Method, apparatus, storage medium and electronic device for determining DOA

Abstract

Embodiments of the present application provide a method, device, storage medium and electronic device for determining DOA, wherein the method comprises: determining a target reference signal and a codebook value corresponding to the target reference signal, and configuring the codebook value to a smart reflective surface (RIS); obtaining a measurement result obtained by measuring the target reference signal by a receiving end after reflecting the target reference signal to the receiving end through the RIS, wherein the RIS reflects the reference signal according to the codebook value; and determining a target direction of arrival (DOA) based on the measurement result. Through the present application, the problems of low beam scanning accuracy and high tracking difficulty in the related art are solved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of communications, and more specifically, to a method, apparatus, storage medium, and electronic device for determining DOA. Background Technology

[0002] Smart reflectors can effectively improve the coverage of wireless communication signals, especially in the millimeter-wave band, where they have a very broad application prospect. Smart reflectors have become a very important evolution direction for B5G (Beyond 5G) and 6G. In practical communication systems, to improve the power gain of smart reflectors, it is usually necessary to increase the reflector area and use a narrow beam to cover user terminals. In the millimeter-wave band, a very small smart reflector can generate a very narrow beam. The narrower the beam, the greater the gain of the smart reflector, but the more beams the smart reflector needs to scan to target the user terminal, resulting in greater beam scanning resource overhead; conversely, widening the beam significantly reduces the power gain provided by the smart reflector.

[0003] Current research on beam scanning and tracking for smart reflectors is limited, while there is considerable research on beam scanning for millimeter-wave base stations. A common low-overhead beam scanning method for millimeter-wave base stations can be summarized as follows: first, a wide-beam scan is used to determine the approximate range of the user terminal; then, within the coverage area of ​​the wide beam, a narrow-beam scan is used to determine a more precise location. The accuracy of this scanning method is ultimately limited by the beamwidth and scanning interval of the narrow beam used. Obviously, to reduce resource overhead, the scanning interval cannot be infinitely reduced. For smart reflectors, the beam scanning method used for millimeter-wave base stations can be referenced. However, smart reflectors, due to their larger reflector area and narrower beamwidth, require scanning a greater number of beams, making high-precision beam scanning and tracking more challenging.

[0004] There is currently no effective solution to the problems of low beam scanning accuracy and high tracking difficulty in related technologies. Summary of the Invention

[0005] This invention provides a method, apparatus, storage medium, and electronic device for determining DOA, in order to at least solve the problems of low beam scanning accuracy and high tracking difficulty in related technologies.

[0006] According to an embodiment of the present invention, a method for determining the angle of arrival (DOA) is provided, comprising: determining a target reference signal and a codebook value corresponding to the target reference signal, and configuring the codebook value to a smart reflector RIS; obtaining a measurement result obtained by the receiver measuring the target reference signal after the target reference signal is reflected to a receiver by the RIS, wherein the RIS reflects the reference signal according to the codebook value; and determining the target angle of arrival (DOA) based on the measurement result.

[0007] In one exemplary embodiment, determining the codebook value corresponding to the target reference signal includes: determining the target beam between the RIS and the terminal; and determining the codebook value based on the position of the target beam.

[0008] In an exemplary embodiment, determining the target beam between the RIS and the terminal includes: determining the strongest beam between the RIS and the terminal whose RIS-side energy exceeds a predetermined threshold; and determining the strongest beam and the beams that satisfy the target relationship with the strongest beam as the target beam, wherein the beams that satisfy the target relationship with the strongest beam include at least one of the following: the second strongest beam adjacent to the strongest beam in azimuth, and the second strongest beam adjacent to the strongest beam in elevation.

[0009] In an exemplary embodiment, determining a target reference signal includes: configuring a predetermined number of the target reference signals in a time slot, wherein each target reference signal occupies one orthogonal frequency division multiplexing (OFDM) symbol; after determining the target reference signal, the method further includes: notifying the terminal and the RIS of parameter information of the target reference signal, wherein the parameter information includes at least one of the following: time slot information, OFDM symbol, frequency domain position, and mother code parameters.

[0010] In an exemplary embodiment, after notifying the RIS of the OFDM symbol of the target reference signal and configuring the codebook value to the RIS, the method further includes: the RIS sequentially switching the codebook indicated by the codebook value corresponding to each of the multiple target reference signals on the OFDM symbols where they are distributed; wherein the duration of each codebook is from the start time to the end time of the OFDM symbol.

[0011] In one exemplary embodiment, before acquiring the measurement result, the method further includes: configuring a target uplink reference signal to a terminal to instruct the terminal to transmit the target uplink reference signal, wherein the target reference signal includes the target uplink reference signal; acquiring the measurement result includes: measuring the target uplink reference signal reflected by the RIS to obtain the measurement result.

[0012] In one exemplary embodiment, before acquiring the measurement result, the method further includes: sending a target downlink reference signal to the terminal, wherein the target reference signal includes the target downlink reference signal; acquiring the measurement result includes: acquiring the measurement result obtained and reported by the terminal after measuring the target downlink reference signal reflected by the RIS.

[0013] In an exemplary embodiment, obtaining the measurement results reported by the terminal includes: obtaining the measurement results fed back by the terminal at one time on a predetermined time-frequency resource for each of the target downlink reference signals included in the target downlink reference signal, wherein the feedback order of each measurement result is consistent with the transmission order of the corresponding target downlink reference signal.

[0014] In one exemplary embodiment, determining the target reference signal and the codebook value corresponding to the target reference signal includes: determining the number of target reference signals and the number of codebook values ​​based on the spatial dimension of the target DOA.

[0015] In one exemplary embodiment, when the target reference signal includes a target downlink reference signal, determining the number of the target reference signals based on the spatial dimension of the target DOA includes: determining the number of the target downlink reference signals based on the spatial dimension of the target DOA and information about the target panel.

[0016] In an exemplary embodiment, determining the number of target downlink reference signals based on the spatial dimension of the target DOA and the information of the target panel includes: determining the number of target downlink reference signals to be n×m, where n is an integer greater than the spatial dimension and m is the number of target panels; wherein each group of m target downlink reference signals forms a group and occupies one OFDM symbol, each group of m target downlink reference signals corresponds to m target panels, and each group of m reference signals is transmitted in one OFDM symbol in a frequency division or code division manner.

[0017] In one exemplary embodiment, the method further includes: selecting a RIS beam based on the spatial dimension of the target DOA; and indicating the selected RIS beam to the RIS.

[0018] In one exemplary embodiment, selecting RIS beams based on the spatial dimension of the target DOA includes: when the spatial dimension is one-dimensional, selecting at least two adjacent RIS beams in the spatial dimension; when the spatial dimension is two-dimensional, selecting at least two adjacent azimuth beams and at least two adjacent elevation beams.

[0019] In one exemplary embodiment, indicating the selected RIS beam to the RIS includes: indicating the number of a reference beam included in the RIS beam to the RIS; and indicating the number offset information of other beams included in the RIS beam relative to the reference beam to the RIS, wherein the other beams are beams included in the RIS beam other than the reference beam.

[0020] In one exemplary embodiment, indicating the number offset information of other beams included in the RIS beam relative to the reference beam to the RIS includes: indicating the azimuth phase number offset information and the elevation phase number offset information of other beams included in the RIS beam relative to the reference beam to the RIS.

[0021] According to another embodiment of the present invention, an apparatus for determining the angle of arrival (DOA) is provided, comprising: a determining module, configured to determine a target reference signal and a codebook value corresponding to the target reference signal, and configure the codebook value to a smart reflector RIS; an acquiring module, configured to acquire a measurement result obtained by the receiving end after the target reference signal is reflected to a receiving end by the RIS, wherein the RIS reflects the reference signal according to the codebook value; and a determining module, configured to determine the target angle of arrival (DOA) based on the measurement result.

[0022] According to yet another embodiment of the present invention, a computer-readable storage medium is also provided, wherein a computer program is stored therein, wherein the computer program is configured to perform the steps in any of the above method embodiments when executed.

[0023] According to yet another embodiment of the present invention, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0024] Through this invention, since the target reference signal is reflected to the receiver by the RIS according to the codebook value pre-configured by the base station, information interaction between the base station and the RIS is realized. Based on the interaction result, the codebook value used to reflect the reference signal is adjusted, thereby quickly realizing RIS beam scanning and beam tracking. This effectively solves the problems of low beam scanning accuracy and high tracking difficulty in related technologies, thereby improving beam scanning accuracy and reducing tracking difficulty. Attached Figure Description

[0025] Figure 1 This is a hardware structure block diagram of a mobile terminal for the method of determining DOA according to an embodiment of the present invention;

[0026] Figure 2 This is a flowchart of a method for determining DOA according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram illustrating how the RIS (Radio Router) achieves coarse coverage of the UE (User Equipment) in the beam space using several beams, according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram illustrating how, according to an embodiment of the present invention, RIS achieves UE coverage using a more powerful narrow beam based on the estimated DOA.

[0029] Figure 5 This is a schematic diagram of one-dimensional orientation DOA estimation according to an embodiment of the present invention;

[0030] Figure 6 This is a schematic diagram of one-dimensional pitch DOA estimation according to an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of two-dimensional DOA estimation using three beams according to an embodiment of the present invention;

[0032] Figure 8 This is a schematic diagram of two-dimensional DOA estimation using four beams according to an embodiment of the present invention;

[0033] Figure 9 This is a schematic diagram of two-dimensional DOA estimation using five beams according to an embodiment of the present invention;

[0034] Figure 10 This is a flowchart of the RIS's estimation of the terminal's DOA when the terminal transmits a reference signal according to an embodiment of the present invention;

[0035] Figure 11 This is a flowchart of the RIS's estimation of the terminal's DOA when the base station transmits a reference signal according to an embodiment of the present invention;

[0036] Figure 12 This is a structural block diagram of an apparatus for determining DOA according to an embodiment of the present invention. Detailed Implementation

[0037] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0039] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a method of determining DOA according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0040] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the method for determining DOA in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0041] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0042] This embodiment provides a method for determining DOA. Figure 2 This is a flowchart of a method for determining DOA according to an embodiment of the present invention, as shown below. Figure 2As shown, the process includes the following steps:

[0043] Step S202: Determine the target reference signal and the codebook value corresponding to the target reference signal, and configure the codebook value to the intelligent reflector RIS (Reconfigurable intelligent surface).

[0044] Step S204: Obtain the measurement result obtained by the receiver after the target reference signal is reflected to the receiver by the RIS, wherein the RIS reflects the reference signal according to the codebook value;

[0045] Step S206: Determine the target angle of arrival (DOA) based on the measurement results.

[0046] The entity performing the above operations can be a base station, a processing device installed within the base station, or other network elements with similar processing capabilities. The receiving end in step S204 can be either a base station or a terminal. Specifically, when the target reference signal is a downlink signal, the receiving end is a terminal; that is, the target reference signal needs to be sent from the base station to the terminal via the RIS (Reference Information System). When the target reference signal is an uplink signal, the receiving end is a base station; that is, the target reference signal needs to be sent from the terminal to the base station via the RIS. The two scenarios will be explained in detail later.

[0047] In the above embodiments, since the target reference signal is reflected to the receiver by the RIS according to the codebook value pre-configured by the base station, information interaction between the base station and the RIS is realized. Based on the interaction result, the codebook value used to reflect the reference signal is adjusted, thereby quickly realizing RIS beam scanning and beam tracking. This effectively solves the problems of low beam scanning accuracy and high tracking difficulty in related technologies, thereby improving beam scanning accuracy and reducing tracking difficulty.

[0048] In one exemplary embodiment, determining the codebook value corresponding to the target reference signal includes: determining the target beam between the RIS and the terminal; and determining the codebook value based on the position of the target beam.

[0049] In an exemplary embodiment, determining the target beam between the RIS and the terminal includes: determining the strongest beam whose RIS-side energy exceeds a predetermined threshold between the RIS and the terminal; and determining the strongest beam and beams that satisfy a target relationship with the strongest beam as the target beam, wherein the beams that satisfy the target relationship with the strongest beam include at least one of the following: the second strongest beam adjacent to the strongest beam in azimuth, and the second strongest beam adjacent to the strongest beam in elevation. In this embodiment, the strongest beam is typically a wide beam, but it can also be a narrow beam. When determining the codebook value, it can be determined based on the strongest beam. Of course, if necessary, the codebook value can also be determined comprehensively based on the strongest beam and the second strongest beam in azimuth or elevation. When determining the second strongest beam in azimuth or elevation, it can be obtained through methods such as synchronization reference signals, beam scanning, or prior information.

[0050] In an exemplary embodiment, determining the target reference signal includes: configuring a predetermined number of the target reference signals in a time slot, wherein each target reference signal occupies one orthogonal frequency division multiplexing (OFDM) symbol; after determining the target reference signal, the method further includes: notifying the terminal and the RIS of the parameter information of the target reference signal, wherein the parameter information includes at least one of the following: time slot information, OFDM symbol, frequency domain position, and mother code parameters. In this embodiment, the base station configures n reference signals (corresponding to the predetermined number mentioned above) at one time slot, each reference signal occupies one OFDM symbol, and the base station and the terminal need to know the corresponding parameters of the reference signals (i.e., the parameter information mentioned above). When transmitting the target reference signal (either the base station or the terminal), the base station or the terminal transmits the configured n reference signals at one time on n OFDM symbols in a specified time slot. Additionally, it should be noted that when the aforementioned target reference signal is a downlink reference signal, if the base station needs to use information from multiple panels, for example, information from m panels, the base station configures mn downlink reference signals at once in one time slot. Each group of m reference signals forms a group and occupies one OFDM symbol. Each group of m reference signals corresponds to m panels of the base station. Each group of m reference signals is a frequency division or code division signal within an OFDM symbol. The base station transmits the configured mn reference signals at once on n OFDM symbols in the specified time slot.

[0051] In an exemplary embodiment, after notifying the RIS of the OFDM symbols of the target reference signals and configuring the codebook values ​​to the RIS, the method further includes: the RIS sequentially switching the codebooks indicated by the codebook values ​​corresponding to each target reference signal on the OFDM symbols where the multiple target reference signals are distributed; wherein the effective time of each codebook is from the start time to the end time of the OFDM symbol. In this embodiment, the base station notifies the RIS of the time slots corresponding to the above n reference signals and the positions of the n OFDM symbols where they are located. Simultaneously, the base station also needs to configure n codebooks for the RIS, and a one-to-one correspondence must be established between the reference signals and the codebooks. After receiving the configuration information from the base station, the RIS sequentially switches the n codebooks on the n OFDM symbols where the specified n reference signals are located, with the effective time of each codebook being from the start time to the end time of the OFDM symbol. Alternatively, the base station notifies the RIS of the time slots corresponding to the above mn reference signals and the positions of the n OFDM symbols where they are located. Simultaneously, the base station also needs to configure n codebooks for the RIS, and a one-to-one correspondence must be established between the n symbols where the reference signals are located and the codebooks. After receiving the configuration information from the base station, the RIS sequentially switches n codebooks on the n OFDM symbols containing the specified n reference signals. The duration of each codebook is from the start time to the end time of the OFDM symbol.

[0052] In an exemplary embodiment, before obtaining the measurement result, the method further includes: configuring a target uplink reference signal to a terminal to instruct the terminal to transmit the target uplink reference signal, wherein the target reference signal includes the target uplink reference signal; obtaining the measurement result includes: measuring the target uplink reference signal reflected by the RIS to obtain the measurement result. This embodiment describes the terminal transmitting an uplink reference signal. In this embodiment, after determining the uplink reference signal, the base station configures the uplink reference signal to the terminal, and then the terminal transmits the uplink reference signal to the base station through the RIS.

[0053] In an exemplary embodiment, before acquiring the measurement result, the method further includes: sending a target downlink reference signal to the terminal, wherein the target reference signal includes the target downlink reference signal; acquiring the measurement result includes: acquiring and reporting the measurement result obtained by the terminal after measuring the target downlink reference signal reflected by the RIS. This embodiment describes the transmission of a downlink reference signal by a base station. In this embodiment, the base station transmits its determined downlink reference signal to the terminal via the RIS.

[0054] In an exemplary embodiment, obtaining the measurement results reported by the terminal includes: obtaining the measurement results fed back by the terminal at one time on a predetermined time-frequency resource for each of the target downlink reference signals included in the target downlink reference signal, wherein the feedback order of each measurement result is consistent with the transmission order of the corresponding target downlink reference signal.

[0055] In an exemplary embodiment, determining the target reference signal and the codebook value corresponding to the target reference signal includes: determining the number of target reference signals and the number of codebook values ​​based on the spatial dimension of the target DOA. In this embodiment, the codebook values ​​(or codebooks) that need to be configured are different when performing DOA estimation in different dimensions. For example, when performing DOA estimation in one spatial dimension, the number of RIS codebooks and reference signals configured at one time is at least 2. If the configured parameters can perform DOA estimation in two dimensions at one time, the number of RIS codebooks and reference signals configured at one time is at least 3. In this embodiment, if the downlink reference signal mode is adopted, the terminal needs to feed back the measurement results of all reference signals at once on the time-frequency resources specified by the base station. These measurement results can be complex numbers or real numbers, and the feedback order of the measurement results corresponds one-to-one with the transmission order of the downlink reference signals.

[0056] In one exemplary embodiment, when the target reference signal includes a target downlink reference signal, determining the number of the target reference signals based on the spatial dimension of the target DOA includes: determining the number of the target downlink reference signals based on the spatial dimension of the target DOA and information about the target panel.

[0057] In an exemplary embodiment, determining the number of target downlink reference signals based on the spatial dimension of the target DOA and the information of the target panels includes: determining the number of target downlink reference signals to be n×m, where n is an integer greater than the spatial dimension, and m is the number of target panels; wherein each group of m target downlink reference signals forms a group and occupies one OFDM symbol, each group of m target downlink reference signals corresponds to m target panels, and each group of m reference signals is transmitted in one OFDM symbol in a frequency division or code division manner. In this embodiment, when the base station needs to use the information of m panels, if the configured parameters can only perform DOA estimation in one spatial dimension at a time, then the RIS codebook configured at one time is at least 2, that is, n is greater than or equal to 2, and the number of reference signals is mn; if the configured parameters can perform DOA estimation in two dimensions at a time, then the RIS codebook and the number of reference signals configured at one time are at least 3, that is, n is greater than or equal to 3, and the number of reference signals is mn. In addition, the terminal needs to feed back the measurement results of mn reference signals at once on the time and frequency resources specified by the base station. These measurement results can be complex numbers or real numbers. The feedback order of these mn measurement results corresponds one-to-one with the transmission order of the mn reference signals.

[0058] In one exemplary embodiment, the method further includes: selecting a RIS beam based on the spatial dimension of the target DOA; and indicating the selected RIS beam to the RIS.

[0059] In an exemplary embodiment, selecting RIS beams based on the spatial dimension of the target DOA includes: when the spatial dimension is one-dimensional, selecting at least two adjacent RIS beams in the spatial dimension; when the spatial dimension is two-dimensional, selecting at least two adjacent azimuth beams and at least two adjacent pitch beams. In this embodiment, when performing one-dimensional DOA estimation, the smart reflector beams selected by the base station are two or three adjacent beams in that dimension (or more); when performing two-dimensional DOA estimation, the smart reflector beams selected by the base station should include at least two adjacent azimuth beams and two adjacent pitch beams (or more). When the phase information of the reference signal is used and the phase shift caused by Doppler is unavoidable, the required number of beams needs to be increased by at least one, and the added beam is a repetition of one or more beams.

[0060] In one exemplary embodiment, indicating the selected RIS beam to the RIS includes: indicating the number of a reference beam included in the RIS beam to the RIS; indicating the number offset information of other beams included in the RIS beam relative to the reference beam to the RIS, wherein the other beams are beams included in the RIS beam other than the reference beam.

[0061] In an exemplary embodiment, indicating the numbering offset information of other beams included in the RIS beam relative to the reference beam to the RIS includes: indicating the azimuth phase numbering offset information and the elevation phase numbering offset information of the other beams included in the RIS beam relative to the reference beam to the RIS. In this embodiment, assuming the base station needs to indicate K beams to the RIS, the base station uses one of the beams as the reference beam and indicates the number of the reference beam to the smart reflector. Simultaneously, the base station indicates the numbering offset information of the remaining (K-1) beams relative to the reference beam to the smart reflector. The beams are numbered, and the beam ID is... azi +ID azi,offset ID ele +ID ele,offset Relative Beam (ID) azi ID ele The orientation deviated from the ID. azi,offset The beam deviates from ID in the pitch dimension. ele,offset beams, of which (ID) azi ID ele ) represent the azimuth and elevation numbers respectively, ID azi,offset and ID ele,offset A value greater than 0 or less than 0 indicates the direction of deviation. In this embodiment, when performing DOA estimation, if the base station indicates a maximum of 5 beams to the smart reflector, then the base station selects a reference beam and assigns the reference beam number Beam(ID) to it. azi ID ele The signal is transmitted to the smart reflector, so the remaining four beams only require the base station to transmit (ID) to the smart reflector. azi,offset ID ele,offset This is sufficient; these four beams only require 1 bit of information to indicate the azimuth offset ID. azi,offset 1-bit information indicates pitch offset ID ele,offset That's all.

[0062] The principles of this invention are explained below:

[0063] Since the RIS end cannot acquire data, but its codebook can be modified, the high-precision DOA estimation in this invention first obtains beam domain information by modifying the RIS codebook, and then performs DOA estimation in the beam domain. The specific principle is as follows:

[0064] Assume that each panel of the base station has N elements. bs The number of terminal arrays is N ue The number of RIS panel elements is N ris The channel from RIS to the base station is H. ris-bs Dimension N ris ×N bs The channel from the UE to the RIS is H. ue-ris Dimension N ue ×N ris The weighted values ​​for RIS are:

[0065]

[0066] The cascaded channel of BS, RIS, and UE can be represented as:

[0067] H = H ue-ris Φ w H ris-bs (2)

[0068] The dimension of H is N ue ×N bs .

[0069] Assume the shaping weights on the BS side are w bs Its dimension is 1×N bs The UE-side shaping weight is w ue Its dimension is 1×N ue .

[0070] The received data after shaping by both the BS and UE sides is as follows:

[0071]

[0072] Where `diag()` represents transforming a diagonal matrix into column vectors, and vice versa. A single-path channel can be represented as...

[0073]

[0074] in and These represent the single-path channels from UE to RIS and from RIS to BS, respectively; α ue-ris and α ris-bs Indicates the complex amplitude of this path; a ue-ris and These represent the steering vectors on the UE side and RIS side of the connection path between the UE and RIS, respectively. They are vectors related to the UE-side angle and RIS-side angle of the connection path between the UE and RIS; a ris-bs and Let represent the steering vectors on the RIS and BS sides of the RIS and BS connection paths, respectively. These vectors are related to the RIS-side angle and BS-side angle of the RIS and BS connection paths. Therefore, for a single path, the received data in equation (3) can be expressed as:

[0075]

[0076] Where β ue =w ue a ue-ris and Let be a scalar, and represent the complex amplitudes after shaping this path by the shaping weights on the UE side and BS side, respectively. In equation (5), the essence of the RIS codebook (DOA estimation) is to estimate the steering vector of the RIS. The weights for beam space transformation are diag(Φ). w This refers to the RIS wide-beam codebook that requires multiple switching in this invention. Thus, this invention transforms the RIS coverage enhancement problem for the terminal into a DOA estimation problem in the beamspace. The essence of RIS DOA estimation for the terminal is to estimate the DOA of the beamspace under different Φ values. w From multiple y(Φ) beams in the lower beam space w A more accurate RIS codebook is estimated in the estimation, at which point the UE-side shaping weights w need to be preserved. ue and the shaping weight w of the base station side panel bs The result remains unchanged. Subsequent DOA estimation can employ commonly used beamspace-based DOA estimation methods, y(Φ w The value is a measurement of the beam space. A more accurate estimate of the RIS codebook (from which the corresponding DOA can be obtained) can be expressed by the following formula:

[0077] Φ w,optimal =f(y(Φ) w,1 ),y(Φ w,2 ),...,y(Φ w,K (6)

[0078] Where f() is the method for estimating DOA in the beam space, and K is the number of RIS codebooks used in the beam space.

[0079] The estimated angle is obviously Corresponding guide vector and It is a match, exactly corresponding to the incident angle and reflection angle of the RIS board. This steering vector can be used as a codebook for narrow beams.

[0080] After determining the coarse beam of the terminal relative to the RIS, this invention needs to keep the beamforming weights on both sides of the base station and the terminal unchanged, while switching multiple different codebooks of the RIS to cover the possible positions of the terminal relative to the RIS, such as... Figure 3 As shown.

[0081] When the base station estimates a more accurate codebook (or DOA) for the terminal relative to the RIS using beam space measurement data, it switches the RIS codebook via signaling, thereby enabling the RIS to achieve more accurate beam alignment, tracking, and positioning of the terminal, such as... Figure 4 As shown.

[0082] This invention performs DOA estimation in beam space, which requires selecting multiple beams. Since there are a large number of beams on a smart reflector, if the codebook or beam number of each beam is individually indicated to the smart reflector, the signaling overhead will be very large. This invention provides a low-overhead signaling indication method based on a certain beam: Assuming that the base station needs to indicate K beams to the smart reflector, the base station uses one of the beams as the reference beam and indicates the number of the reference beam to the smart reflector. At the same time, the base station indicates the numbering information of the remaining (K-1) beams relative to the reference beam to the smart reflector.

[0083] The beam is numbered, and the beam is named Beam(ID). azi +ID azi,offset ID ele +ID ele,offset Relative Beam (ID) azi ID ele The orientation deviated from the ID. azi,offset The beam deviates from ID in the pitch dimension. ele,offset beams, of which (ID) azi ID ele ) represent the azimuth and elevation numbers respectively, ID azi,offset and ID ele,offset A value greater than 0 or less than 0 indicates the direction of deviation.

[0084] If the base station selects a reference beam and assigns the reference beam number Beam(ID) to it... azi ID ele If the signal is transmitted to the smart reflector, then for the remaining (K-1) beams, the base station only needs to transmit (ID) to the smart reflector. azi,offset ID ele,offset That's it. For example, if you can select a maximum of 5 beams, i.e., K=5, then besides the indicator beam number Beam(ID)... azi ID ele Each of the remaining beams only needs 1 bit of information to indicate the azimuth offset ID. azi,offset1-bit information indicates pitch offset ID ele,offset That's it. The transmission information of K beams can be abbreviated as Beam(ID) azi ID ele (ID) azi,offset_1 ID ele,offset_1 ), ..., (ID) azi,offset_K-1 ID ele,offset_K-1 Alternatively, it can be sorted in other ways.

[0085] In addition to the methods mentioned above, some fixed beam patterns can be defined. The selected K beams are determined based on the reference beam and the selected beam pattern. These can be roughly divided into the following categories:

[0086] 1. Perform one-dimensional orientation DOA estimation

[0087] like Figure 5 As shown, when only azimuth DOA estimation is performed, two or three adjacent different beams can generally be selected. To reduce complexity, the following beam indication method can be used:

[0088] When using two beams for azimuth DOA estimation, you can specify only the label of one beam, and the other beam will default to its adjacent left or right azimuth beam.

[0089] When using three beams for azimuth DOA estimation, only one beam's label needs to be indicated, while the positions of the other two beams can be pre-defined. For example, the other two beams can be pre-defined as the azimuth-adjacent left and right beams, or they can be pre-defined as the two azimuth-adjacent left or right beams.

[0090] 2. Perform one-dimensional pitch DOA estimation

[0091] like Figure 6 As shown, when only pitch DOA estimation is performed, two or three adjacent different beams can generally be selected. To reduce complexity, the following beam indication method can be used:

[0092] When using two beams for pitch DOA estimation, you can specify only the label of one beam, and the other beam will default to its adjacent pitch-up or pitch-down beam.

[0093] When using three beams for elevation DOA estimation, only one beam's label needs to be indicated, while the positions of the other two beams can be pre-defined. For example, the other two beams can be pre-defined as being in elevation towards the adjacent upper and lower beams, or they can be pre-defined as being in elevation towards the two adjacent upper or lower beams.

[0094] 3. Two-dimensional DOA estimation using three different beams.

[0095] When performing two-dimensional DOA estimation, at least three adjacent distinct beams must be selected. These three beams are characterized by having two adjacent beams in the azimuth direction and two adjacent beams in the elevation direction. One type of beam pattern is shown below. Figure 7 As shown.

[0096] 4. Two-dimensional DOA estimation using four different beams.

[0097] When performing two-dimensional DOA estimation, if four adjacent distinct beams are selected, these four beams are characterized by having at least two adjacent beams in the azimuth direction and at least two adjacent beams in the elevation direction. One type of beam pattern is as follows: Figure 8 As shown.

[0098] 5. Two-dimensional DOA estimation using five different beams.

[0099] When performing two-dimensional DOA estimation, if five adjacent distinct beams are selected, these five beams are characterized by having at least two adjacent beams in the azimuth direction and at least two adjacent beams in the elevation direction. One type of beam pattern is as follows: Figure 9 As shown.

[0100] If only one dimension of the angle is estimated for each DOA estimation, the relevant configuration requirements are as follows:

[0101] When the phase shift across different symbols caused by the Doppler effect is negligible, or when the beam-domain DOA estimation method does not utilize phase information, at least two different beams need to be configured. These beams are distributed across different symbols within a single time slot. In this case, the number of reference signals and RIS codebooks configured at once must be at least two. Each reference signal on each symbol corresponds to one RIS codebook, and the beam pattern corresponding to the RIS codebook is the beam pattern of the beams adjacent to the estimation dimension (e.g., beams in the same direction). Figure 5 or Figure 6 (As shown). Typically, the number of beams, RIS codebooks, and reference signals is 2 or 3. The beams of the base station and the terminal remain unchanged throughout the transmission of the reference signals.

[0102] When the phase shift across different symbols caused by the Doppler is not negligible and the beam-domain DOA estimation method utilizes phase information, the number of each parameter in the above configuration needs to be increased by at least 1. At least two of the configured beams and RIS codebooks must be identical. Typically, the number of beams, RIS codebooks, and reference signals is 3 or 4. The beam pattern corresponding to the RIS codebook is the beam adjacent to the estimation dimension (e.g.,...). Figure 5 or Figure 6As shown in the diagram, one beam needs to be repeated once for Doppler compensation. The beams of the base station and the terminal remain unchanged throughout the transmission of the reference signal.

[0103] It should be noted that if each DOA estimation configuration can only estimate the angle in one dimension, then it is necessary to configure it again to estimate the angle in the other dimension in order to obtain the complete two-dimensional angle.

[0104] If the two-dimensional angle is directly estimated for each DOA estimation, the relevant configuration requirements are as follows:

[0105] When the phase offset caused by Doppler on different symbols is negligible or the beam-domain DOA estimation method does not utilize phase information, then at least three different beams need to be configured. These beams are distributed in different symbols within a time slot. In this case, the base station needs to configure at least three reference signals and RIS codebooks at once. One reference signal per symbol corresponds to one RIS codebook. The beam pattern corresponding to the RIS codebook requires adjacent beams to appear in both the azimuth and elevation directions (e.g., ...). Figure 7 , Figure 8 or Figure 9 (As shown). Typically, the number of beams, RIS codebooks, and reference signals is 3 or 4. The beams of the base station and the terminal remain unchanged throughout the transmission of the reference signals.

[0106] When the phase shift across different symbols caused by Doppler is not negligible and the beam-domain DOA estimation method utilizes phase information, the number of parameters in the above configuration needs to be increased by at least 1. At least two of the configured beams and RIS codebooks must be identical. Typically, the number of beams, RIS codebooks, and parameter signals is 4 or 5. The beam pattern corresponding to the RIS codebook requires adjacent beams to appear in both the azimuth and elevation directions (e.g., ...). Figure 7 , Figure 8 or Figure 9 As shown in the diagram, one beam needs to be repeated once for Doppler compensation. The beams of the base station and the terminal remain unchanged throughout the transmission of the reference signal.

[0107] In all the parameters configured for each DOA estimation, the reference signals corresponding to different symbols should occupy the same RE or at least the same RB.

[0108] If downlink reference signals are used for DOA estimation, and it is desired to use information from multiple panels (let's say n), then the number of reference signals per symbol needs to be increased to n times. n panels should correspond to n reference signals for frequency division or code division per symbol. In this case, the number of reference signals is equal to n times the number of symbols or RIS codebooks used. The terminal feeds back complex measurement values ​​to the base station, and these fed-back complex values ​​should correspond one-to-one with the panels and RIS codebooks.

[0109] The present invention will now be described with reference to specific embodiments:

[0110] Specific embodiment 1, this embodiment is for the terminal transmitting uplink reference signal:

[0111] When the terminal transmits the reference signal, the specific implementation flowchart is as follows: Figure 10 As shown. It includes the following steps:

[0112] Step 1: The base station determines the strongest scanning beam (usually a wide beam, but it can also be a narrow beam) on the RIS side between the RIS and the terminal. If necessary, it also needs to determine the second strongest beam in the azimuth or elevation direction. This process can be obtained through methods such as synchronization reference signals, beam scanning, or prior information.

[0113] Step 2: The base station determines the number of RIS codebooks (i.e., K) and the corresponding RIS codebook value Φ required for DOA estimation based on the strongest beam of the terminal relative to the RIS and the positions of the adjacent second strongest beams in azimuth and elevation. w,1 ,Φ w,2 ,...,Φ w,K As described above, the RIS codebook pattern requires adjacent beams in both the azimuth and elevation directions. If three beams are selected, the strongest beam, the second strongest beam adjacent to the strongest beam in the azimuth direction, and the second strongest beam adjacent to the strongest beam in the elevation direction can be chosen. (When considering the Doppler phase influence between different symbols, at least four sets of codebook values ​​are required, with two sets of codebook values ​​being identical, meaning one beam needs to be repeated once.) The base station can label the codebook of the strongest beam with Beam(ID). azi ID ele The relative shift of the strongest beam's azimuth to the adjacent second strongest beam (ID) azi,offset_1 ,0), the relative shift of the elevation of the strongest beam to the adjacent second strongest beam (0,ID) ele,offset_2 When selecting three beams, the 0 element (i.e., the offset is 0) can be omitted, thereby reducing resource overhead.

[0114] Step 3: The base station configures the uplink reference signal for DOA estimation to the terminal in one go through signaling according to the number of RIS codebooks required in the previous step. Different reference signals should be on different symbols in one time slot.

[0115] Step 4: The base station configures the number of codebook values ​​in Step 2 to the RIS via signaling. Each set of codebook values ​​corresponds to the time domain resource location of the uplink reference signal in Step 3. The duration of this set of codebook values ​​should be from the start of reception of the corresponding reference signal until the end of reception.

[0116] Step 5: The terminal transmits multiple sets of uplink reference signals on the corresponding time-frequency resources according to the base station signaling. The RIS synchronously switches the corresponding codebook values ​​according to the base station signaling. During the transmission of these uplink reference signals, the terminal needs to keep the terminal-side beamforming weights unchanged. The RIS keeps its codebook value unchanged when reflecting each set of reference signals.

[0117] Step 6: The base station receives uplink reference signals. During the reception of these reference signals, the base station needs to maintain a constant receiving beam. The base station maps the received uplink reference signals to the codebook values ​​of RIS one-to-one to obtain y(Φ). w,1 ),y(Φ w,2 ),...,y(Φ w,K Based on the received uplink reference signal, RIS codebook value, and RIS board parameters, the base station estimates a more accurate RIS codebook or DOA in the beam space using a DOA estimation method. If phase values ​​are used in the DOA estimation process, then it is necessary to fill in y(Φ) at different times. w,1 ),y(Φ w,2 ),...,y(Φ w,K The initial phase difference.

[0118] Step 7: Based on the DOA estimated in the previous step, the base station switches the RIS codebook parameters to achieve more accurate beam alignment, beam tracking, positioning and other operations.

[0119] In this embodiment, the base station, RIS, and terminal only have a few signaling interactions and little interactive data.

[0120] Specific embodiment 2, this embodiment is for base station transmitting reference signals:

[0121] When the base station transmits the reference signal, the specific implementation flowchart is as follows: Figure 11 As shown. It includes the following steps:

[0122] Step 1: The base station determines the strongest scanning beam (usually a wide beam, but it can also be a narrow beam) on the RIS side between the RIS and the terminal. If necessary, it also needs to determine the second strongest beam in the azimuth or elevation direction. This process can be obtained through methods such as synchronization reference signals, beam scanning, or prior information.

[0123] Step 2: The base station determines the number of RIS codebooks required for DOA estimation and the corresponding RIS codebook value Φ based on the strongest beam of the terminal relative to the RIS and the positions of the adjacent second strongest beams in azimuth and elevation. w,1 ,Φ w,2 ,...,Φ w,K The RIS codebook pattern, as described above, requires adjacent beams in both the azimuth and elevation directions. If three beams are selected, the strongest beam, the second strongest beam adjacent to the strongest beam in the azimuth direction, and the second strongest beam adjacent to the strongest beam in the elevation direction can be chosen. (When considering the Doppler phase influence between different symbols, at least four sets of codebook values ​​are needed, with two sets being identical, meaning one beam needs to be repeated once; the strongest beam can be repeated once.) The base station can label the codebook of the strongest beam with Beam(ID). azi ID ele The relative shift of the strongest beam's azimuth to the adjacent second strongest beam (ID) azi,offset_1 ,0), the relative shift of the elevation of the strongest beam to the adjacent second strongest beam (0,ID) ele,offset_2 When selecting three beams, the 0 element can be omitted, thereby reducing resource consumption.

[0124] Step 3: The base station configures the downlink reference signals for DOA estimation to the terminal in one go via signaling, based on the number of RIS codebooks required in the previous step. Different reference signals should be on different symbols within the same time slot. If the base station needs multiple panels to jointly estimate DOA, assuming n panels are required, then the number of downlink reference signals to be configured is n times the number of RIS codebooks, with n frequency division or code division reference signals configured on each symbol.

[0125] Step 4: The base station configures the codebook values ​​from Step 2 to the RIS via signaling. Each set of codebook values ​​corresponds to a downlink reference signal resource location on one symbol in Step 3. The duration of this set of codebook values ​​should be from the start of reception of the corresponding reference signal until the end of reception.

[0126] Step 5: The base station transmits multiple sets of downlink reference signals on the configured time-frequency resources. The RIS switches the corresponding codebook values ​​synchronously according to the base station signaling. The base station needs to keep the beamforming weights on the base station side unchanged during the transmission of these downlink reference signals. The codebook value of the RIS remains unchanged when reflecting each set of reference signals.

[0127] Step 6: The terminal receives downlink reference signals. During this process, the terminal needs to maintain a constant receiving beam. After measuring the downlink reference signals, the terminal feeds back the measured values ​​to the base station, such as the strongest path corresponding to the time-domain tap of the feedback channel or the complex amplitude of multiple paths. These feedback values ​​should correspond one-to-one with the RIS codebook and panel, and be known to the base station. The feedback order can be agreed upon in advance or indicated by indicator values. The terminal can provide feedback through, but is not limited to, RRC.

[0128] Step 7: The base station maps the downlink reference signal measurement values ​​fed back by the terminal to the RIS codebook corresponding to each group of reference signals one by one, and obtains y(Φ w,1 ),y(Φ w,2 ),...,y(Φ w,K If the base station uses n panels to jointly estimate the DOA, then the information fed back by the terminal needs to be amplified by n times. This can be achieved by having each of the n panels feed back individually or jointly. Based on the measured values, RIS codebook values, RIS board parameters, etc., fed back by the terminal, the base station uses the DOA estimation method to estimate a more accurate RIS codebook or DOA in the beam space. If phase values ​​are used in the DOA estimation process, then it is necessary to fill in the y(Φ) values ​​at different times. w,1 ),y(Φ w,2 ),...,y(Φ w,K The initial phase difference.

[0129] Step 8: Based on the DOA estimated in the previous step, the base station switches the RIS codebook parameters to achieve more accurate beam alignment, beam tracking, positioning and other operations.

[0130] With this embodiment, the downlink reference signal power is high, which can achieve high angle measurement accuracy.

[0131] This invention relates to a high-precision DOA estimation method for intelligent reflectors, particularly concerning angle estimation, beam training, and beam tracking of intelligent reflectors (RIS) in the communications field. This invention achieves high-precision angle estimation in the beam domain by repeatedly changing the shaping weights of the intelligent reflector, effectively reducing the number of scanned beams during beam training and enhancing receiver power.

[0132] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0133] This embodiment also provides an apparatus for determining DOA, which is used to implement the above embodiments and preferred embodiments, and will not be repeated as already described. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0134] Figure 12 This is a structural block diagram of an apparatus for determining DOA according to an embodiment of the present invention, as shown below. Figure 12 As shown, the device includes:

[0135] The first determining module 122 is used to determine the target reference signal and the codebook value corresponding to the target reference signal, and to configure the codebook value to the intelligent reflector RIS.

[0136] The acquisition module 124 is used to acquire the measurement result obtained by the receiver after the target reference signal is reflected to the receiver by the RIS, wherein the RIS reflects the reference signal according to the codebook value;

[0137] The second determining module 126 is used to determine the target angle of arrival (DOA) based on the measurement results.

[0138] In an exemplary embodiment, the first determining module 122 is configured to determine the codebook value corresponding to the target reference signal by: determining the target beam between the RIS and the terminal; and determining the codebook value based on the position of the target beam.

[0139] In an exemplary embodiment, the first determining module 122 is configured to determine the target beam between the RIS and the terminal by: determining the strongest beam between the RIS and the terminal whose RIS-side energy exceeds a predetermined threshold; determining the strongest beam and the beams that satisfy the target relationship with the strongest beam as the target beam, wherein the beams that satisfy the target relationship with the strongest beam include at least one of the following: the second strongest beam adjacent to the strongest beam in azimuth, and the second strongest beam adjacent to the strongest beam in elevation.

[0140] In an exemplary embodiment, the first determining module 122 is configured to determine a target reference signal by configuring a predetermined number of the target reference signals in a time slot, wherein each target reference signal occupies one orthogonal frequency division multiplexing (OFDM) symbol; after determining the target reference signal, the method further includes notifying the terminal and the RIS of parameter information of the target reference signal, wherein the parameter information includes at least one of the following: time slot information, OFDM symbol, frequency domain position, and mother code parameters.

[0141] In an exemplary embodiment, the RIS is used to receive the OFDM symbol of the target reference signal notified by the base station and the codebook value configured thereon, and then sequentially switch the codebook indicated by the codebook value corresponding to each target reference signal on the OFDM symbols where the multiple target reference signals are distributed; wherein, the effective time of each codebook is from the start time to the end time of the OFDM symbol.

[0142] In an exemplary embodiment, the above-described apparatus is further configured to configure a target uplink reference signal to a terminal before acquiring the measurement result, so as to instruct the terminal to transmit the target uplink reference signal, wherein the target reference signal includes the target uplink reference signal; acquiring the measurement result includes: measuring the target uplink reference signal reflected by the RIS to obtain the measurement result.

[0143] In an exemplary embodiment, the above-described apparatus is further configured to send a target downlink reference signal to the terminal before acquiring the measurement result, wherein the target reference signal includes the target downlink reference signal; acquiring the measurement result includes: acquiring the measurement result obtained and reported by the terminal after measuring the target downlink reference signal reflected by the RIS.

[0144] In an exemplary embodiment, the above-described apparatus is configured to acquire the measurement results reported by the terminal in the following manner: acquiring the measurement results fed back by the terminal at one time on a predetermined time-frequency resource for each target downlink reference signal included in the target downlink reference signal, wherein the feedback order of each measurement result is consistent with the transmission order of the corresponding target downlink reference signal.

[0145] In an exemplary embodiment, the first determining module 122 is configured to determine a target reference signal and a codebook value corresponding to the target reference signal by determining the number of target reference signals and the number of codebook values ​​based on the spatial dimension of the target DOA.

[0146] In an exemplary embodiment, when the target reference signal includes a target downlink reference signal, the determining module 122 is configured to determine the number of target reference signals by realizing the spatial dimension of the target DOA in the following manner: determining the number of target downlink reference signals based on the spatial dimension of the target DOA and information of the target panel.

[0147] In an exemplary embodiment, the first determining module 122 is configured to determine the number of target downlink reference signals based on the spatial dimension of the target DOA and the information of the target panel in the following manner: the number of target downlink reference signals is determined to be n×m, where n is an integer greater than the spatial dimension and m is the number of target panels; wherein each group of m target downlink reference signals is a group and occupies one OFDM symbol, each group of m target downlink reference signals corresponds to m target panels, and each group of m reference signals is transmitted in one OFDM symbol in a frequency division or code division manner.

[0148] In one exemplary embodiment, the apparatus is further configured to: select a RIS beam based on the spatial dimension of the target DOA; and indicate the selected RIS beam to the RIS.

[0149] In an exemplary embodiment, the apparatus is configured to select RIS beams based on the spatial dimension of the target DOA in the following manner: when the spatial dimension is one-dimensional, selecting at least two adjacent RIS beams in the spatial dimension; when the spatial dimension is two-dimensional, selecting at least two adjacent azimuth beams and at least two adjacent elevation beams.

[0150] In one exemplary embodiment, the apparatus is configured to indicate the selected RIS beam to the RIS by: indicating the number of a reference beam included in the RIS beam to the RIS; and indicating the number offset information of other beams included in the RIS beam relative to the reference beam to the RIS, wherein the other beams are beams included in the RIS beam other than the reference beam.

[0151] In an exemplary embodiment, the apparatus is configured to indicate to the RIS the numbering offset information of other beams included in the RIS beam relative to the reference beam by indicating the azimuth phase numbering offset information and the elevation phase numbering offset information of other beams included in the RIS beam relative to the reference beam.

[0152] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0153] Embodiments of the present invention also provide a computer-readable storage medium storing a computer program, wherein the computer program is configured to perform the steps in any of the above method embodiments when executed.

[0154] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0155] Embodiments of the present invention also provide an electronic device including a memory and a processor, the memory storing a computer program and the processor being configured to run the computer program to perform the steps in any of the above method embodiments.

[0156] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0157] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0158] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0159] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining DOA, characterized in that, include: Multiple target reference signals and codebook values ​​corresponding to each target reference signal are determined, and the multiple codebook values ​​are configured to the intelligent reflective surface RIS at one time. After the multiple target reference signals are reflected to the receiving end by the RIS, the receiving end measures the multiple target reference signals respectively, and obtains multiple measurement results. The RIS reflects the target reference signals according to the codebook value corresponding to each target reference signal, and the multiple measurement results are fed back by the receiving end at one time. The target angle of arrival (DOA) is determined based on multiple measurement results.

2. The method according to claim 1, characterized in that, Determining the codebook value corresponding to the target reference signal includes: Determine the target beam between the RIS and the terminal; The codebook value is determined based on the position of the target beam.

3. The method according to claim 2, characterized in that, Determining the target beam between the RIS and the terminal includes: Determine the strongest beam whose RIS-side energy exceeds a predetermined threshold between the RIS and the terminal; The strongest beam and the beams that satisfy the target relationship with the strongest beam are determined as the target beam, wherein the beams that satisfy the target relationship with the strongest beam include at least one of the following: The second strongest beam adjacent to the strongest beam in azimuth, and the second strongest beam adjacent to the strongest beam in elevation.

4. The method according to claim 1, characterized in that, Determining the target reference signal includes: configuring a predetermined number of the target reference signals in a time slot, wherein each target reference signal occupies one orthogonal frequency division multiplexing (OFDM) symbol; After determining the target reference signal, the method further includes: notifying the terminal and the RIS of the parameter information of the target reference signal, wherein the parameter information includes at least one of the following: time slot information, OFDM symbol, frequency domain position, and mother code parameters.

5. The method according to claim 4, characterized in that, After informing the RIS of the OFDM symbol of the target reference signal and configuring the codebook value to the RIS, the method further includes: The RIS sequentially switches the codebook indicated by the codebook value corresponding to each of the multiple target reference signals on the OFDM symbols where the target reference signals are distributed; The duration of each codebook is from the start time to the end time of the OFDM symbol.

6. The method according to claim 1, characterized in that, Before acquiring the measurement result, the method further includes: configuring a target uplink reference signal to a terminal to instruct the terminal to transmit the target uplink reference signal, wherein the target reference signal includes the target uplink reference signal; Obtaining the measurement result includes: measuring the target uplink reference signal reflected by the RIS to obtain the measurement result.

7. The method according to claim 1, characterized in that, Before acquiring the measurement result, the method further includes: sending a target downlink reference signal to the terminal, wherein the target reference signal includes the target downlink reference signal; Obtaining the measurement results includes: obtaining and reporting the measurement results obtained by the terminal after measuring the target downlink reference signal reflected by the RIS.

8. The method according to claim 7, characterized in that, Obtaining the measurement results reported by the terminal includes: The measurement results of each target downlink reference signal included in the target downlink reference signal are obtained by the terminal on a predetermined time-frequency resource at one time, wherein the feedback order of each measurement result is consistent with the transmission order of the corresponding target downlink reference signal.

9. The method according to claim 1, characterized in that, Determining the target reference signal and the codebook value corresponding to the target reference signal includes: The number of target reference signals and the number of codebook values ​​are determined based on the spatial dimension of the target DOA.

10. The method according to claim 9, characterized in that, When the target reference signal includes a target downlink reference signal, determining the number of the target reference signals based on the spatial dimension of the target DOA includes: The number of downlink reference signals for the target is determined based on the spatial dimension of the target DOA and the information of the target panel.

11. The method according to claim 10, characterized in that, Determining the number of downlink reference signals for the target based on the spatial dimension of the target DOA and the information of the target panel includes: The number of target downlink reference signals is determined to be n×m, where n is an integer greater than the spatial dimension and m is the number of target panels; Each set of m target downlink reference signals is a group and occupies one OFDM symbol. Each group of m target downlink reference signals corresponds to m target panels. Each group of m reference signals is transmitted in one OFDM symbol in a frequency division or code division manner.

12. The method according to claim 1, characterized in that, The method further includes: Select the RIS beam based on the spatial dimension of the target DOA; The selected RIS beam is directed to the RIS.

13. The method according to claim 12, characterized in that, Selecting the RIS beam based on the spatial dimension of the target DOA includes: When the spatial dimension is one-dimensional, at least two adjacent RIS beams in the spatial dimension are selected; In the case where the spatial dimension is two-dimensional, at least two adjacent beams are selected for the azimuth phase and at least two adjacent beams for the elevation phase.

14. The method according to claim 12, characterized in that, Instructing the selected RIS beam to the RIS includes: The reference beam number included in the RIS beam is indicated to the RIS; The number offset information of other beams included in the RIS beam relative to the reference beam is indicated to the RIS, wherein the other beams are beams included in the RIS beam other than the reference beam.

15. The method according to claim 14, characterized in that, Indicating the number offset information of other beams included in the RIS beam relative to the reference beam to the RIS includes: The azimuth phase number offset information and elevation phase number offset information of other beams included in the RIS beam relative to the reference beam are indicated to the RIS.

16. An apparatus for determining DOA, characterized in that, include: The determination module is used to determine multiple target reference signals and codebook values ​​corresponding to each target reference signal, and to configure the multiple codebook values ​​to the intelligent reflector RIS at one time; The acquisition module is used to acquire multiple measurement results obtained by the receiver after the multiple target reference signals are reflected to the receiver by the RIS, and the receiver measures the multiple target reference signals respectively. The RIS reflects the target reference signals according to the codebook value corresponding to each target reference signal, and the multiple measurement results are fed back by the receiver at one time. The determination module is used to determine the target angle of arrival (DOA) based on multiple measurement results.

17. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method described in any one of claims 1 to 15.

18. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method described in any one of claims 1 to 15.

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