号处理方法、设备及系统
CN102938688A (zh) * 2011-08-15 2013-02-20 上海贝尔股份有限公司 用于多维天线阵列的信道测量和反馈的方法和设备
WO2013191503A1 (en) * 2012-06-21 2013-12-27 Samsung Electronics Co., Ltd. Method for cqi feedback without spatial feedback (pmi/ri) for tdd coordinated multi-point and carrier aggregation scenarios
CN104580033A (zh) * 2013-10-22 2015-04-29 电信科学技术研究院 信道状态信息的反馈方法和装置、及信息传输方法和装置

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7426198B2 (en) * 2006-02-06 2008-09-16 Motorola, Inc. Method and apparatus for performing spatial-division multiple access
US8649456B2 (en) * 2009-03-12 2014-02-11 Futurewei Technologies, Inc. System and method for channel information feedback in a wireless communications system
JP5357126B2 (ja) 2010-10-04 2013-12-04 株式会社エヌ・ティ・ティ・ドコモ フィードバック方法、移動端末装置及び無線基地局装置
WO2012081843A1 (ko) * 2010-12-16 2012-06-21 엘지전자 주식회사 다중 안테나 무선 통신 시스템에서 채널 상태 정보를 보고하는 방법 및 이를 위한 장치
CN103001678B (zh) 2011-09-10 2016-05-25 华为技术有限公司 多节点协作传输的方法和装置
WO2013055093A1 (ko) * 2011-10-10 2013-04-18 엘지전자 주식회사 무선 통신 시스템에서 채널상태정보 보고 방법 및 장치
US9407343B2 (en) * 2012-08-31 2016-08-02 Google Technology Holdings LLC Method and apparatus for mitigating downlink interference
CN104202073A (zh) * 2014-03-04 2014-12-10 中兴通讯股份有限公司 信道信息的反馈方法、导频及波束发送方法、系统及装置
US10020860B2 (en) * 2014-12-02 2018-07-10 Samsung Electronics Co., Ltd. Downlink signaling for partially precoded CSI-RS and CSI feedback
CN104539335B (zh) * 2014-12-24 2017-11-03 无锡北邮感知技术产业研究院有限公司 一种大规模天线系统的有限反馈方法及装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102468916A (zh) * 2010-11-16 2012-05-23 华为技术有限公司 信号处理方法、设备及系统
CN102938688A (zh) * 2011-08-15 2013-02-20 上海贝尔股份有限公司 用于多维天线阵列的信道测量和反馈的方法和设备
WO2013191503A1 (en) * 2012-06-21 2013-12-27 Samsung Electronics Co., Ltd. Method for cqi feedback without spatial feedback (pmi/ri) for tdd coordinated multi-point and carrier aggregation scenarios
CN104580033A (zh) * 2013-10-22 2015-04-29 电信科学技术研究院 信道状态信息的反馈方法和装置、及信息传输方法和装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3301841A4 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110168949A (zh) * 2017-01-26 2019-08-23 华为技术有限公司 用于反馈信道状态信息的方法、终端设备和网络设备
KR20190104597A (ko) * 2017-01-26 2019-09-10 후아웨이 테크놀러지 컴퍼니 리미티드 채널 상태 정보 피드백 방법, 단말 디바이스, 및 네트워크 디바이스
EP3565133A4 (en) * 2017-01-26 2019-11-13 Huawei Technologies Co., Ltd. METHOD FOR RESENDING CHANNEL STATE INFORMATION, TERMINAL DEVICE, AND NETWORK DEVICE
US10778294B2 (en) 2017-01-26 2020-09-15 Huawei Technologies Co., Ltd. Channel state information feedback method, terminal device, and network device
KR102202364B1 (ko) 2017-01-26 2021-01-13 후아웨이 테크놀러지 컴퍼니 리미티드 채널 상태 정보 피드백 방법, 단말 디바이스, 및 네트워크 디바이스
CN110168949B (zh) * 2017-01-26 2021-06-01 华为技术有限公司 用于反馈信道状态信息的方法、终端设备和网络设备

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