Ultrasonic signal long-distance wireless transmission device based on laser intensity modulation
By adopting a long-distance wireless transmission device of ultrasonic signal based on laser intensity modulation in ultrasonic attack technology, the problems of limited attack distance, large environmental interference, and insufficient transmission accuracy and concealment in traditional ultrasonic attack technology are solved, and longer distance, more stable and more concealed ultrasonic signal transmission is achieved.
Patent Information
- Application Number
- CN202510233527.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2025-05-27
AI Technical Summary
The existing ultrasonic attack technology faces problems such as limited attack distance, large impact on environmental interference, and insufficient transmission accuracy and concealment.
The ultrasonic signal long-distance wireless transmission device based on laser intensity modulation is used to generate an ultrasonic signal through the FPGA, and modulate it into a laser signal for transmission using an optical modulation module. The receiving end then demodulates the laser signal into an ultrasonic signal for output.
It significantly extends the attack distance, reduces the impact of environmental interference, improves signal stability and consistency, and enhances the concealment and accuracy of the attack.
Smart Images
Figure CN120049975A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of wireless transmission, and particularly relates to the long-distance wireless transmission of ultrasonic signals. Background Art
[0002] In recent years, ultrasonic attack technology (such as Dolphin Attack) is a technology that uses ultrasonic signals to control voice assistants or other intelligent devices. In recent years, with the popularization of voice assistants and Internet of Things devices, this attack technology has attracted wide attention. The core of ultrasonic attack is to use ultrasonic signals (with frequencies higher than 20 kHz) to manipulate the microphones of devices. Since the human ear cannot hear ultrasonic waves, but the microphones of devices can receive and process these signals, specific ultrasonic instructions can be sent to drive the devices to perform operations.
[0003] The existing ultrasonic attack methods mainly face the following challenges:
[0004] 1. Limited attack distance: Traditional ultrasonic attacks usually directly emit ultrasonic waves to attack target devices. However, since ultrasonic waves attenuate rapidly when propagating in the air, especially in long-distance and open environments, the signal intensity significantly decreases, resulting in a limited effective attack range.
[0005] 2. Great influence of environmental interference: In outdoor or open environments, ultrasonic signals are easily interfered by factors such as wind noise, air flow, and obstacles, affecting the signal quality and attack effect. Especially during long-distance propagation, it is difficult to ensure the stability and consistency of ultrasonic signals.
[0006] 3. Insufficient transmission accuracy and concealment: Traditional ultrasonic attack methods use ultrasonic speakers to directly emit signals. Although ultrasonic waves cannot be heard by the human ear, secondary sound waves may be generated during propagation, increasing the risk of detection and recognition. Summary of the Invention
[0007] The present invention aims to solve the problems of limited attack distance, great influence of environmental interference, and insufficient transmission accuracy and concealment in existing ultrasonic attack technologies. Now, a long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation is provided.
[0008] The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation includes: a transmitting end and a receiving end. The transmitting end is used to generate an ultrasonic signal from a control instruction and modulate the ultrasonic signal into a laser signal and send it to the receiving end. The receiving end demodulates the received laser signal into an ultrasonic signal and converts the demodulated ultrasonic signal into a sound wave for output.
[0009] Further, the transmitting end includes: an FPGA real-time ultrasonic signal generation module and an optical modulation module 5,
[0010] The FPGA real-time ultrasonic signal generation module is used to collect control instructions and generate ultrasonic signals from the control instructions. The optical modulation module 5 modulates the ultrasonic signals into laser signals and transmits them to the receiving end.
[0011] Furthermore, the FPGA real-time ultrasonic signal generation module includes a signal acquisition module 1, a signal processing module 2, an ultrasonic signal generation module 3, and a signal output interface module 4 that are connected in sequence.
[0012] The signal acquisition module 1 collects control instructions, amplifies and performs A / D conversion on the control instructions to obtain digital signals, and transmits the digital signals to the signal processing module 2.
[0013] The signal processing module 2 sequentially filters, modulates, and encodes the digital signals through the FPGA to generate intermediate signals and transmits the intermediate signals to the ultrasonic signal generation module 3. The modulation is amplitude modulation, frequency modulation, or phase modulation.
[0014] The ultrasonic signal generation module 3 converts the intermediate signals into analog signals, and then boosts the signals to the voltage level required by the optical modulation module 5 through power amplification to generate high-frequency ultrasonic signals.
[0015] The high-frequency ultrasonic signals are transmitted to the optical modulation module 5 through the signal output interface module 4.
[0016] Furthermore, the optical modulation module 5 includes: an operational amplifier U2, resistors R1 to R5, capacitors C1 to C4, and a laser driver circuit.
[0017] The negative electrode of the capacitor C1 serves as the signal input terminal of the optical modulation module 5. The positive electrode of the capacitor C1 is respectively connected to the non-inverting input terminal of the operational amplifier U2 and one end of the resistor R1. The inverting input terminal of the operational amplifier U2 is respectively connected to one end of the resistor R2 and the resistor R3. The other end of the resistor R2 is connected to the positive electrode of the capacitor C2. The other end of the resistor R3 is respectively connected to the output terminal of the operational amplifier U2, one end of the resistor R4, and one end of the resistor R5. The other end of the resistor R4 is connected to one end of the capacitor C4. One end of the resistor R5 is connected to one end of the capacitor C3. The other end of the capacitor C4 is connected to the input terminal of the laser driver circuit. The laser emission terminal of the laser driver circuit serves as the laser signal output terminal of the optical modulation module 5. The other end of the resistor R1, the negative electrode of the capacitor C2, and the other end of the capacitor C3 are all connected to the power ground terminal.
[0018] Furthermore, the laser driver circuit includes: a linear voltage regulator U1, a resistor R6, capacitors C5 to C6, a diode D2, and a laser diode D1.
[0019] The positive electrode of the laser diode D1, one end of the capacitor C6, the ADJ pin of the linear voltage regulator U1, and one end of the resistor R6 are connected together and used as the input end of the laser driving circuit. The other end of the resistor R6 is connected to the Vout pin of the linear voltage regulator U1. The Vin pin of the linear voltage regulator U1 is respectively connected to the negative electrode of the diode D2, one end of the capacitor C5, and the positive power supply. The negative electrode of the laser diode D1, the other end of the capacitor C6, the positive electrode of the diode D2, and the other end of the capacitor C5 are all connected to the power ground.
[0020] Further, the transmission wavelength range of the laser signal output by the optical modulation module 5 is from 300 nm to 1100 nm.
[0021] Further, the receiving end includes: a photoelectric converter module 6 and an ultrasonic playback module 7;
[0022] The photoelectric converter module 6 receives the laser signal sent by the transmitting end and demodulates the laser signal into an ultrasonic signal. The ultrasonic playback module 7 amplifies the demodulated ultrasonic signal and converts it into a sound wave for output.
[0023] Further, the photoelectric converter module 6 includes: a silicon photodiode D3, capacitors C7 to C9, resistors R7 to R10, and an operational amplifier U3;
[0024] The silicon photodiode D3 is used to collect the laser signal sent by the transmitting end. The positive electrode of the silicon photodiode D3 is connected to the negative electrode of the capacitor C9. The positive electrode of the capacitor C9 is respectively connected to one end of the resistor R10 and the non-inverting input terminal of the operational amplifier U3. The inverting input terminal of the operational amplifier U3 is respectively connected to one end of the resistor R8 and one end of the resistor R7. The output terminal of the operational amplifier U3 is respectively connected to the other end of the resistor R7, one end of the resistor R9, and the positive electrode of the ultrasonic playback module 7. The other end of the resistor R9 is connected to one end of the capacitor C8. The other end of the resistor R8 is connected to the positive electrode of the capacitor C7. The negative electrode of the silicon photodiode D3, the other end of the resistor R10, the negative electrode of the capacitor C7, and the other end of the capacitor C8 are all connected to the power ground.
[0025] Further, the ultrasonic playback module 7 is an ultrasonic speaker or an ultrasonic transducer array.
[0026] Further, the ultrasonic playback module 7 generates ultrasonic waves with a frequency range of 20 kHz to 100 kHz.
[0027] The ultrasonic signal long-distance wireless transmission device based on laser intensity modulation according to the present invention can transmit ultrasonic signals from a long-distance outdoor environment to the photoelectric converter module in the target room by using laser as the transmission medium for ultrasonic signals outdoors. After the laser signal is demodulated, the power amplifier module and the ultrasonic speaker or ultrasonic transducer array module retransmit the ultrasonic signal to complete the attack on the target device. This method has the following advantages:
[0028] 1. Significantly extend the attack distance: Laser has extremely high directivity and low scattering, and can effectively transmit the modulated ultrasonic signal over a long distance, thus extending the transmission distance from the transmitter to the indoor photoelectric converter module and realizing long-distance covert attack.
[0029] 2. Reduce the influence of environmental interference: Laser transmission is less affected by air flow and environmental noise, which can ensure the signal stability and consistency during long-distance transmission and improve the success rate of the attack.
[0030] 3. Enhance concealment and attack effect: The laser transmission process cannot be perceived by the human ear, and at the same time reduces the generation of infrasound waves, reducing the risk of being detected. Re-emitting ultrasonic waves by the ultrasonic speaker indoors ensures the directivity and accuracy of the attack.
[0031] In summary, the present invention transmits ultrasonic signals to the indoor photoelectric converter module by using laser, and the ultrasonic speaker or ultrasonic transducer array module indoors re-transmits them, so as to achieve the purpose of improving the attack distance and effect, and is applicable to ultrasonic attack scenarios. Brief Description of the Drawings
[0032] Figure 1 It is the overall structure diagram of the ultrasonic signal long-distance wireless transmission device based on laser intensity modulation;
[0033] Figure 2 It is the circuit diagram of the optical modulation module;
[0034] Figure 3 It is the circuit diagram of the photoelectric converter module. Detailed Embodiments
[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.
[0036] Refer toFigures 1 to 3 Specifically, in this embodiment, for the long-distance wireless transmission device of ultrasonic signals based on laser intensity modulation, at the transmitting end, the FPGA real-time ultrasonic signal generation module uses the FPGA to record and generate ultrasonic signals of a specific frequency in real time. The optical modulation module 5 modulates the ultrasonic signal into a laser signal through intensity modulation technology for long-distance transmission. At the receiving end, the optoelectronic converter module 6 receives and demodulates the laser signal into an ultrasonic signal, and a high-sensitivity optoelectronic conversion device is used to ensure the efficiency and accuracy of signal recovery. The ultrasonic playback module 7 amplifies and reproduces the ultrasonic signal, and converts the demodulated ultrasonic signal into sound waves for output. The long-distance wireless transmission device of ultrasonic signals realizes the long-distance transmission of ultrasonic signals through lasers, overcomes the problems of short transmission distance and poor stability of traditional ultrasonic attack systems, has the characteristics of high directivity, anti-electromagnetic interference and enhanced concealment, and can accurately and covertly transmit signals and attack targets at a long distance.
[0037] Specifically, as Figure 1 shown, the FPGA real-time ultrasonic signal generation module includes a signal acquisition module 1, a signal processing module 2, an ultrasonic signal generation module 3, and a signal output interface module 4 that are connected in sequence. The FPGA real-time ultrasonic signal generation module takes the FPGA as the core, and its peripheral circuit includes an A / D conversion module, an operational amplifier circuit, and a DAC module. The signal acquisition module 1 collects the input signal by collecting the audio signal through a microphone, performs preliminary amplification through an operational amplifier, and then inputs the A / D conversion module to convert the analog signal into a digital signal and transmit it to the signal processing module 2. The signal processing module 2 is completed by the FPGA for processing such as filtering, modulation, and encoding of the digital signal, and generates an intermediate signal that meets the requirements. Among them, the modulation method can select amplitude modulation, frequency modulation, or phase modulation, and the algorithm is adjusted according to the application scenario to adapt to different transmission requirements. The modulated intermediate signal is transmitted to the ultrasonic signal generation module 3, converted into an analog signal through the DAC module, and then boosted to the voltage level required by the laser modulation module through a power amplifier to generate a high-frequency ultrasonic signal. The high-frequency ultrasonic signal is transmitted to the optical modulation module 5 through the signal output interface module 4 to realize the optical encoding of the signal.
[0038] The optical modulation module 5 includes a high-power laser diode and a laser drive circuit, which can dynamically adjust the laser output power according to different transmission distances. The laser transmission wavelength range is from 300nm to 1100nm, and it supports integrating the optoelectronic converter module 6 and the ultrasonic playback module 7 into an independent device to improve portability and concealment. Specifically, as Figure 2As shown, the optical modulation module 5 includes the TDA2030 operational amplifier U2, the LM317H linear voltage regulator U1, resistors R1 to R6, capacitors C1 to C6, the 1N4007 diode D2, and the laser probe (laser diode D1). The DC power supply V1 provides the input voltage, with VDD being +12V and VEE being -12V to meet the voltage requirements of each component in the circuit. The non-inverting input terminal of the operational amplifier U2 is connected to the input signal through the capacitor C1 and is also grounded through the resistor R1; the inverting input terminal of the operational amplifier U2 is connected to its output terminal through the resistor R3 to form a feedback loop and forms a voltage-dividing circuit with the resistor R2 and the capacitor C2 to ground; the output terminal of the operational amplifier U2 is coupled to the laser drive circuit through the resistor R4 and the capacitor C4 and is also part of the feedback loop. At the same time, the output terminal of the operational amplifier U2 is also grounded through the resistor R5 and the capacitor C3; the VDD of the operational amplifier U2 is connected to the +12V power supply, and the VEE is connected to the -12V power supply to provide a negative voltage. The Vin pin of the linear voltage regulator U1 is connected to the power supply V1 and is grounded through the capacitor C5 for filtering; the Vout pin of the linear voltage regulator U1 is connected to the resistor R6 for current limiting and then connected to the positive electrode of the laser diode D1 and is also connected to the filtering capacitor C6; the ADJ pin of the linear voltage regulator U1 is grounded through R6 and C6 for adjusting the output parameters; the positive electrode of the diode D2 is connected to the negative electrode of the power supply, and the negative electrode is connected to Vin to prevent reverse current; the negative electrode of the laser diode D1 is grounded to complete the drive circuit.
[0039] The photoelectric converter module 6 converts the optical signal into an electrical signal to drive the ultrasonic playback module 7 to emit ultrasonic signals. The entire process realizes the full-link closed-loop processing from signal acquisition to ultrasonic output, so as to achieve the purpose of using laser signals to transmit ultrasonic audio signals for long-distance ultrasonic attacks. Specifically, as Figure 3 shown, the photoelectric converter module 6 includes: a silicon photodiode D3, capacitors C7 to C9, resistors R7 to R10, and a TDA2030 operational amplifier U3. The positive electrode of the silicon photodiode D3 is connected to the negative electrode of the capacitor C9, and the positive electrode of the capacitor C9 is respectively connected to one end of the resistor R10 and the non-inverting input terminal of the operational amplifier U3. The other end of the resistor R10 is grounded. The inverting input terminal of the operational amplifier U3 is connected to its output terminal through the feedback resistor R7 to form a negative feedback loop. At the same time, the inverting input terminal is also grounded through the coupling resistor R8 and the capacitor C7. The positive power input terminal of the TDA2030 is connected to the +12V power supply, and the negative power input terminal is connected to the -12V power supply. The output terminal of the operational amplifier U3 is grounded through the resistor R9 and the coupling capacitor C8 and is also connected to the positive electrode of the ultrasonic playback module 7, and the negative electrode of the ultrasonic playback module 7 is directly grounded.
[0040] The ultrasonic playback module 7 is an ultrasonic speaker or an ultrasonic transducer array, which is the final link for signal playback. It uses a high-frequency ultrasonic transducer to convert an electrical signal into an ultrasonic signal, generating ultrasonic waves with a frequency range of 20 kHz to 100 kHz.
[0041] When designing the ultrasonic playback module 7, it is necessary to ensure that its output power is large enough to achieve long-distance signal transmission and efficient restoration. The entire system realizes the whole process of ultrasonic signal generation to long-distance restoration through FPGA modulation, laser modulation and transmission at the transmitting end, and photoelectric conversion, demodulation and signal amplification at the receiving end. This circuit design has the advantages of high stability and strong anti-interference ability, and is suitable for application in long-distance precise signal transmission scenarios, especially showing broad application prospects in fields such as ultrasonic attacks.
[0042] In summary, the long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation described in this embodiment records and generates ultrasonic signals through an FPGA. The signals are modulated into laser signals by an optical modulator module for long-distance transmission. The receiving end restores the ultrasonic signals through a photoelectric converter module and plays them using an ultrasonic speaker or an ultrasonic transducer array module. Compared with the traditional method of transmitting ultrasonic signals using electromagnetic waves, using lasers for transmission can effectively increase the transmission distance and directivity of ultrasonic attacks, avoid electromagnetic interference, and enhance the concealment and attack effect of the signals. This system is particularly suitable for covert attack scenarios that require long-distance and high-precision ultrasonic signal transmission, such as Dolphin Attack.
[0043] Although the present invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed, as long as they do not deviate from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the different dependent claims and the features described herein can be combined in a manner different from that described in the original claims. It should also be understood that the features described in connection with a single embodiment can be used in other described embodiments.
Claims
1. A long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation, characterized in that: include: A transmitting end and a receiving end, wherein the transmitting end is used to generate a control instruction into an ultrasonic signal and modulate the ultrasonic signal into a laser signal and send it to the receiving end, and the receiving end demodulates the received laser signal into an ultrasonic signal and converts the demodulated ultrasonic signal into a sound wave output.
2. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 1, characterized in that: The transmitting end comprises: an FPGA real-time ultrasonic signal generating module and an optical modulation module (5), The FPGA real-time ultrasonic signal generation module is used to collect control instructions and generate the control instructions into ultrasonic signals, and the optical modulation module (5) modulates the ultrasonic signals into laser signals and transmits them to the receiving end.
3. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 2, characterized in that: The FPGA real-time ultrasonic signal generation module comprises a signal acquisition module (1), a signal processing module (2), an ultrasonic signal generation module (3) and a signal output interface module (4) which are connected in sequence; The signal acquisition module (1) acquires control instructions, amplifies and performs A / D conversion on the control instructions to obtain digital signals, and transmits the digital signals to the signal processing module (2); The signal processing module (2) sequentially filters, modulates and encodes the digital signal through FPGA to generate an intermediate signal and transmits the intermediate signal to the ultrasonic signal generation module (3), wherein the modulation is amplitude modulation, frequency modulation or phase modulation; The ultrasonic signal generation module (3) converts the intermediate signal into an analog signal, and then increases the voltage level required by the optical modulation module (5) through power amplification to generate a high-frequency ultrasonic signal; The high-frequency ultrasonic signal is transmitted to the optical modulation module (5) through the signal output interface module (4).
4. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 2 or 3, characterized in that: The optical modulation module (5) comprises: an operational amplifier U2, resistors R1 to R5, capacitors C1 to C4 and a laser driving circuit; The negative electrode of the capacitor C1 serves as the signal input end of the optical modulation module (5); the positive electrode of the capacitor C1 is respectively connected to the in-phase input end of the operational amplifier U2 and one end of the resistor R1; the inverting input end of the operational amplifier U2 is respectively connected to one end of the resistor R2 and one end of the resistor R3; the other end of the resistor R2 is connected to the positive electrode of the capacitor C2; the other end of the resistor R3 is respectively connected to the output end of the operational amplifier U2, one end of the resistor R4 and one end of the resistor R5; the other end of the resistor R4 is connected to one end of the capacitor C4; the other end of the resistor R5 is connected to one end of the capacitor C3; the other end of the capacitor C4 is connected to the input end of the laser driving circuit; the laser emitting end of the laser driving circuit serves as the laser signal output end of the optical modulation module (5); the other end of the resistor R1, the negative electrode of the capacitor C2 and the other end of the capacitor C3 are all connected to the power ground end.
5. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 4, characterized in that: The laser driving circuit includes: a linear regulator U1, a resistor R6, capacitors C5-C6, a diode D2 and a laser diode D1; the positive electrode of the laser diode D1, one end of the capacitor C6, the ADJ pin of the linear regulator U1 and one end of the resistor R6 are connected and serve as the input end of the laser driving circuit, the other end of the resistor R6 is connected to the Vout pin of the linear regulator U1, the Vin pin of the linear regulator U1 is respectively connected to the negative electrode of the diode D2, one end of the capacitor C5 and the positive electrode of the power supply, and the negative electrode of the laser diode D1, the other end of the capacitor C6, the positive electrode of the diode D2 and the other end of the capacitor C5 are all connected to the power ground.
6. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 4, characterized in that: The transmission wavelength range of the laser signal output by the optical modulation module (5) is 300 nm to 1100 nm.
7. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 1, 2, 3, 5 or 6, characterized in that: The receiving end comprises: a photoelectric converter module (6) and an ultrasonic playback module (7); The photoelectric converter module (6) receives the laser signal sent by the transmitting end and demodulates the laser signal into an ultrasonic signal, and the ultrasonic playback module (7) amplifies the demodulated ultrasonic signal and converts it into a sound wave output.
8. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 7, characterized in that: The photoelectric converter module (6) comprises: a silicon photodiode D3, capacitors C7-C9, resistors R7-R10 and an operational amplifier U3; The silicon photodiode D3 is used to collect the laser signal sent by the transmitting end. The positive electrode of the silicon photodiode D3 is connected to the negative electrode of the capacitor C9. The positive electrode of the capacitor C9 is respectively connected to one end of the resistor R10 and the non-inverting input end of the operational amplifier U3. The inverting input end of the operational amplifier U3 is respectively connected to one end of the resistor R8 and one end of the resistor R7. The output end of the operational amplifier U3 is respectively connected to the other end of the resistor R7, one end of the resistor R9 and the positive electrode of the ultrasonic playback module (7). The other end of the resistor R9 is connected to one end of the capacitor C8. The other end of the resistor R8 is connected to the positive electrode of the capacitor C7. The negative electrode of the silicon photodiode D3, the other end of the resistor R10, the negative electrode of the capacitor C7 and the other end of the capacitor C8 are all connected to the power ground.
9. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 7, characterized in that: The ultrasonic playback module (7) is an ultrasonic speaker or an ultrasonic transducer array.
10. The long-distance wireless transmission device for ultrasonic signals based on laser intensity modulation according to claim 9, characterized in that: The ultrasonic broadcasting module (7) generates ultrasonic waves with a frequency range of 20 kHz to 100 kHz.