Wireless multi-channel parallel communication method, device and equipment based on acoustic holography

Abstract

The present invention discloses a wireless multi-channel parallel communication method, device and equipment based on acoustic holography. A spatial multi-focus for communication is constructed through an acoustic holographic transmitting base station. After the signal is sent, it can only be received at the focus position, realizing end-to-end communication. This end-to-end communication has strong confidentiality. The encryption is based on the physical process of sound propagation. The effective signal can only be received at the focus. The spacing between its spatial multi-focus can be very small. By applying 40kHz ultrasound in the air and cooperating with acoustic holography technology, complete decoupling of the space within 3cm can be achieved. That is, two receiving devices can receive signals independently even if the distance between them is less than 3cm, without being affected by other channels, realizing high-density spatial multiplexing; or realizing multi-channel reception of small devices, realizing high-speed communication, and realizing high-density information transmission. It is particularly suitable for use in electromagnetically sensitive situations and occasions where electromagnetic waves are difficult to propagate.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications, and in particular relates to a wireless multi-channel parallel communication method, device and equipment based on acoustic holography. Background Art

[0002] With the development of the Internet of Things (IoT), a large number of micro-devices, such as communicators and sensors, are being wirelessly deployed in industrial and domestic environments, sensing environmental changes and providing data to facilitate our lives. Today, almost all smart devices require network connectivity and power, but it's impossible to connect all devices using wired connections.

[0003] Wireless communications are rapidly developing, but they are susceptible to electromagnetic interference and shielding. Furthermore, considering electromagnetic attenuation, communicating with smart devices underwater or inside the human body is extremely difficult. Increasing power also introduces safety concerns, especially for implanted devices. Due to their wavelike nature, sound waves also carry energy and information during propagation, making them suitable for wireless communications as another wave form. Summary of the Invention

[0004] The purpose of the present invention is to provide a wireless multi-channel parallel communication method, device and equipment based on acoustic holography, which constructs spatial multi-focus based on the characteristics of sound waves and acoustic holography technology to realize multi-channel information transmission based on acoustic spatial multiplexing.

[0005] In order to solve the above problems, the technical solution of the present invention is:

[0006] A wireless multi-channel parallel communication method based on acoustic holography, comprising:

[0007] Obtain the initial parameters of the acoustic holography transmitting base station and initialize the acoustic holography algorithm;

[0008] Obtain the number of parallel channels of the acoustic holography transmitting base station and the spatial position of each receiving device, and construct a focal sound field at the position of each receiving device based on the acoustic holography algorithm;

[0009] According to the communication protocol and the demodulation method of the receiving device, the communication signal is digitally encoded and modulated to achieve independent control of the amplitude, phase and / or frequency of each focus to obtain optimized transmission parameters;

[0010] Based on the transmission parameters, the transmission state of each transmission unit is set, and the ultrasonic signal is transmitted according to the modulation mode of each focus, so that the ultrasonic signal at each focus fluctuates according to the required coding and modulation mode, realizing end-to-end multi-channel parallel communication.

[0011] According to an embodiment of the present invention, constructing a focal sound field at each receiving device position further includes:

[0012] Based on the acoustic holography algorithm, the spatial multiple focuses are decoupled so that each focus can carry information independently, forming multi-channel transmission.

[0013] According to an embodiment of the present invention, constructing a focal sound field at each receiving device position further includes:

[0014] The distance between two adjacent focal points in the spatial multi-focal point constructed based on the acoustic holography algorithm is less than 3 cm, achieving complete decoupling of the space within 3 cm.

[0015] According to an embodiment of the present invention, the obtaining of initial parameters of the acoustic holography transmitting base station and the completion of calculation initialization based on the acoustic holography algorithm further include:

[0016] According to the characteristics of the acoustic holographic transmitting base station, the radiation source is defined;

[0017] Automatically generate a grid based on the frequency, shape, size, position and angle of the transmitting unit of the acoustic holographic transmitting base station;

[0018] The transmission parameters of the transmitting unit can be set to a conventional uniform array, a non-uniform array or a sparse array; each array element can be independently set to any shape and any deflection angle;

[0019] For regularly shaped transmitting units, the grid can be reused and only non-repeated grids are generated; for the same array elements in the array, reuse can also be achieved and only a grid is generated for one array element.

[0020] According to an embodiment of the present invention, the optimized transmission parameters further include:

[0021] Simulate the sound propagation process and propagate the target sound field in reverse to the transmitting plane of the acoustic holographic transmitting base station;

[0022] The feedback information of the sound field distribution propagated back to the emission plane is obtained, and the emission parameters of the emission plane are calculated.

[0023] According to an embodiment of the present invention, the simulated sound propagation process of propagating the target sound field back to the emission plane further includes:

[0024] For homogeneous media, a back propagation operation based on a physical model can be used. Based on the conjugate Green's function, numerical calculation methods including Rayleigh integral, finite element, and finite difference are used to achieve back propagation based on the physical model. The homogeneous medium here refers to the medium for sound wave propagation that is uniformly distributed and does not change with time, such as the still air in free space. Sound waves or light waves can propagate freely without interference introduced by the medium.

[0025] For complex media, the error back propagation algorithm can be used. Based on mathematical optimization methods, the error is propagated back to the transmitting plane according to the target sound field. Complex media here refer to media with complex distribution, uneven distribution, or time-varying distribution. For example, in foggy weather, light scatters everywhere, making distant objects unclear. For example, glass with uneven thickness causes objects to appear distorted. For example, the Doppler effect caused by time-varying distribution.

[0026] Based on the back propagation process of mathematical models or physical models, the sound field information is encoded into the entire transmitting plane. The sound field constructed based on this has strong robustness and anti-interference capabilities.

[0027] According to an embodiment of the present invention, obtaining feedback information of the sound field distribution that is back-propagated to the emission plane and calculating the emission parameters of the emission plane further includes:

[0028] The result of the back propagation is feedback information;

[0029] Based on the back propagation of the physical model, the sound pressure at the transmitting surface in the feedback information is extracted, and the sound pressure on the surface of each transmitting unit on the transmitting surface is integrated or spatially filtered to obtain the emission amplitude and phase of each transmitting unit on the transmitting surface;

[0030] Based on the back propagation of mathematical optimization models, the amplitude and phase of the transmitting unit are adjusted according to different optimization algorithms;

[0031] After obtaining the transmission amplitude and phase of each transmitting unit in each iteration, they are corrected again according to the radiation performance of the transmitting unit of the transmitting device used, and the transmission amplitude and phase are quantized in a hierarchical manner to calibrate the consistency and quantization error to obtain the transmission parameters suitable for the current transmitting device.

[0032] A wireless multi-channel parallel communication device based on acoustic holography, comprising:

[0033] The initialization module is used to obtain the initial parameters of the acoustic holography transmitting base station and complete the calculation initialization based on the acoustic holography algorithm;

[0034] The sound field construction module is used to obtain the number of parallel channels of the acoustic holography transmitting base station and the spatial position of each receiving device, and construct a focal sound field at the position of each receiving device based on the acoustic holography algorithm;

[0035] The signal processing module is used to digitally encode and modulate the communication signal according to the communication protocol and the demodulation method of the receiving device, so as to achieve independent control of the amplitude, phase and / or frequency of each focus and obtain optimized transmission parameters;

[0036] The parallel transmission module is used to set the transmission state of each transmission unit based on the transmission parameters, and transmit the ultrasonic signal according to the modulation mode of each focus, so that the ultrasonic signal at each focus fluctuates according to the required coding and modulation mode, thereby realizing end-to-end multi-channel parallel communication.

[0037] A wireless multi-channel parallel communication device based on acoustic holography includes: a memory and a processor, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, the processor executes the steps of the wireless multi-channel parallel communication method based on acoustic holography in one embodiment of the present invention.

[0038] A storage medium storing computer-readable instructions, which, when executed by one or more processors, enables the one or more processors to execute the steps of a wireless multi-channel parallel communication method based on acoustic holography in an embodiment of the present invention.

[0039] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0040] 1) In one embodiment of the present invention, a wireless multi-channel parallel communication method based on acoustic holography is used. Traditional acoustic communication methods usually only use frequency multiplexing, time multiplexing and other methods for multi-user communication. Due to the limit of channel capacity, the information transmission rate is limited. A spatial multi-focus for communication is constructed through an acoustic holographic transmitting base station. After the signal is sent, it can only be received at the focal position, realizing end-to-end communication. This end-to-end communication has strong confidentiality. The encryption is based on the physical process of sound propagation. Only at the focal point can a valid signal be received. Listening at other positions can only obtain a multi-channel mixed signal, and decoupling cannot be performed. Only when receiving at the predetermined receiving position can valid information be received.

[0041] 2) In one embodiment of the present invention, the wireless multi-channel parallel communication method based on acoustic holography can have a very small spacing between the spatial multi-foci. For example, by applying 40kHz ultrasound in the air, combined with acoustic holography technology, complete decoupling of the space within 3cm can be achieved. That is, two receiving devices can receive signals independently even if the distance between them is less than 3cm, without being affected by other channels, thereby realizing high-density spatial multiplexing; or realizing multi-channel reception of small devices, achieving high-speed communication, and realizing high-density information transmission.

[0042] 3) The wireless multi-channel parallel communication method based on acoustic holography in one embodiment of the present invention, based on acoustic principles, does not generate or receive electromagnetic interference, while ensuring biocompatibility and safety. It can be used for wireless communication in everyday environments, electromagnetically sensitive environments, underwater, and within living organisms.

[0043] 4) The wireless multi-channel parallel communication method based on acoustic holography in one embodiment of the present invention can perform decoupling operations based on the spatial multiple focal points for communication generated by acoustic holography, so that each focal point can carry information independently, and the information transmission rate can be multiplied while the channel bandwidth and signal-to-noise ratio remain unchanged.

[0044] 5) In an embodiment of the present invention, the wireless multi-channel parallel communication method based on acoustic holography generates a multi-focal sound field after the transmitting plane transmits according to the acoustic holographic encoding. This is the result of the combined action of each transmitting unit on the transmitting plane, rather than a single focal point corresponding to a specific area of the transmitting plane. This multi-focal sound field has strong anti-interference capabilities, and even if a local error occurs, other areas can compensate. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Flowchart of a wireless multi-channel parallel communication method based on acoustic holography in one embodiment of the present invention;

[0046] Figure 2 Schematic diagram of the transmission plane of the acoustic holography transmission base station in one embodiment of the present invention;

[0047] Figure 3 Schematic diagram of a QR code and its binary sequence in one embodiment of the present invention;

[0048] Figure 4 Schematic diagram of a binary sequence after amplitude modulation in one embodiment of the present invention;

[0049] Figure 5 Schematic diagram of a binary sequence after amplitude modulation decoding in one embodiment of the present invention;

[0050] Figure 6 Schematic diagram of a two-dimensional code reconstructed by amplitude modulation in one embodiment of the present invention;

[0051] Figure 7 Schematic diagram of a binary sequence after phase modulation in one embodiment of the present invention;

[0052] Figure 8 Schematic diagram of a binary sequence after phase modulation decoding in one embodiment of the present invention;

[0053] Figure 9 Schematic diagram of a two-dimensional code reconstructed by phase modulation in one embodiment of the present invention;

[0054] Figure 10 This is a block diagram of a wireless multi-channel parallel communication device based on acoustic holography in one embodiment of the present invention;

[0055] Figure 11 Schematic diagram of a wireless multi-channel parallel communication device based on acoustic holography in one embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following is a further detailed description of a wireless multi-channel parallel communication method based on acoustic holography proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims.

[0057] Example 1

[0058] Please see Figure 1 The wireless multi-channel parallel communication method based on acoustic holography comprises the following steps:

[0059] S1: Obtain the initial parameters of the acoustic holography transmitting base station and initialize the acoustic holography algorithm;

[0060] S2: Obtain the number of parallel channels of the acoustic holography transmitting base station and the spatial position of each receiving device, and construct a focal sound field at the position of each receiving device based on the acoustic holography algorithm;

[0061] S3: Digitally encode and modulate the communication signal according to the communication protocol and the demodulation method of the receiving device to achieve independent control of the amplitude, phase and / or frequency of each focus to obtain optimized transmission parameters;

[0062] S4: Based on the transmission parameters, the transmission state of each transmission unit is set, and the ultrasonic signal is transmitted according to the modulation mode of each focus, so that the ultrasonic signal at each focus fluctuates according to the required coding and modulation mode, realizing end-to-end multi-channel parallel communication.

[0063] In step S1, the acoustic holographic transmitting base station is usually a phased array formed by arranging many small transmitting units, or is assisted by artificially designed metamaterials to transmit sound waves.

[0064] This embodiment defines the physical parameters of the sound propagation medium, such as sound velocity, density, and attenuation coefficient. When using a simplified model, only the sound velocity of the medium needs to be defined. For example, the sound velocity of air at room temperature is about 343 (m / s), and the sound velocity in water is about 1485 (m / s). The acoustic holographic operating frequency is defined. The wavelength (λ=c / f) can be converted based on the frequency and sound velocity, which will be used to determine the grid space interval. The radiation source is defined, and the radiation characteristics such as sensitivity are set according to the characteristics of the transmitting unit used. It can be optimized for phased arrays and metamaterials, and the radiation grid can be automatically generated based on the shape, size, position, angle, etc. of the transmitting unit. Figure 2 Automatically generate according to the following parameters, where black represents the effective radiation area (excluding the border), the array elements are circular with a diameter of 7 (mm), the array elements are arranged in a two-dimensional uniform grid, a total of 16×16, with a spacing of 10.5 (mm), and the angle between the emission axis and the xy plane is 90 degrees. You can also manually divide the grid and generate it outside the acoustic holography algorithm. Figure 2 Similar two-dimensional matrices can be imported and used directly by the algorithm.

[0065] In practical applications, the acoustic holography transmission base station comprises several transmitting units and an FPGA controller. The FPGA controller hosts the acoustic holography algorithm, calculates the transmission parameters for each transmitting unit, assigns these parameters to the corresponding transmitting unit, and encodes the information transmitted by each channel into the acoustic field holographic distribution. The acoustic holography algorithm can run on the FPGA or be calculated using a personal computer, with the results uploaded to the FPGA for control. The acoustic holography algorithm allows for flexible setting of the transmission frequency and calculation of sound waves of different frequencies for frequency modulation. Both amplitude and phase distributions can be defined within the acoustic holography algorithm.

[0066] In step S2, the number of parallel channels of the acoustic holography transmitting base station and the spatial position of each receiving device are obtained, and a focal sound field is constructed at the position of each receiving device based on the acoustic holography algorithm.

[0067] When defining a multi-focus sound field in this embodiment, it is necessary to define the sound field type, intensity, and spatial coordinates. The sound field type is multi-focus; the intensity represents the amplitude of the sound wave. Different components in the sound field can be assigned different intensities to achieve independent control; the spatial coordinates are relative coordinates relative to the radiation source, which can determine the z-direction height and xy offset of the sound field. Each component of the sound field can be assigned a sound intensity. For example, when defining a multi-point focus, the intensity of each focus is 1 (W / cm 2 ).

[0068] Through acoustic holography algorithm optimization, the acoustic holography transmitting base station can decouple multiple spatial focal points, allowing each focal point to independently carry information. This means that different focal points can independently transmit information as different channels. Furthermore, the spacing between multiple spatial focal points can be very small. For example, using 40kHz ultrasound in air, combined with acoustic holography, complete decoupling can be achieved within 3cm of space. This means that two receiving devices less than 3cm apart can independently receive signals without being affected by other channels, achieving high-density spatial multiplexing.

[0069] In practical applications, the receiving device may be a plurality of receiving sensors, each receiving sensor corresponding to a focal position, and the plurality of receiving sensors may be arranged in a regular shape or an irregular shape.

[0070] For example, the multi-channel sound receiving module is in the shape of a ring, and the receiving sensors are arranged at equal intervals on the ring.

[0071] For another example, the multi-channel sound receiving module is square, and the receiving sensors are arranged in an array on the multi-channel sound receiving module.

[0072] Of course, the multi-channel sound receiving module can also be in other shapes. It can be designed into any regular or irregular shape, but the distribution density of its reception will be limited by the transmitting array of the acoustic holographic transmitting base station.

[0073] In step S3, the communication signal is digitally encoded and modulated according to the communication protocol and the demodulation method of the receiving device to achieve independent control of the amplitude, phase and / or frequency of each focus to obtain optimized transmission parameters.

[0074] The spatial multi-focal point for communication based on acoustic holography in this embodiment is compatible with amplitude modulation, phase modulation and frequency modulation.

[0075] For example, define the amplitude coding of each focus for multi-point focusing, that is, the focus intensity changes with time. The intensity of each focus defined above is 1 (W / cm 2 ) becomes the maximum amplitude of the amplitude coding, that is, the amplitude can be between 0-1 (W / cm 2 ) between any modulation changes; if the phase encoding of each focus of the multi-point focus is defined, the intensity of each focus defined before must be 1 (W / cm 2 ) is added to the phase constraint condition, that is, some focus phase is 0, some focus phase is pi, etc.; if the frequency encoding of each focus of multi-point focusing is defined, then by setting the transmission frequency, the intensity generated by different frequencies at the corresponding focus position is 1 (W / cm 2 )'s focus.

[0076] In the process of obtaining optimized transmission parameters, the following steps can be performed:

[0077] Simulate the sound propagation process and propagate the target sound field in reverse to the transmitting plane of the acoustic holographic transmitting base station;

[0078] The feedback information of the sound field distribution propagated back to the emission plane is obtained, and the emission parameters of the emission plane are calculated.

[0079] Among them, the sound propagation process is simulated, and the target sound field (focused sound field) is propagated back to the emission plane. The back propagation process based on the physical model can be completed using calculation methods such as finite element method, finite difference method, boundary integral method, etc. The following uses the boundary integral method as an example to briefly describe the sound propagation process. Considering the time harmonic situation, the active acoustic wave equation can be described as:

[0080]

[0081] make The free space Green's function is obtained:

[0082]

[0083] in is the wave number, and the sound field distribution satisfies the Kirchhoff-Helmholtz integral formula:

[0084]

[0085] in is the normal direction of the radiation source plane. After the sound pressure distribution on the radiation plane is given, the following formula (1) can be used to calculate the sound field:

[0086]

[0087] make Therefore, the spatial sound pressure can be calculated by convolution p = p0 * h or by using the angular spectrum method in the Fourier domain P = P0·H. The target sound field is propagated back to the emission plane using formula (1).

[0088] The finite element method and finite difference method will not be introduced here for the time being. The acoustic holography algorithm is compatible with these traditional sound field simulation methods.

[0089] Based on the back-propagation process of the mathematical model, the error between the calculated output value (the initial value in the first step) and the objective function is calculated. Different objective functions can be designed, including the value of the reference sound field to be constructed and derivative operations related to the constructed reference sound field. Examples include the total error of the sound field, the peak signal-to-noise ratio of the sound field, the average noise level of the sound field, etc. There are also unique objective functions for different types of sound fields, such as the focal intensity and focal full width at half maximum of multi-point focusing; the angular spectrum purity of the acoustic vortex, etc.

[0090] The aforementioned backpropagation calculation based on physical models is applicable to homogeneous media, meaning that the medium through which sound waves propagate is uniformly distributed and time-invariant. For example, in still air in free space, both sound and light waves propagate freely without interference introduced by the medium. However, the backpropagation calculation based on mathematical models is applicable to complex media, meaning that the medium's distribution is complex, uneven, or time-varying. For example, in foggy conditions, light scatters, making distant objects unclear; in glass with uneven thickness, objects appear distorted; and in other cases, the Doppler effect, which is caused by time-varying light.

[0091] Based on the back propagation process of mathematical models or physical models, the sound field information is encoded into the entire transmitting plane. The sound field constructed based on this has strong robustness and anti-interference capabilities.

[0092] The feedback information of the sound field distribution propagated back to the emission plane is obtained, and the emission parameters of the emission plane are calculated.

[0093] Back propagation based on the physical model: Calculate the emission amplitude and phase of the emission plane based on the sound field distribution of the emission plane obtained by back propagation. Simulate the actual reception situation and integrate the sound pressure propagated to the array element surface:

[0094]

[0095] The p obtained from the above integral is tn is a complex number representing the amplitude and phase of the transmission of the nth array element.

[0096] Back propagation based on mathematical models: According to the back propagation of errors, the partial derivatives of the transmit array elements and the errors are solved, and the gradient descent method is used to change the transmit parameters of each transmit array element.

[0097] p tn * =w(p z ,Δp z ,p ref )p tn

[0098] If it is a screening algorithm such as a genetic algorithm, the population is screened and mutated based on the error to obtain better emission parameters.

[0099] After obtaining the transmit parameters, they must be quantized hierarchically based on array element performance. For example, if both amplitude and phase are quantized at level m, round(p*m) / m is used, where 'round' indicates rounding. Due to the characteristics of some metamaterials, where amplitude and phase have non-uniform distributions, specific performance values can be incorporated into the algorithm and corrected using nearest neighbor matching.

[0100] In step S4, based on the transmission parameters, the transmission state of each transmission unit is set, and the ultrasonic signal is transmitted according to the modulation method of each focus, so that the ultrasonic signal at each focus fluctuates according to the required coding and modulation method, realizing end-to-end multi-channel parallel communication.

[0101] Using the above method, an acoustic holographic transmitting base station can construct multiple spatial focal points for communication. After a signal is transmitted, it can only be received at the focal point, achieving end-to-end communication. Through algorithm optimization, decoupling of the spatial multiple focal points is achieved, allowing each focal point to independently carry information. This spatial multiplexing is compatible with amplitude modulation, phase modulation, and frequency modulation, and does not impose strict channel requirements. It can also exponentially increase the information transmission rate while maintaining the same channel bandwidth and signal-to-noise ratio. This end-to-end communication offers strong confidentiality. This encryption is based on the physics of sound propagation, ensuring that valid signals are received only at the focal point. Furthermore, the spacing between the spatial multiple focal points can be very small. For example, using 40kHz ultrasound in air, combined with acoustic holography, complete spatial decoupling can be achieved within 3cm. This means that two receiving devices less than 3cm apart can independently receive signals without being affected by other channels, enabling high-density spatial multiplexing. Alternatively, it can implement multi-channel reception on small devices, enabling high-speed communication and high-density information transmission. It has broad application prospects in the fields of Internet of Things, smart home appliances, smart medical care, underwater communications, etc., and is particularly suitable for use in electromagnetically sensitive environments and places where electromagnetic waves are difficult to propagate.

[0102] The following is a specific example to illustrate the effect achieved by the wireless multi-channel parallel communication method based on acoustic holography:

[0103] The acoustic holographic transmission base station in this embodiment uses 256 acoustic emission units, controlled by an FPGA, and has an acoustic emission frequency of 40kHz. The multi-channel acoustic receiving module is equipped with 11 receiving sensors for receiving multi-channel acoustic signals. These 11 receiving sensors are distributed in a ring, with a distance of only 2.8cm between the receiving sensors.

[0104] Taking the QR code as the information to be transmitted, 10 spatial multiplexing channels are set up in the experiment, and the QR code is encoded into 10 binary sequences. Figure 3 The QR codes and their binary sequences used in the experiment are shown.

[0105] The following performs amplitude modulation transmission and phase modulation transmission on the QR code information respectively:

[0106] Amplitude modulation transmission: Amplitude modulation is performed on the QR code sequence displayed at different focal points. The multi-channel receiving signal after amplitude modulation is as follows: Figure 4 As shown, Figure 4 Channel 0 is the clock signal, and channels 1-10 are 10 binary sequences carrying the QR code information. Although the distance between the receiving sensors is very small, the amplitude modulated signal can still be clearly received by each sensor without mutual interference. After demodulation according to the clock signal, we get Figure 5 The binary sequence shown can be reconstructed to obtain the transmitted QR code information. Please refer to Figure 6, the reconstructed QR code is error-free.

[0107] Phase modulation transmission: Phase modulation is performed on the QR code information displayed at different focal points. The multi-channel receiving signal after phase modulation is as follows: Figure 7 As shown, Figure 7 Channel 0 is the reference signal, and channels 1-10 are 10 binary sequences carrying QR code information. After demodulating the phase according to the reference signal, we get Figure 8 The binary sequence shown can be reconstructed to obtain the transmitted QR code information. Please refer to Figure 9 , the reconstructed QR code is error-free.

[0108] As an experimental demonstration, the transmission rate of each channel is 80 bit / s. After creating 10 spatial multiplexing channels, the information transmission speed becomes 10 times that of a single channel, reaching 800 bit / s.

[0109] Example 2

[0110] This embodiment provides a wireless multi-channel parallel communication device based on acoustic holography. Figure 10 The wireless multi-channel parallel communication device based on acoustic holography includes:

[0111] Initialization module 1 is used to obtain the initial parameters of the acoustic holography transmitting base station and complete the calculation initialization based on the acoustic holography algorithm;

[0112] Sound field construction module 2 is used to obtain the number of parallel channels of the acoustic holographic transmitting base station and the spatial position of each receiving device, and construct a focal sound field at the position of each receiving device based on the acoustic holographic algorithm;

[0113] Signal processing module 3, used to digitally encode and modulate the communication signal according to the communication protocol and the demodulation method of the receiving device, to achieve independent control of the amplitude, phase and / or frequency of each focus, and obtain optimized transmission parameters;

[0114] The parallel transmission module 4 is used to set the transmission state of each transmission unit based on the transmission parameters, and transmit the ultrasonic signal according to the modulation method of each focus, so that the ultrasonic signal at each focus fluctuates according to the required coding and modulation method, thereby realizing end-to-end multi-channel parallel communication.

[0115] The functions and implementation methods of the initialization module 1 , the sound field construction module 2 , the signal processing module 3 and the parallel transmission module 4 are the same as those described in the first embodiment, and will not be repeated here.

[0116] Example 3

[0117] This embodiment provides a wireless multi-channel parallel communication device based on acoustic holography. Figure 11 The wireless multi-channel parallel communication device 500 based on acoustic holography may have relatively large differences due to different configurations or performances, and may include one or more processors (central processing units, CPU) 510 (for example, x86, ARM architecture processors or FPGAs) and memory 520, and one or more storage media 530 (for example, one or more mass storage devices) storing application programs 533 or data 532. The memory 520 and the storage medium 530 may be temporary storage or permanent storage. The program stored in the storage medium 530 may include one or more modules (not shown in the figure), each of which may include a series of instruction operations in the wireless multi-channel parallel communication device 500 based on acoustic holography.

[0118] Furthermore, the processor 510 may be configured to communicate with the storage medium 530 and execute a series of instruction operations in the storage medium 530 on the wireless multi-channel parallel communication device 500 based on acoustic holography.

[0119] The wireless multi-channel parallel communication device 500 based on acoustic holography may also include one or more power supplies 540, one or more wired or wireless network interfaces 550, one or more input and output interfaces 560, and / or one or more operating systems 531, such as Windows Serve, Vista, etc.

[0120] Those skilled in the art will understand that Figure 11 The structure of the wireless multi-channel parallel communication device based on acoustic holography shown does not constitute a limitation of the wireless multi-channel parallel communication device based on acoustic holography, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0121] Another embodiment of the present invention further provides a computer-readable storage medium.

[0122] The computer-readable storage medium may be a non-volatile computer-readable storage medium or a volatile computer-readable storage medium. The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to execute the steps of the method for a wireless multi-channel parallel communication device based on acoustic holography in Example 1.

[0123] If the wireless multi-channel parallel communication method based on acoustic holography is implemented in the form of program instructions and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of software, and the computer software is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present disclosure. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0124] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the identification content specifically executed by the above-described system and device can refer to the corresponding process in the aforementioned method embodiment.

[0125] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the scope of protection of the present invention.

Claims

1. A wireless multi-channel parallel communication method based on acoustic holography, characterized in that: include: Obtain the initial parameters of the acoustic holography transmitting base station and initialize the acoustic holography algorithm; Obtain the number of parallel channels of the acoustic holography transmitting base station and the spatial position of each receiving device, and construct a focal sound field at each receiving device position based on the acoustic holography algorithm; According to the communication protocol and the demodulation method of the receiving device, the communication signal is digitally encoded and modulated to achieve independent control of the amplitude, phase and / or frequency of each focus to obtain optimized transmission parameters; Based on the transmission parameters, the transmission state of each transmission unit is set, and the ultrasonic signal is transmitted according to the modulation mode of each focus, so that the ultrasonic signal at each focus fluctuates according to the required coding and modulation mode, thereby realizing end-to-end multi-channel parallel communication; Wherein, constructing a focal sound field at each receiving device position further includes: The distance between two adjacent focal points in the spatial multi-focal area constructed based on the acoustic holography algorithm is less than 3 cm, achieving complete decoupling of the space within 3 cm. The optimized transmission parameters further include: Simulate the sound propagation process and propagate the target sound field in reverse to the transmitting plane of the acoustic holographic transmitting base station; Obtain feedback information of the sound field distribution that propagates back to the emission plane and calculate the emission parameters of the emission plane; The simulated sound propagation process of propagating the target sound field back to the emission plane further includes: For homogeneous media, backpropagation based on physical models is used. Based on conjugate Green's function, numerical calculation methods including Rayleigh integral, finite element and finite difference are used to realize backpropagation based on physical models. For complex media, the error back propagation operation form is used. Based on the mathematical optimization method, the error is propagated back to the emission plane according to the target sound field. Based on the back propagation process of mathematical models or physical models, the sound field information is encoded into the entire transmitting plane. The sound field constructed based on this has strong robustness and anti-interference capabilities.

2. The wireless multi-channel parallel communication method based on acoustic holography according to claim 1, characterized in that: The constructing of a focal sound field at each receiving device position further comprises: Based on the acoustic holography algorithm, the spatial multiple focuses are decoupled so that each focus can carry information independently, forming multi-channel transmission.

3. The wireless multi-channel parallel communication method based on acoustic holography according to claim 1, characterized in that: The step of obtaining initial parameters of the acoustic holography transmitting base station and completing calculation initialization based on the acoustic holography algorithm further includes: According to the characteristics of the acoustic holographic transmitting base station, the radiation source is defined; Automatically generate a grid based on the frequency, shape, size, position and angle of the transmitting unit of the acoustic holographic transmitting base station; The transmission parameters of the transmitting unit can be set to a conventional uniform array, a non-uniform array or a sparse array; each array element can be independently set to any shape and any deflection angle; For regularly shaped transmitting units, the grid can be reused and only non-repeated grids are generated; for the same array elements in the array, reuse can also be achieved and only a grid is generated for one array element.

4. The wireless multi-channel parallel communication method based on acoustic holography according to claim 1, characterized in that: The obtaining feedback information of the sound field distribution that is back-propagated to the emission plane and calculating the emission parameters of the emission plane further includes: The result of the back propagation is feedback information; Based on the back propagation of the physical model, the sound pressure at the transmitting surface in the feedback information is extracted, and the sound pressure on the surface of each transmitting unit on the transmitting surface is integrated or spatially filtered to obtain the emission amplitude and phase of each transmitting unit on the transmitting surface; Based on the back propagation of mathematical optimization models, the amplitude and phase of the transmitting unit are adjusted according to different optimization algorithms; After obtaining the transmission amplitude and phase of each transmitting unit in each iteration, they are corrected again according to the radiation performance of the transmitting unit of the transmitting device used, and the transmission amplitude and phase are quantized in a hierarchical manner to calibrate the consistency and quantization error to obtain the transmission parameters suitable for the current transmitting device.

5. A wireless multi-channel parallel communication device based on acoustic holography, characterized in that: include: The initialization module is used to obtain the initial parameters of the acoustic holography transmitting base station and complete the calculation initialization based on the acoustic holography algorithm; The sound field construction module is used to obtain the number of parallel channels of the acoustic holographic transmitting base station and the spatial position of each receiving device. Based on the acoustic holographic algorithm, it constructs a focal sound field at the location of each receiving device. The distance between two adjacent focal points is less than 3cm, achieving complete decoupling of the space within 3cm. The signal processing module is used to digitally encode and modulate the communication signal according to the communication protocol and the demodulation method of the receiving device, so as to achieve independent control of the amplitude, phase and / or frequency of each focus and obtain optimized transmission parameters; A parallel transmission module is used to set the transmission state of each transmission unit based on the transmission parameters, and transmit the ultrasonic signal according to the modulation mode of each focus, so that the ultrasonic signal at each focus fluctuates according to the required coding and modulation mode, thereby realizing end-to-end multi-channel parallel communication; Wherein, the signal processing module is further configured to: Simulate the sound propagation process and propagate the target sound field back to the transmitting plane of the acoustic holographic transmitting base station. For uniform media, use the back propagation operation based on the physical model. Based on the conjugate Green's function, use the numerical calculation methods including Rayleigh integral, finite element, and finite difference to realize the back propagation based on the physical model. For complex media, the error back propagation operation form is used. Based on the mathematical optimization method, the error is propagated back to the emission plane according to the target sound field. Based on the back propagation process of mathematical or physical models, the sound field information is encoded into the entire emission plane. The sound field constructed based on this has strong robustness and anti-interference ability. The feedback information of the sound field distribution propagated back to the emission plane is obtained, and the emission parameters of the emission plane are calculated.

6. A wireless multi-channel parallel communication device based on acoustic holography, characterized in that: include: A memory and a processor, wherein the memory stores computer-readable instructions, and when the computer-readable instructions are executed by the processor, the processor executes the steps in the wireless multi-channel parallel communication method based on acoustic holography as described in any one of claims 1 to 4.

7. A storage medium storing computer-readable instructions, characterized in that: When the computer-readable instructions are executed by one or more processors, the one or more processors are caused to perform the steps of the wireless multi-channel parallel communication method based on acoustic holography as claimed in any one of claims 1 to 4.

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