Beamforming method and communication apparatus

Abstract

Embodiments of the present application relate to the technical field of communications, and disclose a beamforming method and a communication apparatus, for use in suppressing the beam squint effect under a large bandwidth and improving the channel capacity. The method comprises: a network device receives first indication information, the first indication information being used for indicating a spatial domain basis of each sub-band among at least one sub-band in a wideband, or the first indication information being used for indicating beam information of each sub-band among at least one sub-band in a wideband; and the network device performs beamforming on the basis of spatial domain bases or beam information respectively corresponding to a plurality of sub-bands in the wideband, the spatial domain bases respectively corresponding to the plurality of sub-bands being determined on the basis of the spatial domain basis of each sub-band among the at least one sub-band, and the beam information respectively corresponding to the plurality of sub-bands being determined on the basis of the beam information of each sub-band among the at least one sub-band. The embodiments of the present application are used for the process of beamforming.

Description

Beamforming method and communication device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on December 29, 2023, with application number 202311863464.0 and application name “A Beamforming Method and Communication Device”, 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 beamforming method and a communication device. Background Art

[0003] Under larger bandwidth, the network side can perform beamforming by feeding back the precoding matrix indicated by the precoding matrix indicator (PMI) on the terminal side. Among them, the precoding matrix is ​​related to the spatial basis, the frequency basis and the combination coefficient. The spatial basis is fed back according to the bandwidth, that is, all subbands in the broadband share a set of broadband basis. This results in beamforming still being performed according to the shared broadband basis even when the multipath angles observed by different subcarriers / subbands / frequencies in the broadband are different. In this case, different subcarriers / subbands / frequencies are beamformed according to the multipath angle of the center frequency. The direction of the beam observed by different subcarriers / subbands / frequencies is different, that is, the beam direction changes with the frequency, and beam squilt occurs, which will lead to a significant decrease in channel capacity. Summary of the Invention

[0004] The embodiments of the present application provide a beamforming method and a communication device, which can suppress the beam squint effect under large bandwidth and improve channel capacity.

[0005] In a first aspect, a beamforming method is provided. Optionally, the method may be performed by a network device, a component or device (such as a processor, chip, or chip system) applied to the network device, or a logic module or software capable of implementing all or part of the network device's functions. The method includes: receiving first indication information, the first indication information being used to indicate a spatial basis for each subband in at least one subband in a broadband; and performing beamforming based on the spatial basis corresponding to each of the multiple subbands of the broadband, where the spatial basis corresponding to each of the multiple subbands is determined based on the spatial basis for each subband in the at least one subband.

[0006] The spatial basis may be the angle information corresponding to the subband or the distance information between the network device and the terminal device, etc. The method may be applied to a process in which the network device performs beamforming based on the precoding matrix indicator (PMI) feedback from the terminal device.

[0007] Therefore, when performing PMI feedback, the present application can report the spatial basis separately according to the sub-band for the bandwidth under the same component carrier (CC), so that the spatial basis corresponding to each sub-band in the broadband can be determined according to the spatial basis corresponding to the reported sub-band, and beamforming can be performed according to the spatial basis corresponding to each sub-band. This is to take into account that under the broadband of the same CC, when the multipath angles of different sub-bands are different, the spatial basis corresponding to different sub-bands are not exactly the same. If beamforming is performed according to the spatial basis corresponding to each sub-band, it is equivalent to considering the above-mentioned problem that due to the different array factors of different frequencies, that is, the different gains at different horizontal angles of different frequencies, the multipath angles of the electromagnetic waves of the beams at different frequencies are different (different spatial basis), thereby resulting in different effects of beam squint on different frequencies (different beam pointing). Moreover, for the base station, it is impossible to know in advance the change of such beam squint. Compared with the existing problem of large beam angle differences, serious beam squint and low channel capacity caused by beam shaping according to the spatial basis of the broadband under the same broadband, this application can suppress the impact of beam squint and improve channel capacity.

[0008] In one possible design, the first indication information includes an index of a spatial basis corresponding to each subband in the at least one subband. Thus, when the network device obtains the index of the spatial basis corresponding to each subband in the at least one subband in the broadband, the network device can determine the spatial basis corresponding to each subband in the at least one subband based on the index, thereby performing beamforming based on the spatial basis of each subband. This mitigates issues such as large beam angle variations and severe beam squint that may occur when beamforming based on the broadband spatial basis.

[0009] In one possible design, the first indication information includes a bitmap indicating at least one subband and an index of the spatial basis corresponding to each of the at least one subband. This is equivalent to the terminal device informing the network device, through the bitmap, of the indices of the spatial basis of the subbands reported, as well as the index of the spatial basis corresponding to each of these subbands. This allows the network device to perform beamforming based on the spatial basis of each subband, thereby mitigating the problems of large beam angle differences and severe beam squint caused by beamforming based on a wideband spatial basis.

[0010] In one possible design, before receiving the first indication information, the method further includes: sending second indication information, where the second indication information is used to instruct the terminal device to report an index of the spatial basis of each subband in the at least one subband. In other words, the network device may proactively query the terminal device to report the index of the spatial basis of each subband in the at least one subband.

[0011] In one possible design, before receiving the first indication information, the method further includes: sending third indication information, the third indication information being used to instruct the terminal device to report the index of the spatial basis corresponding to each subband in the at least one subband upon determining that the subband increment corresponding to the at least one subband is greater than or equal to the increment threshold; wherein the subband increment is the difference in the spatial basis index between the first subband and the second subband in the wideband, or the subband increment is the difference in the multipath angle between the first subband and the second subband in the wideband, or the subband increment is the difference in the absolute value of the coefficients at the same angle between the first subband and the second subband in the wideband. This is because, between adjacent subbands, if the difference in the spatial basis index between the subbands is small, or the difference in the multipath angle is small, or the difference in the absolute value of the coefficients at the same angle is small, the same spatial basis can be used for beamforming, and the difference in beam angle is not significant. This reduces signaling overhead between the network device and the terminal device.

[0012] In one possible design, the first indication information is used to indicate a functional relationship in which an index of a spatial basis of at least one subband varies with a position of the subband, and a parameter of the functional relationship. In this way, when the network device knows the position of each subband in the at least one subband, it can determine the index of the spatial basis of each subband in the at least one subband based on the functional relationship and the parameter of the functional relationship, thereby determining the spatial basis of each subband in the at least one subband based on the index.

[0013] In one possible design, before receiving the first indication information, the method further includes: sending fourth indication information, where the fourth indication information is used to instruct the terminal device to report the functional relationship of how the spatial basis of at least one subband changes with the position of the subband, and the parameters of the functional relationship. That is, the network device can actively query the terminal device for the spatial basis corresponding to each subband in at least one subband. The spatial basis is determined based on the functional relationship of how the reported spatial basis changes with the position of the subband, and the parameters of the functional relationship, so that the network device can perform beamforming based on the spatial basis of each subband, thereby suppressing the problems of large beam angle differences and severe beam squint caused by beamforming based on a wideband spatial basis.

[0014] In one possible design, before receiving the first indication information, the method further includes: sending a query message, the query message being used to inquire whether the terminal device has the ability to report the index of the spatial basis on a subband basis; and receiving a response message, the response message being used to indicate that the terminal device has the ability to report the index of the spatial basis on a subband basis. In this way, for a terminal device capable of reporting the index of the spatial basis on a subband basis, if the terminal device reports the index of the spatial basis on a subband basis, the network device can perform beamforming based on the spatial basis of each subband, thereby suppressing the problems of large beam angle differences and severe beam squint caused by beamforming based on a wideband spatial basis.

[0015] In one possible design, the at least one subband includes a subband with a center frequency, a subband with a maximum frequency, and a subband with a minimum frequency in the broadband. This design can be understood as a default reporting method, meaning that the terminal device does not need to report the spatial basis of each subband in the broadband to the network device. If the terminal device reports the spatial basis of some subbands, the network device can infer the spatial basis of other subbands in the broadband based on the reported spatial basis of some subbands, resulting in low signaling overhead for the terminal device.

[0016] In one possible design, beamforming is performed according to the spatial basis corresponding to the multiple sub-bands of the broadband, including: determining the weights for beamforming corresponding to the multiple sub-bands according to the spatial basis corresponding to the multiple sub-bands; and performing beamforming according to the weight corresponding to each sub-band in the multiple sub-bands. In this way, compared with the problem of more serious large beam squint caused by beamforming according to the spatial basis of the broadband, in this application, the network equipment can determine the weights for beamforming according to the spatial basis corresponding to each sub-band, and perform coherent beam superposition in the same direction according to the weights corresponding to different sub-bands to obtain beams under multiple sub-bands. This application takes into account the problem that the multipath angles of electromagnetic waves of beams at different frequencies are different (different spatial basis), which leads to different effects of beam squint on different frequencies (different beam directions). That is, this application can suppress the effects of beam squint and improve channel capacity.

[0017] In a second aspect, a beamforming method is provided. Optionally, the method may be performed by a terminal device, a component or device (such as a processor, chip, or chip system) applied to a network device, or a logic module or software capable of implementing all or part of the terminal device's functions. The method includes: sending first indication information, the first indication information being used to indicate the spatial basis of each subband in at least one subband in a broadband; and receiving a beam transmitted on the broadband, the beam being obtained by beamforming based on the spatial basis corresponding to each of the multiple subbands of the broadband, the spatial basis corresponding to each of the multiple subbands being determined based on the spatial basis of each subband in the at least one subband.

[0018] The beneficial effects of the second aspect can be found in the description of the first aspect.

[0019] In one possible design, the first indication information includes an index of a spatial basis corresponding to each subband in at least one subband.

[0020] In one possible design, before sending the first indication information, the method also includes: receiving second indication information, where the second indication information is used to instruct the terminal device to report the index of the spatial basis of each subband in at least one subband.

[0021] In one possible design, the first indication information includes a bitmap indicating at least one subband and an index of a spatial basis corresponding to each subband in the at least one subband.

[0022] In one possible design, before sending the first indication information, the method also includes: receiving third indication information, the third indication information being used to instruct the terminal device to report the index of the spatial basis corresponding to each subband in at least one subband when determining that the subband increment corresponding to at least one subband is greater than or equal to the increment threshold; wherein the subband increment is the difference in the index of the spatial basis between the first subband and the second subband in the broadband, or the subband increment is the difference in the multipath angle between the first subband and the second subband in the broadband, or the subband increment is the difference in the absolute value of the coefficients of the first subband and the second subband in the broadband at the same angle.

[0023] In one possible design, the first indication information is used to indicate a functional relationship in which an index of a spatial basis of at least one subband changes with a position of the subband and parameters of the functional relationship.

[0024] In one possible design, before sending the first indication information, the method also includes: receiving fourth indication information, the fourth indication information being used to instruct the terminal device to report the functional relationship of the spatial basis of at least one sub-band as the position of the sub-band changes and the parameters of the functional relationship.

[0025] In one possible design, before sending the first indication information, the method also includes: receiving an inquiry message, the inquiry message being used to inquire whether the terminal device has the ability to report the index of the spatial basis by subband; and sending a response message, the response message being used to indicate that the terminal device has the ability to report the index of the spatial basis by subband.

[0026] In one possible design, the at least one subband includes a subband of a center frequency point, a subband of a maximum frequency point, and a subband of a minimum frequency point in the broadband.

[0027] In a third aspect, a beamforming method is provided. Optionally, the method may be performed by a network device, a component or device (such as a processor, chip, or chip system) applied to the network device, or a logic module or software capable of implementing all or part of the network device's functions. The method includes: receiving first indication information, the first indication information being used to indicate beam information for each subband in at least one subband in a broadband; and performing beamforming based on the beam information corresponding to multiple subbands of the broadband, where the beam information corresponding to the multiple subbands is determined based on the beam information for each subband in the at least one subband.

[0028] In this way, compared to the more serious problem of beam squint caused by beamforming according to the optimal beam identifier of the entire band corresponding to the entire carrier aggregation (CA), in this application, the network equipment can perform beamforming according to the beam corresponding to each sub-band. This application takes into account the different multipath angles of electromagnetic waves of beams at different frequencies (different optimal beams), which leads to different effects of beam squint on different frequencies (different beam directions). In other words, this application can suppress the impact of beam squint and improve channel capacity.

[0029] In one possible design, the first indication information includes an optimal beam identifier corresponding to each of the at least one subband. This allows the network device to perform beamforming based on the optimal beam corresponding to each subband, thereby preventing beam squint in non-center frequency subbands caused by differing multipath angles across subbands.

[0030] In one possible design, the first indication information includes a bitmap of at least one subband and an optimal beam identifier corresponding to each of the at least one subband. This allows the network device to perform beamforming based on the optimal beam for each subband, thereby preventing beam squint in non-center frequency subbands caused by varying multipath angles across subbands.

[0031] In one possible design, before receiving the first indication information, the method further includes: sending second indication information, where the second indication information is used to instruct the terminal device to report beam information corresponding to each subband in at least one subband. That is, the network device may actively instruct the terminal device to report the optimal beam according to the subband to perform subband-level beamforming.

[0032] In one possible design, before receiving the first indication information, the method further includes: sending a query message, the query message being used to inquire whether the terminal device has the capability to report beam information by subband; and receiving a response message, the response message being used to indicate that the terminal device has the capability to report beam information by subband. In this way, for terminal devices capable of reporting beam information by subband, if the terminal device reports beam information by subband, the network device can perform beamforming based on the beam information of each subband, thereby suppressing the problem of large beam angle differences and severe beam squint caused by beamforming based on broadband beam information.

[0033] In a fourth aspect, a beamforming method is provided. Optionally, the method may be performed by a terminal device, a component or device (such as a processor, chip, or chip system) applied to a network device, or a logic module or software capable of implementing all or part of the terminal device's functions. The method includes: sending first indication information, the first indication information being used to indicate beam information for each subband in at least one subband in a broadband; and receiving a beam sent on the broadband, the beam being obtained by beamforming based on beam information corresponding to multiple subbands of the broadband, the beam information corresponding to the multiple subbands being determined based on beam information for each subband in the at least one subband.

[0034] The beneficial effects of the fourth aspect can be found in the description of the third aspect.

[0035] In one possible design, the first indication information includes an optimal beam identifier corresponding to each subband in at least one subband.

[0036] In one possible design, the first indication information includes a bitmap of at least one subband and an optimal beam identifier corresponding to each subband in the at least one subband.

[0037] In one possible design, before sending the first indication information, the method also includes: receiving second indication information, where the second indication information is used to instruct the terminal device to report beam information corresponding to each subband in at least one subband.

[0038] In one possible design, before sending the first indication information, the method also includes: receiving an inquiry message, the inquiry message being used to inquire whether the terminal device has the ability to report beam information by subband; and sending a response message, the response message being used to indicate that the terminal device has the ability to report beam information by subband.

[0039] In a fifth aspect, a communication device is provided, including: a receiving module for receiving first indication information, the first indication information being used to indicate the spatial basis of each subband in at least one subband in a broadband; a processing module for performing beamforming according to the spatial basis corresponding to multiple subbands of the bandwidth, the spatial basis corresponding to the multiple subbands being determined based on the spatial basis of each subband in at least one subband.

[0040] In one possible design, the first indication information includes an index of a spatial basis corresponding to each subband in at least one subband.

[0041] In one possible design, the first indication information includes a bitmap indicating at least one subband and an index of a spatial basis corresponding to each subband in the at least one subband.

[0042] In one possible design, a sending module is also included, which is used to send second indication information, and the second indication information is used to instruct the terminal device to report the index of the spatial basis of each subband in at least one subband.

[0043] In one possible design, it also includes a sending module for sending a third indication information, wherein the third indication information is used to instruct the terminal device to report the index of the spatial basis corresponding to each subband in at least one subband when determining that the subband increment corresponding to at least one subband is greater than or equal to the increment threshold; wherein the subband increment is the difference in the index of the spatial basis between the first subband and the second subband in the broadband, or the subband increment is the difference in the multipath angle between the first subband and the second subband in the broadband, or the subband increment is the difference in the absolute value of the coefficients of the first subband and the second subband in the broadband at the same angle.

[0044] In one possible design, the first indication information is used to indicate a functional relationship in which an index of a spatial basis of at least one subband changes with a position of the subband and parameters of the functional relationship.

[0045] In a possible design, it also includes a sending module for sending fourth indication information, where the fourth indication information is used to instruct the terminal device to report the functional relationship of the spatial basis of at least one sub-band as the position of the sub-band changes, as well as the parameters of the functional relationship.

[0046] In one possible design, it also includes a sending module for sending an inquiry message, where the inquiry message is used to inquire whether the terminal device has the ability to report the index of the spatial basis by subband; the receiving module is also used to receive a response message, where the response message is used to indicate that the terminal device has the ability to report the index of the spatial basis by subband.

[0047] In one possible design, the at least one subband includes a subband of a center frequency point, a subband of a maximum frequency point, and a subband of a minimum frequency point in the broadband.

[0048] In one possible design, the processing module is used to: determine beamforming weights corresponding to the multiple subbands according to the spatial bases corresponding to the multiple subbands; and perform beamforming according to the weight corresponding to each subband in the multiple subbands.

[0049] In a sixth aspect, a communication device is provided, including: a sending module for sending first indication information, the first indication information being used to indicate the spatial basis of each subband in at least one subband in a broadband; a receiving module for receiving a beam sent on the broadband, the beam being obtained by beamforming according to the spatial basis corresponding to multiple subbands of the bandwidth, and the spatial basis corresponding to the multiple subbands being determined according to the spatial basis of each subband in at least one subband.

[0050] In one possible design, the first indication information includes an index of a spatial basis corresponding to each subband in at least one subband.

[0051] In one possible design, the receiving module is also used to receive second indication information, where the second indication information is used to instruct the terminal device to report the index of the spatial basis of each subband in at least one subband.

[0052] In one possible design, the first indication information includes a bitmap indicating at least one subband and an index of a spatial basis corresponding to each subband in the at least one subband.

[0053] In one possible design, the receiving module is further used to receive third indication information, and the third indication information is used to instruct the terminal device to report the index of the spatial basis corresponding to each subband in at least one subband when determining that the subband increment corresponding to at least one subband is greater than or equal to the increment threshold; wherein the subband increment is the difference in the index of the spatial basis between the first subband and the second subband in the broadband, or the subband increment is the difference in the multipath angle between the first subband and the second subband in the broadband, or the subband increment is the difference in the absolute value of the coefficients of the first subband and the second subband in the broadband at the same angle.

[0054] In one possible design, the first indication information is used to indicate a functional relationship in which an index of a spatial basis of at least one subband changes with a position of the subband and parameters of the functional relationship.

[0055] In one possible design, the receiving module is also used to receive fourth indication information, and the fourth indication information is used to instruct the terminal device to report the functional relationship of the spatial basis of at least one sub-band as the position of the sub-band changes and the parameters of the functional relationship.

[0056] In one possible design, the receiving module is also used to receive an inquiry message, which is used to inquire whether the terminal device has the ability to report the index of the spatial basis by subband; the sending module is also used to send a response message, which is used to indicate that the terminal device has the ability to report the index of the spatial basis by subband.

[0057] In one possible design, the at least one subband includes a subband of a center frequency point, a subband of a maximum frequency point, and a subband of a minimum frequency point in the broadband.

[0058] In the seventh aspect, a communication device is provided, including: a receiving module for receiving first indication information, the first indication information being used to indicate beam information of each subband in at least one subband in a broadband; a processing module for performing beam shaping according to the beam information corresponding to multiple subbands of the broadband, the beam information corresponding to multiple subbands being determined based on the beam information of each subband in at least one subband.

[0059] In one possible design, the first indication information includes an optimal beam identifier corresponding to each subband in at least one subband.

[0060] In one possible design, the first indication information includes a bitmap of at least one subband and an optimal beam identifier corresponding to each subband in the at least one subband.

[0061] In a possible design, it also includes a sending module for sending second indication information, where the second indication information is used to instruct the terminal device to report beam information corresponding to each subband in at least one subband.

[0062] In one possible design, it also includes a sending module that sends an inquiry message, where the inquiry message is used to inquire whether the terminal device has the ability to report beam information by subband; the receiving module is also used to receive a response message, where the response message is used to indicate that the terminal device has the ability to report beam information by subband.

[0063] In an eighth aspect, a communication device is provided, including: a sending module for sending first indication information, the first indication information being used to indicate beam information of each subband in at least one subband in a broadband; a receiving module for receiving a beam sent on the broadband, the beam being obtained by beamforming according to beam information corresponding to multiple subbands of the bandwidth, and the beam information corresponding to multiple subbands being determined based on beam information of each subband in at least one subband.

[0064] In one possible design, the first indication information includes an optimal beam identifier corresponding to each subband in at least one subband.

[0065] In one possible design, the first indication information includes a bitmap of at least one subband and an optimal beam identifier corresponding to each subband in the at least one subband.

[0066] In one possible design, the receiving module is also used to receive second indication information, and the second indication information is used to instruct the terminal device to report beam information corresponding to each subband in at least one subband.

[0067] In one possible design, the receiving module is also used to: receive an inquiry message, where the inquiry message is used to inquire whether the terminal device has the ability to report beam information by subband; the sending module is also used to send a response message, where the response message is used to indicate that the terminal device has the ability to report beam information by subband.

[0068] In the ninth aspect, a communication device is provided, which includes a processor and a memory, the memory being used to store computer execution instructions. When the computer execution instructions are executed by the processor, the designs of the first to fourth aspects and any possible design method of the first to fourth aspects are executed.

[0069] In the tenth aspect, a computer-readable storage medium is provided, in which computer instructions are stored. When the computer instructions are executed on a communication device, the communication device executes the design of the first to fourth aspects and the method described in any possible design of the first to fourth aspects.

[0070] In the eleventh aspect, a computer program product is provided, comprising computer instructions, which, when the computer instructions are run on a communication device, enable the communication device to execute the design of the first to fourth aspects and the method described in any possible design of the first to fourth aspects.

[0071] In the twelfth aspect, a communication system is provided, which includes a first communication device and a second communication device. The first communication device can be used to execute the design of the first and third aspects and the method described in any possible design of the first and third aspects. The second communication device can be used to execute the design of the second and fourth aspects and the method described in any possible design of the second and fourth aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] FIG1 is a schematic diagram of a beam squint phenomenon provided by an embodiment of the present application;

[0073] FIG2 is a schematic diagram of array factors at different frequencies and horizontal angles in a MIMO technology provided in an embodiment of the present application;

[0074] FIG3 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0075] FIG4 is a schematic diagram of beam offset (angle deviation) at different desired beam angles provided in an embodiment of the present application;

[0076] FIG5 is a schematic diagram of a flow chart of a beamforming method provided in an embodiment of the present application;

[0077] FIG6 is a schematic diagram of a protocol layer framework of a base station and a UE provided in an embodiment of the present application;

[0078] FIG7 is a schematic diagram of a flow chart of a beamforming method provided in an embodiment of the present application;

[0079] FIG8 is a schematic diagram of a flow chart of a beamforming method provided in an embodiment of the present application;

[0080] FIG9 is a schematic diagram of a flow chart of a beamforming method provided in an embodiment of the present application;

[0081] FIG10 is a schematic diagram of a flow chart of a beamforming method provided in an embodiment of the present application;

[0082] FIG11 is a schematic diagram of a flow chart of a beamforming method provided in an embodiment of the present application;

[0083] FIG12 is a schematic diagram of channel capacity under different ratios of broadband to center frequency provided by an embodiment of the present application;

[0084] FIG13 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0085] FIG14 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0086] For ease of understanding, some examples of concepts related to the embodiments of the present application are provided for reference, as shown below.

[0087] Beam squint: This refers to the fact that, over a wide bandwidth, the beam observed by different subcarriers, subbands, or frequencies points in different directions. Beam squint is also called beam dispersion. This phenomenon is caused by the different multipath angles observed by different subbands, subcarriers, and frequencies.

[0088] Multipath Angle: In a mobile broadcast environment, the signal received by a receiver does not originate from a single path, but rather is a composite of numerous reflected waves from multiple paths. This phenomenon is known as the multipath effect. Specifically, in a wireless channel, there isn't just a single path between the transmitter and receiver, but rather multiple reflection paths with varying amplitudes, phases, delays, and angles of arrival, resulting in a time-dispersed signal in the time domain. Furthermore, each path reaches the receiver at a different angle. The angle at which signals from multiple paths arrive at the receiver can be understood as the multipath angle.

[0089] The beam squint phenomenon is explained here with reference to Figure 1. Figure 1 shows a schematic diagram of the beam squint phenomenon. The cause of beam squint is actually due to the different multipath angles observed by different subbands / subcarriers / frequencies. In other words, the beams point in different directions after beamforming for different subbands / subcarriers / frequencies. For example, Figure 1 shows a base station with a large-scale multiple-input multiple-output (MIMO) antenna array, including N antenna elements: antenna elements 11 to 1N. The bandwidth includes frequencies f6 to f1, and the frequency range of frequencies f6 to f1 gradually decreases. The base station performs beamforming based on the multipath angle of the center frequency f4. However, the multipath angles corresponding to frequencies f1, f2, f3, f5, and f6 are different. If frequencies f1, f2, f3, f5, and f6 are beamformed based on the multipath angle observed by frequency f4, multiple squint beams will be formed. That is, in FIG4 , the beam formed at the center frequency f4 is the desired beam, and the beams formed at the frequencies f1 , f2 , f3 , f5 , and f6 are all squinted beams due to the beam squint phenomenon.

[0090] Figure 2 shows a schematic diagram of array factors at different frequencies and horizontal angles in a MIMO technology. The horizontal axis represents the horizontal angle (azimuth angle) x, and the vertical axis represents the array factor (array factor) y. It is shown by taking a uniform linear array (ULA) with a center frequency fc of 6.5 GHz, a bandwidth of 400 MHz, and an array configuration of 16T (16 antenna elements) as an example. The array factor is expressed as: g(ξψ-ψ F ), formula (1).

[0091] Where ξ=f / fc represents the sub-frequency function, ψ F The current beam pointing angle is represented by ψ, which represents the horizontal angle of the frequency. An array can be understood as an antenna array, and the array factor measures the degree to which a specific characteristic changes due to grouping. In an antenna array, the array factor is the calculated gain at different frequencies and horizontal angles for this array configuration. This gain is used for beamforming.

[0092] The calculation formula of the steering vector is expressed as: β n (ψ F )=2πλ -1 (n-1)dψ F , formula (2).

[0093] Among them, β n represents the steering vector, λ represents the wavelength, ψ FIndicates the angle of the current beam pointing, d indicates the antenna spacing, and n is in the range of [1, N], where N is an integer representing the number of antenna elements.

[0094] According to formula (1) and formula (2), the array factor g(x) can be derived as:

[0095] Where x represents the horizontal angle of the frequency point.

[0096] From Figure 2, we can see that the beam pointing angles ψ at different frequencies f1, fc, and f2 are F Different frequencies have different horizontal angles x. For example, the horizontal angles x of frequencies f1 and f2 differ by more than 7 degrees (93.1059-86.9829). In this case, the array factors of different frequencies differ, meaning that the gains at different horizontal angles differ. This results in different multipath angles for the electromagnetic waves in the beams at different frequencies, leading to different effects on beam squint (different beam pointing directions). However, base stations cannot predict these beam squint changes in advance.

[0097] Beamforming: By adjusting the amplitude and phase of multiple antennas, the antenna radiation pattern is given a specific shape and direction, focusing the wireless signal energy on a narrower beam to enhance coverage and reduce interference.

[0098] Beam management: To ensure continuous seamless coverage, the base station side needs to send multiple beams in different directions as much as possible. To manage multiple beams, beam management technology is required. Beam management mainly includes four steps: 1) Beam sweeping, that is, sending and receiving a set of beams according to predefined time intervals and directions within the beam coverage area. 2) Beam measurement, that is, evaluating the quality of the received signal. The evaluation indicators include reference signal receiving power (RSRP), reference signal received quality (RSRQ), signal to interference plus noise ratio (SINR), etc. 3) Beam determination, that is, selecting the optimal beam (or beam group) based on beam measurement. 4) Beam reporting, that is, the terminal reports beam quality and beam decision information to the base station to establish beam-directional communication between the base station and the terminal.

[0099] Common beam management (CBM): In millimeter-wave multi-carrier systems, there are two main types of common beam management: intra-band carrier aggregation (CA) and inter-band CA. In intra-band CA, multiple carriers share a single RF channel. Therefore, terminals only support CBM and can use a common beam for signal transmission.

[0100] Independent beam management (IBM): Each frequency band selects a separate beam for signal transmission. For inter-band carrier aggregation, a terminal may support either CBM or IBM across two or more frequency bands. Capable terminals may even support both.

[0101] The precoding matrix indicator (PMI) can be used to indicate the precoding matrix, which the network device recovers based on the PMI. The precoding matrix can be a precoding matrix determined by the terminal device based on the channel matrix of each frequency domain unit. The frequency domain unit is the unit of frequency domain resources and can represent different frequency domain resource granularities.

[0102] A spatial domain vector, also known as a beam vector, spatial beam basis vector, spatial basis vector, or spatial basis, represents the weight of each antenna port. By linearly superimposing the signals from each antenna port based on the weights represented by each element in the spatial domain vector, a region with a strong signal can be formed in a certain spatial direction.

[0103] Frequency domain vectors (also called frequency domain bases) are vectors that represent the frequency domain channel's variation patterns. Each frequency domain vector can represent a specific variation pattern. As a signal travels through a wireless channel, it can take multiple paths from the transmitting antenna to the receiving antenna. Multipath delay causes frequency-selective fading, which is a variation of the frequency domain channel. Therefore, different frequency domain vectors can be used to represent the frequency domain channel variation patterns caused by delays along different transmission paths.

[0104] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application. In the description of the embodiments of the present 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, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0105] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this embodiment, unless otherwise specified, "plurality" means two or more.

[0106] The embodiments of the present application can be used in the fifth generation (5G) new radio (NR) system, or in future communication systems or other similar communication systems, as long as there is an entity in the communication system that needs to send transmission direction indication information, another entity needs to receive the indication information and determine the transmission direction within a certain period of time based on the indication information. In addition, the technical solutions provided in the embodiments of the present application can be applied to cellular links, public land mobile networks (PLMN), machine to machine (M2M) networks, Internet of Things (IoT) networks or other networks. It can also be applied to links between devices, such as device to device (D2D) links. D2D links can also be called sidelinks, where sidelinks can also be called side links or side links, etc. In the embodiments of the present application, the above terms all refer to links established between devices of the same type, and their meanings are the same. The so-called devices of the same type can be links between terminal devices, links between base stations, links between relay nodes, etc., and the embodiments of the present application do not limit this. For links between devices, there are D2D links defined in Release (Rel) 12 / 13 of the Third Generation Partnership Project (3GPP), as well as V2X links for vehicle-to-vehicle, vehicle-to-mobile, or vehicle-to-any-entity connections defined by 3GPP for connected vehicles, including Rel-14 / 15. These also include V2X links based on the New Radio (NR) system, currently under research by 3GPP in Rel-18 and subsequent releases.

[0107] Figure 3 shows a schematic diagram of the architecture of a communication system 30 provided in an embodiment of the present application. The communication system 30 includes communication equipment, and the communication equipment can use air interface resources for wireless communication. Among them, the communication equipment may include the network device 301 shown in Figure 3 and 6 types of terminal devices 302 to 307 (high-speed rail equipment, switches, gas station equipment, household appliances, mobile terminals and printers). It should be understood that the terminal devices in Figure 3 are only examples, and there can be more or less. The communication system 30 may also include other network devices, for example, wireless relay devices and wireless backhaul devices, which are not shown in Figure 3. The network device 301 is an access device for the terminal device to access the network through wireless, for example, it can be a base station. Among them, the network device 301 corresponds to different devices in different systems. For example, in the fourth-generation mobile communication technology (4th-generation, 4G) system, it can correspond to an evolved base station (eNB), and in the 5G system, it corresponds to a new generation base station (gNB). Terminal devices 302-307 may also be cellular phones or smart phones, portable computers, handheld communication devices, handheld computing devices, satellite radio devices, global positioning systems, personal digital assistants (PDAs), and / or any other suitable devices for communicating on wireless communication systems, and may be connected to network devices. Air interface resources may include at least one of time domain resources, frequency domain resources, code resources, and space resources. In the embodiments of the present application, at least one may also be described as one or more, and a plurality may be two, three, four, or more, which is not limited in this application.

[0108] The embodiments of the present application can be applied to uplink signal transmission, downlink signal transmission, and D2D signal transmission. For downlink signal transmission, the transmitting device is a network device, and the corresponding receiving device is a terminal device; for uplink signal transmission, the transmitting device is a terminal device, and the corresponding receiving device is a network device; for D2D signal transmission, the transmitting device is a terminal device, and the corresponding receiving device is a terminal device. For example, the three terminal devices shown in the dashed area of ​​Figure 3 can be applied to D2D signal transmission. The embodiments of the present application do not limit the direction of signal transmission.

[0109] For example, in this communication system 30, terminal devices 302-307 can send uplink data to network device 301, and network device 301 needs to receive the uplink data sent by terminal devices 302-307. Furthermore, terminal devices 305-307 can also form a communication system. In this communication system, network device 301 can send downlink information to terminal devices 302-304, etc.; terminal device 306 can also send downlink information to terminal devices 305 and 307.

[0110] The terminal device involved in the embodiments of the present application can also be called a terminal, which can be a device with wireless transceiver function, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water surface (such as ships, etc.); it can also be deployed in the air (for example, on airplanes, balloons and satellites, etc.). The terminal device can be user equipment (UE), wherein the UE includes a handheld device, a vehicle-mounted device, a wearable device or a computing device with wireless communication function. For example, the UE can be a mobile phone, a tablet computer or a computer with wireless transceiver function. The terminal device can also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in unmanned driving, a wireless terminal in telemedicine, a wireless terminal in smart grid, a wireless terminal in smart city, a wireless terminal in smart home, etc. In the embodiments of the present application, the device for realizing the function of the terminal can be a terminal; it can also be a device that can support the terminal to realize the function, such as a chip system, which can be installed in the terminal. In the embodiment of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices. In the technical solution provided in the embodiment of the present application, the device for implementing the functions of the terminal is a terminal, and the terminal is a UE as an example to describe the technical solution provided in the embodiment of the present application.

[0111] The network devices involved in the embodiments of this application include access network devices, such as base stations (BSs). A BS is a device deployed in a wireless access network that can wirelessly communicate with terminals. Base stations may come in various forms, such as TRPs and gNBs. Network devices may be devices used to communicate with mobile devices. A network device can be an AP in a wireless local area network (WLAN), a base transceiver station (BTS) in a global system for mobile communication (GSM) or code division multiple access (CDMA), a base station (NodeB) in wideband code division multiple access (WCDMA), an evolutionary Node B (eNB or eNodeB) in long term evolution (LTE), a relay station or access point, or a network device in an in-vehicle device, wearable device, or future 5G network or future evolved PLMN, or a gNodeB / gNB in ​​a NR system. In some deployments, a gNB may include a centralized unit (CU) and a DU. A gNB may also include an active antenna unit (AAU). The CU implements some gNB functions, while the DU implements some gNB functions. For example, the CU is responsible for processing non-real-time protocols and services, implementing the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers. The DU is responsible for processing physical layer protocols and real-time services, implementing the functions of the radio link control (RLC), medium access control (MAC), and physical (PHY) layers. The AAU implements some physical layer processing functions, RF processing, and active antenna-related functions. Because RRC layer information ultimately becomes PHY layer information, or is converted from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or by both the DU and the AAU. It is understood that a network device can be a device that includes one or more of a CU node, a DU node, or an AAU node.In addition, the CU can be divided into a network device in the access network (radio access network, RAN), or the CU can be divided into a network device in the core network (core network, CN), which is not limited in this application. In addition, in an embodiment of the present application, the network device provides services for a cell, and the terminal device communicates with the network device through the transmission resources used by the cell (for example, frequency domain resources, or spectrum resources). The cell can be a cell corresponding to the network device (for example, a base station). The cell can belong to a macro base station or a base station corresponding to a small cell. The small cell here can include: a metro cell, a micro cell, a pico cell, a femto cell, etc. These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services. In addition, in other possible cases, the network device may be other devices that provide wireless communication functions for terminal devices. The embodiments of the present application do not limit the specific technology and specific device form adopted by the network device. For the convenience of description, in the embodiments of the present application, the device that provides wireless communication functions for terminal devices is referred to as a network device. For example, the network device may also be a device that can support the network device to implement the function, such as a chip system, which can be installed in the network device. In the technical solutions provided in the embodiments of the present application, the device for implementing the function of the network device is a network device, and the network device is a base station as an example to describe the technical solutions provided in the embodiments of the present application.

[0112] The technical solutions provided in the embodiments of this application can be applied to wireless communications between communication devices. Wireless communications between communication devices may include: wireless communications between network devices and terminals, wireless communications between network devices, and wireless communications between terminals. In the embodiments of this application, the term "wireless communications" may also be referred to as "communication," which may also be described as "data transmission," "information transmission," or "transmission."

[0113] When discussing CA, the 3GPP 38.884 standard takes into account the beam squint phenomenon of MIMO antenna arrays and allows for the selection of either common beam management (CBM) or independent beam management (IBM) for the two cells performing CA, depending on the situation. For example, 3GPP considers beam squint and states that when the calculated beam gain offset of two cells at different frequencies is within 1.7dB, the beam squint is considered minor and CA can be performed on the same beam, i.e., CBM. Otherwise, when the calculated beam gain (array factor) offset of two cells at different frequencies is greater than 1.7dB, the beam squint is considered significant and CA needs to be performed on independent beams, i.e., IBM. However, this standard currently only considers beam squint within different component carriers (CCs) and does not address beam squint at different frequencies within the same CC. As shown in the above example of beam squint, under the same CC, the multipath angles of electromagnetic waves in beams at different frequencies are different, which will also cause different effects of beam squint at different frequencies (different beam directions).

[0114] In some technologies, when an antenna of a network device performs beamforming, beamforming may be performed based on PMI feedback of a terminal device.

[0115] For example, formula (4) shows a main form of PMI feedback, where S represents the spatial basis, F represents the frequency basis, C represents the combination coefficient, and W represents the precoding matrix used for beamforming. W = S*C*F H , formula (4).

[0116] For Type I codebooks, terminal devices only provide wideband feedback, including the spatial basis index S and the combined coefficient C. For Ttpe II codebooks, terminal devices can provide either wideband or subband feedback. If feedback is provided by subband, only the combining coefficient C is provided in amplitude and phase, and the frequency basis can also be provided by subband. However, the spatial basis S is shared across all subbands, using a set of bandwidth basis.

[0117] For example, the base station may instruct the UE via the field “CSI-ReportingBand” which subbands’ PMI coefficients C to be fed back, and the UE may feed back via the field “subbandAmplitude” whether the UE has the capability to feed back the PMI coefficients C according to the subbands.

[0118] When beamforming is performed using PMI feedback, if different frequencies are beamformed based on a broadband spatial basis, such as the center frequency, the beam angles at different frequencies will differ. Table 1 shows an example of beam angle differences at different frequencies.

[0119] Table 1

[0120] Corresponding to Table 1, Figure 4 shows a schematic diagram of beam offset (angle deviation) under different desired beam angles. It can be found that the angle difference between different sub-bands / frequencies and the center frequency ranges from 3.2° to 12°. In other words, when the bandwidth is used as the spatial basis for feedback, the beam angles of different sub-bands / frequencies under the same CC vary significantly, and the beam squint phenomenon is more serious. Especially when the antenna array has a large number of elements, considering the smaller beamwidth, the beam angle difference between different sub-bands / frequencies under the same CC is even greater when the bandwidth is used as the spatial basis for feedback.

[0121] In this case where the beam angles in different sub-bands / frequencies are different, the channel capacity will be reduced if beam squint exists, compared to the case where there is no beam squint at the center frequency.

[0122] Therefore, an embodiment of the present application provides a beamforming method and a communication device. In this method, when performing PMI feedback, the spatial basis can be reported separately according to the subband for the bandwidth under the same CC. In this way, the spatial basis corresponding to each subband in the broadband can be determined based on the spatial basis corresponding to the reported subband, and beamforming is performed according to the spatial basis corresponding to each subband. This is to take into account that under the broadband of the same CC, when the multipath angles of different subbands are different, the spatial basis corresponding to different subbands are not exactly the same. If beamforming is performed according to the spatial basis corresponding to each subband, it is equivalent to taking into account the above-mentioned problem that due to the different array factors of different frequencies, that is, the different gains at different horizontal angles of different frequencies, the multipath angles of the electromagnetic waves of the beams at different frequencies are different (different spatial basis), thereby resulting in different effects of beam squint on different frequencies (different beam pointing). Moreover, for the base station, it is impossible to know in advance the change of this beam squint. Compared with the existing problem of large beam angle differences, serious beam squint and low channel capacity caused by beam shaping according to the spatial basis of the broadband under the same broadband, this application can suppress the impact of beam squint and improve channel capacity.

[0123] Based on the above summary, the embodiments of the present application are introduced below.

[0124] FIG5 is a schematic diagram of a process of a beamforming method, which includes the following process.

[0125] 501. A network device receives first indication information, where the first indication information is used to indicate a spatial basis of each subband in at least one subband in a broadband.

[0126] In some embodiments, the network device receives the first indication information sent by the terminal device. Accordingly, the terminal device sends the first indication information, or in other words, the terminal device sends the first indication information to the network device.

[0127] In some embodiments, the network device is a base station, the terminal device is a UE, and the base station can receive the first indication information from the UE.

[0128] In some embodiments, the first indication information includes an index of a spatial basis corresponding to each subband in the at least one subband. Thus, when the network device obtains the index of the spatial basis corresponding to each subband in the at least one subband in the broadband, the network device can determine the spatial basis corresponding to each subband in the at least one subband based on the index.

[0129] In some embodiments, before the network device receives the first indication information, the method further includes: the network device sending second indication information, where the second indication information is used to instruct the terminal device to report the index of the spatial basis of each subband in the at least one subband. Alternatively, the network device sends the second indication information to the terminal device, and the terminal device receives the second indication information sent by the network device. In other words, the network device may proactively query the terminal device to report the index of the spatial basis of each subband in the at least one subband.

[0130] In some embodiments, the first indication information includes a bitmap indicating at least one subband and an index of the spatial basis corresponding to each of the at least one subband. This is equivalent to the terminal device informing the network device, through the bitmap, of the indices of the spatial basis of the subbands reported and the index of the spatial basis corresponding to each of the subbands.

[0131] In some embodiments, before receiving the first indication information, the method further includes: the network device sending third indication information, the third indication information being used to instruct the terminal device to report the index of the spatial basis corresponding to each subband in the at least one subband when determining that the subband increment corresponding to the at least one subband is greater than or equal to the increment threshold. Alternatively, the network device sends the third indication information to the terminal device, and the terminal device receives the third indication information sent by the network device. The subband increment is the difference in the index of the spatial basis between the first subband and the second subband in the wideband, or the difference in the multipath angle between the first subband and the second subband in the wideband, or the difference in the absolute value of the coefficients at the same angle between the first subband and the second subband in the wideband. The first subband and the second subband may be subbands corresponding to adjacent frequency points in the wideband. This is because, if the difference in the index of the spatial basis between adjacent subbands is small, or the difference in the multipath angle is small, or the difference in the absolute value of the coefficients at the same angle is small, the same spatial basis can be used for beamforming, and the beam angle difference is not significant. The coefficient here can be understood as the above-mentioned combination coefficient C.

[0132] In some embodiments, the first indication information is used to indicate a functional relationship in which the index of the spatial basis of the at least one subband changes with the position of the subband, as well as a parameter of the functional relationship. Thus, if the network device knows the position of each subband in the at least one subband, it can determine the index of the spatial basis of each subband in the at least one subband based on the functional relationship and the parameter of the functional relationship, thereby determining the spatial basis of each subband in the at least one subband based on the index.

[0133] In some embodiments, before receiving the first indication information, the method further includes: the network device sending fourth indication information, the fourth indication information being used to instruct the terminal device to report a functional relationship between the spatial basis of at least one subband and the position of the subband, as well as parameters of the functional relationship. Alternatively, the network device sends the fourth indication information to the terminal device, and the terminal device receives the fourth indication information from the network device. In other words, the network device may proactively query the terminal device regarding the spatial basis corresponding to each subband in the at least one subband.

[0134] In some embodiments, before receiving the first indication information, the method further includes: the network device sends an inquiry message, the inquiry message is used to inquire whether the terminal device has the ability to report the index of the spatial basis by subband. The network device receives a response message, the response message is used to indicate that the terminal device has the ability to report the index of the spatial basis by subband. In other words, the network device sends an inquiry message to the terminal device, and the terminal device receives the inquiry message sent by the network device. The terminal device sends a response message to the network device, and the network device receives the response message from the terminal device. In this way, if the terminal device has the ability to report the index of the spatial basis by subband, the network device can obtain the index of the spatial basis corresponding to different subbands under the broadband from the terminal device, so as to perform beamforming according to the fine-grained distinction of the spatial basis of different subbands.

[0135] In some embodiments, the at least one subband includes a subband with a center frequency, a subband with a maximum frequency, and a subband with a minimum frequency within the broadband. This means that the terminal device need not report the index of the spatial basis of every subband within the broadband to the network device; it may only need to report the indexes of the spatial basis of some subbands. The network device can infer the indexes of the spatial basis of other subbands within the broadband based on the reported spatial basis index of the subband according to certain principles. This reduces signaling overhead between the network device and the terminal device.

[0136] 502. The network device performs beamforming according to spatial bases corresponding to a plurality of sub-bands of the bandwidth, where the spatial bases corresponding to the plurality of sub-bands are determined according to a spatial base of each sub-band in at least one sub-band.

[0137] In some embodiments, the network device may determine the weights for beamforming corresponding to the multiple sub-bands according to the spatial bases corresponding to the multiple sub-bands; and perform beamforming according to the weights corresponding to each sub-band in the multiple sub-bands. In this way, compared with the problem of more serious large beam squint caused by beamforming according to the broadband spatial base, in the present application, the network device may determine the weights for beamforming according to the spatial base corresponding to each sub-band, and perform coherent superposition of beams in the same direction according to the weights corresponding to different sub-bands to obtain beams under multiple sub-bands. The present application takes into account the different multipath angles of electromagnetic waves of beams at different frequencies (different spatial bases), which leads to different effects of beam squint on different frequencies (different beam directions). That is, the present application can suppress the effects of beam squint and improve channel capacity.

[0138] The following describes an embodiment of the present application using a network device as a base station and a terminal device as a UE.

[0139] In order to facilitate understanding of the following embodiments, the protocol layer framework of the base station and the UE is first introduced here. As shown in Figure 6, a schematic diagram of a protocol layer framework of the base station and the UE in this application is shown. The base station and the UE may include a radio resource management / control (radio resource control, RRC) layer, a multimedia access management / control (medium access control, MAC) layer and a physical layer (physical layer, PHY). Among them, the RRC layer can be used for the base station and the UE to send and receive RRC signaling. The MAC layer can be used for the base station and the UE to send and receive multimedia access management control (MAC control element, MAC-CE) signaling. The PHY layer can be used for the base station and the UE to send and receive uplink / downlink control signaling, and uplink / downlink data. For example, the base station can send downlink control signaling to the UE through the physical downlink control channel (physical downlink control channel, PDCCH) at the PHY layer, and the base station can send downlink data to the UE through the physical downlink shared channel (physical downlink shared channel, PDSCH) at the PHY layer. The UE can send uplink control signaling to the base station through the physical uplink control channel (PUCCH) at the PHY layer, and the UE can send uplink data to the base station through the physical uplink shared channel (PUSCH) at the PHY layer. Of course, this is just an exemplary introduction to the functions of the RRC layer, MAC layer, and PHY layer, and this application does not limit the functions of the RRC layer, MAC layer, and PHY layer.

[0140] FIG7 is a flow chart of a beamforming method provided in an embodiment of the present application, which includes the following process.

[0141] 701. The base station sends a query message to the UE, where the query message is used to inquire whether the UE has the capability of reporting the index of the spatial basis by subband.

[0142] In some embodiments, the query message may be implemented via MAC-CE signaling. After the base station establishes an RRC link with the UE, the base station may send a first MAC-CE signaling to the UE, where the first MAC-CE signaling is used to inquire whether the UE has the capability to report the index of the spatial basis per subband.

[0143] In some embodiments, the spatial basis in this application may be angle indication information or distance indication information, and this application does not limit the content of the spatial basis. For example, the angle indication information may be the indication information of the multipath angle of electromagnetic waves transmitted between the base station and the UE, and the distance indication information may be the distance information between the base station and the UE.

[0144] 702. The UE sends a response message to the base station, where the response message is used to indicate that the UE has the capability of reporting the index of the spatial basis by subband.

[0145] In some embodiments, the response message may be implemented through MAC-CE signaling. The UE may send a second MAC-CE signaling to the base station, where the second MAC-CE signaling is used to indicate that the UE has the capability of reporting the index of the spatial basis per subband.

[0146] Exemplarily, the second MAC-CE signaling may include a "spatialScalingType" field, and the "spatialScalingType" field is the following:

[0147] spatialScalingType ENUMERTED{wideband,subband}.

[0148] When the content of the "spatialScalingType" field in the second MAC-CE signaling received by the base station is "ENUMERTED{wideband,subband}", it is equivalent to the UE replying to the base station that the UE capability of "reporting the index of the spatial basis by subband" is "yes", and the base station determines that the UE has the ability to report the index of the spatial basis by subband.

[0149] 703. The base station sends a first RRC message to the UE, where the first RRC message is used to instruct the UE to report an index of a spatial basis of each subband in at least one subband in the bandwidth.

[0150] The first RRC message here is an implementation method of the second indication information in step 501 of this application.

[0151] In some embodiments, when the base station determines that the UE has the capability to report the index of the spatial basis per subband, the base station may send a first RRC message to the UE, where the first RRC message indicates the following information:

[0152] 1) The index of the spatial basis needs to be in accordance with the indication information reported by the subband;

[0153] 2) The bitmap of the subband whose spatial basis index needs to be reported.

[0154] For example, in the first RRC message, the base station indicates that the index of the UE spatial basis needs to be reported according to the subband, which can be indicated by the field "subbandSpatial", and the content of the field "subbandSpatial" is "BOOLEAN", that is:

[0155] subbandSpatial BOOLEAN

[0156] For example, if the value of "BOOLEAN" is 1, it indicates that the index of the spatial basis needs to be reported per subband. If the value of "BOOLEAN" is 0, it indicates that the index of the spatial basis does not need to be reported per subband.

[0157] In the first RRC message, the base station may indicate the bitmap of the subband whose index of the spatial basis needs to be reported by the UE through the field "reportSpatialcontiguration". For example, the content of the field "reportSpatialcontiguration" may be:

[0158] This is equivalent to the base station instructing the UE to report the indexes of the spatial bases of the subbands identified as 3, 4, 17, 18, ..., 19, etc.

[0159] For example, 2 in the bitmap bit The bits are the number of subbands in the wideband, and each bit indicates whether the index of the spatial basis of the subband is reported.

[0160] In some embodiments, when the base station determines that the spatial basis of certain subbands is the same, it can also instruct the UE to report the index of the spatial basis of one of these subbands, that is, for these subbands, the base station only needs to indicate the bit of one of the subbands in the bitmap.

[0161] Alternatively, in some embodiments, the base station may not need to indicate the bitmap to the UE, and the UE may simply report the index of the spatial basis of at least one subband according to a default configuration. This default configuration is pre-agreed between the base station and the UE.

[0162] For example, the default configuration indicates that the UE only needs to report the indices of the spatial basis for the maximum subband, minimum subband, and center subband within the wideband. This means that at least one subband includes the maximum subband, minimum subband, and center subband. The base station can calculate the indices of the spatial basis corresponding to other subbands within the wideband according to the default configuration and a preset method. This approach reduces signaling overhead for both the base station and the UE.

[0163] 704. The UE sends a second RRC message to the base station, where the second RRC message is used to indicate an index of a spatial basis of each subband in the at least one subband.

[0164] Among them, the second RRC message is the implementation method of the first indication information in step 501 of this application.

[0165] As described in step 703, the second RRC message may include an index of the corresponding spatial basis of at least one subband corresponding to the bitmap indicated by the base station, or the second RRC message includes an index of the spatial basis corresponding to the maximum subband, minimum subband and center subband in the broadband.

[0166] 705. The base station determines spatial bases corresponding to multiple subbands in the bandwidth according to the index of the spatial base of each subband in the at least one subband, and performs beamforming according to the spatial bases corresponding to the multiple subbands.

[0167] In some embodiments, the base station may determine the spatial basis of each subband in the at least one subband based on the index of the spatial basis of each subband in the at least one subband. The base station may then determine the spatial basis corresponding to the subbands in the broadband other than the at least one subband based on the principle that the spatial basis of adjacent subbands can be the same. The base station determines beamforming weights corresponding to the multiple subbands based on the spatial basis corresponding to the multiple subbands. Based on the weights corresponding to each subband in the multiple subbands, the base station performs beamforming by coherently adding beams in the same direction.

[0168] Exemplarily, there are many ways to perform beamforming. For example, in NR, due to the high frequency band used, antennas usually use a multi-panel structure. In order to build a large-scale antenna array, integrated antenna in package / tile (AIP / AIT) is easy to implement and low cost. In AIP / AIT, different radio frequency (RF) connection structures can be used to implement different beamforming architectures. For example, digital beamforming (DBF), analog beamforming (ABF) or hybrid beamforming (HBF). Among them, DBF can provide flexible beamforming, ABF can provide steering accuracy and flexibility at low cost, and HBF is usually a compromise between DBF and ABF. Among them, the main difference between ABF and DBF is the way to complete beamforming, and whether these two methods require good channel matching. In ABF, membrane analog delay lines and summing can be used, requiring only one (higher resolution) high-speed analog-to-digital converter (ADC), whereas DBF requires multiple high-speed, high-resolution ADCs.

[0169] If DBF or HBF is used for beamforming, the digital domain and the spatial basis corresponding to each subband can be used to determine the beamforming weights corresponding to different subbands. Based on the weights corresponding to each subband in multiple subbands, coherent beam superposition is performed in the same direction to perform beamforming.

[0170] If the ABF method is used for beamforming, a delay device and the spatial basis corresponding to each subband can be used to determine the beamforming weights corresponding to different subbands. Based on the weights corresponding to each subband in multiple subbands, beam coherent superposition is performed in the same direction to perform beamforming.

[0171] Of course, the present application is not limited to these three beamforming modes, and may also be applicable to other beamforming modes and processes.

[0172] In this way, by reporting the spatial basis according to the sub-band granularity in the present application to perform sub-band-level beamforming, that is, to transmit control information or data of the PHY layer between the base station and the UE, the influence of beam squint caused by the different spatial basis of the sub-band can be suppressed, and the channel capacity during beam squint can be improved.

[0173] FIG8 is a flow chart of a beamforming method provided in an embodiment of the present application, which includes the following process.

[0174] 801. The base station sends a query message to the UE, where the query message is used to inquire whether the UE has the capability of reporting the index of the spatial basis by subband.

[0175] The implementation of step 801 can refer to the description of step 701.

[0176] 802. The UE sends a response message to the base station, where the response message is used to indicate that the UE has the capability of reporting the index of the spatial basis by subband.

[0177] The implementation of step 802 can refer to the description of step 702.

[0178] 803. The base station sends a third RRC message to the UE, where the third RRC message is used to instruct the UE to report an index of a spatial basis of each subband in at least one subband in the bandwidth.

[0179] The third RRC message here is an implementation method of the third indication information in step 501 of this application.

[0180] In some embodiments, if the base station determines that the UE has the capability to report the index of the spatial basis per subband, the base station may send a third RRC message to the UE, where the third RRC message indicates the following information:

[0181] 1) The index of the spatial basis needs to be in accordance with the indication information reported by the subband;

[0182] 2) Threshold for sub-band incremental reporting.

[0183] The threshold for reporting subband increments may be used to indicate that when the subband increment between subbands exceeds the threshold, the index of the spatial basis corresponding to the subband needs to be reported.

[0184] In some embodiments, the subband increment can be the subband increment of adjacent subbands in the bandwidth after the subbands are sorted by their frequency magnitude. For example, the subband increment can be the difference in the indices of the spatial basis between adjacent subbands, or the difference in the multipath angle between adjacent subbands, or the difference in the absolute values ​​of the coefficients at the same angle (e.g., the multipath angle) between adjacent subbands. In this way, the at least one subband includes the subband corresponding to the maximum frequency or the subband corresponding to the minimum frequency after the subbands are sorted by their frequency magnitude. This is to ensure that if the subband increment between adjacent subbands does not exceed a threshold, for example, if the difference in the indices of the spatial basis between adjacent subbands is less than the threshold corresponding to the index, the two subbands can be considered to use the same spatial basis for beamforming, and beam squint is not severe. In this case, only the index of the spatial basis of the previous subband in the order is reported. Similarly, if the difference in multipath angles between adjacent subbands is less than the threshold corresponding to the multipath angle, the two subbands can be considered to use the same spatial basis for beamforming, and beam squint is not severe. In this case, only the index of the spatial basis of the previous subband in sequence needs to be reported. Similarly, if the absolute value of the coefficients at the same angle between adjacent subbands is less than the threshold corresponding to the absolute value of the coefficients, the two subbands can be considered to use the same spatial basis for beamforming, and beam squint is not severe. In this case, only the index of the spatial basis of the previous subband in sequence needs to be reported.

[0185] Exemplarily, the third RRC message may include the following two fields:

[0186] subbandspatial BOOLEAN

[0187] thresholdSpatialAddition INTEGER

[0188] The "subbandspatial" field indicates whether the index of the spatial basis should be reported per subband. For example, a value of 1 indicates that the index of the spatial basis should be reported per subband. A value of 0 indicates that the index of the spatial basis does not need to be reported per subband. The "thresholdSpatialAddition" field indicates the threshold for incremental reporting of subbands.

[0189] 804. The UE sends a fourth RRC message to the base station, where the fourth RRC message is used to indicate an index of a spatial basis of each subband in the at least one subband.

[0190] In some embodiments, the fourth RRC message includes the first indication information in step 501 of the present application.

[0191] Exemplarily, the fourth RRC message includes an index of a spatial basis corresponding to each subband in at least one subband determined by the UE according to the incremental threshold, for example, including an identifier of each subband and an index of a spatial basis corresponding to each subband.

[0192] Alternatively, the fourth RRC message includes a bitmap of at least one subband reported by the UE and an index of a spatial basis corresponding to each subband in the at least one subband.

[0193] 805. The base station determines spatial bases corresponding to multiple subbands in the bandwidth according to an index of the spatial base of each subband in at least one subband, and performs beamforming according to the spatial bases corresponding to the multiple subbands.

[0194] The implementation of step 805 can refer to the description of step 705.

[0195] Therefore, by reporting the spatial basis according to the sub-band granularity in the present application to perform sub-band-level beamforming, that is, to transmit control information or data of the PHY layer between the base station and the UE, the influence of beam squint caused by the different spatial basis of the sub-band can be suppressed, and the channel capacity during beam squint can be improved.

[0196] FIG9 is a flow chart of a beamforming method provided in an embodiment of the present application, which includes the following process.

[0197] 901. The base station sends an inquiry message to the UE, where the inquiry message is used to inquire whether the UE has the capability of reporting the index of the spatial basis by subband.

[0198] The implementation of step 901 can refer to the description of step 701.

[0199] 902. The UE sends a response message to the base station, where the response message is used to indicate that the UE has the capability of reporting the index of the spatial basis by subband.

[0200] The implementation of step 902 can refer to the description of step 702.

[0201] 903. The base station sends a fifth RRC message to the UE, where the fifth RRC message is used to instruct the UE to report a functional relationship between a spatial basis of at least one subband and a change in a position of the subband and a parameter of the functional relationship.

[0202] The fifth RRC message here is an implementation method of the fourth indication information in step 501 of this application.

[0203] In some embodiments, if the base station determines that the UE has the capability to report the index of the spatial basis per subband, the base station may send a fifth RRC message to the UE, where the fifth RRC message indicates the following information:

[0204] 1) The index of the spatial basis needs to be in accordance with the indication information reported by the subband;

[0205] 2) Reporting the functional relationship between the spatial basis of at least one subband and the position of the subband and indication information of the parameters of the functional relationship.

[0206] Exemplarily, the fifth RRC message may include the following two fields:

[0207] subbandspatial BOOLEAN

[0208] subbandSpatialRelation BOOLEAN

[0209] Among them, the field "subbandspatial" is the indication information that the index of the above-mentioned spatial basis needs to be reported according to the subband. For example, when the value of the field "subbandspatial" is 1, it indicates that the index of the spatial basis needs to be reported according to the subband. When the value of the field "subbandspatial" is 0, it indicates that the index of the spatial basis does not need to be reported according to the subband. The field "subbandSpatialRelation" indicates the functional relationship of reporting the spatial basis of at least one subband as the position of the subband changes and the parameters of the functional relationship. When the value of the field "subbandSpatialRelation" is 1, it indicates that the functional relationship of reporting the spatial basis of at least one subband as the position of the subband changes and the parameters of the functional relationship need to be reported. When the value of the field "subbandSpatialRelation" is 0, it indicates that the functional relationship of reporting the spatial basis as the position of the subband changes and the parameters of the functional relationship do not need to be reported according to the subband.

[0210] 904. The UE sends a sixth RRC message to the base station, where the sixth RRC message is used to indicate a functional relationship between an index of a spatial basis of at least one subband and a change in a position of the subband and a parameter of the functional relationship.

[0211] In some embodiments, the fourth RRC message includes the first indication information in step 501 of the present application.

[0212] Illustratively, the functional relationship of how the index of the spatial basis varies with the subband may be of various types, such as a linear function, a quadratic function, a cubic function, a sin function, or a function of Taylor coefficient*n bits, where n is an integer, such as 3. The parameters of the functional relationship of how the index of the spatial basis varies with the position of the subband may be, for example, a1, a2, and a3. If each parameter occupies 3 bits, the parameters of the functional relationship of how the index of the spatial basis varies with the position of the subband may occupy 9 bits.

[0213] In some embodiments, if the functional relationship is relatively complex, the base station may calculate the index of the spatial basis by obtaining Taylor coefficients using Taylor expansion. For example, the Taylor coefficients obtained using Taylor expansion are of order 0 to 3, and the Taylor coefficients are in the following form: This application does not limit the form of the Taylor coefficient.

[0214] In this way, for the base station, when receiving the functional relationship and the parameters of the functional relationship, the base station can determine the index of the spatial basis corresponding to each subband in at least one subband based on the functional relationship and the parameters of the functional relationship and the position of at least one subband.

[0215] In some embodiments, the sixth RRC message may further include at least one of the following information: a bitmap of non-zero coefficients, an index of the strongest coefficient (frequency domain and angle index), an index of the selected frequency domain basis, a phase and amplitude of the coefficient, an index of the selected spatial domain basis, or an oversampling rate of the spatial domain basis. The coefficients here may be understood as the above-mentioned combined coefficient C.

[0216] 905. The base station determines spatial bases corresponding to multiple subbands in the bandwidth according to an index of the spatial base of each subband in at least one subband, and performs beamforming according to the spatial bases corresponding to the multiple subbands.

[0217] The implementation of step 905 can refer to the description of step 705.

[0218] Therefore, by reporting the spatial basis according to the sub-band granularity in the present application to perform sub-band-level beamforming, that is, to transmit control information or data of the PHY layer between the base station and the UE, the influence of beam squint caused by the different spatial basis of the sub-band can be suppressed, and the channel capacity during beam squint can be improved.

[0219] The above describes the process of beamforming under PMI feedback.

[0220] In some embodiments, beamforming can also be performed through beam management feedback. The beam management feedback is equivalent to feeding back a full-band optimal beam identity (ID) for the entire CA, and each CC can perform beamforming according to the optimal beam ID. For example, for a base station, the base station can pre-form a variety of wide beams and narrow beams. The UE can select a narrow beam in a wide beam as the optimal beam according to certain beam selection rules and report it to the base station. The base station performs beamforming on each CC in the entire CA according to the reported narrow beam. In this case, it is equivalent to beamforming all subbands in each CC according to the same beam ID. This is similar to the problem of beamforming using the above-mentioned PMI feedback. Since different subbands under a CC correspond to different multipath angles, there is still a problem of beam squint.

[0221] Based on this, an embodiment of the present application also provides a beamforming method, in which the network device may instruct the terminal device to report the beam identifier corresponding to each subband in at least one subband in the broadband, and the network device determines the beam corresponding to each subband in the broadband according to the beam identifier corresponding to each subband in at least one subband, so as to perform beamforming according to the beam corresponding to each subband. The beam identifier corresponding to each subband here can be understood as the identifier of the optimal beam corresponding to each subband. In this way, compared with the more serious problem of beam squint caused by beamforming according to the optimal beam identifier of a full band corresponding to the entire CA, in this application, the network device can perform beamforming according to the beam corresponding to each subband. This application takes into account the different multipath angles of electromagnetic waves of beams at different frequencies (different optimal beams), which leads to different effects of beam squint on different frequencies (different beam directions), that is, this application can suppress the impact of beam squint and improve channel capacity.

[0222] Therefore, as shown in FIG10 , a schematic flow chart of a beamforming method provided in an embodiment of the present application is shown, and the method includes the following process.

[0223] 101. A network device receives first indication information, where the first indication information is used to indicate beam information of each subband in at least one subband in a broadband.

[0224] Similar to the above embodiment, the network device receiving the first indication information includes: the network device receiving the first indication information sent by the terminal device. Correspondingly, the terminal device sends the first indication information to the network device.

[0225] In some embodiments, the network device is a base station and the terminal device is a UE.

[0226] In some embodiments, the beam information of each subband in at least one subband includes the optimal beam identifier corresponding to each subband in at least one subband, for example, specifically includes the identifier / position information of each subband in at least one subband and the optimal beam identifier corresponding to each subband.

[0227] In some embodiments, the beam information of each subband in the at least one subband includes a bitmap of the at least one subband and an optimal beam identifier corresponding to each subband in the at least one subband.

[0228] In some embodiments, before the network device receives the first indication information, the method also includes: the network device sends an inquiry message, the inquiry message is used to inquire whether the terminal device has the ability to report beam information by subband; the network device receives a response message, the response message is used to indicate that the terminal device has the ability to report beam information by subband.

[0229] In some embodiments, before the network device receives the first indication information, the method further includes: the network device sending second indication information, where the second indication information is used to instruct the terminal device to report beam information corresponding to each subband in the at least one subband. Alternatively, the network device sends the second indication information to the terminal device, and the terminal device receives the second indication information sent by the network device.

[0230] 102. The network device performs beamforming according to beam information corresponding to multiple subbands of the broadband, where the beam information corresponding to the multiple subbands is determined based on beam information of each subband in at least one subband.

[0231] In some embodiments, the network device may determine beam information corresponding to subbands other than the at least one subband in the broadband based on beam information corresponding to each subband in the at least one subband in the broadband, thereby obtaining beam information corresponding to multiple subbands in the broadband. The network device may then perform beamforming based on the beam information corresponding to the multiple subbands.

[0232] In this way, this application takes into account the different multipath angles of electromagnetic waves in beams of different frequencies / sub-bands (different optimal beams), which leads to different effects of beam squint on different frequencies (different beam directions). The network device in this application can perform beamforming according to the optimal beam corresponding to each sub-band. In other words, this method of beamforming according to the granularity of the sub-band can suppress the impact of beam squint and improve channel capacity.

[0233] FIG11 is a flow chart of a beamforming method provided in an embodiment of the present application, which includes the following process.

[0234] 111. The base station sends an inquiry message to the UE, where the inquiry message is used to inquire whether the UE has the ability to report beam information by subband.

[0235] In some embodiments, the query message may be implemented via MAC-CE signaling. After the base station establishes an RRC link with the UE, the base station may send a first MAC-CE signaling to the UE, where the first MAC-CE signaling is used to inquire whether the UE has the capability to report beam information by subband.

[0236] In some embodiments, the beam information may be understood as the optimal beam ID corresponding to the subband.

[0237] 112. The UE sends a response message to the base station, where the response message is used to indicate that the UE has the ability to report beam information by subband.

[0238] In some embodiments, the response message may be implemented through MAC-CE signaling. The UE may send a second MAC-CE signaling to the base station, where the second MAC-CE signaling is used to indicate that the UE has the capability to report beam information by subband.

[0239] Exemplarily, the second MAC-CE signaling may include a "beamManagementSubband" field, and the "beamManagementSubband" field may contain the following content:

[0240] beamManagementCSI-RS

[0241] {beamManagementSubband Bool}

[0242] For example, the value of the "beamManagementSubband" field is 1, indicating that the UE has the ability to report beam information by subband, which is equivalent to the UE replying to the base station that the UE capability of "reporting beam information by subband" is "yes"; the value of the "beamManagementSubband" field is 0, indicating that the UE does not have the ability to report beam information by subband.

[0243] 113. The base station sends a first RRC message to the UE, where the first RRC message is used to instruct the terminal device to report beam information corresponding to each subband in at least one subband.

[0244] The first RRC message here is an implementation method of the second indication information in step 101 of this application.

[0245] In some embodiments, when the base station determines that the UE has the capability to report beam information per subband, the base station may send a first RRC message to the UE, where the first RRC message indicates the following information:

[0246] 1) The beam information of the narrow beam must be reported according to the indication information of the sub-band;

[0247] 2) Indication information of at least one subband for which beam information needs to be reported.

[0248] For example, in the first RRC message, the base station may indicate that the UE beam information needs to be reported according to the subband through the field "subbandBeamManagement", and the content of the field "subbandBeamManagement" is "BOOLEAN", that is:

[0249] subbandBeamManagement BOOLEAN

[0250] For example, if the value of "BOOLEAN" is 1, it indicates that the beam information needs to be reported according to the subband. If the value of "BOOLEAN" is 0, it indicates that the beam information does not need to be reported according to the subband.

[0251] In the first RRC message, the base station may indicate the subband for which the UE needs to report beam information through the field "reportBeamSubbandContiguration". For example, the content of the field "reportBeamSubbandContiguration" may be:

[0252] This is equivalent to the base station instructing the UE to report the beam information of subbands identified as 3, 4, 17, 18, ..., 19, etc.

[0253] 114. The UE sends a second RRC message to the base station, where the second RRC message is used to indicate beam information of each subband in at least one subband in the broadband.

[0254] Among them, the second RRC message is the implementation method of the first indication information in step 101 of this application.

[0255] In some embodiments, after scanning and selecting wide beams and narrow beams, the UE may report the optimal beam identifier according to the subband for the optimal narrow beam.

[0256] Exemplarily, the UE may first scan multiple wide beams sent by the base station to determine the channel quality / signal strength corresponding to each wide beam in the multiple wide beams. According to the channel quality / signal strength corresponding to each wide beam, a first wide beam with the best channel quality / signal strength is selected from the multiple wide beams. The UE then scans each narrow beam in the selected first wide beam and measures the channel quality / signal strength of each subband of the first wide beam in at least one subband in the broadband, that is, each subband corresponds to each narrow beam in the first wide beam. That is, the UE here can receive multiple narrow beams in the first wide beam on each subband. Then, based on the channel quality / signal strength of each subband corresponding to each narrow beam in the first wide beam, the UE selects the optimal beam with the best channel quality / signal strength for each subband. The UE then reports the optimal beam ID corresponding to each subband in at least one subband to the base station.

[0257] The wide beam is, for example, a synchronization signal block (SSB), and the narrow beam is a channel state information reference signal (CSI-RS). CSI-RS can be understood as a pilot signal used to measure CSI. This application does not limit the wide beam to only SSB, nor does it limit the narrow beam to only CSI-RS.

[0258] 115. The base station performs subband-level beamforming according to beam information corresponding to multiple subbands in the broadband, where the beam information corresponding to the multiple subbands is determined based on beam information of each subband in at least one subband.

[0259] In some embodiments, the base station may perform subband-level beamforming according to beam information corresponding to multiple subbands in a wideband in various ways, such as DBF, HBF, or ABF.

[0260] Therefore, this application takes into account the different multipath angles of electromagnetic waves in beams of different frequencies / sub-bands (different optimal beams), which leads to different effects of beam squint on different frequencies (different beam directions). The base station in this application can perform beamforming according to the optimal beam corresponding to each sub-band. In other words, this method of beamforming based on sub-band granularity can suppress the impact of beam squint and improve channel capacity.

[0261] The following compares the channel capacity when beamforming is performed based on a subband-level spatial basis or based on subband-level beam information to suppress beam squint, and when beamforming is performed based on a full-band / wideband spatial basis or based on the optimal beam ID for full-band / wideband under CA. Figure 12 shows a schematic diagram of the channel capacity for different wideband-to-center frequency ratios. In Figure 12, the horizontal axis represents different wideband-to-center frequency ratios, and the vertical axis represents the channel capacity (gbits / sec). Among them, curve ① represents the channel capacity corresponding to different broadband to center frequency ratios obtained by statistics when beam squint is achieved by adopting the present application, and the base station uses a uniform linear array (ULA) antenna system with N=64 antenna elements. Curve ② represents the channel capacity corresponding to different broadband to center frequency ratios obtained by statistics when beamforming is performed according to the full-band / broadband spatial basis or according to the optimal beam ID of the full-band / broadband under CA, and when beam squint exists, the base station uses a ULA antenna system with 64 antenna elements. It can be seen that, for the same ULA antenna system with 64 antenna elements, at the same broadband to center frequency ratio, the channel capacity shown by curve ① is higher than the channel capacity shown by curve ②. For example, when the ratio of broadband (400M) to center frequency (6.5GHz) is 0.06, the channel capacity in the case of beam squint is 50% less than the channel capacity in the case of no beam squint; when the ratio of broadband (800M) to center frequency (6.5GHz) is around 0.12, the channel capacity in the case of beam squint is 73% less than the channel capacity in the case of no beam squint.

[0262] Similarly, curve ③ represents the channel capacity corresponding to different broadband to center frequency ratios obtained by statistics when beam squint is achieved by adopting the present application, and the base station uses the ULA antenna system, and the number of antenna elements is N = 32. Curve ④ represents the channel capacity corresponding to different broadband to center frequency ratios obtained by statistics when beamforming is performed according to the full-band / broadband spatial basis or according to the optimal beam ID of the full-band / broadband under CA, and when beam squint exists, the base station uses the ULA antenna system, and the number of antenna elements is 32. It can be seen that, for the same ULA antenna system with 32 antenna elements, at the same broadband to center frequency ratio, the channel capacity shown by curve ③ is higher than the channel capacity shown by curve ④. For example, when the ratio of broadband (400M) to center frequency (6.5GHz) is 0.06, the channel capacity in the case of beam squint is 7% less than the channel capacity in the case of no beam squint; when the ratio of broadband (800M) to center frequency (6.5GHz) is around 0.12, the channel capacity in the case of beam squint is 40% less than the channel capacity in the case of no beam squint.

[0263] Therefore, compared with the case without beam squint, the channel capacity is significantly reduced when beam squint exists, and the reduction is approximately 7% to 73% of the channel capacity in the case without beam squint.

[0264] It is understood that in order to implement the functions in the above embodiments, the network devices and terminal devices include hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily appreciate that, in combination with the units and method steps of each example described in the embodiments disclosed in this application, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in hardware or in a manner driven by computer software depends on the specific application scenario and design constraints of the technical solution.

[0265] Figures 13 and 14 are schematic diagrams of the structures of possible communication devices provided in the embodiments of the present application. These communication devices can be used to implement the functions of the network device and the terminal device in the above-mentioned method embodiment, and thus can also achieve the beneficial effects possessed by the above-mentioned method embodiment. In the embodiment of the present application, the communication device can be one of the devices 301 or 302 to 307 as shown in Figure 3, or a communication module (such as a chip or chipset) applied to these devices. The relevant communication device is used to implement data transmission, for example, it can be used to implement the beamforming mentioned above.

[0266] As shown in Figure 13, the communication device 130 includes a processing module 1310 and a transceiver module 1320. The communication device 130 is used to implement the functions of the network device or terminal device in the method embodiments shown in Figures 5 to 11 above.

[0267] When the communication device 130 is used to implement the functions of the network device in the method embodiments shown in Figures 5 to 11: the transceiver module 1320 can be used to receive the first indication information, send the inquiry message, receive the response message, send the first RRC message, the third RRC message, or the fifth RRC message, and receive the second RRC message, the fourth RRC message, or the sixth RRC message; the processing module 1310 can be used to perform beamforming based on the spatial basis or beam information corresponding to the multiple sub-bands of the bandwidth;

[0268] When the communication device 130 is used to implement the function of the terminal device in the method embodiments shown in FIG5 to FIG11: the transceiver module 1320 is used to send the first indication information 、 Receive inquiry messages 、 Send a response message, receive the first RRC message / third RRC message / fifth RRC message, send the second RRC message / fourth RRC message / sixth RRC message; the processing module 1310 can be used to perform wide beam and narrow beam measurements, and process the received data, etc.

[0269] For a more detailed description of the processing module 1310 and the transceiver module 1320 , reference may be made to the relevant descriptions in the method embodiments shown in FIG. 5 to FIG. 11 .

[0270] As shown in Figure 14, communication device 140 includes a processor 1410 and a transceiver 1420. Processor 1410 and transceiver 1420 are coupled to each other. It is understood that transceiver 1420 can be a transceiver or an input / output interface. Optionally, communication device 140 may also include a memory 1430 for storing instructions executed by processor 1410, input data required by processor 1410 to execute instructions, or data generated by processor 1410 after executing instructions.

[0271] When the communication device 140 is used to implement the methods shown in Figures 5 to 11, the processor 1410 is used to implement the functions of the processing module 1310, and the transceiver 1420 is used to implement the functions of the transceiver module 1320. The transceiver 1420 can be an interface chip or a separate IP module integrated in the interface chip.

[0272] When the communication device 140 is an interface chip used in a network device, the interface chip of the network device implements the functions of the network device in the above-mentioned method embodiment. When the interface chip of the network device sends data to the terminal device, it can be understood that the data is first generated by other modules in the network device (such as the source data component) and then sent to the interface chip of the network device by these modules.

[0273] When the interface device 140 is an interface chip used in a terminal device, the interface chip of the terminal device implements the functions of the terminal device in the above-mentioned method embodiment. The interface chip of the terminal device receives data from the terminal device. It can be understood that the data is first received by the interface chip of the terminal device and then sent by the interface chip of the terminal device to the data processing component of the terminal device.

[0274] In this application, when entity A sends information to entity B, it can be A sending it directly to B or A sending it indirectly to B through another entity. Similarly, when entity B receives information from entity A, it can be entity B receiving the information sent by entity A directly or entity B receiving the information sent by entity A indirectly through another entity. Entities A and B here can be the sending side or the receiving side, or they can be modules within the sending side or the receiving side. The sending and receiving of data can be information exchange between the sending side and the receiving side, for example, information exchange between a source device and a sink device; the sending and receiving of data can also be information exchange between different modules within a device, for example, information exchange between an interface chip on the sending side and an interface chip on the receiving side.

[0275] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0276] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions that can be executed by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, mobile hard disk, CD-ROM or any other form of storage medium well known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. The storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC. In addition, the ASIC can be located in a base station or a terminal. The processor and storage medium can also exist in a base station or a terminal as discrete components.

[0277] In the above embodiments, all or part of the embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are performed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions may be transferred from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; an optical medium, such as a digital video disk; or a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or nonvolatile storage medium, or may include both volatile and nonvolatile types of storage media.

[0278] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0279] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "Including at least one of A, B and C" can mean: including A; including B; including C; including A and B; including A and C; including B and C; including A, B and C.

[0280] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

Claims

1. A beamforming method, characterized in that, including: receiving first indication information for indicating the spatial domain basis of each sub-band in at least one sub-band of a broadband; performing beamforming according to the spatial domain bases corresponding to multiple sub-bands of the broadband, where the spatial domain bases corresponding to the multiple sub-bands are determined according to the spatial domain basis of each sub-band in the at least one sub-band.

2. The method according to claim 1, wherein The first indication information includes the index of the spatial domain basis corresponding to each sub-band in the at least one sub-band.

3. The method according to claim 1, characterized in that, The first indication information includes a bitmap indicating the at least one sub-band and the index of the spatial domain basis corresponding to each sub-band in the at least one sub-band.

4. The method according to any one of claims 1 to 3, characterized in that, Before receiving the first indication information, the method further includes: sending second indication information for indicating that a terminal device reports the index of the spatial domain basis of each sub-band in the at least one sub-band.

5. The method according to any one of claims 1 to 3, characterized in that, Before receiving the first indication information, the method further includes: sending third indication information for indicating that the terminal device reports the index of the spatial domain basis corresponding to each sub-band in the at least one sub-band when determining that the sub-band increment corresponding to the at least one sub-band is greater than or equal to an increment threshold; wherein the sub-band increment is the difference between the indices of the spatial domain bases between a first sub-band and a second sub-band in the broadband, or the sub-band increment is the difference between the multipath angles between the first sub-band and the second sub-band in the broadband, or the sub-band increment is the difference between the absolute values of the coefficients of the first sub-band and the second sub-band in the broadband at the same angle.

6. The method according to claim 1, characterized in that The first indication information is used to indicate the functional relationship between the index of the spatial domain basis of the at least one sub-band and the position change of the sub-band and the parameters of the functional relationship.

7. The method according to claim 6, wherein Before receiving the first indication information, the method further includes: sending fourth indication information for indicating that the terminal device reports the functional relationship between the spatial domain basis of the at least one sub-band and the position change of the sub-band and the parameters of the functional relationship.

8. The method according to any one of claims 1 to 7, characterized in that Before receiving the first indication information, the method further includes: sending an inquiry message for asking whether the terminal device has the ability to report the index of the spatial domain basis by sub-band; receiving a response message for indicating that the terminal device has the ability to report the index of the spatial domain basis by sub-band.

9. The method according to any one of claims 1-8, characterized in that, The at least one sub-band includes the sub-band of the center frequency point, the sub-band of the maximum frequency point, and the sub-band of the minimum frequency point in the broadband.

10. The method according to any one of claims 1-9, characterized in that, The performing beamforming according to the spatial domain bases corresponding to multiple sub-bands of the broadband includes: determining the weights for beamforming corresponding to the multiple sub-bands according to the spatial domain bases corresponding to the multiple sub-bands; performing beamforming according to the weights corresponding to each sub-band in the multiple sub-bands.

11. A beamforming method, characterized in that, including: sending first indication information for indicating the spatial domain basis of each sub-band in at least one sub-band of a broadband; Receive the beam transmitted on the broadband, where the beam is formed by beamforming according to the spatial domain bases corresponding to multiple sub-bands of the bandwidth, and the spatial domain bases corresponding to the multiple sub-bands are determined according to the spatial domain bases of each sub-band in the at least one sub-band.

12. The method according to claim 11, wherein The first indication information includes the indexes of the spatial domain bases corresponding to each sub-band in the at least one sub-band.

13. The method according to claim 12, wherein Before sending the first indication information, the method further includes: Receiving second indication information, where the second indication information is used to instruct the terminal device to report the indexes of the spatial domain bases of each sub-band in the at least one sub-band.

14. The method according to claim 11, wherein The first indication information includes a bitmap indicating the at least one sub-band and the indexes of the spatial domain bases corresponding to each sub-band in the at least one sub-band.

15. The method according to claim 14, wherein Before sending the first indication information, the method further includes: Receiving third indication information, where the third indication information is used to instruct the terminal device to report the indexes of the spatial domain bases corresponding to each sub-band in the at least one sub-band when it is determined that the sub-band increment corresponding to the at least one sub-band is greater than or equal to an increment threshold; wherein, the sub-band increment is the difference between the indexes of the spatial domain bases of the first sub-band and the second sub-band in the broadband, or the sub-band increment is the difference between the multipath angles of the first sub-band and the second sub-band in the broadband, or the sub-band increment is the difference between the absolute values of the coefficients of the first sub-band and the second sub-band in the broadband at the same angle.

16. The method according to claim 11, wherein The first indication information is used to indicate the functional relationship between the indexes of the spatial domain bases of the at least one sub-band and the change in the position of the sub-band, and the parameters of the functional relationship.

17. The method according to claim 16, wherein Before sending the first indication information, the method further includes: Receiving fourth indication information, where the fourth indication information is used to instruct the terminal device to report the functional relationship between the spatial domain bases of the at least one sub-band and the change in the position of the sub-band, and the parameters of the functional relationship.

18. The method according to any one of claims 11-17, characterized in that, Before sending the first indication information, the method further includes: Receiving an inquiry message, where the inquiry message is used to inquire whether the terminal device has the ability to report the indexes of the spatial domain bases by sub-band; Sending a response message, where the response message is used to indicate that the terminal device has the ability to report the indexes of the spatial domain bases by sub-band.

19. The method according to any one of claims 11-18, characterized in that, The at least one sub-band includes the sub-band of the center frequency point, the sub-band of the maximum frequency point, and the sub-band of the minimum frequency point in the broadband.

20. A communication device, characterized in that, Comprising: A receiving module, configured to receive first indication information, where the first indication information is used to indicate the spatial domain bases of each sub-band in at least one sub-band in the broadband; A processing module, configured to perform beamforming according to the spatial domain bases corresponding to multiple sub-bands of the bandwidth, where the spatial domain bases corresponding to the multiple sub-bands are determined according to the spatial domain bases of each sub-band in the at least one sub-band.

21. A communication device, characterized in that, Comprising: A sending module, configured to send first indication information, where the first indication information is used to indicate the spatial domain bases of each sub-band in at least one sub-band in the broadband; A receiving module, configured to receive a beam transmitted on the broadband, where the beam is obtained by beamforming according to spatial domain bases respectively corresponding to a plurality of sub-bands of the bandwidth, and the spatial domain bases respectively corresponding to the plurality of sub-bands are determined according to the spatial domain bases of each sub-band in the at least one sub-band.

22. A communication device, characterized in that, The communication device includes a processor and a memory, where the memory is configured to store computer execution instructions, and when the computer execution instructions are run by the processor, the method according to any one of claims 1-19 is executed.

23. A computer-readable storage medium, characterized in that, Computer instructions are stored in the computer-readable storage medium, and when the computer instructions are run on the communication device, the communication device is caused to execute the method according to any one of claims 1-19.

24. A computer program product, characterized in that, It includes computer instructions, and when the computer instructions are run on the communication device, the communication device is caused to execute the method according to any one of claims 1-19.

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