CN115021782A - Method and device for selecting NR system codebook - Google Patents
Method and device for selecting NR system codebook Download PDFInfo
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- CN115021782A CN115021782A CN202210402096.9A CN202210402096A CN115021782A CN 115021782 A CN115021782 A CN 115021782A CN 202210402096 A CN202210402096 A CN 202210402096A CN 115021782 A CN115021782 A CN 115021782A
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- 238000000034 method Methods 0.000 title claims abstract description 31
- 239000011159 matrix material Substances 0.000 claims abstract description 33
- 238000005070 sampling Methods 0.000 claims abstract description 22
- 238000013507 mapping Methods 0.000 claims abstract description 10
- 230000008569 process Effects 0.000 claims description 9
- 238000004590 computer program Methods 0.000 claims description 7
- 238000012216 screening Methods 0.000 claims description 6
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- 238000010187 selection method Methods 0.000 claims description 3
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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
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/309—Measuring or estimating channel quality parameters
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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
- H04B7/0636—Feedback format
- H04B7/0639—Using selective indices, e.g. of a codebook, e.g. pre-distortion matrix index [PMI] or for beam selection
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Abstract
The invention relates to the field of computer communication, in particular to a method and a device for selecting an NR system codebook, which comprises the steps of sending a channel sounding reference signal SRS, carrying out channel estimation on the SRS, carrying out N-time sampling on a channel estimation result according to channel conditions, setting a pmi traversal range as pmi of all layers in a port for the channel estimation value after the down-sampling, respectively multiplying a precoding matrix by a precoding matrix, calculating an equivalent MI value, mapping the MI value to obtain equivalent CQI and mcs, obtaining tbsize from the corresponding layer, taking the layer, mcs and pmi corresponding to the maximum tbsize as a result of the current codebook selection, and recording corresponding information of CQI1, layer1 and pmi1 until the next codebook selection period M. The invention avoids a large amount of calculation and improves pmi searching efficiency. For the 4-port 4-layer case, the complexity can be reduced to 5/62N times at maximum.
Description
Technical Field
The invention relates to the technical field of computer communication, in particular to a method and a device for selecting an NR system codebook.
Background
In the NR system, an uplink shared channel PUSCH supports multi-codeword multi-layer transmission, and a corresponding protocol defines multiple ports and precoding codebooks (pmi) of multiple layers, where a 2 antipna port includes 9 codebooks (including coherent/partially coherent/incoherent codebooks) for 1layer/2layer, and a 4 antipna port includes 62 codebooks for 1layer/2layer/3layer/4 layer. Proper codebook selection has a significant impact on the performance of the PUSCH.
In the prior art, codebook transmission firstly sends a channel sounding reference signal SRS for channel estimation, multiplies a channel estimation result by a precoding matrix, calculates an equivalent signal-to-noise ratio (SNR) after equalization, traverses all codebooks, and selects a codebook corresponding to the maximum value of the equivalent signal-to-noise ratio as an optimal codebook. When the number of codebooks is large, this method will increase the computation amount greatly. Therefore, on the premise of ensuring better reception performance of the PUSCH, how to select the codebook becomes very important.
Disclosure of Invention
The present invention is directed to a method and an apparatus for selecting a codebook of an NR system to solve the above problems in the prior art.
In order to achieve the purpose, the invention provides the following technical scheme:
a method of NR system codebook selection, comprising the steps of:
s101, setting an SRS codebook selection period as M;
s102, sending a channel Sounding Reference Signal (SRS) and carrying out channel estimation;
s103, according to the channel condition, carrying out N-time reduction sampling on the channel estimation result;
s104, channel estimation values after down-sampling are carried out;
s105, setting pmi, multiplying the pmi by a precoding matrix respectively, calculating an equivalent CQI, and obtaining tbsize;
s106, taking pmi corresponding to the maximum tbsize as a result of the current codebook selection, and recording corresponding pmi1 information;
s107,: repeating the step S101 to the step S104, multiplying the result by a pmi1 matrix, calculating an equivalent CQI2, selecting and setting a pmi traversal range according to the difference value of the CQI2 and the CQI1 and the size of a threshold K, and screening out the pmi matrix;
s108, calculating equivalent CQI according to the screened pmi matrix, and obtaining tbsize through a corresponding layer;
s109, taking pmi corresponding to the maximum tbsize as a result of codebook selection at this time, and recording and updating information of the corresponding pmi 1;
and S110, repeating the processes from the step S107 to the step S109 until the next codebook selection period M.
Further, the step S105: setting the pmi traversal range as pmi of all the layers in the port, multiplying the pmi by a precoding matrix respectively, calculating an equivalent MI value, mapping the MI value to obtain equivalent CQI and mcs, and obtaining tbsize through the corresponding layer.
Further, the step S106: layer, mcs and pmi corresponding to the maximum tbsize are taken as the result of the current codebook selection, and corresponding CQI1, layer1 and pmi1 information are recorded.
Further, the step S107: and multiplying the channel estimation value after the down sampling by the pmi1 matrix of the previous time, calculating an equivalent MI value, mapping the MI value to obtain an equivalent CQI2, and calculating a difference value of the CQI2 and the CQI 1.
Further, the step S107: if the CQI difference is smaller than K, setting the pmi traversal range as all pmi matrixes in the current layer, and if the CQI difference is larger than K, setting the pmi traversal range as all pmi matrixes in the current layer and the adjacent layer, wherein the layer is layer2 ═ layer1+ sign (CQI2-CQI 1).
Further, the step S108: and multiplying the SRS channel estimation values after the down sampling respectively according to the screened pmi matrix, calculating an equivalent MI value, mapping the MI value to obtain equivalent CQI and mcs, and obtaining tbsize by a corresponding layer.
Further, the step S109: taking layer, mcs and pmi corresponding to the maximum tbsize as the result of the current codebook selection, and recording and updating information of CQI1, layer1 and pmi1 corresponding to the maximum tbsize.
In order to achieve the above purpose, the invention also provides the following technical scheme:
an apparatus 110 for NR system codebook selection, comprising:
a setting unit 111, configured to set an SRS codebook selection period to M;
a channel estimation unit 112, configured to transmit a channel sounding reference signal SRS and perform channel estimation;
a sampling unit 113, configured to perform N-fold-reduction sampling on a channel estimation result according to a channel condition;
an estimating unit 114, configured to estimate a down-sampled channel estimation value;
a pmi setting unit 115, configured to set pmi, multiply the precoding matrices respectively, calculate an equivalent CQI, obtain tbsize, calculate an equivalent CQI2, select a pmi traversal range according to a difference between CQI2 and CQI1 and a threshold K, and screen out a pmi matrix;
a calculating unit 116, configured to calculate an equivalent CQI according to the screened pmi matrix, and obtain tbsize from a corresponding layer;
a screening codebook unit 117, configured to take pmi corresponding to the largest tbsize as a result of this codebook selection and record corresponding pmi1 information, and take pmi corresponding to the largest tbsize as a result of this codebook selection and record corresponding pmi1 information;
a codebook determining unit 118 for determining a codebook.
In order to achieve the above purpose, the invention also provides the following technical scheme:
a computer device comprising a memory storing a computer program and a processor implementing the steps of the method as claimed in any one of the above when the computer program is executed.
In order to achieve the above purpose, the invention also provides the following technical scheme:
a computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of the preceding claims.
Compared with the prior art, the invention has the beneficial effects that:
1. and according to the channel condition, carrying out N-time reduction sampling on the SRS channel estimation result, and reducing the calculation complexity.
2. In the pmi searching process, channel quality CQI and the like are taken into consideration, when the channel quality changes slowly (the CQI difference value is smaller than a threshold value K), a pmi matrix is searched in the current layer range, otherwise, the pmi matrix is searched in the current layer range and the adjacent layer range, a large amount of calculation is avoided, and the pmi searching efficiency is improved. For the 4-port 4-layer case, the complexity can be reduced to 5/62N times at maximum.
Drawings
Fig. 1 is a schematic diagram illustrating steps of a method for selecting a codebook of an NR system according to the present invention.
Fig. 2 is a flowchart illustrating a method for selecting a codebook of an NR system according to the present invention.
Fig. 3 is a block diagram of an NR system codebook selecting apparatus according to the present invention.
Fig. 4 is an internal structural diagram of a computer device provided by the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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 invention.
Referring to fig. 1-4, the present invention provides a technical solution:
a method and a device for selecting a codebook of an NR system can reduce the complexity of codebook selection on the premise of ensuring the PUSCH receiving performance.
When the codebook transmission is scheduled, the specific implementation process and method are as follows:
setting the SRS codebook selection period as M, wherein the initial codebook selection process comprises the following steps:
1. transmitting a channel Sounding Reference Signal (SRS) for channel estimation
2. According to the channel condition, N times of sampling is carried out on the channel estimation result
3. Setting pmi traversal range as pmi of all layer numbers (layers) in a port (port) for the channel estimation value after down sampling, multiplying a precoding matrix respectively, calculating an equivalent MI value, mapping the MI value to obtain an equivalent Channel Quality Indication (CQI) and a Modulation and Coding Scheme (MCS), and obtaining a code block size (tbsize) by the corresponding layer, wherein in a codebook selection period, the range is as follows: the first time is the pmi of all the layers in the port, and then the pmi of all the layers or adjacent layers of the current port is selected according to the comparison of the CQI calculation difference;
4. taking layer, MCS and pmi corresponding to the maximum tbsize as the result of the current codebook selection, and recording the corresponding CQI1, layer1 and pmi1 information
The next codebook selection process is as follows:
5. transmitting a channel Sounding Reference Signal (SRS) for channel estimation
6. According to the channel condition, N times of sampling is carried out on the channel estimation result
7. Multiplying the channel estimation value after the down sampling by the pmi1 matrix of the previous time, calculating an equivalent MI value, mapping the MI value to obtain an equivalent CQI2, and calculating a difference value of the CQI2 and the CQI1
8. If the CQI difference value is smaller than K, and K refers to the range of the CQI index difference value, setting the pmi traversal range as all pmi matrixes in the current layer
9. If the CQI difference is greater than K, setting pmi traversal range as all pmi matrices in the current layer and the adjacent layer (layer2 ═ layer1+ sign (CQI2-CQI1))
10. Multiplying the pmi matrix selected in the last step by the SRS channel estimation value after the down sampling respectively, calculating an equivalent MI value, mapping the MI value to obtain an equivalent CQI and an MCS, obtaining tbsize by a corresponding layer, taking the layer corresponding to the maximum tbsize, the MCS and the pmi as the result of the codebook selection, and recording and updating information such as the corresponding CQI1, the layer1 and the pmi1
The above 5-10 processes are repeated until the next codebook selection period M, and the 1-10 processes are repeated.
The scheme flow chart is shown in figure 3.
The device mainly comprises the following units: channel estimation unit, screening codebook unit, calculation unit and determining codebook unit
Channel estimation unit
Channel estimation for received Sounding Reference Signal (SRS)
Screening codebook unit
Judging which codebooks can enter the next calculation unit according to conditions
Computing unit
1. Calculating SNR through MMSE equalization;
setting a precoding matrix as P, and obtaining a channel matrix as H and noise power sigma by channel estimation 2 ，() -1 Is matrix inversion () H Transpose matrix for complex conjugate
Calculating an MMSE matrix W:
calculating equivalent noise power
Calculating the signal power S, diag as the diagonal elements:
S＝diag(WH)
calculating the equivalent SNR:
2. calculating MI from SNR
For different modulation modes, Probability Density Functions (PDFs) under log-likelihood ratios (LLRs) follow mixed Gaussian distribution, wherein mutual information quantity is represented as J (-) function, x is SNR, a i Is the coefficient of the J (-) function, satisfies
For different modulation modes, m is an order, SNR is expressed as gamma, and MI calculation function is expressed as I m (γ)
The PDF of LLR in QPSK modulation is represented as I 2 (γ)
The PDF of LLR is represented as I when 16QAM is modulated 4 (γ)
The PDF of LLR is represented as I when 64QAM is modulated 6 (γ)
The PDF of LLR is represented as I when 256QAM is modulated 8 (γ)
MI fit was calculated as in table 1 below:
TABLE 1
When there are n subcarriers, the MI is averaged over each subcarrier.
For MIMO channels, N t A transmitting antenna, N r And (4) calculating an average value M of Mi:
respectively calculating MI values corresponding to the four modulation orders each time;
determining codebook unit
Obtaining a CQI-MI table MITh (as shown in the following table 2) through simulation, namely an MI threshold, preferentially selecting CQI with high modulation order according to the calculated MI, and sequentially selecting the CQI from high to low
Namely:
wherein Len is the length of the CQI table;
start _ idx is the corresponding Start index under different modulation modes
TABLE 2
Advantages of the invention
1. According to the channel condition, the srs channel estimation result is subjected to N-time reduction sampling, and the calculation complexity is reduced.
2. In the pmi searching process, channel quality CQI and the like are taken into consideration, when the channel quality changes slowly (the CQI difference value is smaller than a threshold value K), a pmi matrix is searched in the current layer range, otherwise, the pmi matrix is searched in the current layer range and the adjacent layer range, a large amount of calculation is avoided, and the pmi searching efficiency is improved. For the 4-port 4-layer case, the complexity can be reduced to 5/62N times at maximum.
In the present invention, a computer device may include a memory, a storage controller, one or more processors (only one shown in the figure), and the like, and the elements are electrically connected directly or indirectly to realize the transmission or interaction of data. For example, electrical connections between these components may be made through one or more communication or signal buses. The method of NR system codebook selection comprises at least one software functional module that can be stored in a memory in the form of software or firmware (firmware), respectively, for example a software functional module or a computer program comprised by the apparatus of NR system codebook selection. The memory may store various software programs and modules, such as program instructions/modules corresponding to the NR system codebook selection method and apparatus provided in the embodiments of the present application. The processor executes various functional applications and data processing by running software programs and modules stored in the memory, that is, implements the parsing method in the embodiments of the present application.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (10)
1. A method for NR system codebook selection, comprising:
step 1: setting the SRS codebook selection period as M;
step 2: sending a channel Sounding Reference Signal (SRS) and carrying out channel estimation;
and step 3: according to the channel condition, carrying out N-time reduction sampling on the channel estimation result;
and 4, step 4: estimating the channel after down-sampling;
and 5: setting pmi, multiplying the pmi by a precoding matrix respectively, calculating equivalent CQI, and obtaining tbsize;
step 6: taking pmi corresponding to the maximum tbsize as a result of the current codebook selection, and recording corresponding pmi1 information;
and 7: repeating the steps 1 to 4, multiplying the matrix by a pmi1, calculating an equivalent CQI2, selecting and setting a pmi traversal range according to the difference value of the CQI2 and the CQI1 and the size of a threshold K, and screening out the pmi matrix;
and 8: calculating equivalent CQI according to the screened pmi matrix, and obtaining tbsize through a corresponding layer;
and step 9: taking pmi corresponding to the maximum tbsize as a result of the current codebook selection, and recording and updating information of the corresponding pmi 1;
step 10: and repeating the processes from the step 7 to the step 9 until the next codebook selection period M.
2. The NR system codebook selection method of claim 1, wherein said step 5: setting the pmi traversal range as pmi of all the layers in the port, multiplying the pmi by a precoding matrix respectively, calculating an equivalent MI value, mapping the MI value to obtain equivalent CQI and mcs, and obtaining tbsize through the corresponding layer.
3. The method of NR system codebook selection as claimed in claim 1, wherein said step 6: layer, mcs and pmi corresponding to the maximum tbsize are taken as the result of the codebook selection at this time, and information of corresponding CQI1, layer1 and pmi1 is recorded.
4. The method of NR system codebook selection as claimed in claim 1, wherein said step 7: and multiplying the channel estimation value after the down sampling by the pmi1 matrix of the previous time, calculating an equivalent MI value, mapping the MI value to obtain an equivalent CQI2, and calculating a difference value of the CQI2 and the CQI 1.
5. The method of NR system codebook selection as claimed in claim 1, wherein said step 7: if the CQI difference is smaller than K, setting the pmi traversal range to be all pmi matrixes in the current layer, and if the CQI difference is larger than K, setting the pmi traversal range to be all pmi matrixes in the current layer and an adjacent layer, wherein the layer is layer2 ═ layer1+ sign (CQI2-CQI 1).
6. The method of NR system codebook selection as claimed in claim 1, wherein said step 8: and multiplying the SRS channel estimation values after the down sampling respectively according to the screened pmi matrix, calculating an equivalent MI value, mapping the MI value to obtain equivalent CQI and mcs, and obtaining tbsize by a corresponding layer.
7. The NR system codebook selection method of claim 1, wherein said step 9: taking layer, mcs and pmi corresponding to the maximum tbsize as the result of the current codebook selection, and recording and updating information of CQI1, layer1 and pmi1 corresponding to the maximum tbsize.
8. An apparatus for NR system codebook selection, comprising:
a setting unit, configured to set an SRS codebook selection period to M;
a channel estimation unit, configured to send a channel sounding reference signal SRS and perform channel estimation;
the sampling unit is used for carrying out N-time reduction sampling on the channel estimation result according to the channel condition;
an estimating unit, configured to estimate a channel estimation value after the down-sampling;
a pmi setting unit, configured to set pmi, multiply the precoding matrices respectively, calculate an equivalent CQI, obtain tbsize, calculate an equivalent CQI2, select a pmi traversal range according to a difference between CQI2 and CQI1 and a threshold K, and screen out a pmi matrix;
a calculating unit, configured to calculate an equivalent CQI according to the screened pmi matrix, and obtain tbsize from a corresponding layer;
the screening codebook unit is used for taking pmi corresponding to the maximum tbsize as a result of current codebook selection and recording corresponding pmi1 information, and taking pmi corresponding to the maximum tbsize as a result of current codebook selection and recording and updating corresponding pmi1 information;
and a codebook determining unit for determining a codebook.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method according to any of claims 1 to 7.
10. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 7.
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| US20170279505A1 (en) * | 2014-12-16 | 2017-09-28 | Fujitsu Limited | Downlink Channel Estimation Method and Apparatus Based on Sounding Reference Signal and Communications System |
| CN111801981A (en) * | 2018-02-26 | 2020-10-20 | 瑞典爱立信有限公司 | Sensor data batch processing for efficient early data |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US20170279505A1 (en) * | 2014-12-16 | 2017-09-28 | Fujitsu Limited | Downlink Channel Estimation Method and Apparatus Based on Sounding Reference Signal and Communications System |
| CN111801981A (en) * | 2018-02-26 | 2020-10-20 | 瑞典爱立信有限公司 | Sensor data batch processing for efficient early data |
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