A hybrid beamforming method and apparatus for ITS assisted satellite communication

Abstract

The application discloses a kind of hybrid beamforming method and device for ITS assisted satellite communication, belong to high frequency wireless broadband beamforming technical field, the method includes: according to the angle information in the system configuration information and channel state information of ITS assisted satellite communication system, obtain the ITS phase shift matrix based on center subcarrier;Utilize the virtual ITS phase shift matrix and the illumination matrix corresponding to the mth subcarrier to construct the virtual equivalent channel matrix of the mth subcarrier, and then solve its virtual digital precoding matrix;Utilize the ITS phase shift matrix corresponding to center subcarrier, the virtual ITS phase shift matrix and the virtual digital precoding matrix of the illumination matrix corresponding to the mth subcarrier determine the target digital precoding of the mth subcarrier, and then obtain the hybrid beamforming matrix of each subcarrier, to carry out hybrid beamforming.Therein, using virtual digital precoding inverse, effectively suppresses the serious beam squint problem of phased array in high frequency broadband large-scale MIMO communication.

Description

Technical Field

[0001] This invention belongs to the field of high-frequency wireless broadband beamforming technology, and more specifically, relates to a hybrid beamforming method and apparatus for ITS-assisted satellite communication. Background Technology

[0002] Satellite communications can provide vital supplementary services in areas lacking terrestrial infrastructure coverage and play an indispensable role in 6G. Terahertz communication is one of the key technologies for improving the throughput of 6G and future communications. Furthermore, the W-band (up to 110 GHz) has already been used for satellite communications. Therefore, the integration of terahertz and satellite communications will be inevitable.

[0003] To overcome the severe path loss in the terahertz band, massively multi-input multiple-output (MIMO) technology has been proposed. This technology can provide sufficient antenna gain through beamforming to compensate for the transmission loss in terahertz frequencies. However, satellite payloads are limited and cannot be afforded due to the cost and power consumption of extensive RF chains, phase shifters, transmit antennas, etc., necessitating efficient and innovative solutions. In recent years, ITS has emerged as a promising wireless technology. It consists of numerous passive components and is capable of adjusting the phase of the incident signal with low power consumption and low hardware cost.

[0004] ITS (Integrated Transmission System) holds promise as a potential technology for massive MIMO systems, inspiring related research. However, the synergistic integration of ITS and terahertz communication remains an open question. Currently, there is no research on ITS-based terahertz broadband massive MIMO satellite communication, and due to the limited hardware cost and power consumption in satellite communication, existing research has not considered the beam-squinting problem in ITS-assisted terahertz broadband systems. Summary of the Invention

[0005] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a hybrid beamforming method and apparatus for ITS-assisted satellite communication. Its purpose is to effectively suppress the severe beam squint problem in high-frequency broadband massive MIMO communication of phased arrays by inverting virtual digital precoding, thereby achieving near-optimal performance of the system and rate through fully digital precoding.

[0006] To achieve the above objectives, according to one aspect of the present invention, a hybrid beamforming method for ITS-assisted satellite communication is provided, comprising:

[0007] S1: Obtain the array response vector of the center subcarrier based on the angle information in the system configuration information and channel state information of the ITS-assisted satellite communication system. And based on the array response vector of the center subcarrier Obtain the intelligent transmitter plane ITS phase shift matrix Θ T In the transmitting end of the ITS-assisted satellite communication system, each active antenna is connected to a separate radio frequency chain. The data transmitted by the active antenna is mapped onto the surface of the ITS through the illumination matrix, and then refracted out by the ITS to obtain considerable array gain.

[0008] S2: Construct the illumination matrix T corresponding to the m-th subcarrier using the subcarrier frequency information. m and virtual ITS phase shift matrix M is the total number of subcarriers;

[0009] S3: Using the illumination matrix T corresponding to the m-th subcarrier m and virtual ITS phase shift matrix Construct the virtual equivalent channel matrix for the m-th subcarrier. use Solve for the virtual ITS phase shift matrix of the m-th subcarrier. Corresponding virtual digital precoding matrix

[0010] S4: Utilizing the ITS phase shift matrix Θ corresponding to the central subcarrier T The illumination matrix T of the m-th subcarrier m The virtual ITS phase shift matrix of the m-th subcarrier The virtual digital precoding matrix of the m-th subcarrier Determine the target digital precoding F for the m-th subcarrier BB,m This allows for the acquisition of the hybrid beamforming matrix for each subcarrier, enabling hybrid beamforming.

[0011] In one embodiment, S1 includes: obtaining an array response vector based on the center subcarrier according to the angle information in the system configuration information and channel state information. Diagonalizing it yields the ITS phase shift matrix Θ T ;

[0012] The angle information in the channel state information includes: azimuth and elevation angles (φ, θ) representing the base station ITS, and azimuth and elevation angles representing the user terminal. The horizontal steering vector representing the ITS array response corresponding to the center subcarrier. M represents the vertical steering vector of the ITS array response corresponding to the center subcarrier; T This indicates the number of passive elements in the ITS, with a total of [number] rows. The total number of columns is

[0013] In one embodiment, S2 includes:

[0014] T1. Based on the subcarrier frequency information and the system configuration information, solve for the frequency f of the m-th subcarrier. m Wavelength λ m .

[0015] T2, using the frequency f of the m-th subcarrier m and wavelength λ m Calculate the illumination matrix T of the m-th subcarrier. m This is used to address the impact of different wavelengths of different subcarriers in broadband systems;

[0016] T3. Use formula Solve for the virtual ITS phase shift matrix of the m-th subcarrier. Used to characterize the target with the largest gain among different subcarrier arrays in a broadband system;

[0017] in, φ represents the array response vector corresponding to the m-th subcarrier, φ and θ are the azimuth and elevation angles of the ITS respectively, and diag(·) represents the diagonal array operation.

[0018] In one embodiment, S3 includes:

[0019] R1, Channel matrix H based on the m-th subcarrier m Using the virtual ITS phase shift matrix corresponding to the m-th subcarrier and illumination matrix T m Construct the virtual equivalent channel matrix for the m-th subcarrier.

[0020] R2, the virtual equivalent channel matrix for the m-th subcarrier. Perform singular value decomposition to obtain the virtual ITS phase shift matrix of the m-th subcarrier. Corresponding virtual digital precoding matrix

[0021] In one embodiment, R1 includes:

[0022] Using formula Construct the virtual equivalent channel matrix for the m-th subcarrier.

[0023] In one embodiment, R1:

[0024] The channel matrix H m Represented as

[0025] Where α is the complex gain of the satellite system channel, τ is the time delay, and f mLet m be the frequency of the m-th subcarrier. a is the frequency-dependent array response vector at the receiver. ITS (φ,θ) represents the frequency-dependent array response vector at the base station ITS transmitter; (φ,θ) represents the azimuth and elevation angles at the ITS. For the azimuth and elevation angles of the user terminal, the superscript H represents the conjugate transpose operation.

[0026] In one embodiment, S4 includes:

[0027] Using formula Determine the target digital precoding for the m-th subcarrier. Represents the pseudo-inverse of a matrix;

[0028] Using formula Θ T T m F BB,m The hybrid beamforming matrix of the m-th subcarrier is calculated, and hybrid beamforming is performed using the hybrid beamforming matrix.

[0029] According to another aspect of the present invention, a hybrid beamforming apparatus for ITS-assisted satellite communication is provided, comprising:

[0030] The ITS phase shift matrix acquisition module is used to obtain the array response vector of the center subcarrier based on the angle information in the system configuration information and channel state information of the ITS-assisted satellite communication system. And based on the array response vector of the center subcarrier Obtain the intelligent transmitter plane ITS phase shift matrix Θ T In the transmitting end of the ITS-assisted satellite communication system, each active antenna is connected to a separate radio frequency chain. The data transmitted by the active antenna is mapped onto the surface of the ITS through the illumination matrix, and then refracted out by the ITS to obtain considerable array gain.

[0031] The illumination matrix and virtual ITS phase shift matrix acquisition module is used to construct the illumination matrix T corresponding to the m-th subcarrier using subcarrier frequency information. m and virtual ITS phase shift matrix M is the total number of subcarriers;

[0032] The virtual digital precoding matrix acquisition module is used to obtain the illumination matrix T corresponding to the m-th subcarrier. m and virtual ITS phase shift matrix Construct the virtual equivalent channel matrix for the m-th subcarrier. use Solve for the virtual ITS phase shift matrix of the m-th subcarrier. Corresponding virtual digital precoding matrix

[0033] The digital precoding acquisition module is used to utilize the ITS phase shift matrix Θ corresponding to the center subcarrier. T The illumination matrix T of the m-th subcarrier m The virtual ITS phase shift matrix of the m-th subcarrier The virtual digital precoding matrix of the m-th subcarrier Determine the target digital precoding F for the m-th subcarrier BB,m This allows for the acquisition of the hybrid beamforming matrix for each subcarrier, enabling hybrid beamforming.

[0034] According to another aspect of the present invention, an ITS-assisted satellite communication system is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described method.

[0035] According to another aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, performs the above-described steps.

[0036] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0037] (1) This invention obtains the ITS phase shift matrix based on the center subcarrier from the system configuration information and channel state information of the ITS-assisted satellite communication system; constructs the virtual equivalent channel matrix of the m-th subcarrier using the illumination matrix corresponding to the m-th subcarrier and the virtual ITS phase shift matrix, and then solves the virtual digital precoding matrix of the m-th subcarrier; determines the target digital precoding of the m-th subcarrier using the ITS phase shift matrix corresponding to the center subcarrier, the illumination matrix corresponding to the m-th subcarrier, the virtual ITS phase shift matrix, and the virtual digital precoding matrix, and then obtains the hybrid beamforming matrix of each subcarrier, thereby performing hybrid beamforming. The use of virtual digital precoding inversion effectively suppresses the severe beam squint problem in high-frequency broadband massive MIMO communication, achieving near-optimal performance for both system and rate of all-digital precoding. Furthermore, by utilizing ITS composed of passive components, low-cost, low-power analog domain beamforming is achieved, obtaining the same array gain as traditional architectures, thus providing a possibility for the realization of massive MIMO satellite communication. The 3D hybrid beamforming method proposed in this application makes good use of the low power consumption characteristics of the ITS passive architecture to achieve optimal system energy efficiency, which is significantly better than other architectures and methods.

[0038] (2) This scheme obtains the array response vector based on the center subcarrier based on the angle information in the system configuration information and channel state information. Diagonalizing it yields the ITS phase shift matrix ΘT It can design ITS phase shift matrices based on angle information, achieving low-complexity ITS phase shift matrix design.

[0039] (3) This scheme utilizes the formula Solve for the virtual ITS phase shift matrix of the m-th subcarrier. It can use the virtual ITS phase shift matrix to suppress beam squint, and under the condition of limited ITS hardware, it can transfer the influence of beam squint on frequency-independent analog beamforming to frequency-dependent digital precoding.

[0040] (4) This scheme is based on the channel matrix H of the m-th subcarrier. m Using the virtual ITS phase shift matrix corresponding to the m-th subcarrier and illumination matrix T m Construct the virtual equivalent channel matrix for the m-th subcarrier. Virtual equivalent channel matrix for the m-th subcarrier Perform singular value decomposition to obtain the virtual ITS phase shift matrix of the m-th subcarrier. Corresponding virtual digital precoding matrix It can solve for the optimal digital precoding corresponding to the virtual ITS phase shift matrix and obtain the baseline of the optimal hybrid beamforming matrix under ideal conditions.

[0041] (5) This scheme utilizes the formula Construct the virtual equivalent channel matrix for the m-th subcarrier. The solution for virtual optimal digital precoding can be achieved by utilizing the virtual equivalent channel matrix.

[0042] (6) This scheme utilizes the formula Determine the target digital precoding for the m-th subcarrier; use formula Θ T T m F BB,m The hybrid beamforming matrix of the m-th subcarrier is calculated. By using the hybrid beamforming matrix for hybrid beamforming, the beam squint effect on the frequency-independent ITS phase shift matrix can be transformed into frequency-dependent digital precoding, thus achieving an effective beam squint suppression effect. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of a scenario provided for an embodiment of the present invention.

[0044] Figure 2 A flowchart of the ITS-assisted hybrid beamforming method provided in an embodiment of the present invention.

[0045] Figure 3The simulation graph of average spectral efficiency is provided for the embodiments of the present invention.

[0046] Figure 4 The average energy efficiency simulation diagram is provided for the embodiments of the present invention.

[0047] Figure 5 This is a schematic diagram of an ITS-assisted satellite communication system provided in an embodiment of the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0049] To reduce the cost and power consumption of massive MIMO, the Intelligent Transmission Surface (ITS) architecture has been proposed. ITS benefits from its composition of numerous passive components, resulting in extremely low power consumption, making it well-suited for integration with terahertz massive MIMO broadband communication systems and addressing the cost and power consumption limitations in satellite communication.

[0050] Based on this, embodiments of the present invention provide an ITS-assisted hybrid beamforming method for use in satellite high-frequency massive MIMO broadband communication systems. This method can solve the power consumption and beam slant problems of existing hybrid precoding architectures in massive MIMO broadband communication systems, and is particularly suitable for satellite high-frequency massive MIMO broadband communication systems.

[0051] The communication system model is a single-user terahertz massive MIMO broadband satellite communication system, such as... Figure 1 As shown, the transmitting end is equipped with N active antennas, possessing The passive element ITS, the receiver is equipped with For a single user with a uniform planar array (UPA) receiving antenna, the transmitted data stream is N. s The number of RF chains is equal to the number of active antennas, and satisfies N RF ≥N s =N r For the m-th subcarrier, the transmitted signal First, digital precoding The signal is processed and then emitted through the activated antenna, passing through the illumination matrix T. mThe signal is transmitted to the ITS receiving surface, and after passing through the ITS phase shift matrix, it is transmitted through the ITS transmitting surface. The ITS phase shift matrix satisfies the constant mode constraint, and is also subject to the total power constraint ||F. BB,m || F =N s Then the received signal of the m-th subcarrier is y. m =H m Θ T T m F BB,m x m +n m ,, Let n be the channel matrix of the m-th subcarrier. m The noise follows a Gaussian distribution with a mean of 0 and a variance of 1.

[0052] In terahertz massive MIMO broadband satellite communication systems, considering only the line-of-sight channel and the accompanying beam squint effect, the channel matrix is:

[0053]

[0054] Where (φ,θ) and These are the Angle of Departure (AOD) and Angle of Arrival (AOA) information for the ITS and the user, respectively. Let a be the array response vector at the receiving end. ITS (φ,θ) is the array response vector at the base station ITS.

[0055] Assuming the ITS is modeled on the xy plane, taking the ITS end array response vector as an example, Represents the horizontal steering vector. This represents the vertical steering vector, which is related to different subcarrier frequencies f. m Related, the expressions are as follows:

[0056]

[0057]

[0058] Since this application focuses on the hybrid precoding design at the transmitting end, the hybrid receiver matrix design at the receiving end is ignored, and perfect reception is assumed to be achievable. Therefore, the overall spectral efficiency of the system is: The system's energy efficiency is Where P totalThe total power consumption includes transmit power, baseband digital processing power consumption, RF chain power consumption, phase shifter power consumption, and other active device power consumption. The hybrid beamforming design first maximizes array gain by constructing a virtual ITS phase shift matrix and solves the corresponding virtual digital precoding. Then, it solves the digital precoding under a fixed ITS phase shift matrix by matrix inversion.

[0059] The flowchart of the ITS-assisted hybrid beamforming method proposed in this embodiment of the invention is as follows: Figure 2 As shown below, steps S1-S4 of this hybrid precoding method are described in detail. Specifically, they include:

[0060] S1: Obtain the array response vector of the center subcarrier based on the angle information in the system configuration information and channel state information of the ITS-assisted satellite communication system. And based on the array response vector of the center subcarrier Obtain the intelligent transmitter plane ITS phase shift matrix Θ T In the transmitting end of the ITS-assisted satellite communication system, each active antenna is connected to a separate radio frequency chain. The data transmitted by the active antenna is mapped onto the surface of the ITS through the illumination matrix, and then refracted out by the ITS to obtain considerable array gain.

[0061] S2: Construct the illumination matrix T corresponding to the m-th subcarrier using the subcarrier frequency information. m and virtual ITS phase shift matrix M is the total number of subcarriers;

[0062] S3: Using the illumination matrix T corresponding to the m-th subcarrier m and virtual ITS phase shift matrix Construct the virtual equivalent channel matrix for the m-th subcarrier. use Solve for the virtual ITS phase shift matrix of the m-th subcarrier. Corresponding virtual digital precoding matrix

[0063] S4: Utilizing the ITS phase shift matrix Θ corresponding to the center subcarrier T The illumination matrix T of the m-th subcarrier m The virtual ITS phase shift matrix of the m-th subcarrier The virtual digital precoding matrix of the m-th subcarrier Determine the target digital precoding F for the m-th subcarrier BB,m This allows for the acquisition of the hybrid beamforming matrix for each subcarrier, enabling hybrid beamforming.

[0064] Regarding S1, the array response vector based on the center subcarrier is obtained from the angle information in the system configuration information and channel state information of the ITS-assisted satellite communication system. The corresponding intelligent transmitter surface ITS phase shift matrix Θ T .

[0065] Specifically, the communication system is an ITS-assisted terahertz broadband massive MIMO satellite communication system. Each active antenna in the transmitting end of the communication system is connected to a separate RF chain to acquire ITS-based terahertz channel state information, including AOA, AOD, channel matrix H, and basic system configuration information, including the number of active antennas being N and the number of passive ITS elements being [missing information]. Number of receiving antennas Number of data streams N s Number of subcarriers M, bandwidth B, center frequency f c wait.

[0066] The channel matrix is ​​the line-of-sight channel matrix in a terahertz massive MIMO satellite broadband communication system, and its expression for the m-th subcarrier is: Taking the base station ITS end array response vector as an example, Represents the horizontal steering vector. This represents the vertical steering vector, which is related to different subcarrier frequencies f. m Relatedly, when using ITS for analog domain signal processing, a severe beam squint effect will occur.

[0067] The channel matrix is ​​the line-of-sight channel matrix in a terahertz satellite broadband massive MIMO communication system, with a center frequency f. c Between 0.1 and 100 THz, the system bandwidth B is in the range of tens or hundreds of GHz. The expression for the channel matrix of the m-th subcarrier is:

[0068]

[0069] Where (φ,θ) and These are the AOA and AOD information for the base station ITS and the user terminal, respectively. Each AOA and AOD includes azimuth and elevation angles, i.e., (φ, θ) represents the azimuth and elevation angles of the base station ITS. For the user's azimuth and pitch angles; a is the frequency-dependent array response vector at the receiver. ITS (φ,θ) is the frequency-dependent array response vector of the base station ITS transmitter, L is the number of channel paths, and f m Let m be the frequency of the m-th subcarrier.

[0070] The base station ITS terminal array response vector is related to different subcarrier frequencies f m The phase shift is related to the phase shift matrix generated by ITS, while the phase shift is frequency-independent.

[0071] Based on the angle information in the system configuration information and channel state information mentioned above, the ITS phase shift matrix is ​​designed based on the ITS array response vector of the center subcarrier.

[0072]

[0073] in, Thus, the ITS phase shift matrix can be obtained.

[0074] Regarding S2, the illumination matrix T corresponding to the m-th subcarrier is constructed using the subcarrier frequency information. m and virtual ITS phase shift matrix M is the total number of subcarriers.

[0075] Specifically, based on the angle information and system configuration information obtained in S1, the illumination matrix and virtual ITS phase shift matrix of the m-th subcarrier are calculated. The calculation method is as follows:

[0076] Since ITS can only generate frequency-independent phase shift matrices, the phase shift changes are equal across all frequencies. However, for broadband systems, different subcarrier frequencies are different. To maximize array gain, frequency-dependent phase shift matrices need to be generated for different subcarriers. Therefore, the corresponding digital precoding matrix is ​​solved by solving the frequency-dependent virtual ITS phase shift matrix, thereby obtaining the optimal hybrid beamforming matrix. Then, by matrix inversion, the optimal digital precoding matrix is ​​obtained under a fixed frequency-independent ITS phase shift matrix.

[0077] The frequencies f of different subcarriers are obtained through subcarrier indexing. m The illumination matrix of the m-th subcarrier can then be solved using the following formula:

[0078]

[0079] pass Solve for the phase shift matrix of the virtual ITS for the m-th subcarrier;

[0080] in, φ and θ are the azimuth and elevation angles of the ITS, respectively;

[0081] Regarding S3, using the illumination matrix T corresponding to the m-th subcarrier... m and virtual ITS phase shift matrix Construct the virtual equivalent channel matrix for the m-th subcarrier. use Solve for the virtual ITS phase shift matrix of the m-th subcarrier. Corresponding virtual digital precoding matrix

[0082] Specifically, based on the frequency-dependent virtual ITS phase shift matrix and the corresponding virtual digital precoding matrix obtained in S2, the virtual equivalent channel matrix of the m-th subcarrier is constructed. Perform SVD decomposition Obtain the virtual digital precoding matrix

[0083] Regarding S4, the ITS phase shift matrix Θ corresponding to the center subcarrier is used. T The illumination matrix T of the m-th subcarrier m The virtual ITS phase shift matrix of the m-th subcarrier The virtual digital precoding matrix of the m-th subcarrier Determine the target digital precoding F for the m-th subcarrier BB,m This allows for the acquisition of the hybrid beamforming matrix for each subcarrier, enabling hybrid beamforming.

[0084] Specifically, obtaining the virtual optimal hybrid beamforming matrix Finding the inverse of a matrix:

[0085]

[0086] Calculate the corresponding optimal digital precoding under a fixed frequency-independent ITS phase shift matrix.

[0087] The following comparisons are made with the existing optimal all-digital SVD decomposition precoding method, a hybrid precoding method based on a traditional phase shifter architecture, and a hybrid precoding method based on true time delay (TTD) to further verify the beneficial effects of the ITS-assisted hybrid beamforming method provided in this embodiment of the invention compared to existing technologies. Figure 3 In the diagram, the horizontal axis represents bandwidth in Hz, and the vertical axis represents the system's average spectral efficiency, which represents the transmission rate per subcarrier per unit time. Figure 3 The paper presents the average spectral efficiency versus bandwidth relationship obtained from four precoding methods: optimal all-digital SVD decomposition precoding, hybrid precoding based on traditional phase shifter architecture, hybrid precoding based on TTD, and the ITS-assisted hybrid precoding method of this application. Figure 4 In the figure, the horizontal axis represents the transmission power in dBm, and the vertical axis represents the system average energy efficiency, which represents the transmission rate per unit power and time for each subcarrier. Figure 4 The relationship between average energy efficiency and transmission power obtained by four precoding methods is provided: optimal all-digital SVD decomposition precoding, hybrid precoding based on traditional phase shifter architecture, hybrid precoding based on TTD, and the hybrid precoding method assisted by ITS in this application.

[0088] exist Figure 3 In the configuration, the number of transmit antennas is 4, and the ITS element is M. T =32×32, the number of receiving antennas is N r With a configuration of 4×4, a center frequency of 300GHz, a bandwidth of 60GHz, 128 subcarriers, and 1 data stream, the system transmission rate of the ITS-assisted hybrid precoding method in this application approaches that of the optimal all-digital SVD decomposition precoding. Compared to traditional architectures, the ITS-assisted hybrid precoding method in this application exhibits stable performance that does not decrease with increasing bandwidth, and demonstrates stronger resistance to beam squint in terahertz massive MIMO broadband satellite communication systems.

[0089] exist Figure 4 In the configuration, the number of transmit antennas is 4, and the ITS element is M. T =32×32, the number of receiving antennas is N r =4×4, with a center frequency of 300GHz, a bandwidth of 60GHz, 128 subcarriers, and 1 data stream, the energy efficiency of the ITS-assisted hybrid precoding method in this application is far superior to other methods, achieving the optimal energy efficiency of (11.5) bits / s / Hz / W at a transmission power of 20dBm. Compared to traditional phase shifter architectures, its low power consumption and low cost characteristics are more suitable for terahertz massive MIMO broadband satellite communication systems.

[0090] The ITS-assisted hybrid beamforming apparatus provided by the present invention will be described below. The ITS-assisted hybrid beamforming apparatus described below can be referred to in correspondence with the ITS-assisted hybrid beamforming method described above.

[0091] This invention provides a hybrid beamforming apparatus for ITS-assisted satellite communication, comprising:

[0092] The ITS phase shift matrix acquisition module is used to obtain the array response vector of the center subcarrier based on the angle information in the system configuration information and channel state information of the ITS-assisted satellite communication system. And based on the array response vector of the center subcarrier Obtain the intelligent transmitter plane ITS phase shift matrix Θ T ;

[0093] The communication system is an ITS-assisted terahertz broadband massive MIMO satellite communication system, with N active antennas and the number of passive ITS elements being [missing information]. In the transmitting end of the communication system, each active antenna is connected to a separate RF chain. Data transmitted by the active antenna is mapped onto the ITS surface through an illumination matrix and then refracted out through the ITS. The illumination matrix and virtual ITS phase shift matrix acquisition module is used to construct the illumination matrix T corresponding to the m-th subcarrier using the subcarrier frequency information.m and virtual ITS phase shift matrix M is the total number of subcarriers;

[0094] The virtual digital precoding matrix acquisition module is used to obtain the illumination matrix T corresponding to the m-th subcarrier. m and virtual ITS phase shift matrix Construct the virtual equivalent channel matrix for the m-th subcarrier. use Solve for the virtual ITS phase shift matrix of the m-th subcarrier. Corresponding virtual digital precoding matrix

[0095] The digital precoding acquisition module is used to utilize the ITS phase shift matrix Θ corresponding to the center subcarrier. T The illumination matrix T of the m-th subcarrier m The virtual ITS phase shift matrix of the m-th subcarrier The virtual digital precoding matrix of the m-th subcarrier Determine the target digital precoding for the m-th subcarrier Then, the hybrid beamforming matrix of each subcarrier is obtained, thereby performing hybrid beamforming.

[0096] It is understandable that this device also includes a channel state information and system configuration parameter acquisition module, which is used to acquire corresponding channel state information and system configuration parameters.

[0097] The device provided in this invention is applicable to all satellite high-frequency massive MIMO broadband communication systems that exhibit beam-squinting effects.

[0098] This invention provides an ITS-assisted satellite communication system, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method as described in any of the above embodiments.

[0099] This invention provides an ITS-assisted hybrid beamforming system 300, such as... Figure 4 As shown, it includes: a computer-readable storage medium 320 and a processor 310;

[0100] The computer-readable storage medium is used to store executable instructions;

[0101] The processor is configured to read executable instructions stored in the computer-readable storage medium and execute the method as described in any of the above embodiments.

[0102] Specifically, processor 310 may include, for example, a general-purpose microprocessor, an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)). Processor 310 may also include onboard memory for caching purposes. Processor 310 may be used to execute the above-described... Figures 1-4 The method flow described according to embodiments of this disclosure refers to a single processing unit or multiple processing units performing different actions.

[0103] Computer-readable storage medium 320 may be any medium capable of containing, storing, transmitting, propagating, or transmitting instructions. For example, readable storage media may include, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, apparatuses, or propagation media. Specific examples of readable storage media include: magnetic storage devices such as magnetic tape or hard disk drives (HDDs); optical storage devices such as optical discs (CD-ROMs); memories such as random access memory (RAM) or flash memory; and / or wired / wireless communication links.

[0104] The computer-readable storage medium 320 may include a computer program 321, which may include code / computer-executable instructions that, when executed by the processor 310, cause the processor 310 to perform, for example, the method flow described in any of the above embodiments and any variations thereof.

[0105] Computer program 321 can be configured to have, for example, computer program code including computer program modules. Figure 5 As shown, in the example embodiment, the code in computer program 321 may include one or more program modules, such as module 321A, module 321B, ... It should be noted that the division method and number of modules are not fixed. Those skilled in the art can use appropriate program modules or combinations of program modules according to the actual situation. When these combinations of program modules are executed by processor 310, processor 310 can execute the method flow described in any of the above embodiments and any variations thereof.

[0106] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hybrid beamforming method for ITS-assisted satellite communication, characterized in that, include: S1: Obtain the array response vector of the center subcarrier based on the angle information in the system configuration information and channel state information of the ITS-assisted satellite communication system. and based on the array response vector of the center subcarrier. Obtain the intelligent transmitter plane ITS phase shift matrix ; In the transmitting end of the ITS-assisted satellite communication system, each active antenna is connected to a separate radio frequency chain. The data transmitted by the active antenna is mapped onto the surface of the ITS through the illumination matrix, and then refracted out by the ITS to obtain array gain. S2: Construct the illumination matrix corresponding to the m-th subcarrier using the subcarrier frequency information. and virtual ITS phase shift matrix , M is the total number of subcarriers; S3: Utilizing the aforementioned first m The illumination matrix corresponding to each subcarrier and virtual ITS phase shift matrix Construct the first m Virtual equivalent channel matrix of subcarriers ; use Solve the first m Virtual ITS phase shift matrix for each subcarrier Corresponding virtual digital precoding matrix ; S4: Utilizing the ITS phase shift matrix corresponding to the central subcarrier , No. m Illumination matrix of subcarriers , No. m Virtual ITS phase shift matrix for each subcarrier and the m Virtual digital precoding matrix for each subcarrier Determine the first m Target digital precoding of each subcarrier This allows for the acquisition of the hybrid beamforming matrix for each subcarrier, enabling hybrid beamforming. S2 includes: T1, solving the first subcarrier frequency information and the system configuration information. m The frequency of each subcarrier ,wavelength T2, using the first m The frequency of each subcarrier and wavelength Calculate the first m Illumination matrix of subcarriers This is used to address the impact of different wavelengths of different subcarriers in broadband systems; T3, using the formula Solve the first m Virtual ITS phase shift matrix for each subcarrier This is used to characterize the target with the maximum gain among different subcarrier arrays in a broadband system; among them, This represents the array response vector corresponding to the m-th subcarrier. and These are the azimuth and elevation angles of the ITS, respectively. This represents the operation of taking the diagonal matrix.

2. The hybrid beamforming method for ITS-assisted satellite communication as described in claim 1, characterized in that, S1 includes: obtaining the array response vector based on the center subcarrier according to the angle information in the system configuration information and channel state information. Diagonalizing it yields the ITS phase shift matrix. ; The angle information in the channel state information includes: the azimuth angle representing the base station ITS. and pitch angle , representing the azimuth angle of the user terminal and pitch angle ; The horizontal steering vector representing the ITS array response corresponding to the center subcarrier. The vertical steering vector representing the ITS end array response corresponding to the center subcarrier; This indicates the number of passive elements in the ITS, with a total of [number] rows. The total number of columns is .

3. The hybrid beamforming method for ITS-assisted satellite communication as described in claim 1, characterized in that, S3 includes: R1, based on the first m Channel matrix of subcarriers , using the m The virtual ITS phase shift matrix corresponding to each subcarrier and illumination matrix Construct the first m Virtual equivalent channel matrix of subcarriers ; R2, for the first m Virtual equivalent channel matrix of subcarriers Perform singular value decomposition to obtain the first m Virtual ITS phase shift matrix for each subcarrier Corresponding virtual digital precoding matrix .

4. The hybrid beamforming method for ITS-assisted satellite communication as described in claim 3, characterized in that, R1 includes: Using formula Construct the first m Virtual equivalent channel matrix of subcarriers .

5. The hybrid beamforming method for ITS-assisted satellite communication as described in claim 3, characterized in that, In R1: The channel matrix Represented as ; in, For satellite system channel complex gain, For time delay, For the first m The frequency of each subcarrier This is the frequency-dependent array response vector at the receiver. This is the frequency-dependent array response vector of the base station ITS transmitter; and For the azimuth and elevation angles at the ITS end, For the azimuth and elevation angles of the user terminal, the superscript H represents the conjugate transpose operation.

6. The hybrid beamforming method for ITS-assisted satellite communication as described in any one of claims 1-5, characterized in that, S4 includes: Using formula Determine the first m Target digital precoding of each subcarrier Represents the pseudo-inverse of a matrix; Using formula Calculation yields the first m A hybrid beamforming matrix for each subcarrier is used to perform hybrid beamforming.

7. A hybrid beamforming device for ITS-assisted satellite communication, characterized in that, A hybrid beamforming method for performing ITS-assisted satellite communications as described in any one of claims 1-6, comprising: The ITS phase shift matrix acquisition module is used to obtain the array response vector of the center subcarrier based on the angle information in the system configuration information and channel state information of the ITS-assisted satellite communication system. and based on the array response vector of the center subcarrier. Obtain the intelligent transmitter plane ITS phase shift matrix In the transmitting end of the ITS-assisted satellite communication system, each active antenna is connected to a separate radio frequency chain. The data transmitted by the active antenna is mapped onto the surface of the ITS through an illumination matrix, and then refracted out by the ITS to obtain array gain. The illumination matrix and virtual ITS phase shift matrix acquisition module is used to construct the illumination matrix corresponding to the m-th subcarrier using subcarrier frequency information. and virtual ITS phase shift matrix , M is the total number of subcarriers; The virtual digital precoding matrix acquisition module is used to utilize the first... m The illumination matrix corresponding to each subcarrier and virtual ITS phase shift matrix Construct the first m Virtual equivalent channel matrix of subcarriers ;use Solve the first m Virtual ITS phase shift matrix for each subcarrier Corresponding virtual digital precoding matrix ; The digital precoding acquisition module is used to utilize the ITS phase shift matrix corresponding to the center subcarrier. , No. m Illumination matrix of subcarriers , No. m Virtual ITS phase shift matrix for each subcarrier and the m Virtual digital precoding matrix for each subcarrier Determine the first m Target digital precoding of each subcarrier This allows for the acquisition of the hybrid beamforming matrix for each subcarrier, enabling hybrid beamforming.

8. An ITS-assisted satellite communication system, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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