Broadband beam forming method

Abstract

The invention discloses a broadband beam forming method, and belongs to the technical field of beam forming. The method comprises the following steps: acquiring a channel with a communication user, a channel with a sensing target and a broadband beam forming matrix of a current time slot; calculating a broadband beamforming matrix of a next time slot, and sensing SINR and a data rate; and constructing a target function according to the broadband beam forming matrix of the current time slot, the broadband beam forming matrix of the next time slot, the sensing SINR and the data rate, and optimizing the target function by taking the maximization of the total data rate as a target to obtain a broadband beam forming result. According to the invention, efficient environment sensing and dynamic beam forming can be realized by utilizing the controllable split beam, and energy efficiency-achievable total rate-sensing precision combined Pareto optimization is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of beamforming, and in particular to a broadband beamforming method. Background Art

[0002] The iterative evolution of mobile communication technology and the rapid adoption of smart devices have created an urgent need for efficient information transmission and reliable communication services. Research on 6th Generation Mobile Communication (6G) technology has entered a critical stage of system architecture design and technology roadmap formation.

[0003] Amidst the increasingly limited spectrum resources for wireless communications, millimeter-wave (30-300 GHz) and terahertz (0.1-10 THz) frequency bands have become a research hotspot due to their ultra-high data rates and vast bandwidth compared to the already saturated traditional microwave bands. However, high-frequency electromagnetic waves face dual constraints during propagation, including free-space path loss and absorption attenuation by atmospheric molecules. This makes wide-area coverage and long-distance transmission difficult to achieve within existing system architectures and transmission power constraints. To overcome these technical bottlenecks, current research focuses on the coordinated optimization of massive MIMO (Multiple Input Multiple Output) and precoding techniques to improve the achievable overall rate and interference mitigation capabilities. However, while these solutions perform well in narrowband systems, they struggle to adapt to the ultra-wideband requirements of high-band massive MIMO. A key challenge lies in the unique "beam splitting effect" that arises when combining massive antenna arrays with ultra-wideband transmission. This effect involves the propagation delay of electromagnetic waves along the antenna array aperture, causing the main lobe of the frequency-domain beam to split in the spatial domain, resulting in significant array gain loss.

[0004] To solve this problem, existing research has proposed a beamforming scheme based on a True Time Delay (TTD) network: relying on TTD components to provide frequency-related delay compensation, calibrating the propagation delay differences of the antenna array, so that the beam direction of each subcarrier remains consistent, thereby achieving a beam focusing effect aligned with the narrowband system. However, current research still has certain limitations: (1) Insufficient exploration of the value of beam splitting. Existing work has widely focused on suppressing the negative impact of beam splitting, but has not fully explored the potential value of split beams in spatial information detection. (2) Resource and computing bottlenecks. Traditional beamforming strategies rely on high resource overhead (such as pilot signals) and high computing efficiency (such as high-dimensional matrix operations), and are difficult to adapt to high-frequency broadband transmission scenarios. Therefore, it is urgent to develop a new broadband beamforming scheme by combining 6G emerging technologies such as Integrated Sensing and Communications (ISAC) while considering the beam splitting effect. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a broadband beamforming method that can achieve efficient environmental perception and dynamic beamforming using controllable split beams, thereby realizing the joint Pareto optimization of energy efficiency, achievable total rate, and perception accuracy.

[0006] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0007] The present invention provides a broadband beamforming method, comprising:

[0008] Obtaining the channel between the communication user, the channel between the perception target, and the broadband beamforming matrix of the current time slot;

[0009] Calculate the ISAC signal based on the broadband beamforming matrix of the current time slot, send the ISAC signal to the communication user through the channel between the communication user and the perception target through the channel between the ISAC signal and the perception target;

[0010] Calculating an echo signal reflected by a sensing target according to the ISAC signal, receiving the echo signal reflected by the sensing target through a channel between the sensing target and the sensing target, and calculating a sensing SINR;

[0011] Calculate the broadband beamforming matrix for the next time slot based on the broadband beamforming matrix for the current time slot and the echo signal reflected by the sensed target;

[0012] calculating a communication signal received by a communication user, and calculating a data rate at which the communication user transmits an ISAC signal based on the communication signal received by the communication user;

[0013] An objective function is constructed according to the broadband beamforming matrix of the current time slot, the broadband beamforming matrix of the next time slot, the perceived SINR, and the data rate, and the objective function is optimized with the goal of maximizing the total data rate to obtain a broadband beamforming result.

[0014] Optionally, the acquiring of the channel with the communication user includes: ; ; ; ; in, represents the channel between the base station and the u-th communication user at the f-th subcarrier at the t-th time; represents the small-scale attenuation coefficient of the u-th communication user at time t; represents the carrier frequency of the f-th subcarrier; represents the propagation delay of the u-th communication user at time t; Represents the sending end array steering vector; represents an imaginary unit; Indicates the number of transmitting antennas; Indicates the spatial channel direction of the u-th communication user at the f-th subcarrier at the t-th time; represents the conjugate transpose of a matrix; Indicates the antenna spacing; represents the speed of light; Indicates the physical channel direction; Indicates the wavelength corresponding to the center frequency; Indicates the center carrier frequency.

[0015] Optionally, acquiring the channel with the sensing target includes: ; ; in, represents the channel between the base station and the g-th sensing target at the f-th subcarrier at the t-th time; represents the perceived channel gain; Represents the receiving end array steering vector; represents the conjugate transpose of the steering vector of the transmitting array; Indicates the spatial channel direction of the g-th sensing target at the f-th subcarrier at the t-th time; Indicates the number of receiving antennas; represents an imaginary unit; Represents the conjugate transpose of a matrix.

[0016] Optionally, obtaining the broadband beamforming matrix of the current time slot includes: ; ; ; ; ; ; ; in, represents the broadband beamforming matrix at time t; represents the broadband beamforming matrix implemented by the frequency-independent phase shifter network at time t; represents the broadband beamforming matrix implemented by the frequency-dependent TTD network at time t; 、 、…、 denote the beamforming matrix implemented by the phase shifter network connected to the first RF chain at time t, the beamforming matrix implemented by the phase shifter network connected to the second RF chain, ..., the beamforming matrix implemented by the phase shifter network connected to the U-th RF chain at time t, respectively; 、 They represent the beamforming matrix realized by the phase shifter network connected to the u-th communication user at time t and the beamforming matrix realized by the phase shifter network connected to the g-th sensing target at time t respectively; 、 、…、 They represent the beamforming vector of the uth communication user connected to the first TTD element, the beamforming vector connected to the second TTD element, ..., the beamforming vector connected to the The beamforming vector of each TTD element; 、 、…、 They represent the beamforming vector of the g-th sensing target connected to the first TTD element, the beamforming vector connected to the second TTD element, ..., the beamforming vector connected to the first TTD element, and the beamforming vector connected to the second TTD element, respectively. The beamforming vector of each TTD element; represents a block diagonal matrix; 、 、…、 They represent the intermediate variables of the user corresponding to the first RF chain at time t, the intermediate variables of the user corresponding to the second RF chain, …, the intermediate variables of the user corresponding to the U-th RF chain; 、 They represent the intermediate variables of the u-th communication user at time t and the g-th perception target at time t respectively; 、 They represent the direction turning vector of the u-th communication user and the direction turning vector of the g-th perception target at the t-th moment respectively; Indicates the number of TTD components; represents the imaginary unit; T represents the transpose of the matrix.

[0017] Optionally, the ISAC signal is represented as: ; in, Indicates ISAC signal; 、 They represent the broadband beamforming matrix of the communication user and the broadband beamforming matrix of the sensing target at the fth subcarrier at the tth time respectively; 、 They represent the communication symbol vector and the perception symbol vector at time t respectively; 、 They represent the total broadband beamforming matrix and total transmitted symbols for the f-th subcarrier at the t-th time, respectively.

[0018] Optionally, the echo signal reflected by the sensing target is expressed as: ; in, represents the echo signal reflected by the g-th sensing target at the f-th subcarrier at the t-th time; represents the reflection coefficient of the g-th sensing target at the f-th subcarrier at the t-th time; represents the channel between the base station and the g-th sensing target at the f-th subcarrier at the t-th time; Indicates ISAC signal; represents the reflection coefficient of the i-th sensing target at the f-th subcarrier at the t-th time; represents the channel between the base station and the i-th sensing target at the f-th subcarrier at the t-th time; represents the self-interference signal of the base station in full-duplex mode; represents the Gaussian additive white noise vector of the g-th perceived target at the t-th moment; Represents a collection of perception targets.

[0019] Optionally, the perceived SINR is expressed as: ; in, represents the perceived SINR; represents the receiving beam; They represent the reflection coefficient of the g-th sensing target at the f-th subcarrier and the reflection coefficient of the i-th sensing target at the f-th subcarrier at the t-th time respectively; They represent the channel between the base station and the g-th sensing target at the f-th subcarrier, and the channel between the base station and the i-th sensing target at the f-th subcarrier, respectively; Indicates ISAC signal; represents the set of perception targets; represents the Gaussian white noise vector at time t; represents the covariance matrix of the ISAC signal; represents the noise power; represents a unit vector of length M; represents the conjugate transpose of a matrix; represents the mathematical expectation.

[0020] Optionally, the broadband beamforming matrix of the next time slot is expressed as: ; ; in, They represent the beamforming matrix realized by the phase shifter network connected to the u-th communication user at time t+1 and the beamforming matrix realized by the phase shifter network connected to the g-th sensing target, respectively; They represent the direction turning vector of the u-th communication user and the direction turning vector of the g-th perception target at the t+1th time respectively; Represents the received signal at the previous t moments in history; They represent the shaping vector of the communication user and the shaping vector of the perception target in the first t moments respectively; represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; They represent the set of communication users and the set of perception targets respectively.

[0021] Optionally, the data rate at which the communication user transmits the ISAC signal is expressed as: ; ; in, represents the communication signal received by the kth communication user at time t; represents the channel of the f-th carrier for the k-th communication user at time t; They represent the communication shaping vector of the kth communication user at time t, the communication shaping vector of the k'th communication user, and the perception shaping vector of the gth perception target respectively; They represent the baseband processing signal for the kth communication user, the baseband processing signal for the k'th communication user, and the baseband processing signal for the gth sensing target at the tth moment respectively; represents a collection of communicating users; represents the set of perception targets; represents the additive white Gaussian noise of the kth communication user on the fth subcarrier at the tth time; represents the data rate of the kth communication user on the fth subcarrier at the tth time; represents the noise power; Represents the conjugate transpose of a matrix.

[0022] Optionally, the construction of the objective function includes: ; ; ; ; ; ; in, represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; represents the receiving beam; represents the total set of perception shaping vectors and communication shaping vectors; Indicates the total number of time slots; represents the expectation of the long-term achievable rate; Represents constraints; They represent the beamforming matrix realized by the phase shifter network connected to the u-th communication user at time t+1 and the beamforming matrix realized by the phase shifter network connected to the g-th sensing target, respectively; They represent the direction turning vector of the u-th communication user and the direction turning vector of the g-th perception target at the t+1th time respectively; Represents the received signal at the previous t moments in history; They represent the communication shaping vector of the u-th communication user and the perception shaping vector of the g-th perception target in the previous t moments respectively; represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; They represent the set of communication users and the set of perception targets respectively; ; It represents the minimum SINR threshold that the sensing target needs to maintain at time t to complete the sensing task; represents the phase shift matrix of the phase shifter; represents a carrier set; represents the data rate of the kth communication user on the fth subcarrier at the tth time; represents the minimum quality of service requirement of the kth communication user at time t; represents the total wideband beamforming matrix at the fth subcarrier at time t; Indicates the maximum available power of the base station; Represents a matrix diagonal operation.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] Aiming at the development trend of 6G interawareness integration technology, this invention overcomes the beam splitting problem caused by the coupling of broadband transmission and large-scale arrays. On the one hand, through the collaborative design of environmental perception and broadband beamforming matrix, the controllable beam splitting is achieved during the ISAC signal transmission and reception stage. On the other hand, based on the predictive beamforming method, the long-term achievable data rate of the base station can be maximized while ensuring the requirements of radar perception, user service quality, transmission power and other indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG2 is a flow chart of a broadband beamforming method according to an embodiment of the present invention;

[0026] Figure 2 FIG2 is a schematic diagram showing the structure of a MIMO-ISAC system based on split sensing in one embodiment of the present invention;

[0027] Figure 3 FIG. 1 is a schematic diagram of the structure of a hybrid beamforming architecture according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0029] The term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " generally indicates an "or" relationship between the related objects.

[0030] Example 1

[0031] like Figure 1 As shown, the embodiment introduces a broadband beamforming method, including the following steps:

[0032] Step 1: Build a MIMO-ISAC (Multiple-Input Multiple-Output Integrated Sensing and Communications) system based on split sensing, using a hybrid beamforming architecture that supports TTD networks. Specifically:

[0033] like Figure 2 As shown in the figure, consider a multi-antenna base station with integrated communication and sensing functions. The base station is equipped with two Root transmitting antenna and A uniform linear array (ULA) is composed of receiving antennas. single-antenna communication users, and radars perceive the target, respectively using the set and For the convenience of explanation, the set of communication users and perception targets is defined as the server = ,in At the same time, Figure 3 As shown in the figure, the base station adopts a hybrid beamforming architecture that supports true delay network, with Each RF chain serves a user or a sensing target during signal transmission. Based on full-duplex radio technology, the base station's transmitting antenna sends the ISAC signal with integrated communication and sensing functions, while maintaining uninterrupted downlink communication and receiving the echo signal reflected from the sensing target through the receiving antenna. In addition, the system adopts Orthogonal Frequency Division Multiplexing (OFDM) technology, using The spectrum is divided into multiple narrowband subcarriers by orthogonal subcarriers. At the same time, and Where, and represent the transmission bandwidth and center carrier frequency, respectively. Since both communication users and sensing targets reflect ISAC signals, and since communication users and the base station coverage network use a unified communication protocol, it is assumed that the communication users know the reflected echo signals and can perform channel estimation. The base station receiver can use the communication user's feedback to eliminate its echo signals, thereby distinguishing the echo signals reflected by the communication user from those reflected by the sensing target.

[0034] Affected by the beam splitting effect, considering the signal propagation delay along the antenna aperture, a frequency-dependent high-frequency broadband channel model is constructed; based on the far-field plane wave transmission assumption, we adopt a ray channel model and introduce a block fading channel model to assume that the channel maintains quasi-static characteristics within the coherence time. In view of the extremely high penetration loss problem of high-frequency transmission, combined with its high path attenuation and weak diffraction characteristics, it is assumed that the communication between the base station and the user mainly relies on the line-of-sight transmission link to complete.

[0035] use The channel between the base station and the u-th communication user at the f-th subcarrier at time t satisfies the following formula:

[0036] ;

[0037] in, represents the small-scale attenuation coefficient of the u-th communication user at the t-th time, represents a complex normal distribution with a mean of 0 and a variance of 1; Indicates the The carrier frequency of the subcarriers; represents the propagation delay of the u-th communication user at time t; represents an imaginary unit; Indicates the system bandwidth; Indicates the number of subcarriers; Indicates subcarrier; Represents the sending end array steering vector, expressed as:

[0038] ;

[0039] in, Represents a vector of size M rows and 1 column; Indicates the spatial channel direction of the u-th communication user at the f-th subcarrier at the t-th time; Indicates the physical channel direction; represents the antenna spacing, Indicates the wavelength corresponding to the center frequency; represents the speed of light; Represents the conjugate transpose of a matrix.

[0040] For the perception channel model, the common single-point reflector model is adopted. Under the single-path model, the channel between the transmitting and receiving antennas passing through the reflector is It is defined as the channel between the base station and the g-th sensing target at the f-th subcarrier at the t-th time, expressed as:

[0041] ;

[0042] in, represents the perceived channel gain; represents the conjugate transpose of the steering vector of the transmitting array; Indicates the spatial channel direction of the g-th sensing target at the f-th subcarrier at the t-th time; Represents the receiving end array steering vector, expressed as:

[0043] .

[0044] like Figure 3 As shown in the figure, a new hybrid beamforming architecture is built based on a time delay network. By compensating the propagation delay along the antenna aperture, a frequency-dependent analog beamformer is designed.

[0045] like Figure 3 As shown in the figure, a hybrid beamforming architecture different from the traditional fully connected one is adopted. A TTD network layer is inserted between each RF chain and phase shifter network to compensate for the propagation delay of the signal along the antenna aperture in the traditional beamforming architecture. Specifically, each RF chain is connected to TTD components, and each TTD component is connected to Since the TTD network can provide a frequency-varying phase shift through the time delay component, it is used represents the broadband beamforming matrix under the hybrid beamforming architecture based on TTD network, where 、 、…、 represent the first broadband beamforming vector, the second broadband beamforming vector, ..., the The proposed wideband beamforming matrix can be divided into two parts according to the hardware architecture, which can be expressed as .in, represents the broadband beamforming matrix implemented by the frequency-independent phase shifter network at time t, which is implemented by the frequency-independent phase shifter network in the architecture and is expressed as:

[0046] ;

[0047] ;

[0048] ;

[0049] in, 、 、…、 denote the beamforming matrix implemented by the phase shifter network connected to the first RF chain at time t, the beamforming matrix implemented by the phase shifter network connected to the second RF chain, ..., the beamforming matrix implemented by the phase shifter network connected to the U-th RF chain at time t, respectively; 、 They represent the beamforming matrix realized by the phase shifter network connected to the u-th communication user at time t and the beamforming matrix realized by the phase shifter network connected to the g-th sensing target at time t respectively; 、 、…、 They represent the beamforming vector of the uth communication user connected to the first TTD element, the beamforming vector connected to the second TTD element, ..., the beamforming vector connected to the The beamforming vector of the TTD elements is given by The beamforming vectors controlled by the PSs are connected to the TTD components, and ; 、 、…、 They represent the beamforming vector of the g-th sensing target connected to the first TTD element, the beamforming vector connected to the second TTD element, ..., the beamforming vector connected to the first TTD element, and the beamforming vector connected to the second TTD element, respectively. The beamforming vector of each TTD element; represents a block diagonal matrix.

[0050] then, represents the broadband beamforming matrix implemented by the frequency-dependent TTD network at time t. It is the frequency-dependent part of the analog beamformer controlled by the TTD network and is expressed as:

[0051] ;

[0052] in, 、 、…、 They represent the The time delay component controlled by the TTD element is connected by the second RF chain at time t. The time delay components controlled by the TTD elements, ..., connected by the U-th RF chain at the t-th time The time delay component controlled by the TTD element. To facilitate control, we introduce a direction steering vector of the u-th communication user at the t-th time The following constraints are met: ,in , introduce a direction turning vector of the g-th perceived target at the t-th moment The following constraints are met: Therefore, an intermediate variable of the u-th communication user at time t can be introduced , the intermediate variable of the g-th perception target at time t , the broadband beamforming matrix implemented by the frequency-dependent TTD network at time t is Converts to:

[0053] ;

[0054] ;

[0055] ;

[0056] in, 、 、…、 They represent the intermediate variables of the first server at time t, the intermediate variables of the second server at time t, ..., the intermediate variables of the U-th server at time t respectively; T represents the transpose of the matrix.

[0057] Therefore, in a frequency-dependent analog beamformer, the direction of the steering vector 、 , the splitting direction of the beam under different subcarrier frequencies can be controlled.

[0058] Step 2: The base station sends an ISAC signal, synchronously performs communication transmission and radar sensing tasks, and receives the target's reflected echo signal. Specifically:

[0059] The base station designs and sends ISAC signals, completing environmental perception and user communication at the same time. The ISAC signal transmitted by the base station at time t on the fth subcarrier is given by the following formula:

[0060] ;

[0061] in, 、 They represent the broadband beamforming matrix of the communication user and the broadband beamforming matrix of the sensing target at the fth subcarrier at the tth time respectively; 、 Represent the communication symbol vector and perception symbol vector at time t, respectively, satisfying 、 , and assume that its components are statistically independent of each other; 、 They represent the total broadband beamforming matrix and total transmitted symbols for the f-th subcarrier at the t-th time, respectively.

[0062] The base station receives the echo signal reflected by the sensing target and uses the Signal to Interference plus Noise Ratio (SINR) as an indicator to evaluate the sensing performance. The echo signal of the sensing target is modeled. Assume that at time t, the base station The linear array of receiving antennas receives the signals from the sensing target. The echo reflected by the scattering point is received by the base station at the time t by the g-th sensing target at the f-th subcarrier. Will be given by:

[0063] ;

[0064] in, represents the reflection coefficient of the g-th sensing target at the f-th subcarrier at the t-th time; represents the reflection coefficient of the i-th sensing target at the f-th subcarrier at the t-th time; represents the channel between the base station and the i-th sensing target at the f-th subcarrier at the t-th time; represents the self-interference signal of the base station in full-duplex mode; represents the g-th Gaussian additive white noise vector at time t; Represents a collection of perception targets.

[0065] In order to reduce the self-interference power, the self-interference cancellation (SI cancellation, SIC) technology is introduced. Based on the asymptotic orthogonality of large-scale antenna arrays, that is, for all , both This characteristic makes the beam interference between sensing targets in the uplink echo approximately negligible, and the base station can achieve independent decoupling processing of multiple sensing targets based on the arrival angle difference. Generally speaking, the performance of radar and communication systems mainly depends on the corresponding SINR. Especially in MIMO radar systems, the detection probability of point targets is usually a monotonically increasing function of the output SINR. Therefore, SINR is directly used as the sensing performance indicator, and the receive beam is applied to the received signal. , to capture the desired reflected signal of a point target, the perceived SINR is given by:

[0066] ;

[0067] in, represents the perceived SINR; represents the receiving beam; They represent the reflection coefficient of the g-th sensing target at the f-th subcarrier and the reflection coefficient of the i-th sensing target at the f-th subcarrier at the t-th time respectively; They represent the channel between the base station and the g-th sensing target at the f-th subcarrier, and the channel between the base station and the i-th sensing target at the f-th subcarrier, respectively; Indicates ISAC signal; is a Gaussian white noise vector; represents the covariance matrix of the ISAC signal; represents the noise power; represents a unit vector of length M; represents the mathematical expectation.

[0068] In view of the characteristics of high-frequency broadband transmission, ignoring the multipath effect and considering only the line-of-sight propagation path, the communication signal received by the kth communication user at time t is Expressed as:

[0069] ;

[0070] in, represents the channel of the f-th carrier for the k-th communication user at time t; They represent the communication shaping vector of the kth communication user at time t, the communication shaping vector of the k'th communication user, and the perception shaping vector of the gth perception target respectively; They represent the baseband processing signal for the kth communication user, the baseband processing signal for the k'th communication user, and the baseband processing signal for the gth sensing target at the tth moment respectively; represents a collection of communicating users; represents the set of perception targets; It represents the additive white Gaussian noise of the kth communication user at the fth subcarrier at the tth time, and its distribution satisfies , Represents the noise power. The signal received by the communication user includes the useful signal and noise. According to the specific components of the signal received by the communication user, the data rate of the kth communication user at the fth subcarrier at the tth time is derived. Expressed as:

[0071] .

[0072] Step 3: The base station associates the real-time echo characteristics with the historical observation sequence to model and predict the broadband beamforming matrix for the next time slot. Specifically:

[0073] The base station integrates the current echo data with historical observation information to generate the broadband beamforming matrix at time t+1, completing the cross-time slot closed-loop control. That is, according to the broadband beamforming matrix of the current time slot and the echo signal reflected by the perceived target, the broadband beamforming matrix of the next time slot is calculated. The beamforming matrix implemented by the phase shifter network connected to the u-th communication user at time t+1 is , the beamforming matrix implemented by the phase shifter network connected to the g-th sensing target Respectively expressed as:

[0074] ;

[0075] ;

[0076] in, They represent the direction turning vector of the u-th communication user and the direction turning vector of the g-th perception target at the t+1th time respectively; Represents the received signal at the previous t moments in history; They represent the shaping vector of the communication user and the shaping vector of the perception target in the first t moments respectively; represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; They represent the set of communication users and the set of perception targets respectively.

[0077] The objective function is constructed based on the broadband beamforming matrix of the current time slot, the broadband beamforming matrix of the next time slot, the perceived SINR and the data rate. The objective function is optimized with the goal of maximizing the total data rate to obtain the broadband beamforming result.

[0078] The construction of the objective function includes:

[0079] ;

[0080] ;

[0081] ;

[0082] ;

[0083] ;

[0084] ;

[0085] in, represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; represents the receiving beam; represents the total set of perception shaping vectors and communication shaping vectors; Indicates the total number of time slots; represents the expectation of the long-term achievable rate; Represents constraints; They represent the beamforming matrix realized by the phase shifter network connected to the u-th communication user at time t+1 and the beamforming matrix realized by the phase shifter network connected to the g-th sensing target, respectively; They represent the direction turning vector of the u-th communication user and the direction turning vector of the g-th perception target at the t+1th time respectively; Represents the received signal at the previous t moments in history; They represent the communication shaping vector of the u-th communication user and the perception shaping vector of the g-th perception target in the previous t moments respectively; represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; They represent the set of communication users and the set of perception targets respectively; ; It represents the minimum SINR threshold that the sensing target needs to maintain at time t to complete the sensing task; represents the phase shift matrix of the phase shifter; represents a carrier set; represents the data rate of the kth communication user on the fth subcarrier at the tth time; represents the minimum quality of service requirement of the kth communication user at time t; represents the total wideband beamforming matrix at the fth subcarrier at time t; Indicates the maximum available power of the base station; Represents a matrix diagonal operation.

[0086] The objective function is a mixed-integer nonlinear programming (MINLP) problem, characterized by both nonconvexity and combinatorial optimization properties. Given that this problem is essentially a long-term cumulative rate maximization problem with time-varying characteristics, it can be modeled as a Markov decision process, using reinforcement learning to optimize the policy in a dynamic environment. This modeling approach effectively handles the high-dimensional nature of the system state space and the coupled relationship between the time dimension, providing a scalable framework for solving cross-time-slot resource allocation problems under complex constraints.

[0087] Based on the environmental information perceived from the echo signal and the communication information based on historical observations, and guided by the idea of ​​effectively utilizing the beam splitting effect, a broadband beamforming strategy is adopted to jointly optimize perception and communication. While ensuring the requirements of radar perception, user QoS, transmit power and other indicators, the long-term achievable data rate of the base station is maximized.

[0088] Example 2

[0089] This embodiment introduces a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the steps in the method described in Example 1 are implemented.

[0090] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0091] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0092] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0093] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0094] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A broadband beamforming method, characterized in that: include: Obtaining the channel between the communication user, the channel between the perception target, and the broadband beamforming matrix of the current time slot; Calculate the ISAC signal based on the broadband beamforming matrix of the current time slot, send the ISAC signal to the communication user through the channel between the communication user and the perception target through the channel between the ISAC signal and the perception target; Calculating an echo signal reflected by a sensing target according to the ISAC signal, receiving the echo signal reflected by the sensing target through a channel between the sensing target and the sensing target, and calculating a sensing SINR; Calculate the broadband beamforming matrix for the next time slot based on the broadband beamforming matrix for the current time slot and the echo signal reflected by the sensed target; calculating a communication signal received by a communication user, and calculating a data rate at which the communication user transmits an ISAC signal based on the communication signal received by the communication user; An objective function is constructed according to the broadband beamforming matrix of the current time slot, the broadband beamforming matrix of the next time slot, the perceived SINR, and the data rate, and the objective function is optimized with the goal of maximizing the total data rate to obtain a broadband beamforming result.

2. The broadband beamforming method according to claim 1, wherein: The acquisition of a channel with a communication user includes: ； ； ； ； in, represents the channel between the base station and the u-th communication user at the f-th subcarrier at the t-th time; represents the small-scale attenuation coefficient of the u-th communication user at time t; represents the carrier frequency of the f-th subcarrier; represents the propagation delay of the u-th communication user at time t; Represents the sending end array steering vector; represents an imaginary unit; Indicates the number of transmitting antennas; Indicates the spatial channel direction of the u-th communication user at the f-th subcarrier at the t-th time; represents the conjugate transpose of a matrix; Indicates the antenna spacing; represents the speed of light; Indicates the physical channel direction; Indicates the wavelength corresponding to the center frequency; Indicates the center carrier frequency.

3. The broadband beamforming method according to claim 1, wherein: The acquisition of the channel between the sensing target includes: ； ； in, represents the channel between the base station and the g-th sensing target at the f-th subcarrier at the t-th time; represents the perceived channel gain; Represents the receiving end array steering vector; represents the conjugate transpose of the steering vector of the transmitting array; Indicates the spatial channel direction of the g-th sensing target at the f-th subcarrier at the t-th time; Indicates the number of receiving antennas; represents an imaginary unit; Represents the conjugate transpose of a matrix.

4. The broadband beamforming method according to claim 1, wherein: The acquisition of the broadband beamforming matrix of the current time slot includes: ； ； ； ； ； ； ； in, represents the broadband beamforming matrix at time t; represents the broadband beamforming matrix implemented by the frequency-independent phase shifter network at time t; represents the broadband beamforming matrix implemented by the frequency-dependent TTD network at time t; 、 、…、 denote the beamforming matrix implemented by the phase shifter network connected to the first RF chain at time t, the beamforming matrix implemented by the phase shifter network connected to the second RF chain, ..., the beamforming matrix implemented by the phase shifter network connected to the U-th RF chain at time t, respectively; 、 They represent the beamforming matrix realized by the phase shifter network connected to the u-th communication user at time t and the beamforming matrix realized by the phase shifter network connected to the g-th sensing target at time t respectively; 、 、…、 They represent the beamforming vector of the uth communication user connected to the first TTD element, the beamforming vector connected to the second TTD element, ..., the beamforming vector connected to the The beamforming vector of each TTD element; 、 、…、 They represent the beamforming vector of the g-th sensing target connected to the first TTD element, the beamforming vector connected to the second TTD element, ..., the beamforming vector connected to the first TTD element, and the beamforming vector connected to the second TTD element, respectively. The beamforming vector of each TTD element; represents a block diagonal matrix; 、 、…、 They represent the intermediate variables of the user corresponding to the first RF chain at time t, the intermediate variables of the user corresponding to the second RF chain, …, the intermediate variables of the user corresponding to the U-th RF chain; 、 They represent the intermediate variables of the u-th communication user at time t and the g-th perception target at time t respectively; 、 They represent the direction turning vector of the u-th communication user and the direction turning vector of the g-th perception target at the t-th moment respectively; Indicates the number of TTD components; represents the imaginary unit; T represents the transpose of the matrix.

5. The broadband beamforming method according to claim 1, wherein: The ISAC signal is represented as: ； in, Indicates ISAC signal; 、 They represent the broadband beamforming matrix of the communication user and the broadband beamforming matrix of the sensing target at the fth subcarrier at the tth time respectively; 、 They represent the communication symbol vector and the perception symbol vector at time t respectively; 、 They represent the total broadband beamforming matrix and total transmitted symbols for the f-th subcarrier at the t-th time, respectively.

6. The broadband beamforming method according to claim 1, wherein: The echo signal reflected by the sensing target is expressed as: ； in, represents the echo signal reflected by the g-th sensing target at the f-th subcarrier at the t-th time; represents the reflection coefficient of the g-th sensing target at the f-th subcarrier at the t-th time; represents the channel between the base station and the g-th sensing target at the f-th subcarrier at the t-th time; Indicates ISAC signal; represents the reflection coefficient of the i-th sensing target at the f-th subcarrier at the t-th time; represents the channel between the base station and the i-th sensing target at the f-th subcarrier at the t-th time; represents the self-interference signal of the base station in full-duplex mode; represents the Gaussian additive white noise vector of the g-th perceived target at the t-th moment; Represents a collection of perception targets.

7. The broadband beamforming method according to claim 1, wherein: The perceived SINR is expressed as: ； in, represents the perceived SINR; represents the receiving beam; They represent the reflection coefficient of the g-th sensing target at the f-th subcarrier and the reflection coefficient of the i-th sensing target at the f-th subcarrier at the t-th time respectively; They represent the channel between the base station and the g-th sensing target at the f-th subcarrier, and the channel between the base station and the i-th sensing target at the f-th subcarrier, respectively; Indicates ISAC signal; represents the set of perception targets; represents the Gaussian white noise vector at time t; represents the covariance matrix of the ISAC signal; represents the noise power; represents a unit vector of length M; represents the conjugate transpose of a matrix; represents the mathematical expectation.

8. The broadband beamforming method according to claim 1, wherein: The broadband beamforming matrix of the next time slot is expressed as: ； ； in, They represent the beamforming matrix realized by the phase shifter network connected to the u-th communication user at time t+1 and the beamforming matrix realized by the phase shifter network connected to the g-th sensing target, respectively; They represent the direction turning vector of the u-th communication user and the direction turning vector of the g-th perception target at the t+1th time respectively; Represents the received signal at the previous t moments in history; They represent the shaping vector of the communication user and the shaping vector of the perception target in the first t moments respectively; represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; They represent the set of communication users and the set of perception targets respectively.

9. The broadband beamforming method according to claim 1, wherein: The data rate at which the communication user transmits the ISAC signal is expressed as: ； ； in, represents the communication signal received by the kth communication user at time t; represents the channel of the f-th carrier for the k-th communication user at time t; They represent the communication shaping vector of the kth communication user at time t, the communication shaping vector of the k'th communication user, and the perception shaping vector of the gth perception target respectively; They represent the baseband processing signal for the kth communication user, the baseband processing signal for the k'th communication user, and the baseband processing signal for the gth sensing target at the tth moment respectively; represents a collection of communicating users; represents the set of perception targets; represents the additive white Gaussian noise of the kth communication user on the fth subcarrier at the tth time; represents the data rate of the kth communication user on the fth subcarrier at the tth time; represents the noise power; Represents the conjugate transpose of a matrix.

10. The broadband beamforming method according to claim 1, wherein: The construction of the objective function includes: ； ； ； ； ； ； in, represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; represents the receiving beam; represents the total set of perception shaping vectors and communication shaping vectors; Indicates the total number of time slots; represents the expectation of the long-term achievable rate; Represents constraints; They represent the beamforming matrix realized by the phase shifter network connected to the u-th communication user at time t+1 and the beamforming matrix realized by the phase shifter network connected to the g-th sensing target, respectively; They represent the direction turning vector of the u-th communication user and the direction turning vector of the g-th perception target at the t+1th time respectively; Represents the received signal at the previous t moments in history; They represent the communication shaping vector of the u-th communication user and the perception shaping vector of the g-th perception target in the previous t moments respectively; represents the broadband beamforming strategy on the 𝑓th subcarrier at the 𝑡th time; They represent the set of communication users and the set of perception targets respectively; ; It represents the minimum SINR threshold that the sensing target needs to maintain at time t to complete the sensing task; represents the phase shift matrix of the phase shifter; represents a carrier set; represents the data rate of the kth communication user on the fth subcarrier at the tth time; represents the minimum quality of service requirement of the kth communication user at time t; represents the total wideband beamforming matrix at the fth subcarrier at time t; Indicates the maximum available power of the base station; Represents a matrix diagonal operation.

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