Beam forming method and communication device

Abstract

The embodiment of the invention discloses a beam forming method and a communication device, relates to the technical field of communication, and can suppress a beam squint effect under a large bandwidth and improve channel capacity. The method comprises: a network device receiving first indication information, the first indication information being used for indicating an airspace base of each sub-band in at least one sub-band in a broadband, or the first indication information being used for indicating beam information of each sub-band in the at least one sub-band in the broadband. The network device performs beamforming according to airspace substrates or beam information corresponding to a plurality of sub-bands of the bandwidth, and the airspace substrates corresponding to the plurality of sub-bands are determined according to the airspace substrate of each sub-band in the at least one sub-band. The beam information corresponding to the plurality of sub-bands is determined according to the beam information of each sub-band in the at least one sub-band. The embodiment of the invention is used for a beam forming process.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a beamforming method and a communication device. Background Art

[0002] In a large bandwidth, the network side can perform beamforming through the precoding matrix indicated by the feedback of the precoding matrix indicator (PMI) on the terminal side. Among them, the precoding matrix is related to the spatial domain basis, the frequency domain basis, and the combination coefficient. The spatial domain basis is fed back according to the bandwidth, that is, all sub-bands in the wideband share a set of wideband bases. This leads to beamforming still being performed according to the shared wideband bases when the multipath angles observed at different subcarriers / sub-bands / frequency points in the wideband are different. In this case, different subcarriers / sub-bands / frequency points are all beamformed according to the multipath angle of the center frequency point, and the pointing directions of the beams observed at different subcarriers / sub-bands / frequency points are different, that is, the beam direction changes with the frequency point, resulting in beam squint, which will cause a significant decrease in the channel capacity. Summary of the Invention

[0003] Embodiments of this application provide a beamforming method and a communication device, which can suppress the beam squint effect in a large bandwidth and improve the channel capacity.

[0004] In a first aspect, a beamforming method is provided. Optionally, the execution subject of this method can be a network device, or a component or device applied to the network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the network device. The method includes: receiving first indication information, where the first indication information is used to indicate the spatial domain basis of each sub-band in at least one sub-band in the wideband; and performing beamforming according to the spatial domain bases respectively corresponding to multiple sub-bands in the wideband, where the spatial domain bases respectively corresponding to the multiple sub-bands are determined according to the spatial domain basis of each sub-band in at least one sub-band.

[0005] Among them, the spatial domain basis can be the angle information corresponding to the sub-band, the distance information between the network device and the terminal device, etc. This method can be applied to the process of the network device performing beamforming according to the feedback of the precoding matrix indicator (PMI) of the terminal device.

[0006] Therefore, when the present application performs PMI feedback, for the bandwidth under the same component carrier (CC), the spatial domain basis can be reported separately according to sub-bands. In this way, the spatial domain basis corresponding to each sub-band in the wideband can be determined according to the spatial domain basis corresponding to the reported sub-band, and beamforming can be performed according to the spatial domain basis corresponding to each sub-band. This is considered because when the multipath angles of different sub-bands are different under the wideband of the same CC, the spatial domain bases corresponding to different sub-bands are not exactly the same. If beamforming is performed according to the spatial domain basis corresponding to each sub-band, it is equivalent to considering the above problem that the array factors of different frequency points are different, that is, the gains at different horizontal angles of different frequency points are different, which will cause the multipath angles of the electromagnetic waves of the beams at different frequency points to be different (the spatial domain bases are different), resulting in different influences of beam squint on different frequency points (different beam directions). Moreover, for the base station, it is impossible to know in advance this change in beam squint. Compared with the problems of large beam angle differences, relatively serious beam squint, and low channel capacity caused by beamforming according to the spatial domain basis of the wideband in the prior art, the present application can suppress the influence caused by beam squint and improve the channel capacity.

[0007] In a possible design, the first indication information includes the indexes of the spatial domain bases corresponding to each sub-band in at least one sub-band. In this way, when the network device obtains the indexes of the spatial domain bases corresponding to each sub-band in at least one sub-band in the wideband, the network device can determine the spatial domain bases corresponding to each sub-band in at least one sub-band according to the indexes, and thus perform beamforming according to the spatial domain basis of each sub-band, suppressing the problems of large beam angle differences and relatively serious beam squint caused by beamforming according to the spatial domain basis of the wideband.

[0008] In a possible design, the first indication information includes a bitmap indicating at least one sub-band and the indexes of the spatial domain bases corresponding to each sub-band in at least one sub-band. That is to say, the terminal device informs the network device through the bitmap which sub-bands' spatial domain basis indexes are reported and the indexes of the spatial domain bases corresponding to each sub-band in these sub-bands. In this way, the network device can perform beamforming according to the spatial domain basis of each sub-band, suppressing the problems of large beam angle differences and relatively serious beam squint caused by beamforming according to the spatial domain basis of the wideband.

[0009] In a 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 the indexes of the spatial domain bases corresponding to each sub-band in at least one sub-band. That is to say, the network device can actively ask the terminal device to report the indexes of the spatial domain bases corresponding to each sub-band in at least one sub-band.

[0010] In a possible design, before receiving the first indication information, the method further includes: sending third indication information, where the third indication information is used to indicate that when the terminal device determines that the subband increment corresponding to at least one subband is greater than or equal to the increment threshold, report the index of the spatial domain basis corresponding to each subband in the at least one subband; where the subband increment is the difference between the indexes of the spatial domain bases between the first subband and the second subband in the wideband, or the subband increment is the difference between the multipath angles between the first subband and the second subband in the wideband, or the subband increment is the difference between the absolute values of the coefficients of the first subband and the second subband in the wideband at the same angle. This is because, between adjacent subbands, if the difference between the indexes of the spatial domain bases between the subbands is small, or the difference between the multipath angles is small, or the difference between the absolute values of the coefficients at the same angle is small, the same spatial domain basis can be used for beamforming, and the beam angles do not differ much. In this way, the signaling overhead between the network device and the terminal device is saved.

[0011] In a possible design, the first indication information is used to indicate the functional relationship between the index of the spatial domain basis of at least one subband and the position change of the subband and the parameters 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 domain basis of each subband in the at least one subband according to the functional relationship and the parameters of the functional relationship, and thus determine the spatial domain basis of each subband in the at least one subband according to the index.

[0012] In a possible design, before receiving the first indication information, the method further includes: sending fourth indication information, where the fourth indication information is used to indicate that the terminal device reports the functional relationship between the spatial domain basis of at least one subband and the position change of the subband and the parameters of the functional relationship. That is, the network device can actively ask the terminal device for the spatial domain basis corresponding to each subband in the at least one subband. The spatial domain basis is determined according to the reported functional relationship between the spatial domain basis and the position change of the subband and the parameters of the functional relationship, so that the network device can perform beamforming according to the spatial domain basis of each subband, and suppress the problems of large beam angle difference and serious beam squint caused by beamforming according to the spatial domain basis of the wideband.

[0013] In a possible design, before receiving the first indication information, the method further includes: sending an inquiry message, where the inquiry message is used to ask whether the terminal device has the ability to report the index of the spatial domain basis by subband; receiving 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 domain basis by subband. In this way, for a terminal device with the ability to report the index of the spatial domain basis by subband, when the terminal device reports the index of the spatial domain basis by subband, the network device can perform beamforming according to the spatial domain basis of each subband, and suppress the problems of large beam angle difference and serious beam squint caused by beamforming according to the spatial domain basis of the wideband.

[0014] In a possible design, at least one sub-band includes the sub-band of the central frequency point in the wideband, the sub-band of the maximum frequency point, and the sub-band of the minimum frequency point. This design can be understood as the reporting method of the default configuration, that is, the terminal device does not need to report the spatial domain basis of each sub-band in the wideband to the network device. In the case where the terminal device reports the spatial domain basis of some sub-bands, the network device can infer the spatial domain basis of other sub-bands in the wideband according to the reported spatial domain basis of some sub-bands, and the signaling overhead of the terminal device is small.

[0015] In a possible design, beamforming according to the spatial domain basis corresponding to multiple sub-bands of a wideband includes: determining the weights for beamforming corresponding to multiple sub-bands respectively according to the spatial domain basis corresponding to multiple sub-bands; performing beamforming according to the weights corresponding to each sub-band among multiple sub-bands. In this way, compared with the problem of more serious beam squint when performing beamforming according to the spatial domain basis of the wideband, in this application, the network device can determine the weights for beamforming according to the spatial domain basis corresponding to each sub-band, and perform beam coherent superposition in the same direction according to the weights corresponding to different sub-bands to obtain the beams under multiple sub-bands. This application considers the problem that the multipath angles of the electromagnetic waves of the beams at different frequency points are different (the spatial domain basis is different), resulting in different influences on beam squint at different frequency points (different beam directions), that is, this application can suppress the influence brought by beam squint and improve the channel capacity.

[0016] In a second aspect, a beamforming method is provided. Optionally, the execution subject of this method can be a terminal device, or a component or device applied to a network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the terminal device. The method includes: sending first indication information, where the first indication information is used to indicate the spatial domain basis of each sub-band in at least one sub-band of the wideband; receiving the beam sent on the wideband, where the beam is obtained by performing beamforming according to the spatial domain basis corresponding to multiple sub-bands of the bandwidth, and the spatial domain basis corresponding to multiple sub-bands is determined according to the spatial domain basis of each sub-band in at least one sub-band.

[0017] For the beneficial effects of the second aspect, reference can be made to the description of the first aspect.

[0018] In a possible design, the first indication information includes the index of the spatial domain basis corresponding to each sub-band in at least one sub-band.

[0019] In a possible design, before sending the first indication information, the method further includes: receiving second indication information, where the second indication information is used to indicate the terminal device to report the index of the spatial domain basis of each sub-band in at least one sub-band.

[0020] In a possible design, the first indication information includes a bitmap indicating at least one subband and indices of spatial domain bases corresponding to each of the at least one subband.

[0021] In a possible design, before sending the first indication information, the method further includes: receiving third indication information, where the third indication information is used to indicate that when the terminal device determines that the subband increment corresponding to at least one subband is greater than or equal to an increment threshold, report the indices of the spatial domain bases corresponding to each of the at least one subband; where the subband increment is the difference in the indices of the spatial domain bases between a first subband and a second subband in a wideband, or the subband increment is the difference in the multipath angles between the first subband and the second subband in the wideband, or the subband increment is the difference in the absolute values of the coefficients of the first subband and the second subband in the wideband at the same angle.

[0022] In a possible design, the first indication information is used to indicate the functional relationship between the indices of the spatial domain bases of at least one subband and the position change of the subband and the parameters of the functional relationship.

[0023] In a possible design, before sending the first indication information, the method further includes: receiving fourth indication information, where the fourth indication information is used to indicate that the terminal device reports the functional relationship between the spatial domain bases of at least one subband and the position change of the subband and the parameters of the functional relationship.

[0024] In a possible design, 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 indices of the spatial domain bases by subband; sending a response message, where the response message is used to indicate that the terminal device has the ability to report the indices of the spatial domain bases by subband.

[0025] In a possible design, the at least one subband includes a subband at the center frequency point, a subband at the maximum frequency point, and a subband at the minimum frequency point in the wideband.

[0026] In a third aspect, a beamforming method is provided. Optionally, the execution subject of the method may be a network device, or a component or device applied to the network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software capable of implementing all or part of the functions of the network device. The method includes: receiving first indication information, where the first indication information is used to indicate beam information of each subband in at least one subband in a wideband; performing beamforming according to the beam information corresponding to multiple subbands in the wideband, and the beam information corresponding to multiple subbands is determined according to the beam information of each subband in at least one subband.

[0027] In this way, compared with the problem of relatively serious beam squint caused by beamforming according to the optimal beam identifier of a full band corresponding to the entire carrier aggregation (CA), in this application, the network device can perform beamforming according to the beam corresponding to each sub-band. This application takes into account that the multipath angles of the electromagnetic waves of the beams at different frequency points are different (the optimal beams are different), resulting in different effects of beam squint on different frequency points (different beam directions), that is, this application can suppress the influence brought by beam squint and improve the channel capacity.

[0028] In a possible design, the first indication information includes the optimal beam identifier corresponding to each sub-band in at least one sub-band. In this way, when the network device performs beamforming according to the optimal beam corresponding to each sub-band, the problem of beam squint in the sub-bands with non-center frequency points caused by different multipath angles of different sub-bands can be suppressed.

[0029] In a possible design, the first indication information includes the bitmap of at least one sub-band and the optimal beam identifier corresponding to each sub-band in at least one sub-band. In this way, when the network device knows the optimal beam corresponding to each sub-band and performs beamforming, the problem of beam squint in the sub-bands with non-center frequency points caused by different multipath angles of different sub-bands can be suppressed.

[0030] In a 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 the beam information corresponding to each sub-band in at least one sub-band. That is, the network device can actively instruct the terminal device to report the optimal beam according to the sub-band for sub-band-level beamforming.

[0031] In a possible design, before receiving the first indication information, the method further includes: sending an inquiry message, where the inquiry message is used to ask whether the terminal device has the ability to report beam information according to the sub-band; receiving a response message, where the response message is used to indicate that the terminal device has the ability to report beam information according to the sub-band. In this way, for the terminal device with the ability to report beam information according to the sub-band, when the terminal device reports the beam information according to the sub-band, the network device can perform beamforming according to the beam information of each sub-band, suppressing the problems of large beam angle difference and relatively serious beam squint caused by beamforming according to the beam information of the wideband.

[0032] Fourth aspect, a beamforming method is provided. Optionally, the execution subject of this method can be a terminal device, or a component or device applied to a network device (such as a processor, a chip, or a chip system, etc.), or a logic module or software that can implement all or part of the functions of the terminal device. The method includes: sending first indication information, where the first indication information is used to indicate the beam information of each sub-band in at least one sub-band in a broadband; receiving a beam sent on the broadband, where the beam is obtained by beamforming according to the beam information corresponding to multiple sub-bands of the bandwidth, and the beam information corresponding to multiple sub-bands is determined according to the beam information of each sub-band in at least one sub-band.

[0033] For the beneficial effects of the fourth aspect, reference can be made to the description of the third aspect.

[0034] In a possible design, the first indication information includes the optimal beam identifier corresponding to each sub-band in at least one sub-band.

[0035] In a possible design, the first indication information includes a bitmap of at least one sub-band and the optimal beam identifier corresponding to each sub-band in at least one sub-band.

[0036] In a possible design, before sending the first indication information, the method further includes: receiving second indication information, where the second indication information is used to indicate that the terminal device reports the beam information corresponding to each sub-band in at least one sub-band.

[0037] In a possible design, 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 beam information by sub-band; sending a response message, where the response message is used to indicate that the terminal device has the ability to report beam information by sub-band.

[0038] Fifth aspect, a communication device is provided, including: a receiving module, configured to receive first indication information, where the first indication information is used to indicate the spatial domain basis of each sub-band in at least one sub-band in a broadband; a processing module, configured to perform beamforming according to the spatial domain basis corresponding to multiple sub-bands of the bandwidth, where the spatial domain basis corresponding to multiple sub-bands is determined according to the spatial domain basis of each sub-band in at least one sub-band.

[0039] In a possible design, the first indication information includes the index of the spatial domain basis corresponding to each sub-band in at least one sub-band.

[0040] In a possible design, the first indication information includes a bitmap indicating at least one sub-band and the index of the spatial domain basis corresponding to each sub-band in at least one sub-band.

[0041] In a possible design, it further includes a sending module, configured to send second indication information, where the second indication information is used to indicate the terminal device to report the index of the spatial domain basis of each subband in at least one subband.

[0042] In a possible design, it further includes a sending module, configured to send third indication information, where the third indication information is used to indicate the terminal device to report the index of the spatial domain basis corresponding to each subband in at least one subband when it is determined that the subband increment corresponding to at least one subband is greater than or equal to an increment threshold; where the subband increment is the difference between the indices of the spatial domain bases between the first subband and the second subband in the wideband, or the subband increment is the difference between the multipath angles between the first subband and the second subband in the wideband, or the subband increment is the difference between the absolute values of the coefficients of the first subband and the second subband in the wideband at the same angle.

[0043] In a possible design, the first indication information is used to indicate the functional relationship between the index of the spatial domain basis of at least one subband and the change of the subband position and the parameters of the functional relationship.

[0044] In a possible design, it further includes a sending module, configured to send fourth indication information, where the fourth indication information is used to indicate the terminal device to report the functional relationship between the spatial domain basis of at least one subband and the change of the subband position and the parameters of the functional relationship.

[0045] In a possible design, it further includes a sending module, configured to send 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 domain basis by subband; a receiving module is further configured 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 domain basis by subband.

[0046] In a possible design, at least one subband includes the subband of the center frequency point, the subband of the maximum frequency point, and the subband of the minimum frequency point in the wideband.

[0047] In a possible design, the processing module is configured to: determine the weights for beamforming corresponding to multiple subbands according to the spatial domain bases corresponding to the multiple subbands respectively; perform beamforming according to the weights corresponding to each subband in the multiple subbands.

[0048] In a sixth aspect, a communication device is provided, including: a sending module, configured to send first indication information, where the first indication information is used to indicate the spatial domain basis of each subband in at least one subband in the wideband; a receiving module, configured to receive the beam sent on the wideband, where the beam is obtained by performing beamforming according to the spatial domain bases corresponding to multiple subbands of the bandwidth respectively, and the spatial domain bases corresponding to the multiple subbands are determined according to the spatial domain basis of each subband in at least one subband.

[0049] In a possible design, the first indication information includes the index of the spatial domain basis corresponding to each sub-band in at least one sub-band.

[0050] In a possible design, the receiving module is further configured to receive second indication information, where the second indication information is used to indicate that the terminal device reports the index of the spatial domain basis corresponding to each sub-band in at least one sub-band.

[0051] In a possible design, the first indication information includes a bitmap indicating at least one sub-band and the index of the spatial domain basis corresponding to each sub-band in at least one sub-band.

[0052] In a possible design, the receiving module is further configured to receive third indication information, where the third indication information is used to indicate that when the terminal device determines that the sub-band increment corresponding to at least one sub-band is greater than or equal to the increment threshold, the terminal device reports the index of the spatial domain basis corresponding to each sub-band in at least one sub-band; where the sub-band increment is the difference between the indices of the spatial domain bases between the first sub-band and the second sub-band in the wideband, or the sub-band increment is the difference between the multipath angles between the first sub-band and the second sub-band in the wideband, 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 wideband at the same angle.

[0053] In a possible design, the first indication information is used to indicate the functional relationship between the index of the spatial domain basis of at least one sub-band and the position change of the sub-band and the parameters of the functional relationship.

[0054] In a possible design, the receiving module is further configured to receive fourth indication information, where the fourth indication information is used to indicate that the terminal device reports the functional relationship between the spatial domain basis of at least one sub-band and the position change of the sub-band and the parameters of the functional relationship.

[0055] In a possible design, the receiving module is further configured to receive 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 domain basis by sub-band; the sending module is further configured to send 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 domain basis by sub-band.

[0056] In a possible design, 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 wideband.

[0057] In a seventh aspect, a communication device is provided, including: a receiving module, configured to receive first indication information, where the first indication information is used to indicate the beam information of each sub-band in at least one sub-band in a wideband; a processing module, configured to perform beamforming according to the beam information corresponding to multiple sub-bands of the wideband, where the beam information corresponding to multiple sub-bands is determined according to the beam information of each sub-band in at least one sub-band.

[0058] In a possible design, the first indication information includes the optimal beam identifier corresponding to each of at least one sub-band.

[0059] In a possible design, the first indication information includes a bitmap of at least one sub-band and the optimal beam identifier corresponding to each of at least one sub-band.

[0060] In a possible design, it further includes a sending module for sending second indication information, where the second indication information is used to instruct the terminal device to report the beam information corresponding to each of at least one sub-band.

[0061] In a possible design, it further includes a sending module for sending an inquiry message, where the inquiry message is used to ask whether the terminal device has the ability to report beam information by sub-band; and a receiving module is further 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 sub-band.

[0062] In an eighth aspect, a communication device is provided, including: a sending module for sending first indication information, where the first indication information is used to indicate the beam information of each of at least one sub-band in a wideband; a receiving module for receiving a beam sent on the wideband, where the beam is obtained by beamforming according to the beam information corresponding to multiple sub-bands of the bandwidth, and the beam information corresponding to multiple sub-bands is determined according to the beam information of each of at least one sub-band.

[0063] In a possible design, the first indication information includes the optimal beam identifier corresponding to each of at least one sub-band.

[0064] In a possible design, the first indication information includes a bitmap of at least one sub-band and the optimal beam identifier corresponding to each of at least one sub-band.

[0065] In a possible design, the receiving module is further used to receive second indication information, where the second indication information is used to instruct the terminal device to report the beam information corresponding to each of at least one sub-band.

[0066] In a possible design, the receiving module is further used to: receive an inquiry message, where the inquiry message is used to ask whether the terminal device has the ability to report beam information by sub-band; and the sending module is further 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 sub-band.

[0067] In a ninth aspect, a communication device is provided, where the communication device includes a processor and a memory, and the memory is used to store computer execution instructions. When the computer execution instructions are run by the processor, the designs of the first aspect to the fourth aspect and the methods of any possible design among the first aspect to the fourth aspect are executed.

[0068] In a tenth aspect, there is provided a computer-readable storage medium storing computer instructions which, when run on a communication device, cause the communication device to execute the designs of the first aspect to the fourth aspect and the methods described in any possible design of the first aspect to the fourth aspect.

[0069] In an eleventh aspect, there is provided a computer program product comprising computer instructions which, when run on a communication device, cause the communication device to execute the designs of the first aspect to the fourth aspect and the methods described in any possible design of the first aspect to the fourth aspect.

[0070] In a twelfth aspect, there is provided a communication system comprising a first communication device and a second communication device. The first communication device can be used to execute the designs of the first aspect and the third aspect and the methods described in any possible design of the first aspect and the third aspect. The second communication device can be used to execute the designs of the second aspect and the fourth aspect and the methods described in any possible design of the second aspect and the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Figure 1 It is a schematic diagram of a beam squint phenomenon provided by an embodiment of the present application;

[0072] Figure 2 It is a schematic diagram of an array factor under different frequency points and different horizontal angles in an MIMO technology provided by an embodiment of the present application;

[0073] Figure 3 It is a schematic diagram of the architecture of a communication system provided by an embodiment of the present application;

[0074] Figure 4 It is a schematic diagram of beam offset (angle deviation) under different desired beam angles provided by an embodiment of the present application;

[0075] Figure 5 It is a schematic flowchart of a beamforming method provided by an embodiment of the present application;

[0076] Figure 6 It is a schematic diagram of a protocol layer framework of a base station and a UE provided by an embodiment of the present application;

[0077] Figure 7 It is a schematic flowchart of a beamforming method provided by an embodiment of the present application;

[0078] Figure 8 It is a schematic flowchart of a beamforming method provided by an embodiment of the present application;

[0079] Figure 9Schematic flowchart of a beamforming method provided by an embodiment of the present application;

[0080] Figure 10 Schematic flowchart of a beamforming method provided by an embodiment of the present application;

[0081] Figure 11 Schematic flowchart of a beamforming method provided by an embodiment of the present application;

[0082] Figure 12 Schematic diagram of channel capacity under different ratios of broadband to center frequency provided by an embodiment of the present application;

[0083] Figure 13 Schematic diagram of the structure of a communication device provided by an embodiment of the present application;

[0084] Figure 14 Schematic diagram of the structure of a communication device provided by an embodiment of the present application. Detailed implementation manners

[0085] For ease of understanding, some explanations of concepts related to the embodiments of the present application are given as examples for reference as follows.

[0086] Beam squint: It means that under a large bandwidth, the directions of the beams observed by different subcarriers / subbands / frequency points are different. Beam squint can also be called beam dispersion. The reason for this beam squint phenomenon is that the multipath angles observed by different subbands / subcarriers / frequency points are different.

[0087] Multipath angle: In a mobile relay environment, the signal received by the receiver does not come from a single path, but from the synthesis of many reflected waves from many paths. This phenomenon is called multipath effect. That is, in a wireless channel, there is not only one path between the transmitter and the receiver, but there are reflected paths with different amplitudes, phases, time delays, and arrival angles, resulting in a time-dispersed signal in the time domain. Moreover, the angles at which the channels of each path reach the receiver are different, and the angles at which the signals of multiple paths reach the receiver can be understood as the multipath angle.

[0088] Here, in combination with Figure 1 the beam squint phenomenon is described. Figure 1 A schematic diagram of a beam squint phenomenon is shown. The reason is that beam squint actually occurs because the multipath angles of the beams observed by different subbands / subcarriers / frequency points are different, or rather, the directions of the beams after beamforming for different subbands / subcarriers / frequency points are different. For example Figure 1It is shown that the base station has a massive multiple-input multiple-output (MIMO) antenna array, including N antenna elements: antenna elements 11 to 1N. The frequency points of the bandwidth include f6 to f1, and the frequency magnitudes of the frequency points f6 to f1 gradually decrease. The base station performs beamforming according to the multipath angle of the center frequency point f4. However, the multipath angles corresponding to the frequency points f1, f2, f3, f5, and f6 are different. If the frequency points f1, f2, f3, f5, and f6 perform beamforming according to the multipath angles observed at the frequency point f4, multiple squinted beams will be formed. That is Figure 4 In it, the beam formed by shaping the center frequency point f4 is the desired beam, and the beams formed by shaping the frequency points f1, f2, f3, f5, and f6 are all squinted beams caused by the beam squint phenomenon.

[0089] As Figure 2 shown is a schematic diagram of the array factor at different frequency points and different horizontal angles in a MIMO technology. The horizontal axis represents the azimuth angle x, and the vertical axis represents the array factor y. It is shown taking a uniform linear array (ULA) with a center frequency point fc of 6.5 GHz, a bandwidth of 400 M, and an array form of 16T (16 antenna elements) as an example. Among them, the array factor is expressed as:

[0090] g(ξψ - ψ F ), Formula (1).

[0091] Among them, ξ = f / fc represents the sub-frequency point function, ψ F represents the angle of the current beam direction, and ψ represents the horizontal angle of the frequency point. The array can be understood as an antenna array, and the array factor is a measure of the degree of change of a specific characteristic due to grouping. In an antenna array, the array factor can be understood as the gain at different frequency points and different horizontal angles calculated in this array form, and the gain is used for beamforming.

[0092] The calculation formula of the steering vector is expressed as:

[0093] β n (ψ F ) = 2πλ -1 (n - 1)dψ F , Formula (2).

[0094] Among them, β n represents the steering vector, λ represents the wavelength, ψ FIndicates the angle of the current beam direction, d represents the antenna spacing, the value range of n is [1, N], and N is an integer representing the number of antenna elements.

[0095] According to formula (1) and formula (2), the array factor g(x) can be deduced and expressed as:

[0096] Where x represents the horizontal angle of the frequency point.

[0097] From Figure 2 It can be found that the beam direction angles ψ of different frequency points f1, fc, and f2 F Are different, the horizontal angles x of the frequency points are different. For example, the difference in the horizontal angles x between frequency points f1 and f2 is greater than 7 degrees (93.1059 - 86.9829). In this case, the array factors of different frequency points are different, that is, the gains at different horizontal angles of different frequency points are different, which will cause the multipath angles of the electromagnetic waves of the beams at different frequency points to be different, thus resulting in different effects of beam squint on different frequency points (different beam directions). However, for the base station, it is impossible to know this change in beam squint in advance.

[0098] Beamforming: By adjusting the amplitude and phase of multiple antennas, a specific shape and direction are given to the antenna radiation pattern, so that the wireless signal energy is concentrated on a narrower beam to enhance the coverage range and reduce interference.

[0099] 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, within the beam coverage range, a group of beams are sent and received according to predefined time intervals and directions. 2) Beam measurement, that is, evaluating the quality of the received signal, and the evaluation metrics 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) according to the beam measurement. 4) Beam reporting, that is, the terminal reports the beam quality and beam decision information to the base station to establish beam-oriented communication between the base station and the terminal.

[0100] Common Beam Management (CBM): In a multi-carrier system in the millimeter wave band, it is mainly divided into in-band carrier aggregation (CA) and inter-band carrier aggregation. For in-band carrier aggregation, multiple carriers share the same radio frequency channel. Therefore, the terminal only supports CBM and can use a common beam for signal transmission.

[0101] Independent Beam Management (IBM): That is, a beam is selected for signal transmission for each band respectively. For inter-band carrier aggregation, the terminal may support CBM or IBM between two or more bands, and a terminal with stronger capabilities may also support both IBM and CBM simultaneously.

[0102] Precoding Matrix Indicator (PMI) can be used to indicate the precoding matrix, and the network device recovers the precoding matrix based on the PMI. Among them, the precoding matrix can be the precoding matrix determined by the terminal device based on the channel matrix of each frequency domain unit. A frequency domain unit, that is, the unit of frequency domain resources, can represent different granularities of frequency domain resources.

[0103] Spatial domain vector, also known as beam vector, spatial beam basis vector or spatial basis vector or spatial basis. Each element in the spatial domain vector can represent the weights of each antenna port. Based on the weights of each antenna port represented by each element in the spatial domain vector, the signals of each antenna port are linearly superimposed, and a region with stronger signals can be formed in a certain direction in space.

[0104] Frequency domain vector, which can also be called the frequency domain basis, is a vector that can be used to represent the variation law of the channel in the frequency domain. Each frequency domain vector can represent a variation law. Since the signal can reach the receiving antenna through multiple paths when transmitted through the wireless channel. The multi-path delay causes frequency selective fading, which is the variation of the frequency domain channel. Therefore, different frequency domain vectors can be used to represent the variation laws of the channel in the frequency domain caused by the delay on different transmission paths.

[0105] Next, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means "or". For example, A / B may represent A or B; herein, "and / or" is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality of" means two or more than two.

[0106] Hereinafter, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this embodiment, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0107] Embodiments of the present application can be applied to the 5th generation (5G) new radio (NR) system, or applied to future communication systems or other similar communication systems, as long as there are entities in the communication system that need to send transmission direction indication information, and another entity needs to receive the indication information and determine the transmission direction within a certain period of time according to the indication information. In addition, the technical solutions provided by the embodiments of the present application can be applied to cellular links, public land mobile networks (PLMNs), 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. A D2D link can also be referred to as a sidelink, where the sidelink can also be referred to as a side link or a secondary link, etc. In the embodiments of the present application, the above terms all refer to links established between devices of the same type, and they have the same meaning. The so-called devices of the same type can be links between terminal devices, links between base stations, or links between relay nodes, etc. The embodiments of the present application do not limit this. For the link between terminal devices, there is the D2D link defined in Release 12 / 13 of the 3rd Generation Partnership Project (3GPP), and there are also vehicle-to-vehicle, vehicle-to-mobile phone, or vehicle-to-any entity V2X links defined by 3GPP for vehicle networking, including Release 14 / 15. It also includes the V2X link based on the new radio (NR) system in Release 18 and subsequent versions currently being studied by 3GPP, etc.

[0108] Figure 3 FIG. shows a schematic architecture diagram of a communication system 30 provided by an embodiment of the present application. The communication system 30 includes communication devices, and the communication devices can perform wireless communication by using air interface resources. Among them, the communication devices may include Figure 3 the network device 301 and six types of terminal devices 302 to 307 (high-speed rail devices, switches, gas station devices, household appliances, mobile terminals, and printers) shown in FIG. It should be understood that Figure 3 the terminal devices in FIG. are only examples, and there may be more or fewer. The communication system 30 may further include other network devices, such as wireless relay devices and wireless backhaul devices. Figure 3It is not shown in the figure. The network device 301 is an access device for the terminal device to access the wireless access network, and can be, for example, a base station. Among them, the network device 301 corresponds to different devices in different systems. For example, in the 4th-generation (4G) mobile communication technology system, it can correspond to an evolved Node B (eNB), and in the 5G system, it corresponds to a new generation Node B (gNB). The terminal devices 302 to 307 can 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 a wireless communication system, and can all be connected to the network device. The air interface resources can 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 can also be described as one or more, and multiple can be two, three, four, or more. The present application does not make any restrictions.

[0109] The embodiments of the present application can be applicable to uplink signal transmission, can also be applicable to downlink signal transmission, and can also be applicable to D2D signal transmission. For downlink signal transmission, the sending device is the network device, and the corresponding receiving device is the terminal device; for uplink signal transmission, the sending device is the terminal device, and the corresponding receiving device is the network device; for D2D signal transmission, the sending device is the terminal device, and the receiving device is also the terminal device. For example, as Figure 3 The three terminal devices indicated by the dotted line area can be applicable to D2D signal transmission. The embodiments of the present application do not limit the direction of signal transmission.

[0110] Exemplarily, in the communication system 30, the terminal devices 302 to 307 can send uplink data to the network device 301, and the network device 301 needs to receive the uplink data sent by the terminal devices 302 to 307. In addition, the terminal devices 305 to 307 can also form a communication system. In this communication system, the network device 301 can send downlink information to the terminal devices 302 to 304, etc.; the terminal device 306 can also send downlink information to the terminal devices 305 and 307.

[0111] The terminal device involved in the embodiments of this application can also be referred to as a terminal, which can be a device with wireless transceiver functions. It can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water surface (such as a ship, etc.); it can also be deployed in the air (such as an airplane, a balloon, a satellite, etc.). The terminal device can be a user equipment (UE), where the UE includes a handheld device, a vehicle-mounted device, a wearable device, or a computing device with wireless communication functions. Exemplarily, the UE can be a mobile phone, a tablet computer, or a computer with wireless transceiver functions. 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 autonomous driving, a wireless terminal in remote medical treatment, a wireless terminal in a smart grid, a wireless terminal in a smart city, a wireless terminal in a smart home, and so on. In the embodiments of this application, the device for implementing the functions of the terminal can be the terminal; it can also be a device capable of supporting the terminal to implement such functions, such as a chip system, and this device can be installed in the terminal. In the embodiments of this application, the chip system can be composed of chips, or can include chips and other discrete devices. In the technical solutions provided in the embodiments of this application, taking the device for implementing the functions of the terminal as the terminal and the terminal being a UE as an example, the technical solutions provided in the embodiments of this application are described.

[0112] The network devices involved in the embodiments of this application include access network devices, such as base stations (BS). A BS can be a device deployed in a radio access network that can communicate wirelessly with terminals. Among them, base stations may have various forms, such as TRP and gNB. The network device can be a device for communicating with mobile devices. The 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, NB) in wideband code division multiple access (WCDMA), an evolved base station (evolutional Node B, eNB or eNodeB) in long term evolution (LTE), or a relay station or access point, or a vehicle-mounted device, a wearable device, and network devices in future 5G networks or network devices in future evolved PLMNs, or gNodeB / gNB in the NR system, etc.; in some deployments, a gNB can include a centralized unit (CU) and a DU. A gNB can also include an active antenna unit (AAU). The CU implements part of the functions of the gNB, and the DU implements part of the functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, implementing radio resource control (RRC), and the functions of the packet data convergence protocol (PDCP) layer. The DU is responsible for processing physical layer protocols and real-time services, implementing the functions of the radio link control (RLC) layer, the medium access control (MAC) layer, and the physical (PHY) layer. The AAU implements part of the physical layer processing functions, radio frequency processing, and related functions of active antennas. Since the information in the RRC layer will ultimately become the information in the PHY layer, or is transformed from the information in the PHY layer, thus, in this architecture, high-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or sent by the DU and the AAU. It can be understood that the network device can be a device including one or more of the CU node, DU node, and AAU node.In addition, the CU can be divided into network devices in the radio access network (RAN), or it can be divided into network devices in the core network (CN). This application does not make any limitations in this regard. Additionally, in the embodiments of this application, the network device provides services for a cell, and the terminal device communicates with the network device through the transmission resources used by this cell (for example, frequency domain resources, or in other words, spectrum resources). This cell can be the cell corresponding to the network device (such as a base station). The cell can belong to a macro base station or the base station corresponding to a small cell. Here, small cells can include: Metro cell, Micro cell, Pico cell, Femto cell, etc. These small cells have the characteristics of a small coverage area and low transmission power, and are suitable for providing high-rate data transmission services. In addition, in other possible cases, the network device can be other devices that provide wireless communication functions for the terminal device. The embodiments of this application do not make any limitations on the specific technologies and specific device forms adopted by the network device. For the convenience of description, in the embodiments of this application, the device that provides wireless communication functions for the terminal device is referred to as a network device. For example, the network device can also be a device that can support the network device to implement this function, such as a chip system, and this device can be installed in the network device. In the technical solutions provided in the embodiments of this application, taking the device for implementing the functions of the network device as the network device and taking the network device as a base station as an example, the technical solutions provided in the embodiments of this application are described.

[0113] The technical solutions provided in the embodiments of this application can be applied to wireless communication between communication devices. Wireless communication between communication devices can include: wireless communication between a network device and a terminal, wireless communication between network devices, and wireless communication between terminals. Among them, in the embodiments of this application, the term "wireless communication" can also be abbreviated as "communication", and the term "communication" can also be described as "data transmission", "information transmission", or "transmission".

[0114] When discussing carrier aggregation (CA) in 3GPP 38.884 standard, considering the phenomenon of beam squint in the MIMO antenna array, it is possible to choose to perform common beam management (CBM) or independent beam management (IBM) for the two cells performing CA according to the situation. For example, considering the phenomenon of beam squint, when the gain offset of the beams calculated for the two cells at different frequency points is within 1.7 dB, it can be considered that the beam squint of the two cells is not serious, and the two cells can perform CA under the same beam, that is, choose to perform CBM. Otherwise, when the gain (array factor) offset of the beams calculated for the two cells at different frequency points is greater than 1.7 dB, it can be considered that the beam squint of the two cells is relatively serious, and the two cells need to perform CA under independent beams respectively, that is, choose to perform IBM. However, currently the target only considers the beam squint problem under different component carriers (CCs), and does not consider the beam squint problem of different frequency points under the same CC. From the above example of beam squint, it can be seen that under the same CC, the multipath angles of the electromagnetic waves of the beams at different frequency points are different, and the influence of beam squint on different frequency points is also different (the beam directions are different).

[0115] In some technologies, when beamforming is performed on the antenna of a network device, beamforming can be performed according to the PMI feedback of a terminal device.

[0116] Exemplarily, formula (4) shows a main form of PMI feedback, where S represents the spatial domain basis, F represents the frequency domain basis, C represents the combination coefficient, and W represents the precoding matrix used for beamforming.

[0117] W = S * C * F H , formula (4).

[0118] For Type I codebook: The terminal device only feeds back broadband, including the spatial domain basis index S and the combination system C; for Type II codebook: The terminal device can feed back in the bandwidth or subbands. If the feedback is in subbands, only the combination coefficient C feeds back the amplitude and phase in subbands, and the frequency domain basis can also be fed back in subbands, but the spatial domain basis S shares a set of bandwidth bases for all subbands.

[0119] Exemplarily, the base station can indicate which subbands' PMI coefficients C the UE feeds back through the field "CSI-ReportingBand", and the UE can feedback whether it has the ability to feed back the PMI coefficient C in subbands through the field "subbandAmplitude".

[0120] In the case of beamforming through PMI feedback, if different frequency points perform beamforming according to the wideband spatial domain basis, such as the spatial domain basis of the central frequency point, there will be differences in the beam angles under different frequency points. Table 1 shows an example of the beam angle differences under different frequency points.

[0121] Table 1

[0122]

[0123] 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 differences between different subbands / frequency points and the central frequency point are between 3.2° and 12°. That is to say, in the case of feedback of the spatial domain basis according to the bandwidth, the beam angle differences between different subbands / frequency points under the same CC are relatively large, and the beam squint phenomenon is relatively serious. Especially when the number of antenna array elements is large, considering that the beam width is smaller, if the spatial domain basis is also feedback according to the bandwidth, the beam angle differences between different subbands / frequency points under the same CC will be even larger.

[0124] In this case where the beam angles under different subbands / frequency points are different, compared with the case where there is no beam squint at the central frequency point, if there is beam squint, the channel capacity will also decrease.

[0125] Therefore, the embodiments of the present application provide a beamforming method and a communication device. In this method, when performing PMI feedback, for the bandwidth under the same CC, the spatial domain basis can be reported separately according to subbands, so that the spatial domain basis corresponding to each subband in the wideband can be determined according to the reported spatial domain basis of the subbands, and beamforming is performed according to the spatial domain basis corresponding to each subband. This is considered because when the multipath angles of different subbands are different under the wideband of the same CC, the spatial domain bases corresponding to different subbands are not exactly the same. If beamforming is performed according to the spatial domain basis corresponding to each subband, it is equivalent to considering the above problem that due to the different array factors of different frequency points, that is, the gains at different horizontal angles of different frequency points are different, which will cause the multipath angles of the electromagnetic waves of the beams at different frequency points to be different (the spatial domain bases are different), resulting in different effects of beam squint on different frequency points (different beam directions). Moreover, for the base station, it is impossible to know in advance this change in beam squint. Compared with the existing problem of large beam angle differences, serious beam squint, and low channel capacity caused by beamforming according to the wideband spatial domain basis in the same wideband, the present application can suppress the influence of beam squint and improve the channel capacity.

[0126] Based on the above summary description, the embodiments of the present application will be introduced below.

[0127] As Figure 5The figure shows a schematic flowchart of a beamforming method, and the method includes the following processes.

[0128] 501. The network device receives first indication information, which is used to indicate the spatial domain basis of each sub-band in at least one sub-band of the broadband.

[0129] In some embodiments, the network device receives the first indication information sent by the terminal device. Correspondingly, the terminal device sends the first indication information, or rather, the terminal device sends the first indication information to the network device.

[0130] 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.

[0131] In some embodiments, the first indication information includes the index of the spatial domain basis corresponding to each sub-band in at least one sub-band. In this way, when the network device obtains the index of the spatial domain basis corresponding to each sub-band in at least one sub-band of the broadband, the network device can determine the spatial domain basis corresponding to each sub-band in at least one sub-band according to the index.

[0132] In some embodiments, before receiving the first indication information, the method further includes: the network device sends second indication information, which is used to indicate the terminal device to report the index of the spatial domain basis of each sub-band in at least one sub-band. Or rather, the network device sends the second indication information to the terminal device. Correspondingly, the terminal device receives the second indication information sent by the network device. That is to say, the network device can actively ask the terminal device to report the index of the spatial domain basis of each sub-band in at least one sub-band.

[0133] In some embodiments, the first indication information includes a bitmap indicating at least one sub-band and the index of the spatial domain basis corresponding to each sub-band in at least one sub-band. That is equivalent to the terminal device informing the network device through the bitmap which sub-bands' spatial domain basis indexes are reported and the index of the spatial domain basis corresponding to each of these sub-bands.

[0134] In some embodiments, before receiving the first indication information, the method further includes: The network device sends third indication information, where the third indication information is used to indicate that when the terminal device determines that the subband increment corresponding to at least one subband is greater than or equal to the increment threshold, report the index of the spatial domain basis corresponding to each subband in the at least one subband. Or, the network device sends third indication information to the terminal device, and correspondingly, the terminal device receives the third indication information sent by the network device. Wherein, the subband increment is the difference between the indices of the spatial domain bases between the first subband and the second subband in the wideband, or the subband increment is the difference between the multipath angles between the first subband and the second subband in the wideband, or the subband increment is the difference between the absolute values of the coefficients of the first subband and the second subband in the wideband at the same angle. Wherein, the first subband and the second subband may be subbands corresponding to adjacent frequency points in the wideband. This is because, between adjacent subbands, if the difference between the indices of the spatial domain bases between the subbands is small, or the difference between the multipath angles is small, or the difference between the absolute values of the coefficients at the same angle is small, the same spatial domain basis can be used for beamforming, and the beam angles do not differ much. Wherein, the coefficient here can be understood as the above-mentioned combined coefficient C.

[0135] In some embodiments, the first indication information is used to indicate the functional relationship between the index of the spatial domain basis of at least one subband and the position change of the subband, as well as the parameters 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 domain basis of each subband in the at least one subband according to the functional relationship and the parameters of the functional relationship, and thus determine the spatial domain basis of each subband in the at least one subband according to the index.

[0136] In some embodiments, before receiving the first indication information, the method further includes: The network device sends fourth indication information, where the fourth indication information is used to indicate that the terminal device reports the functional relationship between the spatial domain basis of at least one subband and the position change of the subband, as well as the parameters of the functional relationship. Or, the network device sends fourth indication information to the terminal device, and the terminal device receives the fourth indication information from the network device. That is, the network device can actively query the spatial domain basis corresponding to each subband in the at least one subband of the terminal device.

[0137] In some embodiments, before receiving the first indication information, the method further includes: The network device sends an inquiry message, which is used to inquire whether the terminal device has the ability to report the index of the spatial domain basis by sub-band. The network device receives a response message, which is used to indicate that the terminal device has the ability to report the index of the spatial domain basis by sub-band. Or rather, 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, when the terminal device has the ability to report the index of the spatial domain basis by sub-band, the network device can obtain from the terminal device the indexes of the spatial domain bases corresponding to different sub-bands under broadband, so as to perform beamforming according to the differentiation of the spatial domain bases of different sub-bands at such a fine granularity.

[0138] In some embodiments, at least one sub-band includes the sub-band of the central frequency point in the broadband, the sub-band of the maximum frequency point, and the sub-band of the minimum frequency point. That is, the terminal device does not need to report the indexes of the spatial domain bases of each sub-band in the broadband to the network device, and only needs to report the indexes of the spatial domain bases of some sub-bands. For the network device, it can infer the indexes of the spatial domain bases of other sub-bands in the bandwidth according to certain principles based on the reported indexes of the spatial domain bases of the sub-bands. In this way, the signaling overhead between the network device and the terminal device is also small.

[0139] 502. The network device performs beamforming according to the spatial domain bases respectively corresponding to multiple sub-bands of the bandwidth, and the spatial domain bases respectively corresponding to the multiple sub-bands are determined according to the spatial domain basis of each sub-band in at least one sub-band.

[0140] In some embodiments, the network device can determine the weights for beamforming respectively corresponding to multiple sub-bands according to the spatial domain bases respectively corresponding to the multiple sub-bands; perform beamforming according to the weights corresponding to each sub-band in the multiple sub-bands. In this way, compared with the problem of relatively serious beam squint caused by beamforming according to the spatial domain basis of the broadband, in this application, the network device can determine the weights for beamforming according to the spatial domain basis corresponding to each sub-band, and perform beam coherent superposition in the same direction according to the weights corresponding to different sub-bands to obtain beams under multiple sub-bands. This application considers the problem that the multipath angles of the electromagnetic waves of the beams at different frequencies are different (the spatial domain bases are different), which leads to different influences on beam squint at different frequencies (different beam directions). That is, this application can suppress the influence brought by beam squint and improve the channel capacity.

[0141] Hereinafter, the embodiments of the present application will be described by taking the network device as a base station and the terminal device as a UE.

[0142] For the convenience of understanding the following embodiments, the protocol layer frameworks of the base station and the UE will be introduced here first. As Figure 6The following is a schematic diagram of a protocol layer framework for a base station and a UE in this application. The base station and the UE may include a radio resource control (RRC) layer, a medium access control (MAC) layer, and a 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 medium access 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 (PDCCH) at the PHY layer, and the base station can send downlink data to the UE through the 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 only an exemplary introduction to the functions of the RRC layer, the MAC layer, and the PHY layer, and this application does not limit the functions of the RRC layer, the MAC layer, and the PHY layer.

[0143] As Figure 7 The following is a schematic flowchart of a beamforming method provided by an embodiment of this application, and this method includes the following processes.

[0144] 701. The base station sends an inquiry message to the UE, and the inquiry message is used to inquire whether the UE has the ability to report the index of the spatial domain basis by sub-band.

[0145] In some embodiments, the inquiry message can be implemented through MAC-CE signaling. After the RRC link is established between the base station and the UE, the base station can send a first MAC-CE signaling to the UE, and the first MAC-CE signaling is used to inquire whether the UE has the ability to report the index of the spatial domain basis by sub-band.

[0146] In some embodiments, the spatial domain basis in this application can be indication information of an angle or indication information of a distance, etc., and this application does not limit the content of the spatial domain basis. For example, the indication information of an angle can be the indication information of the multipath angle of the electromagnetic wave transmitted between the base station and the UE, and the indication information of a distance can be the distance information between the base station and the UE.

[0147] 702. The UE sends a response message to the base station, and the response message is used to indicate that the UE has the ability to report the index of the spatial domain basis by sub-band.

[0148] In some embodiments, the response message can be implemented by MAC-CE signaling. The UE can send a second MAC-CE signaling to the base station, and the second MAC-CE signaling is used to indicate that the UE has the ability to report the index of the spatial domain basis by sub-band.

[0149] Exemplarily, the second MAC-CE signaling may include a "spatialScalingType" field, and the content of the "spatialScalingType" field is as follows:

[0150] spatialScalingType ENUMERTED{wideband,subband}.

[0151] 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 domain basis by sub-band" is "yes", and the base station determines that the UE has the ability to report the index of the spatial domain basis by sub-band.

[0152] 703. The base station sends a first RRC message to the UE, and the first RRC message is used to indicate that the UE reports the index of the spatial domain basis of each sub-band in at least one sub-band of the bandwidth.

[0153] The first RRC message here is a way of implementing the second indication information in step 501 of this application.

[0154] In some embodiments, when the base station determines that the UE has the ability to report the index of the spatial domain basis by sub-band, the base station can send a first RRC message to the UE, and the first RRC message indicates the following information:

[0155] 1) The indication information that the index of the spatial domain basis needs to be reported by sub-band;

[0156] 2) The bitmap of the sub-bands for which the index of the spatial domain basis needs to be reported.

[0157] Exemplarily, in the first RRC message, the base station indicates that the index of the spatial domain basis of the UE needs to be reported by sub-band, which can be indicated by the field "subbandSpatial", and the content of the field "subbandSpatial" is "BOOLEAN", that is:

[0158] subbandSpatial BOOLEAN

[0159] For example, if the value of "BOOLEAN" is 1, it indicates that the index of the spatial domain basis needs to be reported according to subbands. If the value of "BOOLEAN" is 0, it indicates that the index of the spatial domain basis does not need to be reported according to subbands.

[0160] In the first RRC message, the bitmap of the subbands for which the base station instructs the UE to report the index of the spatial domain basis can be indicated by the field "reportSpatialcontiguration". Exemplarily, the content of the field "reportSpatialcontiguration" can be:

[0161]

[0162]

[0163] That is to say, the base station instructs the UE to report the indexes of the spatial domain basis of the subbands identified as 3, 4, 17, 18,..., 19, etc.

[0164] Exemplarily, bit 2 bit in the bitmap is the number of subbands in the wideband, and each bit indicates whether to report the index of the spatial domain basis of the subband.

[0165] In some embodiments, when the base station determines that the spatial domain bases of certain subbands are the same, the base station can also instruct the UE to report only the index of the spatial domain basis of one of these subbands, that is, for these subbands, the base station can only indicate the bit corresponding to one of the subbands in the bitmap.

[0166] Alternatively, in some embodiments, the base station may not need to indicate this bitmap to the UE, and the UE can report the indexes of the spatial domain basis of at least one subband according to the default configuration. This default configuration is pre-agreed between the base station and the UE.

[0167] Exemplarily, the default configuration is used to instruct the UE to report only the indexes of the spatial domain basis of the maximum subband, the minimum subband, and the central subband in the wideband, that is, at least one subband includes the maximum subband, the minimum subband, and the central subband. For the base station, the base station can calculate the indexes of the spatial domain basis corresponding to other subbands in the wideband according to the default configuration and the preset method. For the base station and the UE, the signaling overhead is small in this way.

[0168] 704. The UE sends a second RRC message to the base station, and the second RRC message is used to indicate the index of the spatial domain basis of each subband in at least one subband.

[0169] Among them, the second RRC message is the implementation manner of the first indication information in step 501 of this application.

[0170] According to the instructions in step 703, the second RRC message may include the index of the corresponding spatial domain basis of at least one subband corresponding to the bitmap indicated by the base station, or the second RRC message includes the indexes of the spatial domain bases corresponding to the maximum subband, the minimum subband, and the central subband in the wideband.

[0171] 705. The base station determines the spatial domain bases corresponding to multiple subbands in the bandwidth according to the indexes of the spatial domain bases of each subband in at least one subband, and performs beamforming according to the spatial domain bases corresponding to the multiple subbands respectively.

[0172] In some embodiments, the base station may determine the spatial domain basis of each subband in at least one subband according to the index of the spatial domain basis of each subband in at least one subband. Then, the base station may determine the spatial domain bases corresponding to the other subbands in the wideband except the at least one subband according to the principle that the spatial domain bases of adjacent subbands may be the same. The base station determines the weights for beamforming corresponding to multiple subbands respectively according to the spatial domain bases corresponding to the multiple subbands, and performs beam coherent superposition in the same direction according to the weights corresponding to each subband in the multiple subbands to perform beamforming.

[0173] Exemplarily, there are various ways to perform beamforming. For example, in NR, since the frequency band used is relatively high, the antenna usually uses a multi-panel structure. To construct a large-scale antenna array, integrated antenna in package / tile (AIP / AIT) is easy to implement and has a 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), etc. Among them, DBF can provide flexible beamforming, ABF can provide steering accuracy and flexibility at low cost, and HBF is usually a compromise method adopted between DBF and ABF. The main difference between ABF and DBF lies in the way of completing beamforming, and both of these methods require good inter-channel matching. In ABF, film analog delay lines and summation can be used, and only one (with higher resolution) high-speed analog-to-digital converter (ADC) is required, while DBF requires multiple high-speed high-resolution ADCs.

[0174] If beamforming is performed in the DBF or HBF mode, the weights of beamforming corresponding to different subbands can be determined by using the digital domain and the spatial domain basis corresponding to each subband. According to the weights corresponding to each subband in multiple subbands, beam coherent superposition is performed in the same direction to perform beamforming.

[0175] If beamforming is performed in the ABF mode, the weights of beamforming corresponding to different subbands can be determined by using a delay device and the spatial domain basis corresponding to each subband. According to the weights corresponding to each subband in multiple subbands, beam coherent superposition is performed in the same direction to perform beamforming.

[0176] Of course, the present application is not limited to these three beamforming modes and can also be applied to other beamforming mode processes.

[0177] In this way, by reporting the spatial domain basis at the subband granularity in the present application to perform subband-level beamforming, that is, to transmit control information or data in the PHY layer between the base station and the UE, the influence of beam squint caused by different spatial domain bases of subbands can be suppressed, and the channel capacity during beam squint can be improved.

[0178] As Figure 8 shown in the flowchart of a beamforming method provided by an embodiment of the present application, the method includes the following processes.

[0179] 801. The base station sends an inquiry message to the UE. The inquiry message is used to inquire whether the UE has the ability to report the index of the spatial domain basis according to subbands.

[0180] For the implementation manner of step 801, reference can be made to the description of step 701.

[0181] 802. The UE sends a response message to the base station. The response message is used to indicate that the UE has the ability to report the index of the spatial domain basis according to subbands.

[0182] For the implementation manner of step 802, reference can be made to the description of step 702.

[0183] 803. The base station sends a third RRC message to the UE. The third RRC message is used to indicate the UE to report the index of the spatial domain basis of each subband in at least one subband in the bandwidth.

[0184] The third RRC message here is one implementation manner of the third indication information in step 501 of the present application.

[0185] In some embodiments, when the base station determines that the UE has the ability to report the index of the spatial domain basis according to subbands, the base station may send a third RRC message to the UE. The third RRC message indicates the following information:

[0186] 1) The index of the spatial domain basis needs to follow the indication information reported by sub-bands;

[0187] 2) The threshold for sub-band incremental reporting.

[0188] Among them, the threshold for sub-band incremental reporting can be used to indicate that when the sub-band increment between sub-bands exceeds this threshold, the index of the spatial domain basis corresponding to this sub-band needs to be reported.

[0189] In some embodiments, the sub-band increment can be the sub-band increment between adjacent sub-bands in the bandwidth after sorting the sub-bands according to the frequency point size of the sub-bands. For example, the sub-band increment is the difference in the indexes of the spatial domain bases between adjacent sub-bands, or the difference in the multipath angles between adjacent sub-bands, or the difference in the absolute values of the coefficients between adjacent sub-bands at the same angle (such as the multipath angle). In this way, the above at least one sub-band includes the sub-band corresponding to the maximum frequency point or the minimum frequency point after sorting the sub-bands according to the frequency point size of the sub-bands. This is because if the sub-band increment between adjacent sub-bands does not exceed this threshold, for example, when the difference in the indexes of the spatial domain bases of adjacent sub-bands is less than the corresponding threshold of the index, it can be considered that these two sub-bands can use the same spatial domain basis for beamforming, and the beam squint phenomenon is not serious, and only the index of the spatial domain basis of the previous sub-band in the order needs to be reported for these two sub-bands. Similarly, if the difference in the multipath angles of adjacent sub-bands is less than the corresponding threshold of the multipath angle, it can also be considered that these two sub-bands can use the same spatial domain basis for beamforming, and the beam squint phenomenon is not serious, and only the index of the spatial domain basis of the previous sub-band in the order needs to be reported for these two sub-bands. Similarly, if the absolute value of the coefficient between adjacent sub-bands at the same angle is less than the corresponding threshold of the absolute value of the coefficient, it can also be considered that these two sub-bands can use the same spatial domain basis for beamforming, and the beam squint phenomenon is not serious, and only the index of the spatial domain basis of the previous sub-band in the order needs to be reported for these two sub-bands.

[0190] Exemplarily, the third RRC message may include the following 2 fields:

[0191] subbandspatial BOOLEAN

[0192] thresholdSpatialAddition INTEGER

[0193] Among them, for the field "subbandspatial", which is the index of the above-mentioned spatial domain base, it is necessary to report according to the indication information of subbands. For example, when the value of the field "subbandspatial" is 1, it indicates that the index of the spatial domain base needs to be reported according to subbands; when the value of the field "subbandspatial" is 0, it indicates that there is no need to report the index of the spatial domain base according to subbands. The field "thresholdSpatialAddition" indicates the threshold of the above-mentioned subband incremental reporting.

[0194] 804. The UE sends a fourth RRC message to the base station, and the fourth RRC message is used to indicate the index of the spatial domain base of each subband in at least one subband.

[0195] In some embodiments, the fourth RRC message includes the first indication information in step 501 of this application.

[0196] Exemplarily, the fourth RRC message includes the index of the spatial domain base corresponding to each subband in at least one subband determined by the UE according to the incremental threshold, for example, it includes the identifier of each subband and the index of the spatial domain base corresponding to each subband.

[0197] Alternatively, the fourth RRC message includes the bitmap of at least one subband reported by the UE, and the index of the spatial domain base corresponding to each subband in at least one subband.

[0198] 805. The base station determines the spatial domain bases corresponding to multiple subbands in the bandwidth according to the index of the spatial domain base of each subband in at least one subband, and performs beamforming according to the spatial domain bases corresponding to multiple subbands.

[0199] For the implementation manner of step 805, reference can be made to the description of step 705.

[0200] Thus, by reporting the spatial domain base according to subband granularity in this application to perform subband-level beamforming, that is, to transmit control information or data at the PHY layer between the base station and the UE, the influence of beam squint caused by different spatial domain bases of subbands can be suppressed, and the channel capacity during beam squint can be improved.

[0201] As Figure 9 shown in the flowchart of a beamforming method provided by an embodiment of this application, the method includes the following processes.

[0202] 901. The base station sends an inquiry message to the UE, and the inquiry message is used to inquire whether the UE has the ability to report the index of the spatial domain base according to subbands.

[0203] For the implementation manner of step 901, reference can be made to the description of step 701.

[0204] 902. The UE sends a response message to the base station, and the response message is used to indicate that the UE has the ability to report the index of the spatial domain basis according to sub-bands.

[0205] For the implementation manner of step 902, refer to the description of step 702.

[0206] 903. The base station sends a fifth RRC message to the UE, and the fifth RRC message is used to indicate that the UE reports the functional relationship between the spatial domain bases of at least one sub-band and the position of the sub-band and the parameters of the functional relationship.

[0207] Here, the fifth RRC message is an implementation manner of the fourth indication information in step 501 of this application.

[0208] In some embodiments, when the base station determines that the UE has the ability to report the index of the spatial domain basis according to sub-bands, the base station may send a fifth RRC message to the UE, and the fifth RRC message indicates the following information:

[0209] 1) The indication information that the index of the spatial domain basis needs to be reported according to sub-bands;

[0210] 2) The indication information for reporting the functional relationship between the spatial domain bases of at least one sub-band and the position of the sub-band and the parameters of the functional relationship.

[0211] Exemplarily, the fifth RRC message may include the following 2 fields:

[0212] subbandspatial BOOLEAN

[0213] subbandSpatialRelation BOOLEAN

[0214] Among them, the field "subbandspatial" is the indication information that the index of the spatial domain basis needs to be reported according to sub-bands. For example, when the value of the field "subbandspatial" is 1, it indicates that the index of the spatial domain basis needs to be reported according to sub-bands; when the value of the field "subbandspatial" is 0, it indicates that the index of the spatial domain basis does not need to be reported according to sub-bands. The field "subbandSpatialRelation" indicates the functional relationship between the spatial domain bases of at least one sub-band and the position of the sub-band and the parameters of the functional relationship. When the value of the field "subbandSpatialRelation" is 1, it indicates that the functional relationship between the spatial domain bases of at least one sub-band and the position of the sub-band and the parameters of the functional relationship needs to be reported; when the value of the field "subbandSpatialRelation" is 0, it indicates that the functional relationship between the spatial domain bases of at least one sub-band and the position of the sub-band and the parameters of the functional relationship does not need to be reported according to sub-bands.

[0215] 904. The UE sends a sixth RRC message to the base station. The sixth RRC message is used to indicate the functional relationship between the index of the spatial domain basis of at least one sub-band and the position of the sub-band, as well as the parameters of the functional relationship.

[0216] In some embodiments, the fourth RRC message includes the first indication information in step 501 of this application.

[0217] Exemplarily, there can be various types of functional relationships between the index of the spatial domain basis and the sub-band change. For example, it can be a linear function, a quadratic function, a cubic function, a sin function, or a function of Taylor coefficient * nbit, where n is an integer, for example, n is 3. The parameters of the functional relationship between the index of the spatial domain basis and the position of the sub-band are, for example, a1, a2, and a3. When each parameter occupies 3 bits, the parameters of the functional relationship between the index of the spatial domain basis and the position of the sub-band can occupy 9 bits.

[0218] In some embodiments, if the functional relationship is relatively complex, the base station can calculate the index of the spatial domain basis by using Taylor expansion to obtain the Taylor coefficients. For example, using Taylor expansion to obtain Taylor coefficients of order 0 to 3. For example, the Taylor coefficients are in the following form: This application does not limit the form of the Taylor coefficients.

[0219] In this way, for the base station, when receiving the functional relationship and the parameters of the functional relationship, it can determine the index of the spatial domain basis corresponding to each sub-band in at least one sub-band according to the functional relationship, the parameters of the functional relationship, and the position of at least one sub-band.

[0220] In some embodiments, the sixth RRC message may further include at least one of the following information: the bitmap of non-zero coefficients, the index of the strongest coefficient (the index in the frequency domain and the angle), the index of the selected frequency domain basis, the phase and amplitude of the coefficients, the index of the selected spatial domain basis, or the oversampling rate of the spatial domain basis. Here, the coefficients can be understood as the above combined coefficients C.

[0221] 905. The base station determines the spatial domain basis corresponding to multiple sub-bands in the bandwidth according to the index of the spatial domain basis of each sub-band in at least one sub-band, and performs beamforming according to the spatial domain basis corresponding to multiple sub-bands.

[0222] For the implementation manner of step 905, reference can be made to the description of step 705.

[0223] Thus, by reporting the spatial domain basis at the sub-band granularity in this application to perform sub-band-level beamforming, that is, to transmit control information or data at the PHY layer between the base station and the UE, the influence of beam squint caused by different spatial domain bases of sub-bands can be suppressed, and the channel capacity during beam squint can be improved.

[0224] The above describes the process of beamforming under PMI feedback.

[0225] In some embodiments, beamforming can also be performed through beam management feedback. This beam management feedback is equivalent to feeding back an optimal beam identity (ID) for the entire CA band, and each CC can perform beamforming according to this optimal beam ID. For example, for a base station, the base station can pre-form multiple wide beams and narrow beams in advance. The UE can select a narrow beam in a certain wide beam as the optimal beam according to a certain beam selection rule 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 performing beamforming on all sub-bands in each CC according to the same beam ID. This is similar to the problem existing in beamforming with the above PMI feedback. Since the multipath angles corresponding to different sub-bands under one CC are different, there is still the problem of beam squint.

[0226] Based on this, the embodiments of the present application further provide a beamforming method. In this method, the network device can instruct the terminal device to report the beam identity corresponding to each sub-band in at least one sub-band in the broadband. The network device determines the beam corresponding to each sub-band in the broadband according to the beam identity corresponding to each sub-band in at least one sub-band, so as to perform beamforming according to the beam corresponding to each sub-band. Here, the beam identity corresponding to each sub-band can be understood as the identity of the optimal beam corresponding to each sub-band. In this way, compared with the relatively serious problem of beam squint caused by beamforming according to the optimal beam identity of a whole CA band, in the present application, the network device can perform beamforming according to the beam corresponding to each sub-band. The present application considers that the multipath angles of the electromagnetic waves of the beams at different frequency points are different (the optimal beams are different), which leads to different influences of beam squint on different frequency points (different beam directions). That is, the present application can suppress the influence of beam squint and improve the channel capacity.

[0227] Therefore, as Figure 10 shown in the flowchart of a beamforming method provided by the embodiments of the present application, this method includes the following processes.

[0228] 101. The network device receives first indication information, and the first indication information is used to indicate the beam information of each sub-band in at least one sub-band in the broadband.

[0229] Similar to the above embodiments, the network device receiving the first indication information includes: the network device receives the first indication information sent by the terminal device. Correspondingly, the terminal device sends the first indication information to the network device.

[0230] In some embodiments, the network device is a base station and the terminal device is a UE.

[0231] In some embodiments, the beam information of each sub-band in at least one sub-band includes the optimal beam identifier corresponding to each sub-band in at least one sub-band. For example, specifically, it includes the identifier / position information of each sub-band in at least one sub-band and the optimal beam identifier corresponding to each sub-band.

[0232] In some embodiments, the beam information of each sub-band in at least one sub-band includes a bitmap of at least one sub-band and the optimal beam identifier corresponding to each sub-band in at least one sub-band.

[0233] In some embodiments, before the network device receives the first indication information, the method further includes: the network device sending an inquiry message, where the inquiry message is used to inquire whether the terminal device has the ability to report beam information by sub-band; the network device receiving a response message, where the response message is used to indicate that the terminal device has the ability to report beam information by sub-band.

[0234] 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 beam information corresponding to each sub-band in at least one sub-band. Alternatively, the network device sends second indication information to the terminal device, and correspondingly, the terminal device receives the second indication information sent by the network device.

[0235] 102. The network device performs beamforming according to the beam information corresponding to multiple sub-bands of a broadband, and the beam information corresponding to multiple sub-bands is determined according to the beam information of each sub-band in at least one sub-band.

[0236] In some embodiments, the network device can determine the beam information corresponding to other sub-bands in the broadband except for at least one sub-band according to the beam information corresponding to each sub-band in at least one sub-band in the broadband, so as to obtain the beam information corresponding to multiple sub-bands in the broadband. Then, the network device can perform beamforming according to the beam information corresponding to multiple sub-bands.

[0237] In this way, in the present application, the present application considers the problem that the multipath angles of the electromagnetic waves of the beams in different frequency points / sub-bands are different (the optimal beams are different), resulting in different influences of beam squint on different frequency points (different beam directions). The network device in the present application can perform beamforming according to the optimal beam corresponding to each sub-band. That is, the method of performing beamforming according to the granularity of sub-bands in the present application can suppress the influence brought by beam squint and improve the channel capacity.

[0238] As Figure 11 shown is a schematic flowchart of a beamforming method provided by an embodiment of the present application, and the method includes the following processes.

[0239] 111. The base station sends an inquiry message to the UE. The inquiry message is used to ask whether the UE has the ability to report beam information by sub-band.

[0240] In some embodiments, the inquiry message can be implemented through MAC-CE signaling. After the base station and the UE establish an RRC link, the base station can send a first MAC-CE signaling to the UE. The first MAC-CE signaling is used to ask whether the UE has the ability to report beam information by sub-band.

[0241] In some embodiments, the beam information can be understood as the optimal beam ID corresponding to the sub-band.

[0242] 112. The UE sends a response message to the base station. The response message is used to indicate that the UE has the ability to report beam information by sub-band.

[0243] In some embodiments, the response message can be implemented through MAC-CE signaling. The UE can send a second MAC-CE signaling to the base station. The second MAC-CE signaling is used to indicate that the UE has the ability to report beam information by sub-band.

[0244] Exemplarily, the second MAC-CE signaling may include a "beamManagementSubband" field, and the "beamManagementSubband" field is as follows:

[0245] beamManagementCSI-RS

[0246] {beamManagementSubband Bool}

[0247] For example, if the value of the "beamManagementSubband" field is 1, it indicates that the UE has the ability to report beam information by sub-band, which is equivalent to the UE replying to the base station that the UE ability of "reporting beam information by sub-band" is "yes"; if the value of the "beamManagementSubband" field is 0, it indicates that the UE does not have the ability to report beam information by sub-band.

[0248] 113. The base station sends a first RRC message to the UE. The first RRC message is used to instruct the terminal device to report the beam information corresponding to each sub-band in at least one sub-band.

[0249] Here, the first RRC message is an implementation manner of the second indication information in step 101 of this application.

[0250] In some embodiments, when the base station determines that the UE has the ability to report beam information by sub-band, the base station can send a first RRC message to the UE. The first RRC message indicates the following information:

[0251] 1) The beam information of the narrow beam needs to be reported according to the indication information of the subbands;

[0252] 2) The indication information of at least one subband for which the beam information needs to be reported.

[0253] Exemplarily, in the first RRC message, the base station indicates that the UE beam information needs to be reported according to the subbands, which can be indicated by the field "subbandBeamManagement", and the content of the field "subbandBeamManagement" is "BOOLEAN", that is:

[0254] subbandBeamManagement BOOLEAN

[0255] For example, if the value of "BOOLEAN" is 1, it indicates that the beam information needs to be reported according to the subbands. If the value of "BOOLEAN" is 0, it indicates that the beam information does not need to be reported according to the subbands.

[0256] In the first RRC message, the subbands for which the base station indicates that the UE needs to report the beam information can be indicated by the field "reportBeamSubbandContiguration". Exemplarily, the content of the field "reportBeamSubbandContiguration" can be:

[0257]

[0258] That is to say, the base station indicates that the UE needs to report the beam information of the subbands identified as 3, 4, 17, 18,..., 19, etc.

[0259] 114. The UE sends a second RRC message to the base station, and the second RRC message is used to indicate the beam information of each subband in at least one subband in the wideband.

[0260] Among them, the second RRC message is the implementation manner of the first indication information in step 101 of this application.

[0261] In some embodiments, after the UE performs the scanning and selection of the wide beam and the narrow beam, for the optimal narrow beam, the UE reports the optimal beam identifier according to the subbands.

[0262] 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 among the multiple wide beams. Then, the UE selects a first wide beam with the best channel quality / signal strength from the multiple wide beams according to the channel quality / signal strength corresponding to each wide beam. Next, the UE scans each narrow beam in the selected first wide beam and measures each sub-band in at least one sub-band of the wide band, that is, the channel quality / signal strength corresponding to each sub-band on each narrow beam in the first wide beam. That is to say, the UE can receive multiple narrow beams in the first wide beam on each sub-band. Then, the UE selects an optimal beam with the best channel quality / signal strength for each sub-band according to the channel quality / signal strength corresponding to each sub-band on each narrow beam in the first wide beam. Finally, the UE reports the optimal beam ID corresponding to each sub-band in at least one sub-band to the base station.

[0263] Among them, the wide beam is, for example, a sync singal block (SSB), and the narrow beam is a channel state information reference signal (CSI-RS). The CSI-RS can be understood as a pilot for measuring CSI. This application does not limit the wide beam to only SSB, nor does it limit the narrow beam to only CSI-RS.

[0264] 115. The base station performs sub-band level beamforming according to the beam information corresponding to multiple sub-bands in the wide band, and the beam information corresponding to multiple sub-bands is determined according to the beam information of each sub-band in at least one sub-band.

[0265] In some embodiments, there are various ways for the base station to perform sub-band level beamforming according to the beam information corresponding to multiple sub-bands in the wide band, such as DBF, HBF, or ABF, etc.

[0266] Therefore, this application takes into account the problem that the multipath angles of the electromagnetic waves of the beams in different frequency points / sub-bands are different (the optimal beams are different), resulting in different effects of beam squint on different frequency points (different beam directions). The base station in this application can perform beamforming according to the optimal beam corresponding to each sub-band. That is to say, the way of beamforming according to the granularity of sub-bands in this application can suppress the influence brought by beam squint and improve the channel capacity.

[0267] The following gives a comparison of the channel capacity when suppressing beam squint by performing beamforming according to the spatial domain basis at the sub-band level or according to the beam information at the sub-band level, and the channel capacity when performing beamforming according to the spatial domain basis of the full band / wide band or according to the optimal beam ID of the full band / wide band under CA. As Figure 12The figure shows a schematic diagram of channel capacity under different ratios of bandwidth to center frequency. Figure 12 In the figure, the horizontal axis represents the ratio of different bandwidths to the center frequency, and the vertical axis represents the channel capacity (gbits / sec). Among them, curve ① represents the channel capacity corresponding to different ratios of bandwidth to center frequency obtained by using the antenna system of uniform linear arrays (ULA) with N = 64 antenna elements when the base station achieves no beam squint using the present application. Curve ② represents the channel capacity corresponding to different ratios of bandwidth to center frequency obtained by beamforming according to the spatial domain basis of the full band / bandwidth or according to the optimal beam ID of the full band / bandwidth under CA, when there is beam squint, and the base station uses the ULA antenna system with 64 antenna elements. It can be seen that when using the ULA antenna system with 64 antenna elements, at the same ratio of bandwidth to center frequency, the channel capacity shown by curve ① is higher than that shown by curve ②. For example, when the ratio of bandwidth (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 bandwidth (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.

[0268] Similarly, Curve ③ represents the channel capacity corresponding to the ratio of different bandwidths to the center frequency point obtained by using the ULA antenna system at the base station with the number of antenna elements N = 32 when there is no beam squint in this application. Curve ④ represents the channel capacity corresponding to the ratio of different bandwidths to the center frequency point obtained by performing beamforming according to the spatial domain basis of the full band / bandwidth or according to the optimal beam ID of the full band / bandwidth under CA when there is beam squint, and the base station uses the ULA antenna system with the number of antenna elements being 32. It can be seen that when using the ULA antenna system with the number of antenna elements being 32, at the same ratio of bandwidth to the center frequency point, the channel capacity shown by Curve ③ is higher than that shown by Curve ④. For example, when the ratio of the bandwidth (400M) to the center frequency point (6.5GHz) is 0.06, compared with the channel capacity in the case of no beam squint, 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 the bandwidth (800M) to the center frequency point (6.5GHz) is near 0.12, compared with the channel capacity in the case of no beam squint, the channel capacity in the case of beam squint is 40% less than the channel capacity in the case of no beam squint.

[0269] Therefore, compared with the case of no beam squint, when there is beam squint, the channel capacity is significantly reduced, and the reduction amount is approximately 7% - 73% of the channel capacity in the case of no beam squint.

[0270] It can be understood that in order to implement the functions in the above embodiments, the network device and the terminal device include the corresponding hardware structures and / or software modules for performing each function. Those skilled in the art should easily realize that, combining the units and method steps of each example described in the embodiments disclosed in this application, this application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the way of hardware or computer software driving hardware depends on the specific application scenarios and design constraints of the technical solution.

[0271] Figure 13 and Figure 14 is a schematic structural diagram of a possible communication device provided by the embodiments of this application. These communication devices can be used to implement the functions of the network device and the terminal device in the above method embodiments, and thus can also achieve the beneficial effects possessed by the above method embodiments. In the embodiments of this application, the communication device can be one of the devices 301 or devices 302 - 307 as shown in Figure 3 and can also be a communication module (such as a chip or a chipset) applied to these devices. The relevant communication device is used to implement data transmission, for example, can be used to implement the beamforming mentioned above.

[0272] 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 the terminal device in the method embodiments shown above Figures 5 to 11 .

[0273] When the communication device 130 is used to implement the function of the network device in the method embodiment shown in Figures 5 to 11 : The transceiver module 1320 can be used to receive the first indication information, send an inquiry message, receive a response message, send a first RRC message / a third RRC message / a fifth RRC message, and receive a second RRC message / a fourth RRC message / a sixth RRC message; the processing module 1310 can be used to perform beamforming according to the spatial domain basis or beam information corresponding to multiple sub-bands of the bandwidth;

[0274] When the communication device 130 is used to implement the function of the terminal device in the method embodiment shown in Figures 5 to 11 : The transceiver module 1320 is used to send the first indication information, receive an inquiry message, send a response message, receive a first RRC message / a third RRC message / a fifth RRC message, and send a second RRC message / a fourth RRC message / a sixth RRC message; the processing module 1310 can be used to perform wide beam and narrow beam measurements, and process the received data, etc.

[0275] For a more detailed description of the above processing module 1310 and transceiver module 1320, reference can be made to the relevant descriptions in the method embodiments shown in Figures 5 to 11 .

[0276] As shown in Figure 14 , the communication device 140 includes a processor 1410 and a transceiver 1420. The processor 1410 and the transceiver 1420 are coupled to each other. It can be understood that the transceiver 1420 can be a transceiver or an input / output interface. Optionally, the communication device 140 may further include a memory 1430, which is used to store the instructions executed by the processor 1410 or store the input data required for the processor 1410 to run the instructions or store the data generated after the processor 1410 runs the instructions.

[0277] When the communication device 140 is used to implement the method shown in Figures 5 to 11 , the processor 1410 is used to implement the functions of the above processing module 1310, and the transceiver 1420 is used to implement the functions of the above transceiver module 1320. The transceiver 1420 can be an interface chip or a separate IP module integrated in the interface chip.

[0278] When the communication device 140 is an interface chip applied to a network device, the interface chip of the network device implements the functions of the network device in the above method embodiments. The interface chip of the network device sends data to the terminal device, which can be understood as that the data is first generated by other modules (such as the source data component) in the network device and then sent by these modules to the interface chip of the network device.

[0279] When the interface device 140 is an interface chip applied to a terminal device, the interface chip of the terminal device implements the functions of the terminal device in the above method embodiments. The interface chip of the terminal device receives data from the terminal device, which can be understood as 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.

[0280] In this application, entity A sending information to entity B can be that A directly sends to B or A indirectly sends to B through other entities. Similarly, entity B receiving information from entity A can be that entity B directly receives the information sent by entity A or entity B indirectly receives the information sent by entity A through other entities. Here, entity A and B can be the sending side or the receiving side, or modules inside the sending side or the receiving side. The sending and receiving of data can be the information interaction between the sending side and the receiving side. For example, the information interaction between the source device and the destination device; the sending and receiving of data can also be the information interaction between different modules within a device. For example, the information interaction between the interface chip on the sending side and the interface chip on the receiving side.

[0281] It can be understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor.

[0282] The method steps in the embodiments of the present application can be implemented in hardware or in software instructions executable by a processor. The software instructions can be composed of corresponding software modules, and the software modules can be stored in a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an erasable programmable read-only memory, an electrically erasable programmable read-only memory, a register, a hard disk, a removable hard disk, a CD-ROM, or any other form of storage medium well-known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from the storage medium and write information to the storage medium. The storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC. Additionally, the ASIC can be located in a base station or a terminal. The processor and the storage medium can also exist as discrete components in a base station or a terminal.

[0283] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part 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 executed in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user device, or other programmable devices. The computer program or instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer program or instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired or wireless manner. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server or a data center integrating one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it can also be an optical medium, such as a digital video disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile types of storage media.

[0284] In various embodiments of the present application, if there is no special indication and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0285] In this application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the relationship between associated objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. In the written description of this application, the character " / " generally indicates that the associated objects before and after 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.

[0286] It can be understood that the various numerical numbers involved in the embodiments of this application are only for convenience of description and are not used to limit the scope of the embodiments of this application. The magnitudes of the sequence numbers of the above processes do not mean the order of execution, and the order of execution of each process should be determined by its function and internal logic.

Claims

1. A beamforming method, characterized in that, Comprising: Receiving first indication information, where the first indication information is used to indicate 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 respectively corresponding to multiple sub - bands of the broadband, where the spatial domain bases respectively 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, characterized in that 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, wherein 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, where the second indication information is used to indicate 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, where the third indication information is used to indicate 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 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.

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 change in the position of the sub - band and the parameters of the functional relationship.

7. The method according to claim 6, characterized in that Before receiving the first indication information, the method further includes: Sending fourth indication information, where the fourth indication information is used to indicate that the terminal device reports the functional relationship between the spatial domain basis of the at least one sub - band and the change in the position of the sub - band and the parameters of the functional relationship.

8. The method according to any one of claims 1-7, characterized in that, Before receiving the first indication information, the method further includes: 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 domain basis by sub - band; Receiving 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 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 respectively corresponding to multiple sub - bands of the broadband includes: Determining the weights for beamforming respectively corresponding to the multiple sub - bands according to the spatial domain bases respectively corresponding to the multiple sub - bands; Performing beamforming according to the weight corresponding to each sub - band in the multiple sub - bands.

11. A beamforming method, characterized in that, Comprising: Sending first indication information, where the first indication information is used to indicate 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, characterized in that, 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 determines 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 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.

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, characterized in that, 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, Includes: 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, Includes: 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 multiple sub-bands of the bandwidth, and the spatial domain bases respectively 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.

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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