Signal demodulation method and system based on ion coherent vibration state

Abstract

The invention discloses a signal demodulation method and system based on an ion coherent vibration state, and belongs to the technical field of communication, and the method comprises the steps: obtaining coherent vibration state ions and standard signals of different modulation types, enabling the coherent vibration state ions to fluctuate along with the code element change of the standard signals, and obtaining standard fluctuation ions; measuring standard fluctuation ions to construct a modulation feature library; acquiring a to-be-demodulated signal, and enabling the coherent vibration state ions to fluctuate along with the code element change of the to-be-demodulated signal to obtain fluctuating ions; based on the modulation feature library, performing matching identification on the amplitude and the phase of the fluctuating ions to complete signal demodulation on the to-be-demodulated signal: when the amplitude jumps and the phase is unchanged, performing amplitude demodulation; when the amplitude and the phase jump at the same time and jump directions are opposite, phase demodulation is carried out; and when the jump of the amplitude and the phase presents a sine periodic rule, frequency demodulation is carried out. According to the method disclosed by the invention, the demodulation accuracy and applicability of the communication system can be improved.

Description

Technical Field

[0001] This invention belongs to the field of communication technology, and in particular relates to a signal demodulation method and system based on ion coherent vibration dynamics. Background Technology

[0002] In modern broadcasting, telemetry, and numerous communication electronic systems, efficient and reliable information transmission relies on modulation techniques that load baseband signals onto a carrier wave. Amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM), along with their derivative digital modulation methods (such as ASK, FSK, PSK, QAM, etc.), constitute the most fundamental and widely used techniques. Different application scenarios have varying requirements for spectral efficiency, power efficiency, interference immunity, and implementation cost, directly leading to a significant diversity of modulation methods. Simultaneously, the demand for universal demodulation capabilities in emerging application scenarios is rapidly increasing. This diversity of modulation methods and the development of application scenarios pose serious challenges to demodulation technology at the receiving end.

[0003] For a long time, the design of traditional electric field signal demodulators has followed the pattern of "one demodulator for one modulation method." The fundamental reason for this is the essential difference in the demodulation principles of different modulation methods. For example, AM demodulation relies on envelope detectors or coherent carrier recovery; FM demodulation requires slope discrimination, PLL phase discrimination, or quadrature discrimination; PM / PSK demodulation must be based on phase-locked loops or Costas loops for coherent carrier recovery and phase discrimination. Traditional solutions with multi-mode demodulation capabilities integrate multiple independent, specific modulation-optimized demodulation circuits into the same device, resulting in hardware redundancy, high material costs, significantly increased power consumption, and the introduction of problems such as signal crosstalk and impedance matching. Furthermore, the rigid architecture means the device only supports predefined modulation modes and cannot adapt to new standards or custom signals, leading to slow dynamic switching speeds and low reliability. Therefore, existing technologies in communication systems suffer from low demodulation accuracy and poor applicability. Summary of the Invention

[0004] The present invention aims to provide a signal demodulation method and system based on ion coherent vibration dynamics to solve the above-mentioned technical problems and improve the accuracy and applicability of communication system demodulation.

[0005] To address the aforementioned technical problems, this invention provides a signal demodulation method based on ion coherent vibrational dynamics, comprising the following steps: Acquire coherent vibratory ions and standard signals of different modulation types, and make the coherent vibratory ions fluctuate with the symbol changes of the standard signals to obtain standard fluctuating ions; The amplitude and phase of the standard wave ion are measured to construct a modulation feature library based on the obtained amplitude and phase information; The signal to be demodulated is acquired, and the coherent vibrational ions are made to fluctuate with the symbol changes of the signal to be demodulated to obtain fluctuating ions; Based on the modulation feature library, the amplitude and phase of the wave ions are matched and identified to demodulate the signal to be demodulated. When the amplitude changes abruptly while the phase remains unchanged, amplitude demodulation is performed. When the amplitude and the phase both jump simultaneously and in opposite directions, phase demodulation is performed. When the amplitude and phase transitions exhibit a sinusoidal periodic pattern, frequency demodulation is performed.

[0006] In the above scheme, coherent vibratory ions and a standard signal are acquired. The coherent vibratory ions fluctuate with the symbol changes of the standard signal. Standard fluctuating ions are obtained by the beat frequency interaction between the coherent vibratory ions and the standard signal, thereby constructing a modulation feature library. This can filter out noise interference in the signal and improve the accuracy of signal demodulation. Based on the modulation feature library, the amplitude and phase of the fluctuating ions are matched and identified to complete the amplitude demodulation, phase demodulation, or frequency demodulation of the signal to be demodulated. This is because different modulation types of signals have different effects on the amplitude and phase of the coherent vibratory ions, enabling demodulation of signals to be demodulated with different modulation types. This improves its applicability to general demodulation of different modulation signals, thereby improving the accuracy and applicability of the communication system demodulation.

[0007] Furthermore, the construction of the modulation feature library based on the obtained amplitude and phase information includes: if the amplitude of the standard wave ion jumps while the phase remains unchanged, it is set to amplitude modulation; if the amplitude and phase of the standard wave ion jump simultaneously and in opposite directions, it is set to phase modulation; if the jumps in amplitude and phase of the standard wave ion exhibit a sinusoidal periodicity, it is set to frequency modulation.

[0008] It should be noted that in this scheme, the symbol carrier signal strength of the standard signal can be 75mV, and the symbol time can be 10s; the amplitude modulation intensity can be 30mV, the frequency modulation intensity can be 0.2 Hz, and the phase modulation intensity can be... .

[0009] It should be noted that the construction of the modulation feature library based on the obtained amplitude and phase information can be implemented using an FPGA. After measuring the amplitude and phase of the standard wave ion, the obtained amplitude and phase information are as follows: If the amplitude changes significantly and its amplitude change pattern is synchronized with the symbol of the standard signal, while the phase remains basically unchanged, then the symbol corresponding to the moment with larger amplitude is set to 1, and the symbol corresponding to the moment with smaller amplitude is set to 0, to be set as amplitude modulation; if both amplitude and phase change significantly at the same time, and the directions of amplitude and phase change are opposite, then the symbol corresponding to the moment with smaller amplitude and larger phase is set to 1, and the symbol corresponding to the moment with larger amplitude and smaller phase is set to 0, to be set as phase modulation; if both amplitude and phase exhibit sinusoidal periodic fluctuations, then the symbol corresponding to the moment with the counterclockwise evolution direction in the phase space composed of phase and amplitude is set to 1, and the symbol corresponding to the moment with the clockwise evolution direction is set to 0, to be set as frequency modulation.

[0010] It should be noted that the measurement of the amplitude and phase of the standard wave ion can be achieved using heterodyne detection technology. This scheme uses heterodyne detection technology with a sampling rate of 1 Sa / s and a total sampling time of 50 s. By acquiring the amplitude A(t) and phase φ(t) parameters of the ion vibration state in real time, a modulation feature library is constructed based on the response laws of amplitude and phase.

[0011] In the above scheme, standard wave ions are obtained by acquiring standard signals with different modulation types and causing coherent vibratory ions to fluctuate with the symbol changes of the standard signals. This refers to inputting reference signals with known modulation methods such as amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM), causing coherent vibratory ions to fluctuate with the symbol changes of the standard signals through beat frequency effects to form standard wave ions. Then, the amplitude and phase of the standard wave ions are measured using heterodyne detection technology. Based on the different characteristics of amplitude and phase transitions, amplitude modulation, phase modulation, and frequency modulation are respectively set, and a preset modulation feature library is constructed using FPGA. This process constructs the feature library based on the actual fluctuation characteristics of the standard signals, providing a reference standard for the amplitude and phase matching identification of the signal to be demodulated, avoiding demodulation identification errors, and improving the accuracy of signal demodulation. Meanwhile, in addition to specifically covering the feature judgment rules of the three modulation types of amplitude, phase and frequency, the feature library can also add standard signals of other modulation types, thereby improving the identification basis of different modulation signals, better adapting to the demodulated signals of various modulation types, further strengthening the general demodulation capability of different modulation signals, improving the applicability of demodulation, and thus continuously improving the demodulation accuracy and applicability of the communication system.

[0012] Furthermore, in acquiring coherent vibratory ions and standard signals of different modulation types, and causing the coherent vibratory ions to fluctuate with the symbol changes of the standard signals to obtain standard fluctuating ions, the acquisition of coherent vibratory ions includes: setting up an ion trap to acquire trapped ions; performing Doppler cooling on the trapped ions to obtain cooled ions, and inputting a periodic driving signal of the same frequency into the ion trap to excite the cooled ions to generate coherent vibratory states, thereby obtaining coherent vibratory ions.

[0013] Furthermore, the step of setting up an ion trap to obtain trapped ions specifically involves: setting up an ion trap; performing laser ionization on the pre-acquired calcium atom gas to obtain calcium ions; and loading the calcium ions into the ion trap to obtain trapped ions.

[0014] It should be noted that in this scheme, the ion trap can be powered by both DC and RF power supplies to form a stable trapping potential field. Laser ionization of the pre-acquired calcium atom gas refers to irradiating the calcium atom vapor generated by heating in a calcium furnace with an ionizing laser, causing it to lose electrons and transform into charged calcium ions. 40 Ca + Calcium ions are loaded into an ion trap to capture ionized calcium ions through a trapping potential field, thus obtaining trapped ions.

[0015] In the above scheme, the trapping environment provided by the ion trap, combined with Doppler cooling technology, effectively suppresses environmental thermal noise and random disturbances, giving the coherent vibratory ions long coherence time and high signal-to-noise ratio. The precise matching of the periodic drive signal and the trap frequency ensures the stable establishment and controllable adjustment of the coherent vibratory ions. This allows the coherent vibratory ions to only fluctuate in response to the modulation information of the signal to be demodulated, remaining insensitive to the system's background noise. This provides a basis for detecting amplitude and phase fluctuations caused by subsequent beat frequency effects, thereby improving the accuracy of signal demodulation. Simultaneously, the stable and highly coherent coherent vibratory ions can adapt to the beat frequency response of signals with different modulation types, such as amplitude, phase, and frequency, ensuring universal demodulation capability for various modulated signals and further enhancing the applicability of demodulation. This, in turn, improves the demodulation accuracy and applicability of the communication system.

[0016] Further, the step of performing Doppler cooling on the trapped ions to obtain cooled ions, and inputting a periodic driving signal of the same frequency into the ion trap to excite the cooled ions to generate coherent vibrational states, thereby obtaining coherent vibrational state ions, includes: acquiring a red detuned laser and a cooling laser, and combining the laser beams to obtain a combined laser; inputting the combined laser into the ion trap to perform Doppler cooling on the trapped ions to obtain cooled ions; acquiring a driving signal, adjusting the frequency of the driving signal to be the same as the trap frequency of the ion trap to obtain a periodic driving signal; and inputting the periodic driving signal into the ion trap to excite the cooled ions to generate coherent vibrational states, thereby obtaining coherent vibrational state ions.

[0017] It should be noted that the red detuned laser for Doppler cooling of trapped ions can be obtained by splitting a 397nm laser through a polarization beam splitter (PBS) and then outputting one of the laser beams through a red detuned acousto-optic modulator (AOM); the cooling laser can be obtained by an 866nm laser.

[0018] It should be noted that the driving signal in this scheme can be a sinusoidal signal generated by an arbitrary waveform generator (AWG); the trap frequency of the ion trap in this scheme is... The periodic driving signal strength in this scheme is 600 mV, at which point the amplitude of the coherent vibrational ions is approximately... .

[0019] In the above scheme, the Doppler-cooled laser action is made more precise and efficient through specific laser preparation and beam combining methods, effectively reducing the thermal motion noise of trapped ions and minimizing the influence of irrelevant interference on ion vibration. By generating a sinusoidal driving signal using an AWG and precisely matching it to the ion trap frequency, and then inputting a periodic driving signal with a fixed intensity, coherent vibrational ions with stable amplitudes can be precisely excited. This avoids the decrease in ion coherence caused by driving signal mismatch or poor laser cooling effect, so that the beat frequency interaction between the coherent vibrational ions and the signal to be demodulated can more accurately fluctuate with symbol changes. This provides a more reliable basis for the subsequent extraction of the amplitude and phase of the fluctuating ions, thereby further reducing measurement deviations caused by noise interference, improving the accuracy of signal demodulation, and better adapting to the beat frequency response of different modulation types of signals, ensuring the stability of universal demodulation, and further improving the applicability of demodulation.

[0020] Furthermore, before matching and identifying the amplitude and phase of the wave ions based on the modulation feature library to demodulate the signal to be demodulated, the method further includes: imaging the fluorescence signal generated by the wave ions to obtain wave ion signal light; splitting and combining the wave ion signal light and obtaining the wave ion photocurrent through a photodetector; and measuring the wave ion photocurrent to obtain the amplitude and phase of the wave ions.

[0021] It should be noted that imaging the fluorescence signal generated by the wave ions can be achieved using an imaging mirror to obtain the wave ion signal light; the signal light can be split using a 1:9 beam splitter. The weaker wave ion signal light is input to a preset charge-coupled device (CCD) to observe the spatial position change of the ions. The stronger wave ion signal light is combined with another 397nm heterodyne probe laser obtained by the polarization beam splitter (PBS). The combined laser beam is then input to a photodetector. The wave ion photocurrent output from the photodetector is then input to a preset lock-in amplifier and orthogonally demodulated using the frequency of the periodic drive signal as a reference frequency to obtain the amplitude and phase of the wave ions.

[0022] In the above scheme, the wave ion optical signal is screened and optimized through imaging and beam splitting and combining. The photodetector is used to achieve precise conversion of optical signal to electrical signal, making the measurement of wave ion amplitude and phase more accurate. This effectively reduces noise interference during signal transmission and conversion, thereby avoiding demodulation identification errors caused by measurement deviations and further improving the accuracy of signal demodulation. At the same time, this standardized optical signal processing and current measurement process can be adapted to the detection of wave ion optical signals under different modulation types of signals. It can stably extract the amplitude and phase characteristics of various wave ions, ensuring universal demodulation identification for different modulation signals, further improving the applicability of demodulation, and thus improving the demodulation accuracy and applicability of the communication system.

[0023] This invention also provides a signal demodulation system based on coherent ion vibration dynamics, comprising: a standard wave ion acquisition module, used to acquire coherent vibration dynamic ions and standard signals of different modulation types, so that the coherent vibration dynamic ions fluctuate with the symbol changes of the standard signals to obtain standard wave ions; a modulation feature library construction module, used to measure the amplitude and phase of the standard wave ions to construct a modulation feature library based on the obtained amplitude and phase information; a wave ion acquisition module, used to acquire the signal to be demodulated, so that the coherent vibration dynamic ions fluctuate with the symbol changes of the signal to be demodulated to obtain wave ions; and a matching identification demodulation module, used to match and identify the amplitude and phase of the wave ions based on the modulation feature library to complete signal demodulation of the signal to be demodulated: when the amplitude changes abruptly and the phase remains unchanged, amplitude demodulation is performed; when the amplitude and the phase change abruptly at the same time and the directions of the change are opposite, phase demodulation is performed; when the amplitude and the phase change exhibit a sinusoidal periodic pattern, frequency demodulation is performed.

[0024] Furthermore, in the modulation feature library construction module, the measurement of the amplitude and phase of the standard wave ion to construct the modulation feature library based on the obtained amplitude and phase information includes: if the amplitude of the standard wave ion jumps while the phase remains unchanged, it is set to amplitude modulation; if the amplitude and phase of the standard wave ion jump simultaneously and in opposite directions, it is set to phase modulation; if the jumps in the amplitude and phase of the standard wave ion exhibit a sinusoidal periodicity, it is set to frequency modulation.

[0025] Furthermore, in the standard wave ion acquisition module, coherent vibratory ions and standard signals of different modulation types are acquired, causing the coherent vibratory ions to fluctuate with the symbol changes of the standard signals to obtain standard wave ions. The acquisition of coherent vibratory ions includes: setting up an ion trap to acquire trapped ions; performing Doppler cooling on the trapped ions to obtain cooled ions; and inputting a periodic driving signal of the same frequency into the ion trap to excite the cooled ions to generate coherent vibratory states to obtain coherent vibratory ions.

[0026] Furthermore, the matching and demodulation module, used to match and identify the amplitude and phase of the wave ions based on the modulation feature library before demodulating the signal to be demodulated, further includes: a photoelectric conversion module, used to image the fluorescence signal generated by the wave ions to obtain wave ion signal light; to split and combine the wave ion signal light and obtain the wave ion photocurrent through a photodetector; and to measure the wave ion photocurrent to obtain the amplitude and phase of the wave ions.

[0027] The above solution provides a clear system architecture with well-defined functional divisions and close collaboration among modules, forming a complete signal demodulation process. The standard ion acquisition module is used to acquire coherent vibratory ions and a standard signal. The coherent vibratory ions fluctuate with the symbol changes of the standard signal to obtain standard wave ions. Specifically, a stable trapping potential field is formed in an ion trap. Calcium atoms are obtained by laser ionization of the gas and loaded into the ion trap to form trapped ions. A 397nm laser is split by a polarization beam splitter (PBS) and the red-detuned laser output from an AOM (Aurora Optical Modulator) is combined with a cooled laser obtained from an 866nm laser and input into the ion trap to perform Doppler cooling on the trapped ions, obtaining cooled ions. Simultaneously, a sinusoidal drive signal generated by an arbitrary waveform generator (AWG) is adjusted to match the trap frequency of the ion trap to obtain a periodic drive signal, which excites the cooled ions to become coherent vibratory ions. Finally, the coherent vibratory ions and the standard signal fluctuate with the symbol changes through beat frequency interaction, resulting in standard wave ions.

[0028] The modulation feature library construction module is used to establish a preset modulation feature library. Specifically, it inputs a standard signal with amplitude, frequency, and phase modulation type, so that coherent vibrating dynamic ions change with the standard signal symbol to generate standard wave ions through beat frequency effect. Then, it measures the amplitude and phase of the standard wave ions through heterodyne detection technology. The FPGA constructs the feature library based on the measurement results, sets it to amplitude modulation, phase modulation, or frequency modulation, and sets the corresponding judgment rules for symbol 0 or 1.

[0029] The photoelectric conversion module is used to extract the amplitude and phase of the wave ions before matching and identification. Specifically, the fluorescent signal generated by the wave ions is imaged by the imaging mirror to obtain the wave ion signal light. After being split by a 1:9 beam splitter, the stronger signal light is combined with the 397nm heterodyne probe laser. The signal light is then converted into wave ion photocurrent by the photodetector. The photocurrent is then input into the lock-in amplifier and subjected to quadrature demodulation to obtain the amplitude and phase of the wave ions.

[0030] The matching and recognition demodulation module is used to perform feature matching and recognition on the amplitude and phase of the wave ions extracted by the photoelectric conversion module based on the modulation feature library, so as to complete the signal demodulation according to the matching and recognition results. When the amplitude jumps and the phase remains unchanged, amplitude demodulation is performed; when the amplitude and phase jump simultaneously and in opposite directions, phase demodulation is performed; and when the amplitude and phase jumps show a periodic pattern, frequency demodulation is performed.

[0031] In the above scheme, the entire system abandons the traditional multi-circuit physical integration mode of demodulators. Instead, it forms a universal physical demodulation platform through coherent vibrational ionization. Combined with the standardized collaborative work of each module, it effectively solves the technical problems of hardware redundancy, low demodulation accuracy, and poor adaptability of traditional demodulation schemes. It not only significantly improves the signal demodulation accuracy of the communication system through noise suppression, but also strengthens the universal demodulation capability for signals with different modulation types through the construction of a universal feature library and demodulation recognition, significantly improving the applicability of demodulation. Ultimately, it achieves a dual improvement in the demodulation accuracy and applicability of the communication system, meeting the needs of modern communication for universal and high-precision demodulation. Attached Figure Description

[0032] Figure 1 This is a schematic flowchart of a signal demodulation method based on ion coherent vibration dynamics provided in an embodiment of the present invention; Figure 2 This is a diagram showing the jump pattern of the amplitude and phase of the ion coherent vibration dynamics over time under the action of an amplitude modulation (AM) signal with symbol

[01] , provided in an embodiment of the present invention. Figure 3 This is a diagram showing the jump pattern of the amplitude and phase of the coherent ion vibration dynamics over time under the action of a phase modulation (PM) signal with symbol

[01] , provided in an embodiment of the present invention. Figure 4 This is a diagram showing the jump pattern of the amplitude and phase of the coherent ion vibration dynamics over time under the action of a frequency modulation (FM) signal with symbol

[01] , provided in an embodiment of the present invention. Figure 5 The following is an evolution diagram of the coherent vibrational state of ions in the phase space composed of phase and amplitude under the action of a frequency modulation (FM) signal with symbol

[01] , provided by an embodiment of the present invention. The evolution direction is counterclockwise. Figure 6 The following is an evolution diagram of the coherent vibrational state of ions in the phase space composed of phase and amplitude under the action of a frequency modulation (FM) signal with symbol

[01] , provided by an embodiment of the present invention. The evolution direction is clockwise. Figure 7 This is a schematic diagram of a signal demodulation system architecture based on ion coherent vibration dynamics, provided as an embodiment of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figure 1 This embodiment provides a signal demodulation method based on ion coherent vibrational dynamics, which includes the following steps: Step S1: Obtain coherent vibratory dynamic ions and standard signals of different modulation types, so that the coherent vibratory dynamic ions fluctuate with the symbol changes of the standard signals to obtain standard fluctuating ions; Step S2: Measure the amplitude and phase of the standard wave ion to construct a modulation feature library based on the obtained amplitude and phase information; Step S3: Acquire the signal to be demodulated, and make the coherent vibrational ions fluctuate with the symbol changes of the signal to be demodulated to obtain fluctuating ions; Step S4: Based on the modulation feature library, the amplitude and phase of the wave ion are matched and identified to demodulate the signal to be demodulated: when the amplitude changes abruptly and the phase remains unchanged, amplitude demodulation is performed; when the amplitude and the phase change abruptly at the same time and the directions of the changes are opposite, phase demodulation is performed; when the amplitude and the phase change abruptly exhibit a sinusoidal periodic pattern, frequency demodulation is performed.

[0035] In this embodiment, coherent vibratory ions and a standard signal are acquired. The coherent vibratory ions fluctuate with the symbol changes of the standard signal. Standard fluctuating ions are obtained by the beat frequency interaction between the coherent vibratory ions and the standard signal, thereby constructing a modulation feature library. This library can filter out noise interference in the signal and improve the accuracy of signal demodulation. Based on the modulation feature library, the amplitude and phase of the fluctuating ions are matched and identified to perform amplitude demodulation, phase demodulation, or frequency demodulation of the signal to be demodulated. This is because different modulation types of signals have different effects on the amplitude and phase of the coherent vibratory ions, enabling demodulation of signals with different modulation types. This improves the applicability of the demodulation to different modulation signals, thereby improving the accuracy and applicability of the communication system demodulation.

[0036] Furthermore, the construction of the modulation feature library based on the obtained amplitude and phase information includes: if the amplitude of the standard wave ion jumps while the phase remains unchanged, it is set to amplitude modulation; if the amplitude and phase of the standard wave ion jump simultaneously and in opposite directions, it is set to phase modulation; if the jumps in amplitude and phase of the standard wave ion exhibit a sinusoidal periodicity, it is set to frequency modulation.

[0037] It should be noted that the construction of the modulation feature library based on the obtained amplitude and phase information can be implemented using an FPGA. After measuring the amplitude and phase of the standard wave ion, the obtained amplitude and phase information includes: Figure 2As shown, if the amplitude changes drastically, and the amplitude change pattern is synchronized with the symbol of the standard signal, while the phase remains basically unchanged, then the symbol corresponding to the moment with larger amplitude is set to 1, and the symbol corresponding to the moment with smaller amplitude is set to 0, thus setting it as amplitude modulation; for example... Figure 3 As shown, if both amplitude and phase undergo large jumps simultaneously, and the directions of these jumps are opposite, then the code corresponding to the moment with smaller amplitude and larger phase is set to 1, and the code corresponding to the moment with larger amplitude and smaller phase is set to 0, thus setting it as phase modulation; for example... Figure 4 As shown, if both amplitude and phase fluctuate periodically, then the evolution direction in the phase space composed of phase and amplitude is set to be counterclockwise (e.g., ...). Figure 5 As shown, the corresponding code element is 1, and the evolution direction is clockwise (e.g., ...). Figure 6 The symbol corresponding to the value shown is 0, which is set to frequency modulation; where the horizontal axis Time is time, A (um) is the amplitude change with time t, and φ (rad) is the phase change with time t.

[0038] It should be noted that the measurement of the amplitude and phase of the standard wave ion can be achieved using heterodyne detection technology. In this embodiment, the sampling rate of the heterodyne detection technology is 1 Sa / s, and the total sampling time is 50 s. By acquiring the amplitude A(t) and phase φ(t) parameters of the ion vibration state in real time, a modulation feature library is constructed based on the response laws of amplitude and phase.

[0039] In this embodiment, standard signals of different modulation types are acquired, and coherent vibrating ions are generated by fluctuating with the symbol changes of the standard signals to obtain standard wave ions. This refers to inputting reference signals with known modulation methods such as amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM), causing coherent vibrating ions to fluctuate with the symbol changes of the standard signals through beat frequency effects to form standard wave ions. Then, the amplitude and phase of the standard wave ions are measured using heterodyne detection technology. Based on the different characteristics of amplitude and phase transitions, amplitude modulation, phase modulation, and frequency modulation are respectively set, and a preset modulation feature library is constructed using FPGA. This process constructs the feature library based on the actual fluctuation characteristics of the standard signals, providing a reference standard for amplitude and phase matching identification of the signal to be demodulated, avoiding demodulation identification errors, and improving the accuracy of signal demodulation. Meanwhile, in addition to specifically covering the feature judgment rules of the three modulation types of amplitude, phase and frequency, the feature library can also add standard signals of other modulation types, thereby improving the identification basis of different modulation signals, better adapting to the demodulated signals of various modulation types, further strengthening the general demodulation capability of different modulation signals, improving the applicability of demodulation, and thus continuously improving the demodulation accuracy and applicability of the communication system.

[0040] Furthermore, in acquiring coherent vibratory ions and standard signals of different modulation types, and causing the coherent vibratory ions to fluctuate with the symbol changes of the standard signals to obtain standard fluctuating ions, the acquisition of coherent vibratory ions includes: setting up an ion trap to acquire trapped ions; performing Doppler cooling on the trapped ions to obtain cooled ions, and inputting a periodic driving signal of the same frequency into the ion trap to excite the cooled ions to generate coherent vibratory states, thereby obtaining coherent vibratory ions.

[0041] Furthermore, the step of setting up an ion trap to obtain trapped ions specifically involves: setting up an ion trap; performing laser ionization on the pre-acquired calcium atom gas to obtain calcium ions; and loading the calcium ions into the ion trap to obtain trapped ions.

[0042] In one embodiment, the ion trap can be powered by a DC power supply and a radio frequency power supply to form a stable trapping potential field. Laser ionization of the pre-acquired calcium atom gas refers to irradiating the calcium atom vapor generated by heating in a calcium furnace with an ionizing laser, causing it to lose electrons and transform into charged calcium ions. 40 Ca + Calcium ions are loaded into an ion trap to capture ionized calcium ions through a trapping potential field, thus obtaining trapped ions.

[0043] In this embodiment, the trapping environment provided by the ion trap, combined with Doppler cooling technology, effectively suppresses environmental thermal noise and random disturbances, giving the coherent vibratory ions long coherence time and high signal-to-noise ratio. The precise matching of the periodic drive signal and the trap frequency ensures the stable establishment and controllable adjustment of the coherent vibratory ions. This allows the coherent vibratory ions to only fluctuate in response to the modulation information of the signal to be demodulated, remaining insensitive to the system's background noise. This provides a basis for detecting amplitude and phase fluctuations caused by subsequent beat frequency effects, thereby improving the accuracy of signal demodulation. Simultaneously, the stable and highly coherent coherent vibratory ions can adapt to the beat frequency response of signals with different modulation types such as amplitude, phase, and frequency, ensuring universal demodulation capability for various modulation signals and further enhancing the applicability of demodulation. This, in turn, improves the demodulation accuracy and applicability of the communication system.

[0044] Further, the step of performing Doppler cooling on the trapped ions to obtain cooled ions, and inputting a periodic driving signal of the same frequency into the ion trap to excite the cooled ions to generate coherent vibrational states, thereby obtaining coherent vibrational state ions, includes: acquiring a red detuned laser and a cooling laser, and combining the laser beams to obtain a combined laser; inputting the combined laser into the ion trap to perform Doppler cooling on the trapped ions to obtain cooled ions; acquiring a driving signal, adjusting the frequency of the driving signal to be the same as the trap frequency of the ion trap to obtain a periodic driving signal; and inputting the periodic driving signal into the ion trap to excite the cooled ions to generate coherent vibrational states, thereby obtaining coherent vibrational state ions.

[0045] It should be noted that the red detuned laser for Doppler cooling of trapped ions can be obtained by splitting a 397nm laser through a polarization beam splitter (PBS) and then outputting one of the laser beams through a red detuned acousto-optic modulator (AOM); the cooling laser can be obtained by an 866nm laser.

[0046] In this embodiment, a specific laser preparation and beam combining method makes the Doppler-cooled laser action more precise and efficient, effectively reducing the thermal motion noise of trapped ions and minimizing the influence of irrelevant interference on ion vibration. By generating a sinusoidal driving signal using an AWG and precisely matching it to the ion trap frequency, and then inputting a periodic driving signal with a fixed intensity, coherent vibrational ions with stable amplitudes can be precisely excited. This avoids the decrease in ion coherence caused by driving signal mismatch or poor laser cooling effect, thus enabling the beat frequency interaction between the coherent vibrational ions and the signal to be demodulated to fluctuate more precisely with symbol changes. This provides a more reliable basis for the subsequent extraction of the amplitude and phase of the fluctuating ions, further reducing measurement deviations caused by noise interference, improving the accuracy of signal demodulation, and better adapting to the beat frequency response of different modulation types of signals, ensuring the stability of universal demodulation, and further improving the applicability of demodulation.

[0047] Furthermore, before matching and identifying the amplitude and phase of the wave ions based on the modulation feature library to demodulate the signal to be demodulated, the method further includes: imaging the fluorescence signal generated by the wave ions to obtain wave ion signal light; splitting and combining the wave ion signal light and obtaining the wave ion photocurrent through a photodetector; and measuring the wave ion photocurrent to obtain the amplitude and phase of the wave ions.

[0048] It should be noted that imaging the fluorescence signal generated by the wave ions can be achieved using an imaging mirror to obtain the wave ion signal light; the signal light can be split using a 1:9 beam splitter. The weaker wave ion signal light is input to a preset charge-coupled device (CCD) to observe the spatial position change of the ions. The stronger wave ion signal light is combined with another 397nm heterodyne probe laser obtained by the polarization beam splitter (PBS). The combined laser beam is then input to a photodetector. The wave ion photocurrent output from the photodetector is then input to a preset lock-in amplifier and orthogonally demodulated using the frequency of the periodic drive signal as a reference frequency to obtain the amplitude and phase of the wave ions.

[0049] In this embodiment, the wave ion optical signal is screened and optimized through imaging and beam splitting / combining. A photodetector is used to achieve precise conversion from optical to electrical signals, making the measurement of wave ion amplitude and phase more accurate. This effectively reduces noise interference during signal transmission and conversion, thus avoiding demodulation identification errors caused by measurement deviations and further improving the accuracy of signal demodulation. Simultaneously, this standardized optical signal processing and current measurement process is adaptable to wave ion optical signal detection under different modulation types of signals. It can stably extract the amplitude and phase characteristics of various wave ions, ensuring universal demodulation identification for different modulation signals, further improving the applicability of demodulation, and thus enhancing the demodulation accuracy and applicability of the communication system.

[0050] In one specific embodiment, the driving signal can be a sinusoidal signal generated by an arbitrary waveform generator (AWG), wherein the driving signal is specifically: In the formula, The amplitude of the driving signal is set to 600 mV in this embodiment; The frequency of the driving signal is, in this embodiment... The trap frequency is the same as that of the ion trap, which is 2π*184 kHz. This is also represented as a periodic driving signal. At this time, the amplitude of the coherent vibrational dynamic ions is approximately... .

[0051] In this embodiment, the standard signal can be specifically represented as: In the formula, The time-domain expression of a standard signal. The strength of the carrier signal. The modulation intensity of amplitude modulation. For amplitude modulation symbol functions, The frequency of the carrier signal. The modulation intensity of the frequency modulation. For frequency modulation symbol functions, The modulation intensity of the phase modulation. For the phase-modulated symbol function, t is used as the independent variable to represent time variation; in one embodiment, the symbol carrier signal strength of the standard signal... The amplitude modulation intensity is 75mV, and the symbol time is 10s; The modulation intensity of the frequency modulation is 30 mV. The modulation intensity of the phase modulation is 0.2 Hz. for .

[0052] Under the influence of a standard signal, coherent vibrational ions fluctuate with the symbol changes of the standard signal, resulting in standard wave ions. The equation of motion for these standard wave ions is specifically expressed as follows: Where m is the mass of the calcium ion. This represents the acceleration of the standard wave ion along the Z-axis at time t. The characteristic angular frequency of the ion trap's Z-axis, i.e., the trap frequency, Let be the displacement of the coherent vibrational dynamic ion at time t. To reduce Planck's constant, The wave vector of the red detuned laser. This represents the ion scattering rate under red detuned laser irradiation. The elementary charge is the amount of charge carried by a single electron. The driving signal, in this scheme, can also be represented as a periodic driving signal. The standard signal is referred to therein.

[0053] Among them, the coherent vibrational state of the ions can be regarded as a state along the X-axis, with frequency varying with the driving signal. Simple harmonic motion at the same frequency: in, and Let these be the amplitude and phase of the coherent vibration, respectively. Substituting the above equation into the standard wave ion equation, simplifying it, and integrating the equation over one vibration period, we can obtain the slowly varying amplitude term in the coherent vibration equation. and slow phase term Separate the signal, approximate it using a slow variation method, and substitute relevant experimental conditions to determine the frequency of the periodic driving signal. The frequency of the carrier signal to be demodulated Consistent, the amplitude and phase of the coherent vibrational dynamics of the ions can be further simplified to: In the formula, The steady-state amplitude reference value of the coherent vibrational dynamic ion when there is no signal input, where m is the mass of the calcium ion. The wave vector of the red detuned laser. The elementary charge is the amount of charge carried by a single electron. The strength of the carrier signal. The modulation intensity of amplitude modulation. For amplitude modulation symbol functions, The frequency of the carrier signal. The frequency of the periodic drive signal, The modulation intensity of the frequency modulation. For frequency modulation symbol functions, The modulation intensity of the phase modulation. This is the symbol function for phase modulation.

[0054] The above formula is a general expression of the result obtained after demodulating the standard signal or the signal to be demodulated in this embodiment. The signal to be demodulated causes fluctuations in the amplitude and phase of the coherent vibrating ion, and the modulation type of the signal to be demodulated, namely amplitude modulation (AM), phase modulation (PM), and frequency modulation (FM), respectively causes corresponding changes in the amplitude, phase, and frequency of the amplitude and phase fluctuations of the coherent vibrating ion: For the AM-modulated signal to be demodulated: For the PM-modulated signal to be demodulated: For the FM-modulated signal to be demodulated: In the above formula, The steady-state amplitude reference value of the coherent vibrational dynamic ion when there is no signal input, where m is the mass of the calcium ion. The wave vector of the red detuned laser. The elementary charge is the amount of charge carried by a single electron. The strength of the carrier signal. The modulation intensity of amplitude modulation. For amplitude modulation symbol functions, The frequency of the carrier signal. The frequency of the periodic drive signal, The modulation intensity of the frequency modulation. For frequency modulation symbol functions, The modulation intensity of the phase modulation. This is the symbol function for phase modulation.

[0055] As demonstrated by the above embodiments, coherent vibratory ions exhibit different response results to different types of modulated signals. Therefore, we can use coherent vibratory ions as a universal demodulator to demodulate various types of modulated signals, including AM, PM, and FM. The signal to be demodulated is input into the ion trap electrode, acting on the coherent vibratory ion, causing fluctuations in the amplitude and phase of the vibratory ion. By measuring and analyzing the amplitude and phase fluctuation patterns of the vibratory ion, universal demodulation of modulated signals of different modulation types can be achieved.

[0056] Please see Figure 7 This embodiment also provides a signal demodulation system based on coherent vibrational dynamics of ions, including: a standard wave ion acquisition module, used to acquire coherent vibrational dynamic ions and standard signals of different modulation types, so that the coherent vibrational dynamic ions fluctuate with the symbol changes of the standard signals to obtain standard wave ions; a modulation feature library construction module, used to measure the amplitude and phase of the standard wave ions to construct a modulation feature library based on the obtained amplitude and phase information; a wave ion acquisition module, used to acquire the signal to be demodulated, so that the coherent vibrational dynamic ions fluctuate with the symbol changes of the signal to be demodulated to obtain wave ions; and a matching identification demodulation module, used to match and identify the amplitude and phase of the wave ions based on the modulation feature library to complete signal demodulation of the signal to be demodulated: when the amplitude changes abruptly and the phase remains unchanged, amplitude demodulation is performed; when the amplitude and the phase change abruptly at the same time and the directions of the change are opposite, phase demodulation is performed; when the amplitude and the phase change exhibit a sinusoidal periodicity, frequency demodulation is performed.

[0057] Furthermore, in the modulation feature library construction module, the measurement of the amplitude and phase of the standard wave ion to construct the modulation feature library based on the obtained amplitude and phase information includes: if the amplitude of the standard wave ion jumps while the phase remains unchanged, it is set to amplitude modulation; if the amplitude and phase of the standard wave ion jump simultaneously and in opposite directions, it is set to phase modulation; if the jumps in the amplitude and phase of the standard wave ion exhibit a sinusoidal periodicity, it is set to frequency modulation.

[0058] Furthermore, in the standard wave ion acquisition module, coherent vibratory ions and standard signals of different modulation types are acquired, causing the coherent vibratory ions to fluctuate with the symbol changes of the standard signals to obtain standard wave ions. The acquisition of coherent vibratory ions includes: setting up an ion trap to acquire trapped ions; performing Doppler cooling on the trapped ions to obtain cooled ions; and inputting a periodic driving signal of the same frequency into the ion trap to excite the cooled ions to generate coherent vibratory states to obtain coherent vibratory ions.

[0059] Furthermore, the matching and demodulation module, used to match and identify the amplitude and phase of the wave ions based on the modulation feature library before demodulating the signal to be demodulated, further includes: a photoelectric conversion module, used to image the fluorescence signal generated by the wave ions to obtain wave ion signal light; to split and combine the wave ion signal light and obtain the wave ion photocurrent through a photodetector; and to measure the wave ion photocurrent to obtain the amplitude and phase of the wave ions.

[0060] The system architecture provided by the above embodiments has a clear logical structure, with well-defined functional divisions for each module and close collaboration, forming a complete signal demodulation process: The standard ion acquisition module is used to acquire coherent vibratory ions and a standard signal. The coherent vibratory ions fluctuate with the symbol changes of the standard signal to obtain standard wave ions. Specifically, a stable trapping potential field is formed in an ion trap. Calcium atoms are obtained by laser ionization of the gas and loaded into the ion trap to form trapped ions. A 397nm laser is split by a polarization beam splitter (PBS) and the red-detuned laser output from an AOM (Aurora Optical Modulator) is combined with a cooled laser obtained from an 866nm laser and input into the ion trap to perform Doppler cooling on the trapped ions, obtaining cooled ions. Simultaneously, a sinusoidal drive signal generated by an arbitrary waveform generator (AWG) is adjusted to match the trap frequency of the ion trap to obtain a periodic drive signal, which excites the cooled ions to become coherent vibratory ions. Finally, the coherent vibratory ions and the standard signal fluctuate with the symbol changes through beat frequency interaction, resulting in standard wave ions.

[0061] The modulation feature library construction module is used to establish a preset modulation feature library. Specifically, it inputs a standard signal with amplitude, frequency, and phase modulation type, so that coherent vibrating dynamic ions change with the standard signal symbol to generate standard wave ions through beat frequency effect. Then, it measures the amplitude and phase of the standard wave ions through heterodyne detection technology. The FPGA constructs the feature library based on the measurement results, sets it to amplitude modulation, phase modulation, or frequency modulation, and sets the corresponding judgment rules for symbol 0 or 1.

[0062] The photoelectric conversion module is used to extract the amplitude and phase of the wave ions before matching and identification. Specifically, the fluorescent signal generated by the wave ions is imaged by the imaging mirror to obtain the wave ion signal light. After being split by a 1:9 beam splitter, the stronger signal light is combined with the 397nm heterodyne probe laser. The signal light is then converted into wave ion photocurrent by the photodetector. The photocurrent is then input into the lock-in amplifier and subjected to quadrature demodulation to obtain the amplitude and phase of the wave ions.

[0063] The matching and recognition demodulation module is used to perform feature matching and recognition on the amplitude and phase of the wave ions extracted by the photoelectric conversion module based on the modulation feature library, so as to complete the signal demodulation according to the matching and recognition results. When the amplitude jumps and the phase remains unchanged, amplitude demodulation is performed; when the amplitude and phase jump simultaneously and in opposite directions, phase demodulation is performed; and when the amplitude and phase jumps exhibit a sinusoidal periodicity, frequency demodulation is performed.

[0064] In this embodiment, the entire system abandons the traditional multi-circuit physical integration mode of demodulators. Instead, it forms a universal physical demodulation platform through coherent vibrational dynamic ions. Combined with the standardized collaborative work of each module, it effectively solves the technical problems of hardware redundancy, low demodulation accuracy, and poor adaptability of traditional demodulation schemes. It significantly improves the signal demodulation accuracy of the communication system through noise suppression, and enhances the universal demodulation capability for signals with different modulation types through the construction of a universal feature library and demodulation recognition. This significantly improves the applicability of demodulation and ultimately achieves a dual improvement in the demodulation accuracy and applicability of the communication system, meeting the modern communication demand for universal and high-precision demodulation.

[0065] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A signal demodulation method based on ion coherent vibrational dynamics, characterized in that, include: Acquire coherent vibratory ions and standard signals of different modulation types, and make the coherent vibratory ions fluctuate with the symbol changes of the standard signals to obtain standard fluctuating ions; The amplitude and phase of the standard wave ion are measured to construct a modulation feature library based on the obtained amplitude and phase information; The signal to be demodulated is acquired, and the coherent vibrational ions are made to fluctuate with the symbol changes of the signal to be demodulated to obtain fluctuating ions; Based on the modulation feature library, the amplitude and phase of the wave ions are matched and identified to demodulate the signal to be demodulated. When the amplitude changes abruptly while the phase remains unchanged, amplitude demodulation is performed. When the amplitude and the phase both jump simultaneously and in opposite directions, phase demodulation is performed. When the amplitude and phase transitions exhibit a sinusoidal periodic pattern, frequency demodulation is performed.

2. The signal demodulation method based on ion coherent vibrational dynamics according to claim 1, characterized in that, The step of constructing a modulation feature library based on the obtained amplitude and phase information includes: If the amplitude of the standard wave ion jumps while the phase remains unchanged, then it is set to amplitude modulation. If the amplitude and phase of the standard wave ion jump simultaneously and the jump directions are opposite, it is set as phase modulation; If the amplitude and phase jumps of the standard wave ion exhibit a sinusoidal periodicity, then it is set as frequency modulation.

3. The signal demodulation method based on ion coherent vibrational dynamics according to claim 1, characterized in that, In the process of acquiring coherent vibratory ions and standard signals of different modulation types, and causing the coherent vibratory ions to fluctuate with the symbol changes of the standard signals to obtain standard fluctuating ions, the acquisition of coherent vibratory ions includes: Set up an ion trap to obtain trapped ions; The trapped ions are subjected to Doppler cooling to obtain cooled ions, and a periodic driving signal with the same frequency is input into the ion trap to excite the cooled ions to generate coherent vibrational states, thus obtaining coherent vibrational state ions.

4. The signal demodulation method based on ion coherent vibrational dynamics according to claim 3, characterized in that, The setting of the ion trap to obtain trapped ions specifically involves: Set up an ion trap; The pre-acquired calcium atom gas was ionized by laser to obtain calcium ions; The calcium ions are loaded into the ion trap to obtain trapped ions.

5. The signal demodulation method based on ion coherent vibrational dynamics according to claim 4, characterized in that, The process of Doppler cooling the trapped ions to obtain cooled ions, and inputting a periodic driving signal of the same frequency into the ion trap to excite the cooled ions to generate coherent vibrational states, thereby obtaining coherent vibrational state ions, includes: Obtain red detuned laser and cooled laser, and then combine the laser beams to obtain a combined laser beam; The combined laser beam is input into the ion trap to perform Doppler cooling on the trapped ions to obtain cooled ions. Acquire a driving signal, and adjust the frequency of the driving signal to be the same as the trap frequency of the ion trap to obtain a periodic driving signal; The periodic driving signal is input into the ion trap to excite the cooled ions to generate coherent vibrational states, thereby obtaining coherent vibrational ions.

6. The signal demodulation method based on ion coherent vibrational dynamics according to claim 1, characterized in that, Before performing amplitude and phase matching and identification of the wave ions based on the modulation feature library to complete signal demodulation of the signal to be demodulated, the method further includes: The fluorescence signal generated by the wave ions is imaged to obtain the wave ion signal light; The wave ion signal light is split and combined, and the wave ion photocurrent is obtained through a photodetector. The photocurrent of the wave ion is measured to obtain the amplitude and phase of the wave ion.

7. A signal demodulation system based on ion coherent vibrational dynamics, characterized in that, include: The standard wave ion acquisition module is used to acquire coherent vibratory ions and standard signals of different modulation types, so that the coherent vibratory ions fluctuate with the symbol changes of the standard signals to obtain standard wave ions. The modulation feature library construction module is used to measure the amplitude and phase of the standard wave ion in order to construct a modulation feature library based on the obtained amplitude and phase information. A wave ion acquisition module is used to acquire the signal to be demodulated, and to make the coherent vibrational ions wave with the symbol changes of the signal to be demodulated, thereby obtaining wave ions; The matching and identification demodulation module is used to match and identify the amplitude and phase of the wave ions based on the modulation feature library, so as to complete the signal demodulation of the signal to be demodulated. When the amplitude changes abruptly while the phase remains unchanged, amplitude demodulation is performed. When the amplitude and the phase both jump simultaneously and in opposite directions, phase demodulation is performed. When the amplitude and phase transitions exhibit a sinusoidal periodic pattern, frequency demodulation is performed.

8. A signal demodulation system based on ion coherent vibrational dynamics according to claim 7, characterized in that, In the modulation feature library construction module, the amplitude and phase of the standard wave ion are measured to construct a modulation feature library based on the obtained amplitude and phase information. The construction of the modulation feature library based on the obtained amplitude and phase information includes: If the amplitude of the standard wave ion jumps while the phase remains unchanged, then it is set to amplitude modulation. If the amplitude and phase of the standard wave ion jump simultaneously and the jump directions are opposite, it is set as phase modulation; If the amplitude and phase jumps of the standard wave ion exhibit a sinusoidal periodicity, then it is set as frequency modulation.

9. A signal demodulation system based on ion coherent vibrational dynamics according to claim 7, characterized in that, In the standard wave ion acquisition module, coherent vibratory ions and standard signals of different modulation types are acquired, causing the coherent vibratory ions to fluctuate with the symbol changes of the standard signals to obtain standard wave ions. The acquisition of coherent vibratory ions includes: Set up an ion trap to obtain trapped ions; The trapped ions are subjected to Doppler cooling to obtain cooled ions, and a periodic driving signal with the same frequency is input into the ion trap to excite the cooled ions to generate coherent vibrational states, thus obtaining coherent vibrational state ions.

10. A signal demodulation system based on ion coherent vibration dynamics according to claim 7, characterized in that, The matching and demodulation module, used to match and identify the amplitude and phase of the wave ions based on the modulation feature library before completing signal demodulation of the signal to be demodulated, further includes: The photoelectric conversion module is used to image the fluorescence signal generated by the wave ions to obtain wave ion signal light; to split and combine the wave ion signal light, and to obtain the wave ion photocurrent through a photodetector; and to measure the wave ion photocurrent to obtain the amplitude and phase of the wave ions.

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