Near-field broadband beamforming method, device, electronic device and storage medium

Abstract

The present invention provides a near-field broadband beamforming method, apparatus, electronic device, and storage medium. Among them, the near-field broadband beamforming method is applied to a base station having a first antenna array, and the first antenna array is a very large-scale antenna array. The method includes: dividing the first antenna array of the base station into multiple sub-arrays, where each sub-array includes multiple antennas; determining the far-field codewords of each sub-array based on a preset far-field channel model; determining the near-field codewords of the first antenna array based on a preset near-field channel model and the far-field codewords of each sub-array; and performing beamforming processing on the near-field broadband beam generated by the base station based on the near-field codewords of the first antenna array. By using the near-field broadband beamforming method provided by the present invention, the influence of the near-field broadband effect on the rate of the very large-scale antenna array system can be overcome, and the communication rate of the very large-scale antenna array can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and in particular, to a near-field broadband beamforming method, apparatus, electronic device, and storage medium. Background Art

[0002] As known from related technologies, large-scale array communication technologies based on spatial asymptotic orthogonality can multiply the spectral efficiency of wireless communication systems and are one of the representative communication technologies of 5G technology. In the future, ultra-large-scale array communication technologies with larger array scales are highly expected to further improve system performance and have broad application prospects in 6G mobile communication systems.

[0003] From large-scale arrays to ultra-large-scale arrays, it is not only a simple quantitative change in the number of antennas, but also a qualitative change in the electromagnetic field structure. In ultra-wideband systems, the equal-phase surfaces of the beams generated by traditional phased arrays will shift with frequency, thus introducing serious beam splitting problems, which will seriously affect the strength of the signals received by users. Currently, near-field broadband beamforming schemes for ultra-large-scale arrays have become a research hotspot. Summary of the Invention

[0004] The present invention provides a near-field broadband beamforming method, apparatus, electronic device, and storage medium, which are used to solve the defect that the near-field broadband beams of ultra-large-scale antenna arrays in the prior art are severely split and affect the signal strength received by users, overcome the influence of the near-field broadband effect on the rate of ultra-large-scale antenna array systems, and effectively improve the communication rate of ultra-large-scale antenna arrays.

[0005] The present invention provides a near-field broadband beamforming method. The method is applied to a base station with a first antenna array, and the first antenna array is an ultra-large-scale antenna array. The method includes: dividing the first antenna array of the base station into multiple sub-arrays, where each sub-array includes multiple antennas; determining the far-field codewords of each sub-array based on a preset far-field channel model; determining the near-field codewords of the first antenna array based on a preset near-field channel model and the far-field codewords of each sub-array; and performing beamforming processing on the near-field broadband beams generated by the base station based on the near-field codewords of the first antenna array.

[0006] According to the near-field broadband beamforming method provided by the present invention, a first delay device is provided in the sub-array, and a first phase shifter is provided in the antennas of the sub-array. Determining the far-field codewords of each sub-array based on a preset far-field channel model includes: determining the first delay parameter of the first delay device and determining the first phase shift parameter of the first phase shifter; and determining the far-field codewords of the sub-array based on the preset far-field channel model, the first delay parameter, and the first phase shift parameter.

[0007] According to a near-field broadband beamforming method provided by the present invention, the preset far-field channel model is expressed by the following formula:

[0008]

[0009] where, w q (f) represents the far-field codeword of the q-th subarray, τ′ q represents the first delay parameter of the q-th subarray, represents the first phase shift parameter on the p-th antenna of the q-th subarray, where p = [0, 1, 2, … P-1], f represents the signal frequency transmitted by the antennas in the subarray, and j represents the imaginary unit.

[0010] According to a near-field broadband beamforming method provided by the present invention, the first delay parameter is determined by the following method: determining the first distance between the subarray center of the subarray and the user, and the first angle between the subarray center of the subarray and the normal direction of the user; determining the first delay parameter based on the first distance and the first angle.

[0011] According to a near-field broadband beamforming method provided by the present invention, the determination of the first delay parameter based on the first distance and the first angle is achieved by the following formula:

[0012]

[0013] where, τ′ q represents the first delay parameter, r q represents the first distance, θ q represents the first angle, c represents the speed of light, P represents the number of antennas in the subarray, and d represents the antenna spacing between adjacent antennas in the subarray.

[0014] According to a near-field broadband beamforming method provided by the present invention, the near-field broadband beamforming method further includes: performing a non-negative constraint process on the first delay parameter to obtain a processed first delay parameter; using the processed first delay parameter as the final first delay parameter.

[0015] According to a near-field broadband beamforming method provided by the present invention, the non-negative constraint process on the first delay parameter is achieved by the following formula:

[0016] τ″ q = τ′ q + T

[0017] where, τ″ q represents the processed first delay parameter, τ′ q represents the first delay parameter, T represents the common delay, and T = -minτ′q 。

[0018] A near - field broadband beamforming method provided by the present invention, the first phase - shift parameter is determined by the following method: determining a first included angle between the center of the sub - array and the normal direction of the user; based on the first included angle, determining the first phase - shift parameter.

[0019] A near - field broadband beamforming method provided by the present invention, the determining the first phase - shift parameter based on the first included angle is determined by the following formula:

[0020]

[0021] wherein, represents the first phase - shift parameter, θ q represents the first included angle, P represents the number of antennas in the sub - array, f c represents the frequency of the center carrier of the sub - array, c represents the speed of light, p represents the antenna number of the p - th antenna in the sub - array, and d represents the antenna spacing between adjacent antennas in the sub - array.

[0022] A near - field broadband beamforming method provided by the present invention, the determining the near - field codeword of the first antenna array based on the preset near - field channel model and the far - field codewords of each sub - array includes: determining the number of the first antennas of the first antenna array; based on the preset near - field channel model, the number of the first antennas, and the far - field codewords of each sub - array, determining the near - field codeword of the first antenna array.

[0023] A near - field broadband beamforming method provided by the present invention, the determining the near - field codeword of the first antenna array based on the preset near - field channel model, the number of the first antennas, and the far - field codewords of each sub - array is realized by the following formula:

[0024]

[0025] wherein, w(f) represents the near - field codeword of the first antenna array, N represents the number of the first antennas, w0…w Q-1 represents the far - field codewords of each sub - array.

[0026] The present invention also provides a near-field broadband beamforming device. The device is applied to a base station having a first antenna array, and the first antenna array is a very large-scale antenna array. The device includes: a partitioning module configured to partition the first antenna array of the base station into a plurality of sub-arrays, each sub-array including a plurality of antennas; a processing module configured to determine far-field codewords of each sub-array based on a preset far-field channel model, and to determine near-field codewords of the first antenna array based on a preset near-field channel model and the far-field codewords of each sub-array; and a determination module configured to perform beamforming processing on a near-field broadband beam generated by the base station based on the near-field codewords of the first antenna array.

[0027] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the steps of the near-field broadband beamforming method as described in any one of the above are implemented.

[0028] The present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the near-field broadband beamforming method as described in any one of the above are implemented.

[0029] The present invention also provides a computer program product, including a computer program. When the computer program is executed by a processor, the steps of the near-field broadband beamforming method as described in any one of the above are implemented.

[0030] The near-field broadband beamforming method, device, electronic device, and storage medium provided by the present invention can decouple complex near-field beamforming codewords into far-field codewords within each sub-array and near-field codewords between sub-arrays of the first antenna array by partitioning the first antenna array of the base station into a plurality of sub-arrays, determining far-field codewords of each sub-array based on a preset far-field channel model, and determining near-field codewords of the first antenna array based on a preset near-field channel model and the far-field codewords of each sub-array. And perform beamforming processing on the near-field broadband beam generated by the base station through the near-field codewords of the first antenna array, so that the near-field broadband beam generated by the base station is focused on the user location, overcome the influence of the near-field broadband effect on the rate of the very large-scale antenna array system, and effectively improve the communication rate of the very large-scale antenna array. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0032] Figure 1It is a schematic diagram of the near-field broadband effect;

[0033] Figure 2 It is one of the schematic flowcharts of the near-field broadband beamforming method provided by the present invention;

[0034] Figure 3 It is a schematic diagram of the beam generated by the base station antenna in the far-field channel mode;

[0035] Figure 4 It is a schematic diagram of the beam generated by the base station antenna in the near-field channel mode;

[0036] Figure 5 It is a schematic diagram of the beam generated by the base station antenna in the partitioned far-field channel mode provided by the present invention;

[0037] Figure 6 It is a schematic diagram of the application scenario of the phase-controlled near-field broadband beamforming provided by the present invention;

[0038] Figure 7 It is one of the schematic flowcharts of determining the far-field codewords of each sub-array based on a preset far-field channel model provided by the present invention;

[0039] Figure 8 It is one of the schematic flowcharts of determining the first delay parameter provided by the present invention;

[0040] Figure 9 It is one of the schematic flowcharts of determining the first phase shift parameter provided by the present invention;

[0041] Figure 10 It is one of the schematic flowcharts of determining the near-field codewords of the first antenna array provided by the present invention;

[0042] Figure 11 It is a schematic diagram of the comparison of the system achievable sum rate performance of applying the near-field broadband beamforming method provided by the present invention;

[0043] Figure 12 It is a schematic diagram of the structure of the near-field broadband beamforming device provided by the present invention;

[0044] Figure 13 It is a schematic diagram of the structure of the electronic device provided by the present invention.

[0045] Reference numerals:

[0046] 610: Radio frequency link; 620: Delay layer; 630: Phase shift layer. Detailed implementation manners

[0047] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0048] As known from related technologies, the large-scale array communication technology based on spatial asymptotic orthogonality can multiply improve the spectral efficiency of wireless communication systems and is one of the representative communication technologies of 5G technology. In the future, the ultra-large-scale array communication technology with a larger array scale is highly expected to improve system performance and has broad application prospects in 6G mobile communication systems. Specifically, the potential key technologies of current 6G technology include terahertz communication for improving transmission rate, ultra-large-scale MIMO for improving spectral efficiency, and intelligent metasurface communication for improving coverage ability. The common feature of these three key technologies is that they all adopt ultra-large-scale array communication technology. On the other hand, 6G technology also hopes to adopt ultra-large-scale array communication technologies such as terahertz communication and intelligent metasurfaces to further improve the transmission rate and coverage ability in complex environments. In addition, ultra-large-scale array communication technology can also be applied to scenarios such as satellite communication, deep space communication, and offshore communication, multiplying improving system performance.

[0049] From large-scale arrays to ultra-large-scale arrays, it is not only a simple quantitative change in the number of antennas, but also a qualitative change in the electromagnetic field structure. Limited by the number of antennas, the near-field radius of existing large-scale arrays is relatively small (determined by the Rayleigh distance, proportional to the square of the array aperture divided by the signal wavelength), less than 1 meter, and almost all user activity areas are in the far field. At this time, as Figure 1 shown in a, the beam generated by the array antenna propagates in the form of a plane wave along a certain direction. However, with the significant increase in the number of antennas and the operating frequency, the near-field radius of ultra-large-scale arrays also undergoes a qualitative change. The near-field range of ultra-large-scale arrays is as high as several meters or even dozens of meters, which cannot be ignored in actual systems. At this time, as Figure 1 shown in b, the electromagnetic wave signal focuses the energy in a certain region of physical space in the form of a spherical wave, rather than a single direction. In an ultra-wideband system, the equal-phase surface of the beam generated by a traditional phased array will shift with frequency, thus introducing a serious beam splitting problem. As Figure 1 shown in c, in the far field, the beams of different frequency points propagate along different angles. In a near-field broadband system, as Figure 1 shown in d, the near-field broadband effect will cause the beams of different frequency points to focus on different physical regions in the two dimensions of "distance - angle", deviating from the user's area and seriously affecting the intensity of the signal received by the user.

[0050] The research on beamforming mainly considers the far-field environment. In recent years, a small amount of research has initially involved near-field communication, but only considered the near-field narrowband scenario. Currently, the near-field broadband beamforming scheme for ultra-large-scale arrays has become a research hotspot.

[0051] The present invention provides a near-field broadband beamforming method, which decouples the complex near-field beamforming codewords into far-field codewords within each subarray and inter-subarray near-field codewords of the first antenna array through partitioned far-field beamforming codewords. And through the near-field codewords of the first antenna array, the near-field broadband beam generated by the base station is beamformed, so that the near-field broadband beam generated by the base station is focused on the user location, overcoming the influence of the near-field broadband effect on the rate of the ultra-large-scale antenna array system and effectively improving the communication rate of the ultra-large-scale antenna array.

[0052] The present invention will illustrate the process of the near-field broadband beamforming method in combination with the following embodiments.

[0053] Figure 2 It is one of the schematic flowcharts of the near-field broadband beamforming method provided by the present invention.

[0054] In an exemplary embodiment of the present invention, the near-field broadband beamforming method can be applied to a base station with a first antenna array, where the first antenna array is an ultra-large-scale antenna array. In one example, an antenna array with the number of antennas exceeding a threshold can be referred to as an ultra-large-scale antenna array, where the threshold can be determined according to actual situations. For example, the threshold can be 1000 antennas. In this embodiment, no specific limitation is made on the threshold.

[0055] As Figure 2 shown, the near-field broadband beamforming method can include steps 210 to 240, and each step will be introduced separately below.

[0056] In step 210, the first antenna array of the base station is divided into multiple subarrays, and each subarray includes multiple antennas.

[0057] In one embodiment, the first antenna array can be an ultra-large-scale antenna array. The base station can deploy an ultra-large-scale antenna array and communicate with users. During the application process, as Figure 5 shown, the ultra-large-scale antenna array can be divided into multiple subarrays. It can be understood that since the radius of each subarray is small, each subarray can be in the far-field channel mode, and the first antenna array can be regarded as being in the partitioned far-field channel mode.

[0058] In step 220, based on a preset far-field channel model, the far-field codewords of each subarray are determined.

[0059] In step 230, based on the preset near-field channel model and the far-field codewords of each sub-array, determine the near-field codeword of the first antenna array.

[0060] Combined with Figure 3 - Figure 4 It can be seen that in the far-field channel mode, the antenna array of the base station generates a plane wave, and in the near-field signal, the antenna array of the base station generates a spherical wave. In an ultra-wideband system, the equal-phase surface of the beam generated by the traditional phased array will shift with the frequency, resulting in a beam classification problem.

[0061] In one embodiment, combined with Figure 5 For illustration, in an ultra-wideband system, a very large-scale antenna array can be divided into multiple sub-arrays. Correspondingly, the far-field codeword of the very large-scale antenna array can be regarded as a partitioned far-field codeword, and the partitioned far-field codeword is a segmented approximation of the actual near-field codeword. In the application process, the entire very large-scale antenna array is divided into multiple sub-arrays, and the diameter of each sub-array is much smaller than the diameter of the entire array. Since the diameter of each sub-array is small, the channel model between the sub-array and the user is modeled as a far-field plane wave model, where the channel is determined by the distance and direction angle between the sub-array and the user. In one example, the far-field codewords of each sub-array can be determined based on the preset far-field channel model. Further, since the diameter of the entire very large-scale antenna array is large, the channel model between the entire very large-scale antenna array and the user is modeled as a near-field spherical wave model, that is, the channel between sub-arrays is a near-field channel, and the distance and direction angle between each sub-array and the user are different. In one example, based on the preset near-field channel model and the far-field codewords of each sub-array, the near-field codeword of the first antenna array can be determined.

[0062] In step 240, based on the near-field codeword of the first antenna array, perform beamforming processing on the near-field broadband beam generated by the base station.

[0063] In one embodiment, based on the near-field codeword of the first antenna array, the near-field broadband beam generated by the base station can be beamformed through the phase shifter array in the base station, so that the beamformed near-field broadband beam can be focused on the user location, thereby overcoming the influence of the near-field broadband effect on the rate of the very large-scale antenna array system and effectively improving the communication rate of the very large-scale antenna array.

[0064] The present invention provides a near-field broadband beamforming method, which decouples the complex near-field beamforming codeword into the far-field codewords within each sub-array and the near-field codewords between sub-arrays of the first antenna array through the partitioned far-field beamforming codeword. And through the near-field codeword of the first antenna array, perform beamforming processing on the near-field broadband beam generated by the base station, so that the near-field broadband beam generated by the base station is focused on the user location, overcoming the influence of the near-field broadband effect on the rate of the very large-scale antenna array system and effectively improving the communication rate of the very large-scale antenna array.

[0065] It is understandable that assuming the number of base station antennas is N, the spacing between antennas is d, and the position of the user is (r, θ), where r represents the distance between the user and the base station array, and θ represents the angle between the user and the normal direction of the base station array. The distance r between the nth antenna of the base station and the user (n) can be expressed by formula (1), and the included angle sinθ (n) can be expressed by formula (2). Among them, formula (1) and formula (2) are as follows:

[0066]

[0067] where n = [0, 1, 2, … N - 1] (2)

[0068] Furthermore, it is necessary to design the codeword for beamforming so that the beam generated by the base station is focused on the user position (r, θ). The classical near - field codeword directly uses the near - field steering vector for beamforming. Specifically, for the frequency point f, assuming the speed of light is c, let the wave number Then the near - field codeword focused on the position (r, θ) can be expressed by the following formula:

[0069]

[0070] where j represents the imaginary unit. Since the phase of each element of the near - field codeword is highly correlated with r(n), and r (n) couples the distance r and the angle θ complexly through the radical, the model is relatively complex. Especially in the broadband scenario, when the frequency points f are different, it is very difficult to generate ideal near - field codewords at each frequency point.

[0071] The traditional far - field codeword directly uses the linear approximation of r(n) to replace r(n), thereby simplifying the near - field codeword. Specifically, according to the Taylor expansion formula, there is r (n) ≈ r - ndsinθ. At this time, the far - field codeword can be expressed by the following formula:

[0072]

[0073] Compared with the complex near - field codeword a near (f), the complexity of the far - field codeword a far (f) is greatly reduced, but the model accuracy is also very low. For the near - field communication scenario of a very large - scale antenna array, the far - field codeword a fa r(f) is not applicable.

[0074] For the near - field broadband beamforming method proposed by the present invention, the near - field codeword of the first antenna array (which can also be called the partitioned far - field beamforming codeword) can be a nearHigh-precision and low-complexity approximation of (f), which essentially uses the piecewise linear approximation of distance r (n) to replace r (n) .

[0075] Divide the entire N-element very large-scale antenna array into Q sub-arrays, and each sub-array contains antennas. Among them, q can be used to represent the sub-array number, and p can be used to represent the antenna number within the sub-array, where q = [0, 1, 2,... Q - 1], p = [0, 1, 2,... P - 1]. Then the p-th antenna on the q-th sub-array corresponds to the n = qP + p-th antenna of the entire array. Use r q to represent the distance between the center of the q-th sub-array and the user, and use θ q to represent the angle between the normal direction of the center of the q-th sub-array and the user. Among them, the distance r q and the angle θ q respectively satisfy the following formulas.

[0076]

[0077]

[0078] Furthermore, use to represent the distance between the p-th antenna on the q-th sub-array and the user. Inside the q-th sub-array, using the first-order Taylor expansion, we can get

[0079]

[0080] Through the above approximation, r q - pdsinθ q can be used to replace that is, replace r (n) , where n = qP + p. Therefore, the near-field codeword of the first antenna array can be expressed by the following formula:

[0081]

[0082] where a q represents the codeword on the q-th sub-array and satisfies

[0083]

[0084] Through the above operations, complex near-field codewords are decoupled into multiple far-field codewords. Each far-field codeword corresponds to a plane wave pointing in a different direction and is generated by a single sub-array. By changing the number of sub-arrays Q, the near-field codewords (also known as partitioned far-field codewords) of the first antenna array in the present invention can be mutually converted between far-field codewords and near-field codewords. For example, when Q = 1, the near-field codewords of the first antenna array are equivalent to ideal near-field codewords; when Q = N, the near-field codewords of the first antenna array are equivalent to ideal far-field codewords; when 1 < Q < N, the near-field codewords of the first antenna array are a compromise between far-field codewords and near-field codewords, that is, the characteristics of high precision and low complexity are guaranteed simultaneously.

[0085] Furthermore, whether it is the near-field codewords of the first antenna array, or the existing far-field codewords and near-field codewords, the ideal codewords change with the frequency f or the wave number Specifically, considering a broadband OFDM system with a system bandwidth of B, a number of sub-carriers of M, and a central carrier frequency of f c , and a central wave number of For a classical phased array structure, beamforming is realized by a phase shifter array. Since the phase shifter array can only generate frequency-independent beamforming codewords, the codeword w c is usually directly generated according to the central carrier frequency f c , that is

[0086]

[0087] When the frequency point f is significantly different from the central carrier frequency f c , the codeword w c generated by the phased array will have a large difference from the ideal near-field codeword a near , that is, the actual narrowband beamforming does not match the ideal near-field broadband codeword, which is the near-field broadband effect. At this time, the beam gain at the frequency point f is much less than 1, resulting in a large array gain loss.

[0088] To overcome the system performance loss caused by the near-field broadband effect, in the embodiments of the present invention, the characteristics of the far-field codewords within each sub-array can be matched by using phase shifters respectively, and the near-field codewords between the sub-arrays of the first antenna array can be matched by using delay elements, so as to overcome the influence of the near-field broadband effect on the rate of the very large scale antenna array system.

[0089] Next, the near-field broadband beamforming process with time-phase regulation of the present invention will be described in conjunction with the following embodiments.

[0090] Figure 6 is a schematic diagram of the application scenario of the near-field broadband beamforming with time-phase regulation provided by the present invention.

[0091] In an exemplary embodiment of the present invention, a first delay element may be provided in a sub-array, and a first phase shifter may be provided for each antenna in the sub-array. As Figure 6 shown, each antenna in the sub-array connected to the first phase shifter may form a large-scale phase shift layer 630. Among them, the first phase shifter may be composed of a microstrip line, a switch, an inverter, etc. Further, a first delay element may be inserted between each sub-array and the radio frequency link 610 to form a small-scale delay layer 620. Among them, the first delay element may be implemented by a true delay line, digital baseband processing, etc. Therefore, the beamforming codeword for two-dimensional time-phase control may be jointly implemented by the delay layer 620 and the phase shift layer 630.

[0092] The present invention will be described in conjunction with the following embodiments for the process of determining the far-field codewords of each sub-array based on a preset far-field channel model.

[0093] Figure 7 is one of the schematic flowcharts of determining the far-field codewords of each sub-array based on a preset far-field channel model provided by the present invention.

[0094] In an exemplary embodiment of the present invention, as Figure 7 shown, determining the far-field codewords of each sub-array based on a preset far-field channel model may include step 710 and step 720, and each step will be introduced separately below.

[0095] In step 710, determine the first delay parameter of the first delay element and determine the first phase shift parameter of the first phase shifter.

[0096] In step 720, based on the preset far-field channel model, the first delay parameter, and the first phase shift parameter, determine the far-field codeword of the sub-array.

[0097] In one embodiment, the far-field codeword of the sub-array may be determined by matching the far-field codeword characteristics within each sub-array based on the first delay parameter of the first delay element and the first phase shift parameter of the first phase shifter. Further, based on the far-field codeword of the sub-array, determine the near-field codeword of the first antenna array, and perform beamforming processing on the near-field broadband beam generated by the base station based on the near-field codeword of the first antenna array. Through this embodiment, the influence of the near-field broadband effect on the rate of the ultra-large-scale antenna array system can be overcome.

[0098] In one embodiment, the preset far-field codeword may be expressed by the following formula:

[0099]

[0100] where, w q (f) represents the far-field codeword of the q-th sub-array, τ′ q represents the first delay parameter of the q-th sub-array, Represents the first phase shift parameter on the p-th antenna of the q-th subarray, where p = [0, 1, 2, … P-1], f represents the signal frequency transmitted by the antennas in the subarray, and j represents the imaginary unit.

[0101] The present invention will introduce the determination of the first delay parameter τ′ in combination with the following embodiments q and the first phase shift parameter process.

[0102] Figure 8 is one of the schematic flowcharts for determining the first delay parameter provided by the present invention.

[0103] In an exemplary embodiment of the present invention, as Figure 8 shown, determining the first delay parameter may include step 810 and step 820, and each step will be introduced separately below.

[0104] In step 810, determine the first distance between the subarray center of the subarray and the user, and the first angle between the subarray center of the subarray and the normal direction of the user.

[0105] In step 820, based on the first distance and the first angle, determine the first delay parameter.

[0106] In one embodiment, based on the first distance and the first angle, determining the first delay parameter can be achieved through the following formula:

[0107]

[0108] where τ′ q represents the first delay parameter, r q represents the first distance, θ q represents the first angle, c represents the speed of light, P represents the number of antennas in the subarray, and d represents the antenna spacing between adjacent antennas in the subarray.

[0109] Considering the physical constraints of the actual delay line, only non - negative delays can be achieved. To avoid designing a negative τ′ q a same common delay can be uniformly introduced for all delay lines. At this time, it will neither affect the beamforming gain nor violate the non - negative constraint of the delay line.

[0110] In an exemplary embodiment of the present invention, the near - field broadband beamforming method further includes performing non - negative constraint processing on the first delay parameter to obtain the processed first delay parameter. Further, the processed first delay parameter can be used as the final first delay parameter.

[0111] In one embodiment, the non - negative constraint processing of the first delay parameter can be achieved through the following formula:

[0112] τ″ q= τ′ q + T(13)

[0113] Wherein, τ″ q represents the first delay parameter after processing, τ′ q represents the first delay parameter, T represents the common delay, and T = -min τ′ q .

[0114] In one embodiment, T is the common delay. To ensure the non-negativity of τ″ q , the common delay can be designed as T = -min τ′ q . At this time, for the first delay parameter of any delay element, obviously τ″ q > 0.

[0115] Figure 9 is one of the schematic flowcharts for determining the first phase shift parameter provided by the present invention.

[0116] In an exemplary embodiment of the present invention, as Figure 9 shown, determining the first phase shift parameter may include step 910 and step 920, and each step will be introduced separately below.

[0117] In step 910, determine the first angle between the center of the subarray and the normal direction of the user.

[0118] In step 920, based on the first angle, determine the first phase shift parameter.

[0119] In one embodiment, based on the first angle, the first phase shift parameter can be determined by the following formula:

[0120]

[0121] Wherein, represents the first phase shift parameter, θ q represents the first angle, P represents the number of antennas in the subarray, f c represents the frequency of the center carrier of the subarray, c represents the speed of light, p represents the antenna number of the p-th antenna in the subarray, and d represents the antenna spacing between adjacent antennas in the subarray.

[0122] It should be noted that the first delay parameter τ′ q and the first phase shift parameter can be derived in the following manner.

[0123] The purpose of broadband beamforming is to ensure that the beamforming codeword w(f) generated by each subcarrier generates the ideal near-field codeword a near (f). Since the near-field codeword a near(f) has a relatively complex structure, and a high-precision approximate codeword that approximates the near-field codeword can be selected, that is, the near-field codeword of the first antenna array (also known as: partitioned far-field codeword) a(f). Specifically, according to the structure of a q (f), it is equivalent to generating a plane wave pointing in the direction of θ q . Therefore, when designing the parameters of the subarray phase shifters, we set

[0124]

[0125] where φ′ q is a parameter that can be designed. When designing the first phase shift parameter φ′ q and the first delay parameter τ′ q , it is desired to maximize the array gain at all frequencies, that is, to maximize

[0126]

[0127] where represents the m-th subcarrier. First, calculate the array gain of a single subcarrier

[0128]

[0129] Since the number of antennas P in the subarray is much smaller than the number of antennas N in the array, therefore is usually greater than 0. To maximize the array gain g at all frequencies, we need to design the first delay parameter τ′ q and the first phase shift parameter φ′ q such that each term in the summation of g(f) is in-phase superposed. Obviously, a feasible solution is Consider the phase shift on the p-th antenna of the q-th subarray as Therefore, the designed first delay parameter τ′ q and the first phase shift parameter can be as follows respectively:

[0130]

[0131]

[0132] By determining the first delay parameter τ′ q and the first phase shift parameter through the above embodiments, the beamforming codeword obtained based on time-phase two-dimensional regulation, that is, the near-field codeword of the first antenna array, can highly approximate the ideal near-field codeword while ensuring its simple structure, thereby overcoming the influence of the near-field broadband effect on the rate of the very large-scale antenna array system.

[0133] The present invention will be described in combination with the following embodiments for the process of determining the near-field codeword of the first antenna array based on a preset near-field channel model and the far-field codewords of each sub-array.

[0134] Figure 10 It is one of the schematic flowcharts for determining the near-field codeword of the first antenna array provided by the present invention.

[0135] In an exemplary embodiment of the present invention, as Figure 10 shown, determining the near-field codeword of the first antenna array based on a preset near-field channel model and the far-field codewords of each sub-array may include step 1010 and step 1020. Each step will be introduced separately below.

[0136] In step 1010, determine the number of first antennas of the first antenna array.

[0137] In step 1020, based on the preset near-field channel model, the number of first antennas, and the far-field codewords of each sub-array, determine the near-field codeword of the first antenna array.

[0138] In one embodiment, determining the near-field codeword of the first antenna array based on the preset near-field channel model, the number of first antennas, and the far-field codewords of each sub-array can be achieved through the following formula:

[0139]

[0140] where w(f) represents the near-field codeword of the first antenna array, N represents the number of first antennas, and w0…w Q -1 represents the far-field codewords of each sub-array.

[0141] Through this embodiment, the complex near-field beamforming codeword can be decoupled into the far-field codewords within each sub-array and the inter-sub-array near-field codeword of the first antenna array. And through the near-field codeword of the first antenna array, the near-field broadband beam generated by the base station is beamformed, so that the near-field broadband beam generated by the base station is focused on the user location, overcoming the influence of the near-field broadband effect on the rate of the very large-scale antenna array system.

[0142] Figure 11 It is a schematic diagram of the comparison of the system achievable sum rate performance of the near-field broadband beamforming method provided by the present invention.

[0143] Combined with Figure 11 it can be seen that based on the near-field broadband beamforming method provided by the present invention, that is, the beamforming combined with the phase-time (the first delay parameter of the first delay unit and the first phase shift parameter of the first phase shifter) regulation can achieve near-field broadband beamforming and overcome the influence of the near-field broadband effect on the system performance, thereby improving the achievable rate performance of the very large-scale array.

[0144] According to the above description, the near-field broadband beamforming method provided by the present invention divides the first antenna array of the base station into multiple sub-arrays, determines the far-field codewords of each sub-array based on a preset far-field channel model, and determines the near-field codewords of the first antenna array based on the preset near-field channel model and the far-field codewords of each sub-array, so that the complex near-field beamforming codewords can be decoupled into the far-field codewords within each sub-array and the inter-sub-array near-field codewords of the first antenna array. And through the near-field codewords of the first antenna array, the near-field broadband beam generated by the base station is beamformed, so that the near-field broadband beam generated by the base station is focused on the user location, overcoming the influence of the near-field broadband effect on the rate of the very large-scale antenna array system, and effectively improving the communication rate of the very large-scale antenna array.

[0145] Based on the same concept, the present invention also provides a near-field broadband beamforming device.

[0146] The near-field broadband beamforming device provided by the present invention will be described below. The near-field broadband beamforming device described below can be correspondingly referred to the near-field broadband beamforming device method described above.

[0147] Figure 12 is a schematic structural diagram of the near-field broadband beamforming device provided by the present invention.

[0148] In an exemplary embodiment of the present invention, the near-field broadband beamforming device can be applied to a base station with a first antenna array, where the first antenna array is a very large-scale antenna array. In one example, an antenna array with the number of antennas exceeding a threshold can be called a very large-scale antenna array, where the threshold can be determined according to actual situations. For example, the threshold can be 1000 antennas. In this embodiment, the threshold is not specifically limited.

[0149] As Figure 12 shown, the near-field broadband beamforming device can include a division module 1210, a processing module 1220, and a determination module 1230. Each module will be introduced separately below.

[0150] The division module 1210 can be configured to divide the first antenna array of the base station into multiple sub-arrays, and each sub-array includes multiple antennas.

[0151] The processing module 1220 can be configured to determine the far-field codewords of each sub-array based on a preset far-field channel model, and to determine the near-field codewords of the first antenna array based on the preset near-field channel model and the far-field codewords of each sub-array.

[0152] The determination module 1230 can be configured to perform beamforming processing on the near-field broadband beam generated by the base station based on the near-field codewords of the first antenna array.

[0153] In an exemplary embodiment of the present invention, a first delay element is provided in the subarray, and a first phase shifter is provided in the antenna of the subarray. The processing module 1220 may determine the far-field codewords of each subarray based on a preset far-field channel model in the following manner: determining a first delay parameter of the first delay element and determining a first phase shift parameter of the first phase shifter; and determining the far-field codeword of the subarray based on the preset far-field channel model, the first delay parameter, and the first phase shift parameter.

[0154] In an exemplary embodiment of the present invention, the preset far-field channel model may be expressed by the following formula:

[0155]

[0156] Where, W q (f) represents the far-field codeword of the q-th subarray, τ′ q represents the first delay parameter of the q-th subarray, represents the first phase shift parameter on the p-th antenna of the q-th subarray, where p = [0, 1, 2,..., P−1], f represents the signal frequency transmitted by the antenna in the subarray, and j represents the imaginary unit.

[0157] In an exemplary embodiment of the present invention, the processing module 1220 may determine the first delay parameter in the following manner: determining a first distance between the center of the subarray and the user, and a first angle between the normal direction of the center of the subarray and the user; and determining the first delay parameter based on the first distance and the first angle.

[0158] In an exemplary embodiment of the present invention, determining the first delay parameter based on the first distance and the first angle may be implemented by the following formula:

[0159]

[0160] Where, τ′ q represents the first delay parameter, r q represents the first distance, θ q represents the first angle, c represents the speed of light, P represents the number of antennas in the subarray, and d represents the antenna spacing between adjacent antennas in the subarray.

[0161] In an exemplary embodiment of the present invention, the near-field broadband beamforming device further includes a reprocessing module. The reprocessing module may be configured to perform non-negative constraint processing on the first delay parameter to obtain a processed first delay parameter; and use the processed first delay parameter as the final first delay parameter.

[0162] In an exemplary embodiment of the present invention, the non-negative constraint processing on the first delay parameter may be implemented by the following formula:

[0163] τ″ q= τ' q + T(23)

[0164] where τ″ q represents the first delay parameter after processing, τ' q represents the first delay parameter, T represents the common delay, and T = -min τ' q .

[0165] In an exemplary embodiment of the present invention, the processing module 1220 may determine the first phase shift parameter in the following manner: determining a first angle between the center of the sub-array and the normal direction of the user; based on the first angle, determining the first phase shift parameter.

[0166] In an exemplary embodiment of the present invention, the processing module 1220 may determine the first phase shift parameter based on the first angle through the following formula:

[0167]

[0168] where represents the first phase shift parameter, θ q represents the first angle, P represents the number of antennas in the sub-array, f c represents the frequency of the center carrier of the sub-array, c represents the speed of light, p represents the antenna number of the p-th antenna in the sub-array, and d represents the antenna spacing between adjacent antennas in the sub-array.

[0169] In an exemplary embodiment of the present invention, the processing module 1220 may determine the near-field codeword of the first antenna array based on the preset near-field channel model and the far-field codewords of each sub-array in the following manner: determining the number of the first antennas of the first antenna array; based on the preset near-field channel model, the number of the first antennas, and the far-field codewords of each sub-array, determining the near-field codeword of the first antenna array.

[0170] In an exemplary embodiment of the present invention, the processing module 1220 may determine the near-field codeword of the first antenna array based on the preset near-field channel model, the number of the first antennas, and the far-field codewords of each sub-array through the following formula:

[0171]

[0172] where w(f) represents the near-field codeword of the first antenna array, N represents the number of the first antennas, and w0…W Q-1 represents the far-field codewords of each sub-array.

[0173] Figure 13 Illustrates a schematic diagram of the physical structure of an electronic device, as Figure 13As shown in the figure, the electronic device may include: a processor 1310, a communications interface 1320, a memory 1330, and a communication bus 1340. Among them, the processor 1310, the communications interface 1320, and the memory 1330 complete communication with each other through the communication bus 1340. The processor 1310 may call the logical instructions in the memory 1330 to execute the near-field broadband beamforming method. Among them, the near-field broadband beamforming method is applied to a base station with a first antenna array, and the first antenna array is a very large-scale antenna array. The method includes: dividing the first antenna array of the base station into a plurality of sub-arrays, and each sub-array includes a plurality of antennas; determining the far-field codewords of each sub-array based on a preset far-field channel model; determining the near-field codewords of the first antenna array based on a preset near-field channel model and the far-field codewords of each sub-array; and performing beamforming processing on the near-field broadband beam generated by the base station based on the near-field codewords of the first antenna array.

[0174] In addition, when the logical instructions in the above-mentioned memory 1330 are implemented in the form of software functional units and sold or used as an independent product, they may be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc that can store program codes.

[0175] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the near-field broadband beamforming method provided by each of the above methods. Among them, the near-field broadband beamforming method is applied to a base station with a first antenna array, and the first antenna array is a very large-scale antenna array. The method includes: dividing the first antenna array of the base station into multiple sub-arrays, and each sub-array includes multiple antennas; determining the far-field codewords of each sub-array based on a preset far-field channel model; determining the near-field codewords of the first antenna array based on the preset near-field channel model and the far-field codewords of each sub-array; and performing beamforming processing on the near-field broadband beam generated by the base station based on the near-field codewords of the first antenna array.

[0176] In another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it is implemented to execute the near-field broadband beamforming method provided by each of the above methods. Among them, the near-field broadband beamforming method is applied to a base station with a first antenna array, and the first antenna array is a very large-scale antenna array. The method includes: dividing the first antenna array of the base station into multiple sub-arrays, and each sub-array includes multiple antennas; determining the far-field codewords of each sub-array based on a preset far-field channel model; determining the near-field codewords of the first antenna array based on the preset near-field channel model and the far-field codewords of each sub-array; and performing beamforming processing on the near-field broadband beam generated by the base station based on the near-field codewords of the first antenna array.

[0177] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0178] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0179] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A near-field broadband beamforming method, characterized in that, The method is applied to a base station with a first antenna array, and the first antenna array is a very large-scale antenna array. The method includes: Dividing the first antenna array of the base station into a plurality of sub-arrays, where each sub-array includes a plurality of antennas; Determining the far-field codewords of each sub-array based on a preset far-field channel model; Determining the near-field codewords of the first antenna array based on a preset near-field channel model and the far-field codewords of each sub-array; Performing shaping processing on the near-field broadband beam generated by the base station based on the near-field codewords of the first antenna array. Wherein, a first delay device is provided in the sub-array, and a first phase shifter is provided on the antennas of the sub-array. Determining the far-field codewords of each sub-array based on the preset far-field channel model includes: Determining the first delay parameter of the first delay device and determining the first phase shift parameter of the first phase shifter; Determining the far-field codewords of the sub-array based on the preset far-field channel model, the first delay parameter, and the first phase shift parameter; The preset far-field channel model is expressed by the following formula: where, w q (f) represents the far-field codeword of the q-th subarray, and τ′ q represents the first delay parameter of the q-th subarray, represents the first phase shift parameter on the p-th antenna of the q-th subarray, where p = [0, 1, 2, … P-1], f represents the signal frequency transmitted by the antennas in the subarray, and j represents the imaginary unit; where, Determining the near-field codewords of the first antenna array based on the preset near-field channel model and the far-field codewords of each sub-array includes: Determining the number of the first antennas of the first antenna array; Determining the near-field codewords of the first antenna array based on the preset near-field channel model, the number of the first antennas, and the far-field codewords of each sub-array, where Determining the near-field codewords of the first antenna array based on the preset near-field channel model, the number of the first antennas, and the far-field codewords of each sub-array is achieved through the following formula: Among them, w(f) represents the near-field codeword of the first antenna array, N represents the number of the first antennas, and w0…w Q-1 represents the far-field codewords of the respective sub-arrays.

2. The near-field wideband beamforming method according to claim 1, wherein The first delay parameter is determined in the following manner: Determining the first distance between the center of the sub-array and the user, and the first angle between the normal direction of the center of the sub-array and the user; Determining the first delay parameter based on the first distance and the first angle.

3. The near-field wideband beamforming method according to claim 2, wherein Determining the first delay parameter based on the first distance and the first angle is achieved through the following formula: Among them, τ′ q represents the first delay parameter, r q represents the first distance, θ q represents the first included angle, c represents the speed of light, P represents the number of antennas in the sub-array, and d represents the antenna spacing between adjacent antennas in the sub-array.

4. The near-field wideband beamforming method according to claim 3, wherein The method further includes: Performing non-negative constraint processing on the first delay parameter to obtain the processed first delay parameter; Taking the processed first delay parameter as the final first delay parameter.

5. The near-field wideband beamforming method according to claim 4, wherein Performing non-negative constraint processing on the first delay parameter is achieved through the following formula: τ″ q = τ′ q + T Among them, τ″ q represents the first delay parameter after the processing, τ′ q represents the first delay parameter, T represents the common delay, and T = -minτ′ q .

6. The near-field broadband beamforming method according to claim 1, characterized in that The first phase shift parameter is determined in the following manner: Determining the first angle between the normal direction of the center of the sub-array and the user; Determining the first phase shift parameter based on the first angle.

7. The near-field broadband beamforming method according to claim 6, characterized in that, Determining the first phase shift parameter based on the first angle is determined through the following formula: Among them, represents the first phase shift parameter, θ q represents the first included angle, P represents the number of antennas in the subarray, f c represents the frequency of the center carrier of the subarray, c represents the speed of light, p represents the antenna number of the p-th antenna in the subarray, and d represents the antenna spacing between adjacent antennas in the subarray.

8. A near-field broadband beamforming device, characterized in that, The device is used to implement the near-field broadband beam shaping method described in any one of claims 1 to 7. The device is applied to a base station with a first antenna array, and the first antenna array is a very large-scale antenna array. The device includes: A dividing module, configured to divide the first antenna array of the base station into a plurality of sub-arrays, where each sub-array includes a plurality of antennas; A processing module, configured to determine far-field codewords of each of the sub-arrays based on a preset far-field channel model, and configured to determine near-field codewords of the first antenna array based on a preset near-field channel model and the far-field codewords of each of the sub-arrays; A determination module, configured to perform shaping processing on the near-field broadband beam generated by the base station based on the near-field codewords of the first antenna array.

9. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, the steps of the near-field broadband beamforming method according to any one of claims 1 to 7 are implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, the steps of the near-field broadband beamforming method according to any one of claims 1 to 7 are implemented.

11. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, the steps of the near-field broadband beamforming method according to any one of claims 1 to 7 are implemented.

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