Channel estimation method and apparatus, and communication system and storage medium

Abstract

The present application relates to the technical field of communications. Disclosed are a channel estimation method and apparatus, and a communication system and a storage medium, which are used for improving the multiplexing capability of a reference signal and solving the problem of it being impossible to transmit uplink reference signals to a base station in a timely manner when the number of the uplink reference signals is too large. The method comprises: a terminal device reporting, to a network device, first indication information for a channel feature of a channel between the terminal device and the network device, and acquiring a feature weight of the channel, which is determined by the network device on the basis of the first indication information; and then, determining a first uplink reference signal on the basis of the feature weight and a pilot-frequency base sequence of the terminal device, and sending the first uplink reference signal to the network device.

Description

Channel estimation method, device, communication system and storage medium

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on November 2, 2023, with application number 202311469859.2 and application name “Channel Estimation Method, Device, Communication System and Storage Medium”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a channel estimation method, device, communication system and storage medium. Background Art

[0003] With the continuous development of communication technology, fifth-generation mobile communication technology (5G) communication systems have higher requirements for spectrum efficiency. To improve the spectrum efficiency of 5G communication systems, massive multiple input multiple output (MIMO) technology has been applied.

[0004] When using MIMO technology, a base station (BS) must precode data before sending it to user equipment (UE). During the precoding process, the BS estimates the uplink channel based on the uplink reference signal (SRS) sent by the UE, obtaining channel state information (CSI). Based on the CSI, the BS selects an appropriate precoding matrix to precode the data.

[0005] The terminal device may use time division multiplexing, frequency division multiplexing or code division multiplexing to send an uplink reference signal to the base station. When the terminal device uses code division multiplexing to send an uplink reference signal to the base station, in order to enable the uplink reference signal to be transmitted on the same resource element (RE), the uplink reference signal may be orthogonally multiplexed in the discrete Fourier transform (DFT) domain, that is, the uplink reference signal is orthogonally multiplexed in the delay domain. The orthogonal multiplexing of the uplink reference signal in the DFT transform domain may include: selecting a vector from the DFT matrix as a weight, using the weight to transform the uplink reference signal, and obtaining an equivalent channel corresponding to the channel carrying the uplink reference signal according to the transformed result.

[0006] The DFT transform domain is a method of representing the channel transform domain in a fixed form. However, for different channels, the method of representing the channel transform domain in this fixed form is not necessarily the method with the strongest multiplexing capability, that is, the code division multiplexing capability corresponding to the DFT transform domain is not the optimal method. As a result, when the number of uplink reference signals is too large, that is, when the multiplexing number is high, there is a problem of not being able to transmit the uplink reference signals to the base station in a timely manner.

[0007] Summary of the Invention

[0008] Embodiments of the present application provide a channel estimation method, apparatus, communication system, and storage medium for solving the problem that uplink reference signals cannot be transmitted to a base station in a timely manner when there are too many uplink reference signals.

[0009] To achieve the above objectives, the present invention provides the following technical solutions:

[0010] In a first aspect, a channel estimation method is provided. The method can be performed by a terminal device; alternatively, the method can be performed by a module implemented in the terminal device, such as a chip, a chip system, or a circuit; alternatively, the method can be implemented by a logic module or software that implements all or part of the terminal device's functions, without limitation. For ease of description, the following description uses execution by a terminal device as an example.

[0011] The method includes: reporting first indication information of the channel characteristics of the channel between the terminal device and the network device to the network device, and obtaining the characteristic weight of the channel determined based on the first indication information, and then determining a first uplink reference signal based on the pilot base sequence and the characteristic weight, and sending the first uplink reference signal to the network device.

[0012] In the above technical solution, the first uplink reference signal is generated based on the pilot base sequence and the characteristic weight, and the characteristic weight is determined by the network device based on the channel characteristics of the channel. It can be seen that in the present application, the characteristic weight is not simply obtained from the DFT matrix, but is determined based on the channel characteristics of the channel, that is, the network device can design the characteristic weight based on the channel characteristics, so that the characteristic weight is more in line with the channel characteristics of the corresponding channel, that is, the characteristic weight has the best uplink reference signal multiplexing capability under the channel characteristics. Therefore, the channel estimation method provided by the present application can effectively improve the code division multiplexing capability when the same pilot resource or channel transmits the uplink reference signal, so that when the number of uplink reference signals is too large, the uplink reference signal can also be transmitted to the base station in a timely manner.

[0013] In an optional embodiment, the first indication information indicates a characteristic basis of a channel or a second uplink reference signal. The characteristic basis of the channel can also be understood as a characteristic basis of a downlink channel between the terminal device and the network device, and the second uplink reference signal of the channel can be understood as a reference signal of the uplink channel between the terminal device and the network device.

[0014] In the above technical solution, based on the reciprocity of the channel, that is, the characteristic that the channel characteristics of the uplink channel and the downlink channel are basically the same, the characteristic base of the uplink channel can be reported to indicate the channel characteristics of the uplink channel, or the second reference signal of the uplink channel can be reported to indicate the channel characteristics of the uplink channel, so that the network device can determine the characteristic weight of the channel based on the channel characteristics of the uplink channel or the downlink channel. In this way, it is compatible with multiple application scenarios and improves the diversity and flexibility of reporting the first indication information.

[0015] In an optional embodiment, when the channel includes a time domain channel, the characteristic basis of the channel includes a time domain basis. When the channel includes a frequency domain channel, the characteristic basis of the channel includes a frequency domain basis. When the channel includes a time-frequency domain channel, the characteristic basis of the channel includes a time-frequency domain basis.

[0016] In the above technical solution, uplink reference signal multiplexing can be implemented in the time domain, frequency domain, or any of the time-frequency domains. This allows for compatibility with various multiplexing scenarios, increasing the diversity and flexibility of the implementation of this solution.

[0017] In an optional embodiment, when obtaining the characteristic weight of the channel between the terminal device and the network device, the terminal device can receive second indication information for indicating the characteristic weight, and then obtain the characteristic weight of the channel between the terminal device and the network device based on the second indication information.

[0018] In the above technical solution, the terminal device can directly obtain the characteristic weight from the second indication information, and transform the pilot base sequence based on the characteristic weight to obtain the first uplink reference signal, which can effectively improve the efficiency of generating the first uplink reference signal, and thus effectively improve the efficiency of the base station in channel estimation.

[0019] In an optional embodiment, when obtaining the characteristic weight of the channel between the terminal device and the network device, the terminal device can also receive second indication information for indicating the equivalent basis of the channel, and then obtain the characteristic weight of the channel between the terminal device and the network device based on the equivalent basis and the characteristic basis.

[0020] In the above technical solution, feature weights can be determined by indicating an equivalent basis. Since the equivalent basis is determined based on the feature basis and the feature weight, for example, the equivalent basis can be obtained by multiplying the feature basis and the feature weight, feature weights can be obtained in a variety of ways, increasing the diversity and flexibility of the implementation of this solution.

[0021] In an optional embodiment, the above-mentioned characteristic basis may include multiple basis, and the second indication information may also be used to indicate a first basis, which is one of the basis in the characteristic basis. When obtaining the characteristic weight of the channel between the terminal device and the network device based on the equivalent basis and the characteristic basis, the characteristic weight of the channel between the terminal device and the network device may be obtained based on the equivalent basis and the first basis.

[0022] In the above technical solution, since the equivalent basis of the channel is determined by the characteristic weight and the first basis, optionally, the first basis can be a characteristic basis among multiple characteristic basis that makes the indication overhead (or signaling overhead) of the equivalent basis smaller, so as to further reduce the signaling overhead in the process of indicating the equivalent basis.

[0023] In an optional implementation, the second indication information may indicate a DFT decomposition matrix of an equivalent basis of the channel.

[0024] In the above technical solution, the equivalent basis of the channel can be indicated by the DFT decomposition matrix of the equivalent basis. Since the number of non-zero elements in the DFT decomposition matrix is ​​less than the number of non-zero elements in the equivalent basis, the overhead of the DFT decomposition matrix of the equivalent basis is smaller than that of the equivalent basis. Therefore, by indicating the DFT decomposition matrix of the equivalent basis to further determine the characteristic weight, the signaling overhead in the interaction process can be further reduced, saving communication resources.

[0025] In an optional embodiment, when the first indication information includes the characteristic basis of the channel, before reporting the first indication information of the channel characteristics of the channel between the terminal device and the network device, the terminal device may also receive a downlink reference signal from the network device and determine the characteristic basis of the channel based on the downlink reference signal.

[0026] In the above technical solution, the terminal device can receive a downlink reference signal to perform channel estimation based on the downlink reference signal, obtain the channel characteristics of the channel, and further decompose the channel characteristics of the channel to obtain the characteristic basis of the channel. In this way, the terminal device can obtain an accurate characteristic basis based on the reference signal.

[0027] In the second aspect, a channel estimation method is provided, which is applied to a network device, including: after receiving first indication information from a terminal device for indicating the channel characteristics of a channel between the terminal device and the network device, determining the characteristic weight of the channel based on the first indication information, and then sending second indication information to the terminal device for indicating the characteristic weight.

[0028] In the above technical solution, the characteristic weights are not simply obtained from the DFT matrix, but are determined based on the channel characteristics of the channel. That is, the network equipment can design the characteristic weights based on the channel characteristics so that the characteristic weights are more in line with the channel characteristics of the corresponding channel, that is, the characteristic weights have the optimal uplink reference signal multiplexing capability under the channel characteristics. Therefore, the channel estimation method provided in this application can effectively improve the code division multiplexing capability when the same pilot resource or channel transmits uplink reference signals, so that when the number of uplink reference signals is too large, the uplink reference signals can also be transmitted to the base station in a timely manner.

[0029] In an optional embodiment, the first indication information indicates a characteristic basis of a channel or a second uplink reference signal. The characteristic basis of the channel can also be understood as a characteristic basis of a downlink channel between the terminal device and the network device, and the second uplink reference signal of the channel can be understood as a reference signal of the uplink channel between the terminal device and the network device.

[0030] In the above technical solution, based on the reciprocity of the channel, that is, the characteristic that the channel characteristics of the uplink channel and the downlink channel are basically the same, the characteristic base of the uplink channel can be reported to indicate the channel characteristics of the uplink channel, or the reference signal of the uplink channel can be reported to indicate the channel characteristics of the uplink channel, so that the network device can determine the characteristic weight of the channel based on the channel characteristics of the uplink channel or the downlink channel. In this way, it is compatible with multiple application scenarios and improves the diversity and flexibility of reporting the first indication information.

[0031] In an optional embodiment, when the channel includes a time domain channel, the characteristic basis of the channel includes a time domain basis. When the channel includes a frequency domain channel, the characteristic basis of the channel includes a frequency domain basis. When the channel includes a time-frequency domain channel, the characteristic basis of the channel includes a time-frequency domain basis.

[0032] In the above technical solution, uplink reference signals can be multiplexed in the time domain, frequency domain, or any of the time-frequency domains. This allows for compatibility with various multiplexing scenarios, increasing the diversity and flexibility of the implementation of this solution.

[0033] In an optional implementation, when the second indication information is sent to the terminal device, the second indication information carrying the feature weight may be sent to the terminal device.

[0034] In the above technical solution, the network device can directly send a second indication message carrying a characteristic weight to the terminal device, so that the terminal device can directly obtain the characteristic weight from the second indication message, and transform the pilot base sequence based on the characteristic weight to obtain a first uplink reference signal, which can effectively improve the efficiency of generating the first uplink reference signal, and thereby effectively improve the efficiency of the base station in channel estimation.

[0035] In an optional implementation, the second indication information may be used to indicate an equivalent basis of a channel, and the equivalent basis of the channel is determined by a characteristic weight and a characteristic basis.

[0036] In the above technical solution, feature weights can be determined by indicating an equivalent basis. Since the equivalent basis is determined based on the feature basis and the feature weight, for example, the equivalent basis can be obtained by multiplying the feature basis and the feature weight, feature weights can be obtained in a variety of ways, increasing the diversity and flexibility of the implementation of this solution.

[0037] In an optional embodiment, the characteristic basis may include multiple basis, the second indication information is further used to indicate a first basis, and the first basis is one of the characteristic basis. Accordingly, the equivalent basis of the channel is determined by the characteristic weight and the first basis.

[0038] In the above technical solution, since the equivalent basis of the channel is determined by the characteristic weight and the first basis, optionally, the first basis can be a characteristic basis among multiple characteristic basis that makes the indication overhead (or signaling overhead) of the equivalent basis smaller, so as to further reduce the signaling overhead in the process of indicating the equivalent basis.

[0039] In an optional implementation, the second indication information may indicate a DFT decomposition matrix of an equivalent basis of the channel.

[0040] In the above technical solution, the equivalent basis of the channel can be indicated by the DFT decomposition matrix of the equivalent basis. Since the number of non-zero elements in the DFT decomposition matrix is ​​less than the number of non-zero elements in the equivalent basis, the overhead of the DFT decomposition matrix of the equivalent basis is smaller than that of the equivalent basis. Therefore, by indicating the DFT decomposition matrix of the equivalent basis to further determine the characteristic weight, the signaling overhead in the interaction process can be further reduced, saving communication resources.

[0041] In an optional implementation, after receiving the first uplink reference signal from the terminal device, the network device may further perform channel estimation on the channel between the terminal device and the network device based on the characteristic basis of the channel and the first uplink reference signal.

[0042] In the above technical solution, the network device can receive the first uplink reference signal to perform channel estimation on the channel between the terminal device and the network device based on the characteristic basis of the channel and the first uplink reference signal, so as to be compatible with the standard processing flow of channel estimation.

[0043] In a third aspect, a channel estimation device is provided, which is located in a terminal device and includes: a functional unit for executing any one of the methods provided in the first aspect, and the actions performed by each functional unit are implemented through hardware or through hardware executing corresponding software implementations.

[0044] The apparatus includes a transceiver module and a processing module; wherein the transceiver module is configured to report first indication information to a network device, the first indication information being configured to indicate channel characteristics of a channel between the terminal device and the network device. The processing module is configured to obtain characteristic weights of the channel between the terminal device and the network device; the characteristic weights of the channel are determined based on the first indication information. The processing module is further configured to generate a first uplink reference signal; the first uplink reference signal is determined based on a pilot base sequence and characteristic weights of the terminal device. The transceiver module is further configured to send the first uplink reference signal to the network device.

[0045] In a fourth aspect, a channel estimation device is provided, which is located in a network device and includes: a functional unit for executing any one of the methods provided in the first aspect, wherein the actions performed by each functional unit are implemented through hardware or through hardware executing corresponding software implementations.

[0046] The device includes a transceiver module and a processing module; wherein,

[0047] The transceiver module is configured to receive first indication information from a terminal device, the first indication information being used to indicate channel characteristics of a channel between the terminal device and the network device. The processing module is configured to determine a characteristic weight of the channel based on the first indication information. The transceiver module is further configured to send second indication information to the terminal device, the second indication information being used to indicate the characteristic weight.

[0048] In a fifth aspect, a terminal device is provided, which includes at least one processor coupled to at least one memory: at least one processor is used to execute a computer program or instruction stored in at least one memory, so that the terminal device executes any one of the channel estimation methods provided in the first aspect.

[0049] In a sixth aspect, a network device is provided, which includes at least one processor, and the at least one processor is coupled to at least one memory: the at least one processor is used to execute a computer program or instruction stored in the at least one memory, so that the transmitting end executes any one of the channel estimation methods provided in the second aspect.

[0050] In the seventh aspect, a communication system is provided, which includes: a terminal device and a network device; the terminal device is used to execute any one of the channel estimation methods provided in the first aspect; and the network device is used to execute any one of the channel estimation methods provided in the second aspect.

[0051] In an eighth aspect, a computer-readable storage medium is provided, comprising computer execution instructions. When the computer execution instructions are executed on a computer, the computer executes any one of the channel estimation methods provided in the first and second aspects.

[0052] In the ninth aspect, a chip is provided, which includes: a processor and an interface circuit; the interface circuit is used to receive code instructions and transmit them to the processor; the processor is used to run the code instructions to execute any one of the channel estimation methods provided in the first and second aspects.

[0053] In a tenth aspect, a computer program product is provided, comprising computer execution instructions, which, when the computer execution instructions are executed on a computer, enable the computer to execute any one of the channel estimation methods provided in the first and second aspects.

[0054] It should be noted that the technical effects brought about by any implementation method in the third to tenth aspects can be referred to the technical effects brought about by the corresponding implementation methods in the first and second aspects, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] FIG1 is a schematic diagram of an interactive process of SRS channel estimation provided in the related art;

[0056] FIG2 is a schematic structural diagram of an orthogonal multiplexing method provided in the related art;

[0057] FIG3 is a schematic diagram of a structure of code division multiplexing provided in the related art;

[0058] FIG4 is an application scenario diagram of a communication system provided in an embodiment of the present application;

[0059] FIG5 is a schematic diagram of the structure of a communication system provided in an embodiment of the present application;

[0060] FIG6 is a schematic diagram of an interactive flow of a channel estimation method provided in an embodiment of the present application;

[0061] FIG7 is a schematic structural diagram of a channel estimation device provided in an embodiment of the present application;

[0062] FIG8 is a schematic structural diagram of a channel estimation device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0063] In the description of this application, unless otherwise specified, " / " means "or", for example, A / B can mean A or B. "And / or" in this article is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, "at least one" means one or more, and "a plurality" means two or more. Words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not limit them to be necessarily different.

[0064] It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0065] "Used to indicate" can include direct indication and indirect indication, and can also include explicit indication and implicit indication. When describing "a certain indication information is used to indicate A" or "indication information of A", it can include that the indication information directly indicates A or indirectly indicates A, but it does not mean that the indication information must carry A. The information indicated by a certain information (such as the configuration information described below) is called information to be indicated. In the specific implementation process, there are many ways to indicate the information to be indicated, such as but not limited to, directly indicating the information to be indicated, such as the information to be indicated itself or the index of the information to be indicated. The information to be indicated can also be indirectly indicated by indicating other information, where there is an association between the other information and the information to be indicated. It is also possible to indicate only a part of the information to be indicated, while the other parts of the information to be indicated are known or agreed in advance. For example, the indication of specific information can be achieved by using the arrangement order of each information agreed in advance (such as specified by the protocol), thereby reducing the indication overhead to a certain extent. At the same time, the common parts of each information can be identified and indicated in a unified manner to reduce the indication overhead caused by indicating the same information separately. For example, those skilled in the art will appreciate that a precoding matrix is ​​composed of precoding vectors, and the precoding vectors in the precoding matrix may share common components in terms of composition or other attributes. Furthermore, the specific indication method may also be various existing indication methods, such as, but not limited to, the aforementioned indication methods and their various combinations. The specific details of various indication methods can be referenced in the prior art and will not be elaborated herein. As can be seen from the foregoing, for example, when multiple pieces of information of the same type need to be indicated, different indication methods may be used for different pieces of information. During implementation, the desired indication method can be selected based on specific needs. The embodiments of this application do not limit the selected indication method. Thus, the indication methods described in the embodiments of this application should be understood to encompass various methods for enabling the intended party to obtain information about the information to be indicated. The information to be indicated may be sent as a whole or as multiple sub-information, and the transmission periods and / or transmission timings of these sub-information may be the same or different. The specific transmission method is not limited herein. The transmission periods and / or transmission timings of these sub-information may be predefined, for example, according to a protocol, or may be configured by the transmitting device by sending configuration information to the receiving device. The configuration information may include, for example but not limited to, one of radio resource control signaling, medium access control (MAC) layer signaling, and physical layer signaling, or a combination of at least two of them.The radio resource control signaling includes, for example, radio resource control (RRC) signaling; the MAC layer signaling includes, for example, a MAC control element (CE); and the physical layer signaling includes, for example, downlink control information (DCI).

[0066] With the continuous development of communication technology, 5G communication systems have higher requirements for system capacity and spectrum efficiency. In order to improve the spectrum efficiency of 5G communication systems, MIMO technology has been applied. When applying MIMO technology, the base station needs to use the channel CSI to precode the data before sending data to the UE. In the time division duplexing (TDD) system, the uplink channel and the downlink channel are reciprocal. Therefore, during the precoding process, the base station can perform SRS channel estimation on the uplink channel based on the uplink reference signal sent by the terminal device to obtain CSI, and select an appropriate precoding matrix based on the CSI to precode the data.

[0067] Figure 1 is a schematic diagram of the interactive process of the base station performing SRS channel estimation on the uplink channel in the related art. As shown in Figure 1, the base station can first send a signaling containing channel sounding estimation configuration information to the UE. The signaling can include a time identifier, a channel identifier, and an uplink reference signal resource identifier. After receiving the signaling, the UE can use the pilot resource corresponding to the uplink reference signal resource identifier on the channel corresponding to the channel identifier when the current moment is consistent with the time corresponding to the time identifier to send an uplink reference signal to the base station. After receiving the uplink reference signal, the base station can use the uplink reference signal to perform pilot measurement and perform SRS channel estimation on the channel based on the pilot measurement result, thereby obtaining the CSI of the channel. Afterwards, the base station can use the CSI of the channel to select an appropriate precoding matrix to precode the downlink data sent to the UE, and send the downlink data to the UE after the precoding is completed.

[0068] In the above process, the UE needs to occupy the corresponding pilot resources to send an uplink reference signal to the base station. In the scenario where multiple UEs send uplink reference signals to the base station, in order to distinguish the uplink reference signals sent by different UEs, the UE can send the uplink reference signal to the base station through an uplink reference signal orthogonal multiplexing method (or called an orthogonal multiplexing method), so that the base station can distinguish the received signal corresponding to the uplink reference signal on each pilot resource from the received signal and perform channel estimation. For example, assuming that the uplink reference signal sent on the kth pilot resource is s k The base station can distinguish the received signal y on the kth pilot resource from the received signal based on the orthogonal multiplexing of the pilot resourcek , and based on y k =h k s k Perform channel estimation to obtain the channel h corresponding to the kth pilot resource k .

[0069] Optionally, the orthogonal multiplexing method may include time division multiplexing, frequency division multiplexing or code division multiplexing.

[0070] Time division multiplexing (TDM) means that uplink reference signals can be distributed across different orthogonal frequency division multiplexing (OFDM) symbols in different time slots. Accordingly, the base station can distinguish the received signals of each uplink reference signal by using different slots and OFDM symbols. For example, in the TDM shown in Figure 2, the uplink reference signals sent by UE0 and UE1 occupy OFDM symbol 12 and 13, respectively.

[0071] Frequency division multiplexing can include resource block (RB) frequency division and comb frequency division (or called sparse division), where RB frequency division means that the uplink reference signal can be distributed on different RBs. Accordingly, the base station can distinguish the received signals of each uplink reference signal through different RBs. Sparse division means that the uplink reference signal can be distributed on different resource elements (REs) in the same RB. Accordingly, the base station can distinguish the received signals of each uplink reference signal through different REs. For example, as shown in Figure 2, the uplink reference signals sent by UE0 and UE1 occupy different REs of the same RB.

[0072] Code division multiplexing refers to constructing orthogonal coding through cyclic shift, so that the uplink reference signal can be orthogonal in the delay domain so that the UE can send the uplink reference signal to the base station on the same RE resources.

[0073] In summary, the pilot resources used in time division multiplexing and frequency division multiplexing are different and naturally orthogonal. Therefore, when the UE transmits uplink reference signals to the base station using time division or frequency division, it can use different time-frequency resources to implement pilot resource multiplexing. In code division multiplexing, the UE uses the same pilot resources (or time-frequency resources). In this case, to implement code division multiplexing of the uplink reference signals, the uplink reference signals are transformed (such as DFT) to make them orthogonal in the delay domain (or DFT transform domain). The following describes the process of code division multiplexing of uplink reference signals.

[0074] Assume that when multiple UEs send uplink reference signals in code division multiplexing mode, the multiplexed pilot resources are N resource elements (REs). The frequency domain channel on N REs can be expressed as a column vector H = (h1,h2,…,h N ) T The N-dimensional DFT matrix is ​​represented by D=(D0,D1,…,D N-1 ),in is the kth DFT vector, and the N DFT vectors in the DFT matrix are mutually orthogonal. Assume that the DFT transform domain transform form of the frequency domain channel H can be expressed as H = DC, C is the DFT transform domain channel coefficient, and C = (c1, c2, ..., c K ,0,0,…,0) T , where the number of non-zero coefficients in C is determined by the delay spread of the channel. Delay spread can refer to the difference between the maximum transmission delay and the minimum transmission delay. The larger the delay spread, the more non-zero coefficients in C. Conversely, the smaller the delay spread, the fewer non-zero coefficients in C. The positions of the non-zero coefficients in C are only examples.

[0075] Assume that the UE sends an uplink reference signal s on the nth RE n , at this time, in the uplink reference signal s n Multiply by the weight Then the received signal received by the base station can be expressed as Accordingly, the UE sends an uplink reference signal s on N REs. n It can be equivalent to UE in the channel The uplink reference signal s is sent n , which is equivalent to performing a time delay shift (or delay domain shift) on the N REs (or channels) that transmit the uplink reference signal in the time domain. In the above H = DC, and C = (c1, c2, ..., c K ,0,0,…,0) T Based on this, we can derive the equivalent channel in

[0076] From the above description, it can be seen that when the UE sends an uplink reference signal, the channel for sending the uplink reference signal (or understood as the pilot resource corresponding to the uplink reference signal) is shifted in the delay domain by multiplying the uplink reference signal by an additional weight, thereby changing the channel when sending the uplink reference signal, so that the channels of different UEs sending uplink reference signals on the same pilot resource are orthogonal, so that the base station side can distinguish the uplink reference signals sent by different UEs based on the orthogonal channels, thereby realizing code division multiplexing on the same pilot resource. Exemplarily, as shown in FIG3 , uplink reference signal A and uplink reference signal B are sent to the base station on the same pilot resource (or called time-frequency resource / channel) by code division multiplexing. Originally, the time delays corresponding to the channels of UE1 and UE2 are the same. Sending uplink reference signal A and uplink reference signal B on the same time-frequency resource will cause the base station side to be unable to distinguish uplink reference signal A and uplink reference signal B from the signal received by the time-frequency resource. At this time, the above-mentioned method can be used to multiply the uplink reference signal B by an additional weight to change the channel corresponding to the uplink reference signal B, so that the channel corresponding to the uplink reference signal A and the channel corresponding to the uplink reference signal B can be staggered in the time delay domain, and the two are orthogonal. UE1 and UE2 can use the same time-frequency resource to send uplink reference signal A and uplink reference signal B to the base station respectively. After the base station receives the signal on the time-frequency resource, it can be based on the equivalent channel corresponding to each UE and the channel estimation formula y k =h k s k The received signal is processed to obtain channels corresponding to uplink reference signal A and uplink reference signal B.

[0077] As can be seen from the above, the channel can be obtained based on the DFT matrix and the non-zero coefficients in the DFT transform domain coefficients C. The fewer the number of non-zero transform domain coefficients corresponding to the channel, the more channels that can be measured simultaneously on the same time-frequency resource, and the better the code division multiplexing capability of the uplink reference signal. However, the DFT transform domain is a method of representing the channel transform domain in a fixed form. For different channels, the method of representing the channel transform domain in this fixed form is not necessarily the method with the highest multiplexing capability. In other words, the code division multiplexing capability corresponding to the DFT transform domain is not the optimal method. As a result, when there are too many uplink reference signals, that is, when the multiplexing quantity is high, there is a problem of not being able to transmit the uplink reference signals to the base station in a timely manner. For example: assuming that based on the number of DFT vectors and the delay spread, orthogonal multiplexing of 4 equivalent channels can be achieved, that is, the maximum code division multiplexing capability is 4, at this time, if there are 8 UEs that need to transmit uplink reference signals on the same pilot resource through code division multiplexing, this cannot be achieved.

[0078] In view of this, an embodiment of the present application provides a channel estimation method, in which a terminal device can report first indication information of the channel characteristics of the channel between the terminal device and the network device to a network device, and the network device can determine the characteristic weight of the channel based on the first indication information, and send second indication information for indicating the characteristic weight to the terminal device. After obtaining the characteristic weight, the terminal device can determine a first uplink reference signal based on the pilot base sequence and the characteristic weight, and send the first uplink reference signal to the network device.

[0079] Thus, in the present application, the characteristic weights are not simply obtained from the DFT matrix, but are determined based on the channel characteristics of the channel, that is, the network equipment can design the characteristic weights based on the channel characteristics so that the characteristic weights are more in line with the channel characteristics of the corresponding channel, that is, the characteristic weights have the best uplink reference signal multiplexing capability under the channel characteristics. Therefore, the channel estimation method provided by the present application can effectively improve the code division multiplexing capability when the same pilot resource or channel transmits the uplink reference signal, so that when the number of uplink reference signals is too large, the uplink reference signal can also be transmitted to the base station in a timely manner.

[0080] Figure 4 is an application scenario diagram of a communication system provided by an embodiment of the present application. As shown in Figure 4, the application scenario diagram includes a network device 401 and terminal devices UE1-UE6.

[0081] The terminal device involved in the present application can be a UE, access terminal, terminal unit, user station, terminal station, mobile station, mobile station, remote station, remote terminal, user terminal terminal equipment, TE), mobile device, wireless communication device, terminal agent, tablet computer (pad), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, vehicle-mounted device, vehicle-mounted transceiver unit, wearable device, or terminal device in a 5G network or a public land mobile network (PLMN) evolved after 5G. The access terminal can be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a drone, a robot, a smart point of sale (POS) machine, customer-premises equipment (CPE) or wearable device, virtual reality (VR) terminal device, augmented reality (AR) terminal device. The terminal device may be a wireless terminal device used in augmented reality (AR), industrial control, self-driving, remote medical, smart grid, transportation safety, smart city, or smart home applications. Alternatively, the terminal device may be a terminal with communication capabilities in the Internet of Things (IoT), such as a terminal in V2X (e.g., a vehicle-to-everything (V2X) device), a terminal in D2D communication, or a terminal in M2M communication. The terminal device may be mobile or fixed.

[0082] The embodiments of this application do not limit the form of the terminal device. The device used to implement the functions of the terminal device can be the terminal device; it can also be a device that supports the terminal device to implement the functions, such as a chip system. The device can be installed in the terminal device or used in conjunction with the terminal device. In the embodiments of this application, the chip system can be composed of chips or include chips and other discrete devices.

[0083] The network device involved in the present application may be a device for communicating with a terminal device, for example, it may include an evolved base station (NodeB or eNB or e-NodeB, evolutionary Node B) in a long term evolution (LTE) system or an enhanced LTE (LTE-advanced, LTE-A) system, such as a traditional macro base station eNB and a micro base station eNB in ​​a heterogeneous network scenario. Alternatively, it may include a next generation node B (gNB) in an NR system. Alternatively, it may include a transmission reception point (TRP), a home base station (e.g., home evolved NodeB, or home Node B, HNB), a base band unit (BBU), a base band pool (BBU pool), or a wireless fidelity (WiFi) access point (AP), etc. Alternatively, it may include a base station in a non-terrestrial network (NTN), which can be deployed on an aircraft or satellite. In an NTN, the network device can function as a Layer 1 (L1) relay, a base station, or an integrated access and backhaul (IAB) node. Alternatively, the network device can be a device that implements base station functions in the IoT, such as drone communications, V2X, D2D, or machine-to-machine (M2M) communications.

[0084] In some embodiments, the terminal device may include UE1-UE6 shown in Figure 4. In the communication system, UE1-UE6 may send uplink data to network device 401. After receiving the uplink data sent by UE1-UE6, network device 401 may send downlink data to UE1-UE6.

[0085] In some embodiments, UE4-UE6 in the above-mentioned terminal device 402 can also form a communication system. In this communication system, UE1-UE6 can send uplink data to the network device 401. After receiving the uplink data sent by UE1-UE6, the network device 401 can send downlink data to UE1, UE2, UE3 and UE5, and UE5 can send downlink data to UE4 and UE6.

[0086] To support data transmission between a terminal device and a base station, the terminal device and the base station may include the protocol layer shown in Figure 5. Figure 5 is a schematic diagram of the structure of a communication system provided in an embodiment of the present application. As shown in Figure 5, the schematic diagram includes a network device and a terminal device, wherein the network device is an entity on the network side for transmitting or receiving signals, such as a base station. The terminal device is an entity on the user side for receiving or transmitting signals, such as a user equipment terminal.

[0087] Both network devices and terminal devices may include a radio resource control (RRC) module, a MAC module, and a physical layer (PHY) module. The RRC module is used by network devices and terminal devices to send and receive RRC signaling, the MAC module is used by network devices and terminal devices to send and receive MAC-CE signaling, and the PHY module is used by network devices and terminal devices to send and receive uplink control signaling, downlink control signaling, uplink data, and downlink data.

[0088] In an embodiment of the present application, the first indication information reported by the terminal device can be carried in RRC signaling, MAC-CE signaling, physical uplink control channel (Physical Uplink Control Channel, PUCCH) or physical uplink shared channel (Physical Uplink Shared Channel, PUSCH), and the second indication information sent by the network device can be carried in RRC signaling, MAC-CE signaling, physical downlink control channel (Physical Downlink Control Channel, PDCCH) or physical downlink shared channel (Physical Downlink Shared Channel, PDSCH).

[0089] The following describes the channel estimation method provided by an embodiment of the present application in conjunction with the communication system shown in FIG4. FIG6 is a schematic diagram of the interaction flow of a channel estimation method provided by an embodiment of the present application. As shown in FIG6, the method includes:

[0090] S601: A terminal device reports first indication information to a network device. Correspondingly, the network device receives the first indication information from the terminal device.

[0091] The first indication information is used to indicate the channel characteristics of the channel between the terminal device and the network device.

[0092] The terminal device may be any of UE1-UE6 in Figure 4 . The network device may be the base station in Figure 4 . The terminal device supports sending an uplink reference signal to the network device via code division multiplexing, where the uplink reference signal is composed of a pilot sequence or a pilot base sequence. It should be understood that during code division multiplexing, multiple UEs can simultaneously send uplink reference signals via the same pilot resource or channel. The embodiment shown in Figure 6 uses the process of one UE sending an uplink reference signal as an example. The process of other UEs sending uplink reference signals can refer to this method.

[0093] In the embodiment of the present application, based on the transmission direction of the data on the channel, the channel between the terminal device and the network device may include an uplink channel or a downlink channel, without limitation. The uplink channel may refer to the channel used by the terminal device to send data to the network device, or it may be understood as a channel from the terminal device to the network device. The downlink channel may refer to the channel used by the network device to send data to the terminal device, or it may be understood as a channel from the network device to the terminal device. Since the channel has reciprocity, the channel characteristics of the uplink channel and the downlink channel between the same terminal device and the same network device may be the same, or have a certain correlation. The relevant description of the channel characteristics can be as described above and will not be repeated here.

[0094] From the perspective of the domain corresponding to the channel, the channel between the terminal device and the network device can include time domain channel, frequency domain channel and time-frequency domain channel.

[0095] From the perspective of the transmission direction and domain division of the data corresponding to the channel, the channel between the terminal device and the network device can include the time domain channel corresponding to the uplink channel, the frequency domain channel corresponding to the uplink channel, and the time-frequency domain channel corresponding to the uplink channel, as well as the time domain channel corresponding to the downlink channel, the frequency domain channel corresponding to the downlink channel, and the time-frequency domain channel corresponding to the downlink channel.

[0096] In an embodiment of the present application, the first indication information may be used to directly or indirectly indicate channel characteristics of a channel.

[0097] When the channel between the terminal device and the network device is an uplink channel, the first indication information may include or indicate the characteristic basis of the uplink channel or a second uplink reference signal, wherein the second uplink reference signal can be used to determine the characteristic basis of the uplink channel, and the second uplink reference signal can be pre-specified by the protocol.

[0098] Optionally, when the first indication information includes or indicates a second uplink reference signal of an uplink channel, when the terminal device sends the second uplink reference signal to the network device, the terminal device may adopt time division multiplexing, frequency division multiplexing or code division multiplexing in the relevant technology to send the second uplink reference signal to the network device. For example, when the terminal device sends the second uplink reference signal to the network device by code division multiplexing, the terminal device may select a vector from the DFT matrix as a weight, and use the weight to transform the second uplink reference signal. In this way, the second uplink reference signal can be orthogonally multiplexed in the delay domain, so that the second uplink reference signal can be transmitted to the network device on the same RE.

[0099] In the case where the channel between the terminal device and the network device is a downlink channel, the first indication information may include or indicate a characteristic basis of the downlink channel, or the first indication information may directly or indirectly indicate a channel characteristic of the downlink channel.

[0100] Optionally, the characteristic basis can be obtained by performing singular value decomposition on the statistical covariance matrix of the channel. Assume that the terminal device or network device obtains T channel samples, which are expressed as the channel matrix t=1,2,…,T, where N is the number of channel units. The device calculates the channel statistical covariance matrix And perform singular value decomposition on R to obtain the first K eigenvectors U1, U2, ..., U3 with the largest eigenvalue corresponding to R.

[0101] On the basis that the channel between the above-mentioned terminal device and the network device may include a time domain channel, a frequency domain channel or a time-frequency domain channel, the characteristic basis may include a frequency domain basis, a time domain basis or a time-frequency domain basis, and the above-mentioned channel unit may be a channel frequency domain unit, a channel time domain unit or a channel time-frequency unit.

[0102] Optionally, the network device sends a downlink reference signal to the terminal device, and the terminal device determines a characteristic basis of a channel between the terminal device and the network device based on the downlink reference signal, and then reports first indication information to the network device based on the determined characteristic basis.

[0103] Specifically, the downlink reference signal can be replaced by a pilot signal sent by a network device to a terminal device for measuring CSI. The downlink reference signal can specifically be a channel state information reference signal (Channel State Information-Reference Signal, CSI-RS). After receiving the CSI-RS, the terminal device can measure the CSI-RS to obtain the downlink channel H. After multiple measurements, the channel statistical covariance matrix is ​​determined based on samples of multiple channels H, thereby determining the characteristic basis of the channel between the terminal device and the network device.

[0104] In the above technical solution, the first indication information may include or indicate the characteristic basis of the channel, wherein the characteristic basis is the characteristic vector of the channel in the characteristic transform domain, and the sparsity of the channel in the characteristic transform domain is sparser than that in the DFT transform domain, that is, compared with the DFT transform domain, the number of characteristic coefficients used to represent the channel in the characteristic transform domain is smaller. For example, the same channel needs to be represented by 5 DFT vectors and corresponding coefficients in the DFT transform domain, while in the characteristic transform domain, it only needs to be represented by 3 characteristic bases and corresponding coefficients. Therefore, when the terminal device transforms the pilot base sequence based on the characteristic weights determined by the characteristic basis of the channel, the number of mutually orthogonal equivalent channels obtained will be further enhanced, thereby improving the code division multiplexing capability when transmitting uplink reference signals through the same pilot resource or channel.

[0105] In an optional embodiment, before the terminal device reports the first indication information of the channel characteristics of the channel between the terminal device and the network device, the terminal device may also receive a downlink reference signal from the network device and determine the characteristic basis of the channel based on the downlink reference signal.

[0106] S602: The network device determines a characteristic weight of the channel based on the first indication information.

[0107] Specifically, in some embodiments, when the first indication information includes a characteristic basis of a channel, after receiving the first indication information, the network device may determine a characteristic weight of the channel based on the characteristic basis of the channel included in the first indication information.

[0108] In other embodiments, when the first indication information includes a second uplink reference signal, after receiving the first indication information, the network device may first determine the characteristic basis of the channel between the terminal device and the network device based on the second uplink reference signal included in the first indication information, and then determine the characteristic weight of the channel based on the characteristic basis of the channel.

[0109] In an optional embodiment, the network device determines the characteristic weight of the channel based on the characteristic basis of the channel. The characteristic basis is multiplied element-by-element by the characteristic weight to obtain an equivalent basis. To ensure high channel estimation accuracy, the inner product of different equivalent basis values ​​must be as small as possible, while the inner product of the equivalent basis itself must be as large as possible. Furthermore, the characteristic weight must meet the terminal transmit power limit. Therefore, the characteristic weight must meet the following conditions:

[0110] Where i represents the SRS port number, j represents the feature base number, and U ij represents the characteristic basis, P i represents the feature weight, ⊙ represents element-by-element multiplication, P maxIndicates the maximum transmit power of the terminal device, U mn Indicates that except U ij Another characteristic basis, P m It means except P i Another feature weight besides .

[0111] S603: The network device sends second indication information to the terminal device. Correspondingly, the terminal device receives the second indication information from the network device.

[0112] The second indication information is used to indicate the feature weight.

[0113] In an optional implementation, the second indication information is used to indicate the feature weight, which may include but is not limited to the following two situations:

[0114] A. The second indication information may carry the feature weight.

[0115] B. The second indication information may be used to indicate an equivalent basis of a channel, wherein the equivalent basis of a channel is determined by a characteristic weight and a characteristic basis.

[0116] The following will explain the two situations respectively.

[0117] In some embodiments, the network device may send second indication information carrying feature weights to the terminal device.

[0118] Specifically, after determining the characteristic weight of the channel in S602, the network device may generate second indication information including the characteristic weight, and send the second indication information including the characteristic weight to the terminal device. In the above technical solution, the terminal device can directly obtain the characteristic weight from the second indication information and transform the pilot base sequence based on the characteristic weight to obtain the pilot sequence, which can effectively improve the efficiency of generating the pilot sequence and thereby effectively improve the efficiency of channel estimation performed by the base station.

[0119] In other embodiments, after the network device determines the characteristic weight of the channel through S602, it can first determine the equivalent basis of the channel based on the characteristic weight and the characteristic basis, then generate second indication information for indicating the equivalent basis of the channel, and send the second indication information to the terminal device. In the above technical solution, the characteristic weight can be determined by indicating the equivalent basis. Since the equivalent basis is determined based on the characteristic basis and the characteristic weight, for example, the equivalent basis can be obtained by multiplying the characteristic basis and the characteristic weight, the characteristic weight can be obtained in a variety of ways, thereby increasing the diversity and flexibility of the implementation of this solution.

[0120] In an optional implementation manner, the second indication information is used to indicate the equivalent basis of the channel, which may include but is not limited to the following two situations:

[0121] A. The second indication information may include a DFT decomposition matrix of an equivalent basis of the channel, wherein the DFT decomposition matrix of the equivalent basis refers to a matrix formed by coefficients of the equivalent basis in the DFT transform domain after performing DFT transform on the equivalent basis.

[0122] B. The second indication information may include the equivalent basis of the channel.

[0123] The following will explain the two situations respectively.

[0124] In some embodiments, after the network device determines the characteristic weight of the channel through S602, it can first determine the equivalent basis of the channel based on the characteristic weight and the characteristic basis, and determine the DFT decomposition matrix of the equivalent basis of the channel based on the equivalent basis of the channel, and then generate second indication information including the DFT decomposition matrix of the equivalent basis of the channel, and send the second indication information including the DFT decomposition matrix of the equivalent basis of the channel to the terminal device. In the above technical solution, the second indication information can indicate the equivalent basis of the channel through the DFT decomposition matrix of the equivalent basis. Since the number of non-zero elements in the DFT decomposition matrix is ​​less than the number of non-zero elements in the equivalent basis, the DFT decomposition matrix of the equivalent basis has less overhead than the equivalent basis. Therefore, by indicating the DFT decomposition matrix of the equivalent basis to further determine the characteristic weight, the signaling overhead in the interaction process can be further reduced, saving communication resources.

[0125] In other embodiments, after the network device determines the characteristic weight of the channel through S602, it can first determine the equivalent basis of the channel based on the characteristic weight and the characteristic basis, and then generate second indication information containing the equivalent basis, and send the second indication information containing the equivalent basis to the terminal device.

[0126] In an optional embodiment, the characteristic basis may include multiple basis. Therefore, in the process of determining the equivalent basis of the channel based on the characteristic weight and the characteristic basis, the following two methods may be included but not limited to:

[0127] A. Determine the equivalent basis of the channel based on the pre-specified feature basis and feature weight.

[0128] B. Determine an equivalent basis of the channel according to the characteristic weight and a first basis, wherein the first basis is a basis in the characteristic basis.

[0129] The above two situations will be described below respectively by taking the second indication information including the equivalent basis of the channel as an example.

[0130] Specifically, in some embodiments, after determining the characteristic weight of the channel, the network device may first determine the equivalent basis of the channel based on the characteristic weight and a pre-specified characteristic basis according to the following formula 1, then generate second indication information indicating the equivalent basis, and send the second indication information including the equivalent basis to the terminal device. i1 =U i1 ⊙P i (Formula 1)

[0131] Among them, D i1 represents the equivalent basis, U i1 represents the pre-specified feature basis, P i Represents the feature weight.

[0132] The pre-specified feature base may be a base pre-defined by the protocol. i1 is the feature basis with the largest corresponding eigenvalue among multiple feature bases; or, the protocol predefines U i1 It is the characteristic basis with the smallest corresponding eigenvalue among multiple characteristic bases.

[0133] Exemplarily, in one embodiment, assuming that the pre-specified characteristic basis is basis A, after the network device determines the characteristic weight of the channel, it can first determine the equivalent basis of the channel based on the characteristic weight and basis A, and then generate second indication information containing the equivalent basis, and send the second indication information containing the equivalent basis to the terminal device.

[0134] In other embodiments, after determining the characteristic weight of the channel, the network device may first select a basis from the characteristic basis as a first basis, then determine an equivalent basis of the channel based on the characteristic weight and the first basis according to the following formula 2, then generate second indication information indicating the equivalent basis and the first basis, and send the second indication information including the equivalent basis to the terminal device. i1 =U ij ⊙P i (Formula 2)

[0135] Among them, D i1 represents the equivalent basis, U ij represents the first basis, P i Represents the feature weight.

[0136] In an optional embodiment, the process of the network device selecting a substrate from the characteristic substrate as the first substrate may include but is not limited to the following two methods:

[0137] A. Select any one of the characteristic substrates as the first substrate.

[0138] B. Take the basis with the smallest cost among the equivalent basis corresponding to the characteristic basis as the first basis.

[0139] The following will explain the two situations respectively.

[0140] Specifically, in some embodiments, after the network device determines the characteristic weight of the channel, it can first select any basis from the characteristic basis as the first basis, then determine the equivalent basis of the channel based on the characteristic weight and the first basis, and then generate second indication information for indicating the equivalent basis and the first basis, and send the second indication information to the terminal device.

[0141] Exemplarily, in one embodiment, assuming that the basis selected by the network device from the characteristic basis is basis C, the network device can determine the equivalent basis of the channel based on the characteristic weight and basis C, and then generate second indication information for indicating the equivalent basis and the first basis, and send the second indication information to the terminal device.

[0142] In other embodiments, after the network device determines the characteristic weight of the channel, it can use the basis with the smallest overhead among the equivalent basis corresponding to the characteristic basis as the first basis, and then determine the equivalent basis of the channel based on the characteristic weight and the first basis, and then generate second indication information for indicating the equivalent basis and the first basis, and send the second indication information to the terminal device.

[0143] Exemplarily, in one embodiment, assuming that the basis with the smallest overhead among the equivalent basis corresponding to the characteristic basis is basis B, the network device can determine basis B as the first basis, and determine the equivalent basis of the channel based on the characteristic weight and basis B, and then generate second indication information for indicating the equivalent basis and the first basis, and send the second indication information to the terminal device.

[0144] In the above technical solution, the first basis is one of the characteristic basis, and the basis is a characteristic basis selected by the network device from multiple characteristic basis so that the indication overhead of the equivalent basis is relatively small, which can further reduce the signaling overhead in the process of indicating the equivalent basis.

[0145] In an optional embodiment, each of the multiple substrates included in the characteristic substrate has a corresponding substrate serial number. Accordingly, the second indication information used to indicate the first substrate may include but is not limited to the following two situations:

[0146] A. The second indication information includes the first base.

[0147] B. The second indication information includes the base serial number of the first base.

[0148] The following will illustrate the above two situations respectively by taking the basis with the smallest cost among the equivalent basis corresponding to the characteristic basis as the first basis as an example.

[0149] Specifically, in some embodiments, after the network device determines the characteristic weight of the channel, it can use the basis with the smallest overhead among the equivalent basis corresponding to the characteristic basis as the first basis, and then determine the equivalent basis of the channel based on the characteristic weight and the first basis, and then generate second indication information containing the equivalent basis and the first basis, and send the second indication information to the terminal device.

[0150] In other embodiments, after the network device determines the characteristic weight of the channel, it can use the basis with the smallest overhead among the equivalent basis corresponding to the characteristic basis as the first basis, and then determine the equivalent basis of the channel based on the characteristic weight and the first basis, and then generate second indication information containing the basis sequence number of the equivalent basis and the first basis, and send the second indication information to the terminal device.

[0151] S604: The terminal device obtains a characteristic weight of a channel between the terminal device and the network device.

[0152] The characteristic weight of the channel is determined by the network device based on the first indication information.

[0153] Specifically, after receiving the second indication information from the network device, the terminal device can obtain the characteristic weight of the channel between the terminal device and the network device based on the second indication information.

[0154] In an optional implementation, when the second indication information carries a characteristic weight, the terminal device may directly obtain the characteristic weight of the channel between the terminal device and the network device from the second indication information after receiving the second indication information.

[0155] In an optional embodiment, when the above-mentioned second indication information includes the DFT decomposition matrix of the equivalent basis of the channel, after receiving the second indication information, the terminal device can first determine the corresponding equivalent basis based on the DFT decomposition matrix in the second indication information, and then obtain the characteristic weight of the channel between the terminal device and the network device based on the pre-specified characteristic basis and the equivalent basis.

[0156] In an optional embodiment, in the case where the equivalent basis of the channel is indicated in the above-mentioned second indication information, after receiving the second indication information, the terminal device can obtain the characteristic weight of the channel between the terminal device and the network device based on the equivalent basis in the second indication information and the pre-specified characteristic basis.

[0157] For example, in one embodiment, it is assumed that the pre-specified feature basis is Ui1 , the equivalent basis is D i1 , and U i1 It can be expressed by the following formula 3: i1 It can be expressed by the following formula 4: the terminal device can be based on the equivalent basis D i1 and a pre-specified characteristic basis U i1 The characteristic weight P of the channel between the terminal device and the network device is determined by the following formula 5: i .

[0158] in, represents element-wise division, and N represents the number of REs.

[0159] In an optional embodiment, when the above-mentioned second indication information includes the equivalent basis and the first basis of the channel, after receiving the second indication information, the terminal device can obtain the characteristic weight of the channel between the terminal device and the network device based on the equivalent basis and the first basis in the second indication information.

[0160] In an optional embodiment, when the above-mentioned second indication information includes the equivalent basis of the channel and the basis serial number of the first basis, after receiving the second indication information, the terminal device can first determine the first basis based on the basis serial number in the second indication information, and then obtain the characteristic weight of the channel between the terminal device and the network device based on the equivalent basis and the first basis.

[0161] S605: The terminal device sends a first uplink reference signal to the network device. Correspondingly, the network device receives the first uplink reference signal from the terminal device.

[0162] The first uplink reference signal is determined according to the pilot base sequence and the characteristic weight.

[0163] Exemplarily, the terminal device determines a pilot sequence according to the pilot base sequence and the characteristics, forms a first uplink reference signal with the pilot sequence, and sends the first uplink reference signal to the network device.

[0164] Accordingly, after receiving the first uplink reference signal including the pilot sequence, the network device can perform channel estimation on the channel between the terminal device and the network device based on the characteristic basis of the channel and the pilot sequence.

[0165] After acquiring the characteristic weight in the manner shown in S604 , the terminal device may first determine a pilot sequence based on the pilot base sequence and the characteristic weight, and then send a first uplink reference signal including the pilot sequence to the network device.

[0166] Specifically, after obtaining the characteristic weight, the terminal device determines the pilot sequence according to the following formula 6. L=x i ⊙P i (Formula 6)

[0167] Where L represents the pilot sequence, x i represents the pilot base sequence, P i Represents the feature weight.

[0168] For example, it is assumed that Formula 7 is the feature weight P obtained by the terminal device i , Formula 8 is the pilot base sequence x i , the pilot sequence L determined according to formula 6 can be expressed by formula 9.

[0169] After the terminal device determines the pilot sequence in the above manner, it can send a first uplink reference signal to the network device through the port i corresponding to the terminal device. After receiving the first uplink reference signal, the network device can use a channel estimation algorithm to determine the characteristic coefficient corresponding to the characteristic basis, and perform channel estimation on the channel between the terminal device and the network device based on the characteristic coefficient.

[0170] For example, in one embodiment, after receiving the first uplink reference signal, the network device may use the following formulas 10 and 11 to derive formula 12, and then derive formula 13 from formula 12 to obtain the characteristic coefficient corresponding to the characteristic basis, and perform channel estimation on the channel between the terminal device and the network device based on the characteristic coefficient. k =∑ i H ik ⊙P i ⊙x i (Formula 10) y k =∑ i ∑ j c ijk U ij ⊙P i ⊙x i (Formula 12)

[0171] Among them, H ik represents the channel between the terminal device’s port i and the network device’s antenna k. ijk represents the characteristic coefficients of the terminal device's port i and the network device's antenna k on the characteristic basis j, and c ijk =(c1,c2,…,c B ,0,0,…,0) T .y kIndicates receiving a signal.

[0172] Optionally, if the design of the above feature weights satisfies Under this condition, the above formula 13 can be expressed by the following formula 14.

[0173] Right now

[0174] In the embodiment of the present application, U ij It can be the statistical covariance matrix E(HH H ) is the eigenvector obtained after singular value decomposition.

[0175] In the embodiment of the present application, multiple antennas of a network device may share a set of characteristic bases, but different antennas may have different corresponding characteristic coefficients.

[0176] In the above technical solution, the pilot sequence is generated based on the pilot base sequence and the characteristic weight, and the characteristic weight is determined by the network device based on the channel characteristics of the channel. It can be seen that in the present application, the characteristic weight is not simply obtained from the DFT matrix, but is determined based on the channel characteristics of the channel, that is, the network device can design the characteristic weight based on the channel characteristics, so that the characteristic weight is more in line with the channel characteristics of the corresponding channel, that is, the characteristic weight corresponds to the optimal uplink reference signal multiplexing capability under the channel characteristics. Therefore, the channel estimation method provided by the present application can effectively improve the code division multiplexing capability when the same pilot resource or channel transmits the uplink reference signal, so that when the number of uplink reference signals is too large, the uplink reference signal can also be transmitted to the base station in a timely manner.

[0177] Optionally, an embodiment of the present application provides a flow chart of a channel estimation method, which is applied to a terminal device. The method includes the following steps A to C:

[0178] Step A: Report first indication information to the network device.

[0179] The first indication information is used to indicate the channel characteristics of the channel between the terminal device and the network device.

[0180] Step B: Obtain the characteristic weight of the channel between the terminal device and the network device.

[0181] The characteristic weight of the channel is determined by the network device based on the first indication information.

[0182] Step C: Send a first uplink reference signal to the network device.

[0183] The first uplink reference signal is determined based on the pilot base sequence and characteristic weight of the terminal device.

[0184] Optionally, an embodiment of the present application provides a flow chart of a channel estimation method, which is applied to a network device. The method includes the following steps D to F:

[0185] Step D: Receive first indication information from the terminal device.

[0186] The first indication information is used to indicate the channel characteristics of the channel between the terminal device and the network device.

[0187] Step E: Determine the characteristic weight of the channel based on the first indication information.

[0188] Step F: Send the second indication information to the terminal device.

[0189] The second indication information is used to indicate the feature weight.

[0190] FIG7 is a schematic diagram of the structure of a channel estimation device provided in an embodiment of the present application. The data transmission device is located in a terminal device and includes a transceiver module 701 and a processing module 702.

[0191] The transceiver module 701 is configured to report first indication information to the network device, where the first indication information is used to indicate a channel characteristic of a channel between the terminal device and the network device;

[0192] The processing module 702 is configured to obtain a characteristic weight of a channel between the terminal device and the network device; the characteristic weight of the channel is determined based on the first indication information;

[0193] The processing module 702 is further configured to generate a first uplink reference signal, where the first uplink reference signal is determined based on a pilot base sequence and a characteristic weight of the terminal device;

[0194] The transceiver module 701 is further configured to send a first uplink reference signal to the network device.

[0195] In an optional implementation manner, the first indication information indicates a characteristic basis of a channel; or the first indication information indicates a second uplink reference signal.

[0196] In an optional embodiment, the channel includes a time domain channel, and the characteristic basis of the channel includes a time domain basis; or, the channel includes a frequency domain channel, and the characteristic basis of the channel includes a frequency domain basis; or, the channel includes a time-frequency domain channel, and the characteristic basis of the channel includes a time-frequency domain basis.

[0197] In an optional implementation, the transceiver module 701 is further configured to: receive second indication information, where the second indication information is used to indicate a feature weight.

[0198] The processing module 702 is further configured to: obtain a characteristic weight of a channel between the terminal device and the network device based on the second indication information.

[0199] In an optional implementation, the transceiver module 701 is further configured to: receive second indication information, where the second indication information is used to indicate an equivalent basis of a channel.

[0200] The processing module 702 is further configured to obtain a characteristic weight of a channel between the terminal device and the network device based on the equivalent basis and the characteristic basis.

[0201] In an optional embodiment, the characteristic basis includes multiple basis; the second indication information is further used to indicate a first basis; and the first basis is one of the characteristic basis. The processing module 702 is further used to determine a characteristic weight of a channel between the terminal device and the network device based on the equivalent basis and the first basis.

[0202] In an optional implementation manner, the second indication information indicates a DFT decomposition matrix of an equivalent basis of the channel.

[0203] In an optional implementation, the transceiver module 701 is further configured to: receive a downlink reference signal from a network device,

[0204] The processing module 702 is further configured to determine a characteristic basis of a channel according to the downlink reference signal.

[0205] FIG8 is a schematic diagram of the structure of a channel estimation device provided in an embodiment of the present application. The data transmission device is located in a network device and includes a transceiver module 801 and a processing module 802.

[0206] The transceiver module 801 is used to receive first indication information from a terminal device, where the first indication information is used to indicate channel characteristics of a channel between the terminal device and the network device.

[0207] The processing module 802 is configured to determine a characteristic weight of a channel based on the first indication information.

[0208] The transceiver module 801 is further configured to send second indication information to the terminal device, wherein the second indication information is used to indicate a feature weight.

[0209] In an optional implementation manner, the first indication information indicates a characteristic basis of a channel; or the first indication information indicates an uplink reference signal.

[0210] In an optional embodiment, the channel includes a time domain channel, and the characteristic basis of the channel includes a time domain basis; or, the channel includes a frequency domain channel, and the characteristic basis of the channel includes a frequency domain basis; or, the channel includes a time-frequency domain channel, and the characteristic basis of the channel includes a time-frequency domain basis.

[0211] In an optional implementation, the transceiver module 701 is specifically configured to send second indication information carrying feature weights to the terminal device.

[0212] In an optional implementation, the second indication information is used to indicate an equivalent basis of the channel; the equivalent basis of the channel is determined by the characteristic weight and the characteristic basis.

[0213] In an optional embodiment, the characteristic basis includes multiple bases; the second indication information is further used to indicate the first basis; the first basis is one of the characteristic bases; and the equivalent basis of the channel is determined by the characteristic weight and the first basis.

[0214] In an optional implementation manner, the second indication information indicates a DFT decomposition matrix of an equivalent basis of the channel.

[0215] In an optional implementation, the transceiver module 801 is further configured to receive a first uplink reference signal from a terminal device.

[0216] The processing module 802 is further configured to perform channel estimation on the channel between the terminal device and the network device based on the characteristic basis of the channel and the first uplink reference signal.

[0217] The embodiment of the present application also provides a chip. The chip integrates a control circuit and one or more ports for implementing the functions of the above-mentioned network evaluation device. Optionally, the functions supported by the chip can be referred to above and will not be repeated here. A person of ordinary skill in the art will understand that all or part of the steps of implementing the above-mentioned embodiment can be completed by a program to instruct the relevant hardware. The program can be stored in a computer-readable storage medium. The storage medium mentioned above can be a read-only memory, a random access memory, etc. The above-mentioned processing unit or processor can be a central processing unit, a general-purpose processor, an application specific integrated circuit (ASIC), a microprocessor (digital signal processor, DSP), a field programmable gate array (FPGA) or other programmable logic device, transistor logic device, hardware component or any combination thereof.

[0218] The present application also provides a computer program product comprising instructions, which, when executed on a computer, causes the computer to perform any of the methods described in the above embodiments. The computer program product comprises one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available media may be magnetic media (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., SSD).

[0219] It should be noted that the above-mentioned devices for storing computer instructions or computer programs provided in the embodiments of the present application, such as but not limited to the above-mentioned memories, computer-readable storage media and communication chips, etc., are all non-transitory.

[0220] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware, or any combination thereof. When implemented using a software program, all or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions according to the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0221] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art may understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0222] Although the present application has been described with reference to specific features and embodiments thereof, it is apparent that various modifications and combinations may be made thereto without departing from the spirit and scope of the present application. Accordingly, this specification and the drawings are merely illustrative of the present application as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present application. Obviously, those skilled in the art may make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, the present application is intended to include such modifications and variations as fall within the scope of the claims of the present application and their equivalents.

Claims

1. A channel estimation method, characterized in that: Applied to a terminal device, the method comprises: Reporting first indication information to a network device, where the first indication information is used to indicate a channel characteristic of a channel between the terminal device and the network device; Acquire a characteristic weight of a channel between the terminal device and the network device; the characteristic weight of the channel is determined based on the first indication information; A first uplink reference signal is sent to the network device, where the first uplink reference signal is determined based on the pilot base sequence of the terminal device and the characteristic weight.

2. The method according to claim 1, characterized in that The first indication information indicates a characteristic basis of the channel; or, the first indication information indicates a second uplink reference signal.

3. The method according to claim 2, characterized in that The channel includes a time domain channel, and the characteristic basis of the channel includes a time domain basis; or, the channel includes a frequency domain channel, and the characteristic basis of the channel includes a frequency domain basis; or, the channel includes a time-frequency domain channel, and the characteristic basis of the channel includes a time-frequency domain basis.

4. The method according to claim 1, characterized in that The obtaining of the characteristic weight of the channel between the terminal device and the network device includes: receiving second indication information; the second indication information is used to indicate the feature weight; Based on the second indication information, a characteristic weight of a channel between the terminal device and the network device is obtained.

5. The method according to claim 1, characterized in that The obtaining of the characteristic weight of the channel between the terminal device and the network device includes: receiving second indication information; the second indication information is used to indicate an equivalent basis of the channel; Based on the equivalent basis and the characteristic basis, a characteristic weight of a channel between the terminal device and the network device is determined.

6. The method according to claim 5, characterized in that The characteristic substrate includes a plurality of substrates; the second indication information is also used to indicate a first substrate; the first substrate is one of the characteristic substrates; The determining, based on the equivalent basis and the characteristic basis, the characteristic weight of the channel between the terminal device and the network device comprises: Based on the equivalent basis and the first basis, a characteristic weight of a channel between the terminal device and the network device is determined.

7. The method according to any one of claims 5-6, characterized in that: The second indication information indicates a discrete Fourier transform DFT decomposition matrix of an equivalent basis of the channel.

8. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: Receiving a downlink reference signal from the network device; A characteristic basis of the channel is determined according to the downlink reference signal.

9. A channel estimation method, characterized in that: Applied to a network device, the method comprises: receiving first indication information from a terminal device, where the first indication information is used to indicate a channel characteristic of a channel between the terminal device and the network device; Determining a characteristic weight of the channel based on the first indication information; Sending second indication information to the terminal device, where the second indication information is used to indicate the feature weight.

10. The method according to claim 9, characterized in that The first indication information indicates a characteristic basis of the channel; or, the first indication information indicates a second uplink reference signal.

11. The method according to claim 9, characterized in that The channel includes a time domain channel, and the characteristic basis of the channel includes a time domain basis; or, the channel includes a frequency domain channel, and the characteristic basis of the channel includes a frequency domain basis; or, the channel includes a time-frequency domain channel, and the characteristic basis of the channel includes a time-frequency domain basis.

12. The method according to claim 9, characterized in that The sending the second indication information to the terminal device includes: Sending second indication information carrying the feature weight to the terminal device.

13. The method according to claim 9, characterized in that The second indication information is used to indicate an equivalent basis of the channel; the equivalent basis of the channel is determined by the characteristic weight and the characteristic basis.

14. The method according to claim 13, characterized in that The characteristic basis includes multiple bases; the second indication information is also used to indicate a first basis; the first basis is one of the characteristic bases; the equivalent basis of the channel is determined by the characteristic weight and the first basis.

15. The method according to any one of claims 13-14, characterized in that: The second indication information indicates a discrete Fourier transform DFT decomposition matrix of an equivalent basis of the channel.

16. The method according to any one of claims 9 to 15, characterized in that: The method further comprises: Receiving a first uplink reference signal from the terminal device; Based on the characteristic basis of the channel and the first uplink reference signal, channel estimation is performed on the channel between the terminal device and the network device.

17. A channel estimation device, characterized in that: The device is located in a terminal device, and the device includes: A transceiver module, used to report first indication information to a network device, where the first indication information is used to indicate a channel characteristic of a channel between the terminal device and the network device; A processing module, configured to obtain a characteristic weight of a channel between the terminal device and the network device; the characteristic weight of the channel is determined based on the first indication information; The processing module is further used to generate a first uplink reference signal, where the first uplink reference signal is determined according to the pilot base sequence of the terminal device and the characteristic weight; The transceiver module is further used to send the first uplink reference signal to the network device.

18. The device according to claim 17, characterized in that The first indication information indicates a characteristic basis of the channel; or, the first indication information indicates a second uplink reference signal.

19. The device according to claim 18, characterized in that The channel includes a time domain channel, and the characteristic basis of the channel includes a time domain basis; or, the channel includes a frequency domain channel, and the characteristic basis of the channel includes a frequency domain basis; or, the channel includes a time-frequency domain channel, and the characteristic basis of the channel includes a time-frequency domain basis.

20. The device according to claim 17, characterized in that The transceiver module is also used for: receiving second indication information; the second indication information is used to indicate the feature weight; The processing module is further used to obtain a characteristic weight of a channel between the terminal device and the network device based on the second indication information.

21. The device according to claim 17, characterized in that The transceiver module is also used for: receiving second indication information; the second indication information is used to indicate an equivalent basis of the channel; The processing module is further used to obtain a characteristic weight of a channel between the terminal device and the network device based on the equivalent basis and the characteristic basis.

22. The device according to claim 21, characterized in that The characteristic substrate includes a plurality of substrates; the second indication information is also used to indicate a first substrate; the first substrate is one of the characteristic substrates; the processing module is further used to: Based on the equivalent basis and the first basis, a characteristic weight of a channel between the terminal device and the network device is obtained.

23. The device according to any one of claims 21-22, characterized in that The second indication information indicates a discrete Fourier transform DFT decomposition matrix of an equivalent basis of the channel.

24. The device according to any one of claims 17 to 23, characterized in that The transceiver module is also used for: Receiving a downlink reference signal from the network device; The processing module is further used to determine a characteristic basis of the channel according to the downlink reference signal.

25. A channel estimation device, characterized in that: The device is located in a network device, and the device includes: a transceiver module, configured to receive first indication information from a terminal device, wherein the first indication information is used to indicate a channel characteristic of a channel between the terminal device and the network device; A processing module, configured to determine a characteristic weight of the channel based on the first indication information; The transceiver module is further used to send second indication information to the terminal device, where the second indication information is used to indicate the feature weight.

26. The device according to claim 25, characterized in that The first indication information indicates a characteristic basis of the channel; or, the first indication information indicates a second uplink reference signal.

27. The device according to claim 25, characterized in that The channel includes a time domain channel, and the characteristic basis of the channel includes a time domain basis; or, the channel includes a frequency domain channel, and the characteristic basis of the channel includes a frequency domain basis; or, the channel includes a time-frequency domain channel, and the characteristic basis of the channel includes a time-frequency domain basis.

28. The device according to claim 25, characterized in that The transceiver module is specifically used for: Sending second indication information carrying the feature weight to the terminal device.

29. The device according to claim 25, characterized in that The second indication information is used to indicate an equivalent basis of the channel; the equivalent basis of the channel is determined by the characteristic weight and the characteristic basis.

30. The device according to claim 29, characterized in that The characteristic basis includes multiple bases; the second indication information is also used to indicate a first basis; the first basis is one of the characteristic bases; the equivalent basis of the channel is determined by the characteristic weight and the first basis.

31. The device according to claim 29 or 30, characterized in that The second indication information indicates a discrete Fourier transform DFT decomposition matrix of an equivalent basis of the channel.

32. The device according to any one of claims 25 to 31, characterized in that The transceiver module is also used for: Receiving a first uplink reference signal from the terminal device; The processing module is further used to perform channel estimation on the channel between the terminal device and the network device based on the characteristic basis of the channel and the first uplink reference signal.

33. A communication device, characterized in that: The communication device includes at least one processor coupled to at least one memory: The at least one processor is used to execute the computer program or instructions stored in the at least one memory, so that the communication device executes the channel estimation method according to any one of claims 1-16.

34. The communication device according to claim 33, characterized in that The communication device is a chip.

35. A communication system, characterized in that: The system comprises: a terminal device and a network device; The terminal device is used to perform the channel estimation method according to any one of claims 1 to 8; The network device is used to execute the channel estimation method as described in any one of claims 9-16.

36. A computer-readable storage medium, characterized in that: The method comprises a program code, and when the program code is executed on a computer or a processor, the computer or the processor executes the channel estimation method according to any one of claims 1 to 16.

Images