Channel state information measurement method and related equipment

Abstract

Disclosed are a channel state information measurement method and related equipment, the method comprising: receiving reference signal resource configuration information sent by a base station, the reference signal resource configuration information comprising channel measurement configuration information and N-1 pieces of interference measurement configuration information; the channel measurement configuration information is configuration information of resources used for measuring the channel state of the first user terminal, the interference measurement configuration information is configuration information of resources used for measuring interference brought by the second user terminal, and the first user terminal and the second user terminal are paired terminals; and performing measurement according to the reference signal resource configuration information and reporting channel state information to the base station based on measurement information, so that the base station performs precoding based on the reported channel state information. According to the method provided by the invention, enough user terminal channel state information can be provided for the base station, so that the base station can better realize interference suppression or elimination, and the overall performance of the MU-MIMO system is improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a channel state information measurement method and related equipment. Background Art

[0002] As one of the core technologies of 5G communication systems, Multiple Input Multiple Output (MIMO) technology uses the diversity gain brought by multiple antennas at the transmitter and receiver to improve transmission performance, increase spectrum utilization, and expand system throughput. Normally, a base station is required to communicate with multiple user terminals at the same time, and MIMO technology has been extended to multi-user MIMO (MU-MIMO) scenarios. In a MU-MIMO system, all UEs in the same user group use the same time-frequency resources for data transmission, which can make full use of the resources in the spatial dimension, thereby more effectively improving system throughput. However, due to the simultaneous and co-frequency communication of multiple user terminals, certain interference between users will be caused.

[0003] In order to suppress or eliminate these inter-user interferences, both the base station and the terminal often need to take certain interference suppression measures. Since the computing power of the base station is much stronger than that of the terminal, the base station plays a greater role in the interference elimination or suppression process. If the base station does not eliminate the interference well, the throughput of the user terminal will be affected, thereby affecting the performance of the MU-MIMO system. Therefore, a channel state information measurement method that does not affect the performance of the MU-MIMO system is needed. Summary of the invention

[0004] The present application provides a channel state information measurement method, aiming to effectively solve the above technical problems.

[0005] According to a first aspect of the present application, the present application provides a channel state information measurement method, which is applied to a first user terminal, and the method includes:

[0006] receiving reference signal resource configuration information sent by a base station, the reference signal resource configuration information including channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure a channel state of the first user terminal, the interference measurement configuration information is configuration information of resources used to measure interference caused by a second user terminal, the first user terminal and the second user terminal are paired terminals;

[0007] Measurement is performed according to the reference signal resource configuration information and channel state information is reported to the base station based on the measurement information, so that the base station performs precoding based on the reported channel state information.

[0008] According to a second aspect of the present application, the present application also provides a channel state information measurement method, which is applied to a base station, and the method includes:

[0009] Receiving channel state information reported by N user terminals, determining a precoding matrix based on the N reported channel state information, and using the precoding matrix to weight and transmit data to be transmitted to the user terminal;

[0010] The N user terminals include a paired first user terminal and a second user terminal, the reported channel state information is obtained by the user terminal based on reference signal resource configuration information, the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure the channel state of the first user terminal, and the interference measurement configuration information is configuration information of resources used to measure the interference caused by the second user terminal.

[0011] According to a third aspect of the present application, the present application also provides a channel state information measurement device, applied to a first user terminal, including:

[0012] a configuration information receiving module, configured to receive reference signal resource configuration information sent by a base station, the reference signal resource configuration information including channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure the channel state of the first user terminal, the interference measurement configuration information is configuration information of resources used to measure the interference caused by the second user terminal, the first user terminal and the second user terminal are paired terminals;

[0013] The measurement and reporting module is used to perform measurement according to the reference signal resource configuration information and report channel state information to the base station based on the measurement information, so that the base station performs precoding based on the reported channel state information.

[0014] According to a fourth aspect of the present application, the present application further provides a base station, including:

[0015] A precoding and transmission module, configured to receive channel state information reported by N user terminals, determine a precoding matrix based on the N reported channel state information, and use the precoding matrix to weight and transmit data to be transmitted to the user terminal;

[0016] The N user terminals include a paired first user terminal and a second user terminal, the reported channel state information is obtained by the user terminal based on reference signal resource configuration information, the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure the channel state of the first user terminal, and the interference measurement configuration information is configuration information of resources used to measure the interference caused by the second user terminal.

[0017] Through one or more of the above embodiments in the present application, at least the following technical effects can be achieved: the first user terminal uses the reference signal resource configuration information sent by the base station to perform channel measurement, wherein the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information, and the first user terminal can measure its own user channel information according to the channel measurement configuration information, and can measure and obtain the interference channel information brought by N-1 second user terminals using N-1 interference measurement configuration information. Reporting is performed based on the user channel information and the interference channel information, thereby providing sufficient information for the interference suppression or elimination processing of the base station, so that the base station can better achieve interference suppression or elimination. Furthermore, after completing the channel measurement, the first user terminal reports the channel state information to the base station based on the measurement information, thereby improving the overall performance of the MU-MIMO system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0019] Figure 1 One of the flow charts of the channel state information measurement method provided in an embodiment of the present application;

[0020] Figure 2 The second flowchart of the channel state information measurement method provided in the embodiment of the present application;

[0021] Figure 3 A schematic diagram of CSI-RS resource configuration provided in an embodiment of the present application;

[0022] Figure 4 Flow chart 3 of the channel state information measurement method provided in the embodiment of the present application;

[0023] Figure 5 A schematic diagram of the structure of a channel state information measurement device provided in an embodiment of the present application;

[0024] Figure 6 A schematic diagram of the structure of a base station provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0026] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0027] In a MU-MIMO system, the base station and user terminals often need to take certain measures to suppress or eliminate inter-user interference, such as using MU precoding technology, beamforming technology, maximum likelihood detection technology, etc. Otherwise, the user's demodulation performance will be seriously affected. The interference suppression or elimination methods between user terminals and base stations are as follows:

[0028] From the perspective of the user equipment (UE), the UE uses the channel state information reference signal CSI-RS configured by the base station to not only perform channel measurement and CSI calculation and feedback of the user terminal, but also measure the interference of multiple user terminals in the same cell to the user terminal, so as to enhance the demodulation performance of the user terminal and improve the accuracy and rationality of the feedback CSI. In the 3GPP Release 15 version of 5G, a high-precision Type 2 (Type2) codebook was proposed, which uses the orthogonal vectors of the discrete Fourier transform (DFT) as the basis. Through linear weighting and beam domain compression, it can more accurately characterize the channel characteristics and is more suitable for MU-MIMO scenarios. In the 3GPP Release 16 version, the Type2 codebook was improved and an enhanced Type2 (E-type2) codebook was proposed, which uses the correlation in the frequency domain to further compress the Type2 codebook in the frequency domain to reduce feedback overhead.

[0029] From the perspective of the base station (BS), for some scenarios such as time division duplex (TDD), the uplink sounding signal (SRS) and channel reciprocity measurement can be used to obtain the downlink channel matrix, so as to adopt channel-based precoding schemes such as block diagonalization (BD) and singular value zero forcing (SVD-ZF) algorithms to eliminate multi-user interference and improve gain. The base station can also use beamforming technology to transmit directional beams with user directivity to suppress interference. In addition, the base station can also select users with low channel correlation through certain algorithms for pairing, thereby reducing interference at the source.

[0030] In summary, due to the characteristics of multiple users sharing the same frequency physical resources at the same time, both base stations and terminals need more technologies to assist and support them in order to achieve the best performance of MU-MIMO.

[0031] However, due to the limitations of base stations and terminal products from various manufacturers and the impact of real-world environmental factors, MU-MIMO systems often cannot achieve optimal performance and still face various problems and application limitations. Specifically, they are as follows:

[0032] For the transceiver equipment, high-precision Type2 and E-type2 codebooks require high computing power, especially UE needs to perform matrix decomposition and various calculations on the measured channel to obtain accurate CSI. Therefore, the two codebooks are not widely used at present, and most scenarios use low-precision and low-complexity Type 1 (Type1) codebooks. In addition, in order to reduce power consumption, many UEs usually only configure reference signals on fixed antennas or ports of some antennas, and it is difficult to traverse and switch all antennas. In an environment with a relatively low signal-to-noise ratio (SNR), the accuracy of the channel matrix estimated by the UE is low, which makes the performance of the channel-based precoding scheme poor. Therefore, the channel-based precoding scheme is rarely used in practice. In addition, in order to ensure the demodulation performance of the UE, in the actual MU-MIMO system, the base station requires that the sum of the transmission layers of the paired UE is not greater than the number of receiving antennas of a single user, that is, the sum of the number of layers of the target user and the number of multi-user interference layers is not greater than the number of receiving antennas, but there is no such restriction in theory. This is because when the base station does not have a good way to eliminate or suppress interference, the UE can only suppress it by consuming spatial resources. Therefore, the UE needs to leave enough orthogonal space, which cannot achieve full throughput performance and affects the overall performance of the MU-MIMO system.

[0033] In summary, since the computing power of the base station is much stronger than that of the UE, the base station needs to assume a greater role in eliminating or suppressing interference. If the base station does not suppress or eliminate interference well, the performance of the MU-MIMO system will be limited in actual use and cannot be fully utilized.

[0034] In view of the above problems, the present application provides a channel state information measurement method and related equipment, aiming to ensure that the performance of the MU-MIMO system is not affected, which is described in detail below with reference to the accompanying drawings.

[0035] Figure 1 This is one of the flow charts of the channel state information measurement method provided in the embodiment of the present application, such as Figure 1 As shown, a method for measuring channel state information of a first user terminal specifically includes the following steps:

[0036] S101, receiving reference signal resource configuration information sent by a base station, where the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information.

[0037] The channel measurement configuration information CSI-RS for CM is the configuration information of resources used to measure the channel state of the first user terminal, and the interference measurement configuration information CSI-RS for IM is the configuration information of resources used to measure the interference caused by the second user terminal. The first user terminal and the second user terminal are paired terminals. The total number of the first user terminal and the second user terminal is N, and N-1 interference measurement configuration information can measure the interference caused by N-1 second user terminals to the first user terminal.

[0038] Both the channel measurement configuration information CSI-RS for CM and the interference measurement configuration information CSI-RS for IM can be used to transmit non-zero power CSI reference signals, which are NZP CSI-RS for CM and NZP CSI-RS for IM respectively.

[0039] In addition, the first user terminal and the second user terminal are relative. Schematically, assuming that in a MU-MIMO system, there are 4 paired user terminals, namely UE-A, UE-B, UE-C and UE-D. When UE-A receives the reference signal resource configuration information corresponding to it sent by the base station to measure the channel state information, UE-A is the first user terminal, and the remaining UE-B, UE-C and UE-D will cause inter-user interference to UE-A, and they are all second user terminals. When UE-B receives the reference signal resource configuration information corresponding to it sent to measure the channel state information, UE-B is the first user terminal, and the remaining UE-A, UE-C and UE-D are all second user terminals.

[0040] S102: Perform measurement according to reference signal resource configuration information and report channel state information to the base station based on the measurement information, so that the base station performs precoding based on the reported channel state information.

[0041] In this step, the first user terminal performs channel measurement according to the received reference signal resource configuration information, and uses the channel measurement configuration information CSI-RS for CM to measure the user channel information belonging to the first user terminal, and uses the interference measurement configuration information CSI-RS for IM to measure the interference channel information brought by the second user terminal. Then, the channel state information to be reported is calculated based on the measured user channel information and interference channel information. It should be noted that the first user terminal will use N-1 interference measurement configuration information to measure and obtain N-1 interference channel information, and report to the base station based on the N-1 interference channel information, so that the base station can obtain enough channel information of the first user terminal, so that the base station can better complete interference suppression or elimination.

[0042] The channel state information measurement method applied to the first user terminal provided in the embodiment of the present application, the first user terminal uses the reference signal resource configuration information sent by the base station to perform channel measurement, the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information, the first user terminal can obtain the channel information of the user according to the channel measurement configuration information measurement, and can measure N-1 interference channel information using N-1 interference measurement configuration information. Reporting is performed based on the channel information of the user and the interference channel information, thereby providing enough information for the interference suppression or elimination processing of the base station, so that the base station can better achieve interference suppression or elimination. Furthermore, after completing the channel measurement, the first user terminal reports the channel state information to the base station based on the measurement information, thereby improving the overall performance of the MU-MIMO system.

[0043] Furthermore, the reported channel state information includes first channel state information CSI-I and second channel state information CSI-II.

[0044] Performing measurement according to reference signal resource configuration information and reporting channel state information to a base station based on the measurement information includes:

[0045] The user channel information is measured and obtained by using the channel measurement configuration information, and the first channel state information is calculated based on the user channel information.

[0046] N-1 interference channel information is measured using N-1 interference measurement configuration information, and second channel state information is calculated based on the interference channel information, and the first channel state information and the second channel state information are reported to the base station.

[0047] That is, first use the channel measurement configuration information CSI-RS for CM to measure and obtain the user channel information of the first user terminal, and use the interference measurement configuration information CSI-RS for IM to measure and obtain the interference channel information. Then, calculate the first channel state information CSI-I for reporting based on the user channel information, and calculate the second channel state information CSI-II for reporting based on the interference channel information. Among them, the user channel information includes the channel fading, delay spread, angle, multipath component and other information of the first user terminal, and the interference channel information is used to indicate the interference level caused by N-1 second user terminals to the first user terminal.

[0048] After calculating and obtaining the first channel state information and the second channel state information, the first channel state information and the second channel state information are reported to the base station. The second channel state information CSI-II of the first user terminal can have at most N-1, and each second channel state information CSI-II corresponds to the interference caused by a second user terminal.

[0049] Schematically, as shown in Table 1, the first channel state information CSI-I specifically includes the first CSI resource index indication information CRI-I, the rank indication information RI, the first precoding matrix indication information PMI-I and the channel quality indication information CQI. The second channel state information CSI-II includes the second CSI resource index indication information CRI-II and the second precoding matrix indication information PMI-II corresponding to the maximum rank. Among them, CQI represents the quality of the channel and is used to guide the base station to select the modulation and coding method. PMI indicates the best precoding matrix, which is used to optimize signal transmission. RI indicates the rank of the channel, that is, the maximum number of spatial streams that the channel can support. CRI is used to indicate CSI-RS resources. Each second channel state information CSI-II contains CRI-II and PMI-II, and each group corresponds to the interference channel matrix of a second user terminal.

[0050] In addition, since the first user terminal does not know the number of transmission layers of the second user terminal paired with it, the first user terminal can only report the complete interference channel matrix when reporting the channel state information, and the base station performs interference suppression or elimination processing on the interference channel matrix, so the second channel state information CSI-II needs to include the PMI corresponding to the maximum rank of the interference channel matrix, and does not need to include the rank indication information RI. In addition, since the channel quality indication information CQI is used to allow the base station to determine the transmission code rate, modulation mode and other information of the first user terminal, it is already included in the first channel state information CSI-I, so the second channel state information CSI-II does not need to repeat the channel quality indication information CQI. Among them, LI (Layer Indicator) is information that needs to be reported in the FR2 frequency band (millimeter wave frequency band), and LI is used to indicate the number of layers used for PT-RS transmission, which can solve problems such as phase noise. In other embodiments of the present application, the reported first channel state information may also include SSBRI (SSB Rank Indicator), SRSRI (SRS Rank Indicator), etc., without limitation.

[0051] Table 1 Measurement information diagram

[0052] Measurement information CSI-I CSI-II CRI √ √ RI √ PMI √ √ CQI √ LI(FR2) √

[0053] In some embodiments of the present application, the reference signal resource configuration information may include multiple groups of channel measurement configuration information and N-1 interference measurement configuration information corresponding thereto. That is, the base station may configure multiple groups of channel measurement configuration information CSI-RS for CM and N-1 interference measurement configuration information CSI-RS for IM corresponding thereto for the first user terminal and send them to the first user terminal. It should be noted that one CSI-RS for CM in each group corresponds to N-1 CSI-RS for IM.

[0054] In some embodiments of the present application, if the reference signal resource configuration information includes multiple groups of CSI-RS for CM and N-1 CSI-RS for IM corresponding thereto, the first user terminal may determine the channel state information to be reported according to the measurement information. Specifically:

[0055] Performing measurement according to reference signal resource configuration information and reporting channel state information to a base station based on the measurement information includes:

[0056] Multiple sets of channel measurement configuration information are used to measure and obtain multiple user channel information, and final user channel information is determined from the multiple user channel information.

[0057] The first channel state information is calculated based on the final user channel information.

[0058] The N-1 interference measurement configuration information corresponding to the final user channel information is used to measure and obtain N-1 interference channel information, and the second channel state information is calculated based on the N-1 interference channel information.

[0059] That is, the first user terminal uses the received multiple groups of channel measurement configuration information to perform channel measurement and obtain multiple user channel information, where one user channel information corresponds to a group of channel measurement configuration information, and a group of channel measurement configuration information corresponds to N-1 interference measurement configuration information.

[0060] Then, the user channel information with the best channel quality is determined from the multiple user channel information as the final user channel information. The first channel state information is calculated based on the final user channel information, and at the same time, measurement and calculation are performed based on N-1 interference measurement configuration information corresponding to the final user channel information to obtain N-1 second channel state information.

[0061] In the channel state information measurement method provided in the embodiment of the present application, the reference signal resource configuration information received by the first user terminal includes multiple groups of CSI-RS for CM and N-1 CSI-RS for IM corresponding thereto. The first user terminal uses the multiple groups of CSI-RS for CM to perform channel measurement to obtain multiple user channel information, and selects the user channel information with the best channel quality to calculate CSI-I. At the same time, the corresponding N-1 CSI-RS for IM are used to perform measurement and CSI-II calculation, thereby further improving the effect of base station interference suppression or elimination and improving the MU-MIMO system performance.

[0062] In some embodiments of the present application, in order to further reduce the calculation complexity and feedback overhead of the first user terminal, the first user terminal may perform calculation and reporting based only on part of the interference channel information, specifically:

[0063] Obtaining second channel state information by calculation based on the interference channel information includes:

[0064] According to a preset interference threshold, multiple target interference channel information is determined from N-1 interference channel information, and multiple second channel state information is calculated based on the target interference channel information and reported to the base station. That is to say, the first user terminal first uses N-1 interference measurement configuration information to measure and obtain N-1 interference channel information, and then determines which interference channel information in the N-1 interference channel information needs to be calculated and reported according to the interference situation indicated by the interference channel information and the preset interference threshold. The number of multiple second channel state information is the same as the number of multiple target interference channel information, and is less than or equal to N-1. In this embodiment, the second channel state information corresponds to the target interference channel information. The first user terminal will report the first channel state information and multiple second channel state information to the base station. The interference threshold can be preset based on experience, or it can be calculated based on the actual interference energy situation, and there is no limitation on this.

[0065] The channel state information measurement method provided in the embodiment of the present application can determine multiple target interference channel information from N-1 interference channel information according to a preset interference threshold, and calculate and report CSI-II. That is, some interference channel information is neither calculated nor reported by CSI-II, thereby saving the calculation complexity of the first user terminal and reducing the feedback overhead for the base station.

[0066] In some embodiments of the present application, in order to reduce the feedback overhead to the base station, part of the second channel state information may be selected for reporting, specifically:

[0067] Obtaining second channel state information by calculation based on the interference channel information includes:

[0068] According to the N-1 interference channel information, N-1 second channel state information is calculated, and multiple target second channel state information is determined from the N-1 second channel state information based on a preset interference threshold and reported to the base station. Among them, the interference threshold can be preset based on experience, or calculated based on the actual interference energy situation, which is not limited. It should be noted that in this embodiment, multiple target second channel state information and first channel state information are reported.

[0069] In some embodiments of the present application, the interference threshold is specifically the maximum value of the interference amount caused by the second user terminal that the first user terminal can tolerate, and can be determined by a measurement method of the maximum interference amount that the first user terminal can tolerate, such as the signal-to-interference-plus-noise ratio of the first user terminal, the interference energy of the second user terminal, etc.

[0070] In a schematic manner, after the first user terminal measures and obtains N-1 interference channel information, it is determined whether the interference energy value indicated by the N-1 interference channel information is greater than or equal to the interference threshold α. The interference channel information greater than or equal to α is used as the target interference channel information and is calculated and reported based on this. The interference channel information less than the interference threshold α is ignored.

[0071] In another embodiment, calculations are performed on N-1 interference channel information to obtain N-1 second channel state information, and then a determination is made as to whether the interference energy values ​​indicated by the N-1 interference channel information are greater than or equal to an interference threshold α, and the corresponding second channel state information greater than or equal to α is used as the target second channel state information and reported, while the corresponding second channel state information less than α is ignored.

[0072] In some other embodiments of the present application, the above interference threshold may also be set by the base station according to a preset scenario when configuring the reference signal resource configuration information for the first user terminal. The preset scenario is specifically a scenario in which the channel orthogonality of the user terminal is good and the interference is relatively low. In this scenario, in order to reduce overhead and computational complexity, the user terminal may ignore some interference with low energy and consider that it has a relatively small impact. The base station sends the reference signal resource configuration information together with the interference threshold to the corresponding user terminal.

[0073] like Figure 2 As shown, the present application also provides a channel state information measurement method applied to a base station, which specifically includes the following steps:

[0074] S201, receiving channel state information reported by N user terminals, determining a precoding matrix based on the N reported channel state information, and using the precoding matrix to weight and transmit data to be transmitted to the user terminal.

[0075] Among them, the N user terminals include a paired first user terminal and a second user terminal, and the reported channel state information is obtained by the user terminal based on reference signal resource configuration information, the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is the configuration information of resources used to measure the channel state of the first user terminal, and the interference measurement configuration information is the configuration information of resources used to measure the interference caused by the second user terminal.

[0076] Similarly, the first user terminal and the second user terminal are relative. When a user terminal measures its own channel, the user terminal is the first user terminal, and the role of the remaining paired user terminal becomes the second user terminal that causes interference.

[0077] In this step, the base station will receive N reported channel state information, and each reported channel state information is obtained by different user terminals using their respective received reference signal resource configuration information to perform channel measurement, and the reference signal resource configuration information includes channel measurement configuration information and N-1 interference measurement configuration information corresponding thereto. Since the reported channel state information is obtained based on the channel measurement configuration information and the N-1 interference measurement configuration information corresponding thereto, the channel state information reported by each user terminal can provide enough information to reflect the channel state of each user terminal, and then the base station can use these reported channel state information to achieve better interference suppression or elimination, thereby improving the throughput of the MU-MIMO system. When the SNR is high and the channel quality is good, it is also possible to break through the limitation that the total number of transmission layers of the paired user terminal is not greater than the receiving antenna.

[0078] In the channel state information measurement method applied to a base station provided in an embodiment of the present application, the base station calculates a precoding matrix using N reported channel state information, and then uses the precoding matrix to weight the data to be transmitted to the user terminal. Among them, the channel state information reported by each user terminal can reflect enough channel information of each user terminal, and the base station can achieve better interference suppression or elimination through this enough channel information, thereby improving the overall performance of the system.

[0079] In addition, since the interference in the current solution is not well suppressed on the base station side, the total throughput of the MU-MIMO system paired with multiple user terminals is not as good as the single-user throughput. For example, when there are 4 receiving antennas, the 2layer+2layer pairing performance of 2 user terminals is worse than the single-user 4layer throughput performance. The channel state information measurement method provided in this application performs better interference suppression or elimination on the base station side, so that the user terminal does not need to consume airspace resources to suppress it in scenarios with high SNR and good channel quality, thereby achieving full throughput performance, so that the MU-MIMO system can break through the limitation that the total layer is not greater than the receiving antenna. In the above-mentioned 2layer+2layer, 3layer+2layer, 3layer+3layer or even more can be achieved, which improves the throughput of the MU-MIMO system and gives full play to the advantages of the MU-MIMO system.

[0080] In some embodiments of the present application, the reported channel state information includes first channel state information and second channel state information.

[0081] Determining a precoding matrix based on N reported channel state information includes:

[0082] Reconstructing and obtaining a first equivalent channel according to the first channel state information;

[0083] Recovering the interference channel according to the first channel state information and the second channel state information;

[0084] Determine a second equivalent channel according to the first equivalent channels and interference channels of the N user terminals;

[0085] Based on the second equivalent channel, a precoding matrix is ​​calculated using a preset precoding algorithm.

[0086] That is, the base station uses N first channel state information CSI-I to reconstruct the first equivalent channels of the N user terminals themselves, and also uses N first channel state information CSI-I and N second channel state information CSI-II to restore the interference channels of the N user terminals. Then, the joint equivalent channel of the N user terminals, that is, the second equivalent channel, is obtained through the first equivalent channel and the interference channel. After reconstructing the second equivalent channel, the base station uses the channel-based precoding algorithm to calculate the final precoding matrix, and then uses the precoding matrix to weight the data of each user terminal, and transmits the weighted data downlink.

[0087] Furthermore, the first channel state information includes first precoding matrix indication information and rank indication information, and the second channel state information includes second precoding matrix indication information corresponding to the maximum rank.

[0088] Reconstructing and obtaining a first equivalent channel according to the first channel state information includes:

[0089] The initial equivalent channel of each user terminal is reconstructed according to the first precoding matrix indication information PMI-I, and the N initial equivalent channels are spliced ​​according to the position information of the corresponding user terminal in the paired terminal group to obtain the first equivalent channel corresponding to the N user terminals. The initial equivalent channel corresponds to the user channel information measured by each user terminal using the channel measurement configuration information. The position information of the corresponding user terminal in the paired terminal group refers to the number of the user terminal.

[0090] Specifically, the N initial equivalent channels are in, are the equivalent channel matrices reconstructed by user terminals numbered 0, 1, ..., N-1 based on PMI-I, Yes After concatenating the N initial equivalent channels, the first equivalent channel

[0091] Restoring an interference channel according to the first channel state information and the second channel state information includes:

[0092] A plurality of initial interference channels are recovered for each user terminal according to the rank indication information and the second precoding matrix indication information, and a data stream is extracted from the initial interference channel according to the second precoding matrix indication information to form a final interference channel.

[0093] That is, the channel state information reported by each user terminal includes a second channel state information, and each second channel state information includes a second precoding matrix indication information, so that each user terminal corresponds to a initial interference channel. In addition, since the initial interference channel is reported according to the maximum Rank, the first layer column is extracted from the initial interference channel according to the rank indication information of each user terminal, thereby forming the final interference channel of each user terminal.

[0094] Schematically, the final interference channel matrix corresponding to the user terminal numbered 0 is The final interference channel matrix corresponding to the user terminal numbered 1 is By analogy, the final interference channel matrix corresponding to the user terminal numbered N-1 is in, It refers to the interference channel matrix determined based on the PMI-II reported by the user terminal numbered 0 and the RI reported by the user terminal numbered 1. It is an interference channel matrix determined according to the PMI-II reported by the user terminal numbered 0 and the RI reported by the user terminal numbered N-1. RI is used to indicate the first RI column in the matrix.

[0095] Determining a second equivalent channel according to first equivalent channels and interference channels of N user terminals includes:

[0096] The first equivalent channel is combined with the final interference channel according to the position information of the corresponding user terminal in the paired terminal group (that is, the number information of the user terminal) to obtain the second equivalent channel matrix

[0097] In the second equivalent channel In , the non-diagonal part of each row is the interference suffered by the first user terminal from the other second user terminals. In addition, for the interference channel information that is not reported or calculated by the user terminal, the matrix data is supplemented by filling with zeros.

[0098] The above-mentioned preset precoding algorithm can be a channel-based precoding algorithm such as zero-forcing precoding, minimum mean square error precoding, block diagonalization precoding or singular value zero-forcing precoding, etc., and this application does not limit this.

[0099] Schematically, taking MMSE precoding as an example, the precoding matrix is in is the second equivalent channel, and I is the unit matrix.

[0100] In some embodiments of the present application, before receiving the measurement information fed back by the N user terminals, the method further includes:

[0101] Reference signal resource configuration is performed for each user terminal to obtain N reference signal resource configuration information and send the information to the corresponding user terminal. Specifically, the information can be sent to the corresponding user terminal according to the identity information of the user terminal.

[0102] More specifically, the channel measurement configuration information and the interference measurement configuration information both include the same number of ports, and the N reference signal resource configuration information correspond to the same number of ports. In addition, the channel measurement configuration information and the interference measurement configuration information of the same group include the same code division multiplexing (CDM) type, density, time-frequency domain position and other parameters.

[0103] Indicatively, if Figure 3 As shown, the paired user terminals include UE0 and UE1, and the base station configures a set of CSI-RS for CM and CSI-RS for IM for UE0 and UE1 respectively. Since there are only two user terminals, the CSI-RS for CM only corresponds to one CSI-RS for IM. The number of ports of CSI-RS for CM and CSI-RS for CM is 8.

[0104] In some embodiments of the present application, performing reference signal resource configuration for each user terminal includes:

[0105] According to the number of user terminals or the number of ports, it is determined to configure one set of channel measurement configuration information and interference measurement configuration information, or multiple sets of channel measurement configuration information and interference measurement configuration information for each user terminal.

[0106] That is, when the number of user terminals is large or the number of ports is small, in order to save time-frequency resources, only one set of channel measurement configuration information and N-1 interference measurement configuration information can be configured for each user terminal. When the number of user terminals is small or the number of ports is large, multiple sets of configuration can be fully utilized to enable the user terminal to measure and obtain better channel information.

[0107] like Figure 4 As shown, the present application also provides a channel state information measurement method, the method comprising the following steps:

[0108] S401, the base station configures corresponding CSI-RS resources for each user terminal according to the requirements of multiple users to form reference signal resource configuration information and sends it to each corresponding user terminal.

[0109] The reference signal resource configuration information includes channel measurement configuration information CSI-RS for CM and N-1 interference measurement configuration information CSI-RS for IM, and the user terminal includes user terminal 1, user terminal 2, ..., user terminal N, and there are N user terminals in total. The reference signal resource configuration information corresponds to the user terminal, and includes reference signal resource configuration information 1, reference signal resource configuration information 2, ..., reference signal resource configuration information N.

[0110] It should be noted that when configuring resources for each user terminal, the number of ports in each reference signal resource configuration information is equal and the sum is less than or equal to the number of base station transmitting antennas. On the CSI-RS time-frequency domain resource configured for each user terminal, only the reference signal of the user terminal will be transmitted. The reference signal can be weighted mapped to the transmitting antenna through the outer precoding matrix, or directly mapped to the transmitting antenna. Since only the CSI-RS for CM of a certain user terminal will be sent on this resource, the base station will configure the corresponding CSI-RS for IM for other UEs on this resource, that is, each CSI-RS for CM resource of each UE needs to be configured with N-1 CSI-RS for IM resources. For other paired UEs, no signal will be sent on this resource, similar to zero-power CSI-RS, so that the interference signal and background noise of the target UE can be received, so as to accurately measure the interference information.

[0111] In addition, the number of groups of CSI-RS for CM and N-1 CSI-RS for IM configured for each user terminal can be determined according to the number of user terminals and the number of ports. Specifically, when the number of user terminals is large or the number of ports is small, in order to save time-frequency resources, only one group of channel measurement configuration information and N-1 interference measurement configuration information can be configured for each user terminal. When the number of user terminals is small or the number of ports is large, multiple groups can be configured by fully utilizing time-frequency resources so that the user terminal can measure and obtain better channel information.

[0112] S402, N user terminals perform channel measurement after receiving reference signal resource configuration information sent by the base station, and report channel state information to the base station based on the measurement information.

[0113] The channel measurement configuration information is used to measure the channel state of the user terminal (hereinafter collectively referred to as the first user terminal), and the interference measurement configuration information is used to measure the interference of other user terminals (hereinafter collectively referred to as the second user terminal) to the first user terminal. Different user terminals correspond to their own measurement information and calculate and obtain their own channel state information based on their own measurement information. For example, user terminal 1 reports channel state information 1, user terminal 2 reports channel state information 2, and user terminal N reports channel state information N, so that the base station can obtain N reported channel state information.

[0114] In this step, each user terminal first uses the channel measurement configuration information to measure and obtain the channel matrix of the user, and then calculates the first channel state information CSI-I based on the channel matrix of the user. It also uses N-1 interference measurement configuration information to measure and obtain N-1 interference channel matrices, and then calculates the second channel state information CSI-II based on the N-1 interference channel matrices.

[0115] CSI-I includes the corresponding parameters calculated by the first user terminal according to the feedback mode and configuration requirements, including the first CSI resource index information CRI-I, rank indication information RI, first precoding matrix indication information PMI-I, channel quality indication information CQI, etc. CSI-II only needs to include two indication information, CRI-II and PMI-II.

[0116] In addition, the base station and the user terminal can also select part of the interference information in the CSI-II for measurement and reporting according to their own capabilities or scenario requirements. It can be selected from the N-1 CSI-IIs according to the above interference threshold for reporting, or it can be selected from the N-1 interference channel information according to the preset interference threshold for calculation and reporting.

[0117] S403, after receiving the channel state information reported by N user terminals, the base station reconstructs the joint equivalent channel of the N user terminals based on the N reported channel state information. According to the joint equivalent channel, the final precoding matrix is ​​calculated using the channel-based precoding algorithm, and finally the precoding matrix is ​​used to weight the data of each layer of the user terminal and complete the downlink transmission.

[0118] In the channel state information measurement method provided in the embodiment of the present application, the base station configures reference signal resource configuration information for each user terminal, and the reference signal resource configuration information includes channel measurement configuration information and N-1 interference measurement configuration information. The user terminal can use the channel measurement configuration information and N-1 interference measurement configuration information to measure and obtain sufficient channel information and feed it back to the base station. The base station can better suppress or eliminate interference based on this measurement information, thereby improving the system throughput and improving the performance of the MU-MIMO system.

[0119] like Figure 5 As shown, the present application also provides a channel state information measurement device 500, which is applied to a user terminal and includes:

[0120] The configuration information receiving module 501 is used to receive reference signal resource configuration information sent by the base station, where the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure the channel state of the first user terminal, and the interference measurement configuration information is configuration information of resources used to measure the interference caused by the second user terminal, where the first user terminal and the second user terminal are paired terminals;

[0121] The measurement and reporting module 502 is used to perform measurement according to the reference signal resource configuration information and report channel state information to the base station based on the measurement information, so that the base station performs precoding based on the reported channel state information.

[0122] It should be noted that the channel state information measurement device provided in this embodiment corresponds to the channel state information measurement method applied to the first user terminal, which will not be described in detail here.

[0123] like Figure 6 As shown, the present application also provides a base station 600, which includes:

[0124] The precoding and transmission module 601 is used to receive channel state information reported by N user terminals, determine a precoding matrix based on the N reported channel state information, and use the precoding matrix to weight and transmit data to be transmitted to the user terminal.

[0125] Among them, the N user terminals include a paired first user terminal and a second user terminal, and the reported channel state information is obtained by the user terminal based on reference signal resource configuration information, the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is the configuration information of resources used to measure the channel state of the first user terminal, and the interference measurement configuration information is the configuration information of resources used to measure the interference caused by the second user terminal.

[0126] It should be noted that the base station provided in this embodiment corresponds to the channel state information measurement method applied to the base station, which will not be described in detail here.

[0127] Based on any of the above embodiments, another embodiment of the present invention further provides an electronic device, which may include: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus. The processor may call the logic instructions in the memory to execute the above channel state information measurement method.

[0128] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0129] In addition, the logic instructions in the above-mentioned memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0130] On the other hand, an embodiment of the present invention further provides a storage medium on which a plurality of instructions are stored, and the instructions are suitable for being loaded by a processor to execute the channel state information measurement method provided in the above embodiments.

[0131] In addition, the logic instructions in the above-mentioned storage medium can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art, and the computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0132] On the other hand, an embodiment of the present application further provides a computer program product. When the program code contained in the computer program product is executed by a processor in an electronic device, the channel state information measurement method provided in the above embodiments is implemented.

[0133] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, i.e., they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative effort.

[0134] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods of each embodiment or some parts of the embodiment.

[0135] In summary, although the present application has been disclosed as above with preferred embodiments, the above preferred embodiments are not intended to limit the present application. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined in the claims.

Claims

1. A channel state information measurement method, characterized in that: include: Applied to a first user terminal, the method includes: receiving reference signal resource configuration information sent by a base station, the reference signal resource configuration information including channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure a channel state of the first user terminal, the interference measurement configuration information is configuration information of resources used to measure interference caused by a second user terminal, the first user terminal and the second user terminal are paired terminals; Measurement is performed according to the reference signal resource configuration information and channel state information is reported to the base station based on the measurement information, so that the base station performs precoding based on the reported channel state information.

2. The method according to claim 1, characterized in that The reported channel state information includes first channel state information and second channel state information; The performing measurement according to the reference signal resource configuration information and reporting channel state information to the base station based on the measurement information includes: Using the channel measurement configuration information to measure and obtain user channel information, and calculating and obtaining first channel state information based on the user channel information; The N-1 interference measurement configuration information is used to measure and obtain N-1 interference channel information, and second channel state information is calculated based on the interference channel information, and the first channel state information and the second channel state information are reported to the base station.

3. The method according to claim 2, characterized in that The second channel state information includes second precoding matrix indication information corresponding to the maximum rank.

4. The method according to claim 2, characterized in that The first channel state information includes rank indication information, first precoding matrix indication information and channel quality indication information.

5. The method according to claim 1, characterized in that The reference signal resource configuration information includes multiple groups of channel measurement configuration information and N-1 interference measurement configuration information corresponding thereto.

6. The method according to claim 5, characterized in that The performing measurement according to the reference signal resource configuration information and reporting channel state information to the base station based on the measurement information includes: Using multiple sets of channel measurement configuration information to measure and obtain multiple user channel information, and determining final user channel information from the multiple user channel information; Calculate and obtain first channel state information based on the final user channel information; The N-1 interference measurement configuration information corresponding to the final user channel information is used to measure and obtain N-1 interference channel information, and the second channel state information is calculated based on the N-1 interference channel information.

7. The method according to claim 2, characterized in that The calculating and obtaining the second channel state information based on the interference channel information includes: A plurality of target interference channel information is determined from the N-1 interference channel information according to a preset interference threshold, and a plurality of second channel state information is calculated based on the target interference channel information and reported to the base station.

8. The method according to claim 2, characterized in that The calculating and obtaining the second channel state information based on the interference channel information includes: N-1 second channel state information is calculated based on the N-1 interference channel information, and multiple target second channel state information is determined from the N-1 second channel state information based on a preset interference threshold and reported to the base station.

9. The method according to claim 7 or 8, characterized in that The interference threshold is the maximum value of the interference amount caused by the second user terminal that the first user terminal can tolerate.

10. The method according to claim 9, characterized in that The interference threshold is determined according to a signal-to-interference-plus-noise ratio of the first user terminal or interference energy of the second user terminal.

11. A channel state information measurement method, characterized in that: Applied to a base station, the method comprises: Receiving channel state information reported by N user terminals, determining a precoding matrix based on the N reported channel state information, and using the precoding matrix to weight and transmit data to be transmitted to the user terminal; The N user terminals include a paired first user terminal and a second user terminal, the reported channel state information is obtained by the user terminal based on reference signal resource configuration information, the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure the channel state of the first user terminal, and the interference measurement configuration information is configuration information of resources used to measure the interference caused by the second user terminal.

12. The method according to claim 11, characterized in that The reported channel state information includes first channel state information and second channel state information; The determining of the precoding matrix based on N reported channel state information includes: Reconstructing and obtaining a first equivalent channel according to the first channel state information; Recovering an interference channel according to the first channel state information and the second channel state information; Determine a second equivalent channel according to the first equivalent channels of the N user terminals and the interference channel; Based on the second equivalent channel, a precoding matrix is ​​calculated using a preset precoding algorithm.

13. The method according to claim 12, characterized in that The first channel state information includes first precoding matrix indication information and rank indication information, and the second channel state information includes second precoding matrix indication information corresponding to the maximum rank; The reconstructing and obtaining a first equivalent channel according to the first channel state information includes: Reconstructing an initial equivalent channel of each user terminal according to the first precoding matrix indication information, and splicing N initial equivalent channels according to the position information of the corresponding user terminal in the paired terminal group to obtain a first equivalent channel; The recovering the interference channel according to the first channel state information and the second channel state information includes: Recovering a plurality of initial interference channels for each user terminal according to the rank indication information and the second precoding matrix indication information, and extracting a data stream from the initial interference channel according to the second precoding matrix indication information to form a final interference channel; The determining the second equivalent channel according to the first equivalent channels of the N user terminals and the interference channel comprises: The first equivalent channel is combined with the final interference channel according to the position information of the corresponding user terminal in the paired terminal group to obtain a second equivalent channel.

14. The method according to claim 12, characterized in that The preset precoding algorithm is one of zero-forcing precoding, minimum mean square error precoding, block diagonalization precoding or singular value zero-forcing precoding.

15. The method according to claim 11, characterized in that Before receiving the channel state information reported by N user terminals, the method further includes: Reference signal resource configuration is performed for each user terminal to obtain N reference signal resource configuration information and send them to the corresponding user terminal.

16. The method according to claim 15, characterized in that The channel measurement configuration information and the interference measurement configuration information both include the same number of ports, and the N reference signal resource configuration information correspond to the same number of ports.

17. The method according to claim 15, characterized in that The configuring reference signal resources for each user terminal includes: According to the number of user terminals or the number of ports, it is determined to configure one set of channel measurement configuration information and interference measurement configuration information, or multiple sets of channel measurement configuration information and interference measurement configuration information for each user terminal.

18. A channel state information measuring device, characterized in that: Applied to a first user terminal, comprising: a configuration information receiving module, configured to receive reference signal resource configuration information sent by a base station, the reference signal resource configuration information including channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure the channel state of the first user terminal, the interference measurement configuration information is configuration information of resources used to measure the interference caused by the second user terminal, the first user terminal and the second user terminal are paired terminals; The measurement and reporting module is used to perform measurement according to the reference signal resource configuration information and report channel state information to the base station based on the measurement information, so that the base station performs precoding based on the reported channel state information.

19. A base station, characterized in that: include: A precoding and transmission module, configured to receive channel state information reported by N user terminals, determine a precoding matrix based on the N reported channel state information, and use the precoding matrix to weight and transmit data to be transmitted to the user terminal; The N user terminals include a paired first user terminal and a second user terminal, the reported channel state information is obtained by the user terminal based on reference signal resource configuration information, the reference signal resource configuration information includes channel measurement configuration information and corresponding N-1 interference measurement configuration information; the channel measurement configuration information is configuration information of resources used to measure the channel state of the first user terminal, and the interference measurement configuration information is configuration information of resources used to measure the interference caused by the second user terminal.

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