A method for active anti-jamming of a Rydberg atom receiver

Abstract

The application relates to the field of Rydberg atom communication and discloses an active anti-interference method for a Rydberg atom receiver; a local oscillation control module is added on the basis of an original Rydberg atom receiver, the local oscillation control module controls a local oscillation microwave module of the Rydberg atom receiver to perform single-tone signal scanning, and the phase and power of a signal emitted by the local oscillation microwave module are adjusted until the amplitude of a single-tone interference intermediate frequency signal detected by a receiving signal processing module of the Rydberg atom receiver is minimum, and at this moment, the optimal power and phase for offsetting interference are obtained. The application provides a detection, identification and interference offsetting method for resisting single-frequency interference for the Rydberg atom receiver, so that the Rydberg atom receiver can realize high-performance reception under the condition of strong single-frequency interference.

Description

Technical Field

[0001] This invention relates to the field of Rydberg atomic communication and proposes a method for detecting and countering malicious single-tone interference, specifically an active anti-interference method for Rydberg atomic receivers. Background Technology

[0002] Radio waves affect the energy level states of Rydberg atoms, therefore, changes in radio waves can be inferred from the atomic energy level states. Wireless communication receivers built on this basis are called Rydberg atom receivers. Driven by the new round of information technology revolution, quantum information technology is considered a new source of major technological paradigm shifts and disruptive innovative applications. Quantum technology mainly involves three major fields: quantum communication, quantum computing, and quantum precision measurement. Rydberg atom receivers utilize quantum precision measurement technology and aim to overcome the bottlenecks of classical radio technology. Rydberg atom receivers utilize the electromagnetically induced transparency (EIT) effect and the Autler-Townes (AT) splitting effect to convert radio signals into optical signals, and achieve integrated extraction of radio signal frequency, amplitude, phase, and other information by analyzing the optical signal. Rydberg atom receivers have the following characteristics:

[0003] (1) Ultra-high sensitivity: The theoretical noise power spectral density can reach -189dBm / Hz, which is 15dB lower than that of traditional receivers (-174dBm / Hz). For long-distance communication, such as satellite communication and scatter communication, if the sensitivity is improved by 3dB, it means that the transmission power is reduced by 3dB under the same application indicators (if the transmission power is 2000W, it can be reduced to 1000W after improvement), which will bring a great improvement in cost-effectiveness.

[0004] (2) Wideband characteristics: The working bandwidth can cover the frequency range of 0 to 1 THz, but the instantaneous signal bandwidth is relatively narrow, about KHz to several MHz, which is suitable for ultra-wideband frequency hopping communication and greatly improves anti-interference capability.

[0005] (3) Self-calibration capability: The measurement results can be directly traced back to the basic physical constants.

[0006] (4) Miniaturization potential: The atomic gas cell is much smaller than that of traditional antennas, breaking through the Chu limit of antenna theory, and can be used to receive medium and low frequency signals, reducing the size of receiving equipment.

[0007] The most advanced type of Rydberg atomic receiver currently available is the superheterodyne Rydberg atomic receiver. This type mixes the local oscillator microwave with the signal microwave to obtain the difference frequency signal and phase difference between the two, thereby enabling the detection of amplitude, frequency, and phase. It is more sensitive to electromagnetic waves, such as... Figure 1As shown. However, when there are out-of-band interference signals, especially those within 100MHz, they can have a significant impact on the system. Single-tone interference can cause an increase in the noise floor, leading to a decrease in the performance of the Rydberg atomic receiver. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the above-mentioned background technology and propose an active anti-interference method for Rydberg atomic receivers against single-tone interference, so as to ensure high-sensitivity reception of Rydberg atomic receivers even when interference is present.

[0009] The technical solution adopted in this invention is as follows:

[0010] An active anti-jamming method for a Rydberg atom receiver includes the following steps:

[0011] (1) Construct an active anti-interference system for a Rydberg atom receiver, including a Rydberg atom receiver and a local oscillator control module. The Rydberg atom receiver includes a laser system, an atomic gas cell, a photodetector, an ADC, a receiving signal processing module, and a local oscillator microwave module.

[0012] (2) The atomic gas cell mixes the signal microwave and the signal output from the local oscillator microwave module. The probe light output by the laser system is modulated according to the change in the transmittance of the atomic gas cell. After processing by the photodetector and ADC, it is output to the receiving signal processing module. When the receiving signal processing module detects that the signal-to-noise ratio of the receiver drops to the set threshold, it controls the local oscillator microwave module to start scanning through the local oscillator control module, and at each scanning frequency point... f n Waiting time set t 0 ;

[0013] (3) At each radio frequency scanning point f n Waiting time t 0 If the receiving signal processing module detects a single-tone intermediate frequency (IF) signal for the first time, it calculates the interfering radio frequency (RF) frequency. f 2 Then the receiving signal processing module controls the local oscillator microwave module to end the scan through the local oscillator control module and executes step (4); if no single-tone intermediate frequency signal is detected, the scan continues;

[0014] (4) For the detected single-tone intermediate frequency signal, the local oscillator control module sets the local oscillator signal of the local oscillator microwave module to a dual-frequency signal. , The frequency contained is signal At this time, the receiving signal processing module detects a single-tone intermediate frequency signal as... SIF2 ;

[0015] (5) The local oscillator control module adjusts the phase of the transmitted signal of the local oscillator microwave module until the single-tone intermediate frequency signal detected by the receiving signal processing module is reached. S IF2 Minimum amplitude, then fix the local oscillator microwave module to transmit dual-frequency signals. The phase, and adjust The power, until the single-tone intermediate frequency signal detected by the receiving signal processing module. S IF2 The amplitude reaches its minimum again at this point. In order to achieve the optimal power and phase to cancel out interference, the local oscillator signal of the local oscillator microwave module is then set.

[0016] Furthermore, in step (2), the scanning range is: The scan proceeds from smallest to largest, with a single-frequency scanning signal; among which... The scanning frequency step can be adjusted according to requirements. This is the normal operating frequency of the Rydberg atomic receiver.

[0017] Furthermore, in step (3), the interfering radio frequency... f 2 The calculation method is as follows:

[0018] f 2 = f n +IF 1；

[0019] Wherein, IF1 is the frequency of the single-tone intermediate frequency signal.

[0020] Furthermore, in step (4), the dual-frequency signal for:

[0021] ;

[0022] in, Frequency is , Frequency is , and The frequency difference does not exceed the intermediate frequency range detectable by the Rydberg receiver; at this time, the receiving signal processing module is at the intermediate frequency. A single-tone intermediate frequency signal of S can be detected at this location. IF2。

[0023] Furthermore, in step (5), the local oscillator signal of the local oscillator microwave module is set to:

[0024] ;

[0025] in, This is the local oscillator used when the Rydberg atomic receiver was originally in operation.

[0026] The technical advantages of the present invention compared with the prior art are as follows:

[0027] This invention provides a method for detecting, identifying, and canceling single-frequency interference for Rydberg atomic receivers, enabling Rydberg atomic receivers to achieve high-performance reception under strong single-frequency interference conditions. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0029] Figure 1 This is a superheterodyne Rydberg atomic receiver according to an embodiment of the present invention.

[0030] Figure 2 This invention relates to a Rydberg atomic receiver with interference cancellation functionality. Detailed Implementation

[0031] The overall block diagram of the present invention is as follows: Figure 2 As shown, in Figure 1 Based on the Rydberg atom receiver shown, a local oscillator control module is added, which can adjust the amplitude, frequency, and phase of the local oscillator. The invention will be further described in detail below with reference to the accompanying drawings and embodiments. This embodiment operates at a normal operating frequency. Take the Rydberg atomic receiver at 10 GHz as an example.

[0032] An active anti-jamming method for a Rydberg atom receiver specifically includes the following steps:

[0033] (1) Construct an active anti-interference system for a Rydberg atom receiver, including a Rydberg atom receiver and a local oscillator control module. The Rydberg atom receiver includes a laser system, an atomic gas cell, a photodetector, an ADC, a receiving signal processing module, and a local oscillator microwave module.

[0034] (2) The laser system of the Rydberg atom receiver generates probe light and coupling light to excite Rydberg atoms in the atomic gas chamber (such as the cesium atom gas chamber); the atomic gas chamber receives external signal microwave and local oscillator signal output from the local oscillator microwave module, and modulates the intensity of the probe light after mixing; the photodetector converts the optical signal into an electrical signal, which is sampled by the ADC and sent to the receiving signal processing module (such as FPGA or DSP); the local oscillator control module is implemented by a microprocessor, with built-in anti-interference algorithm, which can control the output of the local oscillator microwave module (such as frequency synthesizer);

[0035] When the receiving signal processing module detects that the receiver signal-to-noise ratio has dropped to a set threshold, it instructs the local oscillator control module to start local oscillator frequency scanning. The local oscillator control module then controls the local oscillator microwave module to begin scanning. The scanning signal is single-frequency, and the scanning range is [missing information]. Scan from smallest to largest, and at each scan frequency f n Waiting time set to t0; where The scanning frequency step can be adjusted according to requirements. It can usually be set to 100MHz. This is the normal operating frequency of the Rydberg atomic receiver;

[0036] Interference detection and frequency scanning examples:

[0037] Assuming the receiver is working normally =10GHz. When the receiving signal processing module detects that the signal-to-noise ratio drops from 20dB to 10dB (threshold set to 10dB), it sends a command to the local oscillator control module to start local oscillator frequency scanning. The local oscillator control module then starts frequency scanning: the scanning range is set to [9.9GHz, 10.1GHz] ( =100MHz), scan step=100kHz, wait time t0=1ms; scan starts from 9.9GHz and gradually increases frequency.

[0038] (3) At each RF scanning frequency point f n If the receiving signal processing module detects a single-tone intermediate frequency (IF) signal for the first time within the waiting time t0, it indicates the presence of single-tone interference. The interfering radio frequency f2 is then calculated as f2 = f2 / t0. n +IF1, where IF1 is the frequency of the single-tone intermediate frequency signal; then the receiving signal processing module informs the local oscillator control module to end the local oscillator frequency scan, and the local oscillator control module controls the local oscillator microwave module to end the scan and execute step (4); if no single-tone intermediate frequency signal is detected, the scan continues; if no single-tone intermediate frequency signal is detected after the set time scan, the process ends and the receiver returns to normal working state of the Rydberg atomic receiver.

[0039] Example of interference frequency calculation:

[0040] When f is scanned n At 9.95 GHz, within t0, the receiving signal processing module first detects a single-tone intermediate frequency (IF) signal with frequency IF1 = 50 kHz. Then, the interfering radio frequency f2 is calculated as f... n + IF1 = 9.95GHz + 5kHz = 9.95005GHz, the local oscillator control module ends the scan.

[0041] (4) For the detected single-tone intermediate frequency signal, the local oscillator control module sets the local oscillator signal of the local oscillator microwave module to a dual-frequency signal according to the interference radio frequency f2 calculated by the receiving signal processing module. ,in Frequency is , Frequency is , and The frequency difference does not exceed the intermediate frequency range (-100kHz-100kHz) detectable by the Rydberg receiver; at this time, the receiving signal processing module is at the intermediate frequency. A single-tone intermediate frequency signal of S can be detected at this location. IF2 ;

[0042] Example of dual-frequency local oscillator configuration:

[0043] The local oscillator control module is configured to output dual-frequency signals from the local oscillator microwave module: The frequency is 9.95005 GHz. Frequency set to =9.95005GHz+ ,in =100kHz (within the detectable intermediate frequency range). Then the intermediate frequency... The receiving signal processing module detected a signal at 100kHz. .

[0044] (5) The local oscillator control module adjusts the phase of the transmitted signal of the local oscillator microwave module until the single-tone intermediate frequency signal S detected by the receiving signal processing module is reached. IF2 Minimum amplitude, then fix the local oscillator microwave module to transmit dual-frequency signals. The phase, and adjust The power, until the single-tone intermediate frequency signal S detected by the receiving signal processing module. IF2 The amplitude reaches its minimum again at this point. That is, to achieve the optimal power and phase for interference cancellation, the local oscillator signal of the local oscillator microwave module is then set to... , The local oscillator used during the original operation of the Rydberg atomic receiver can then return to normal operation.

[0045] Phase and power adjustment examples:

[0046] The local oscillator control module first adjusts... The phase is scanned from 0° to 360° in 1° steps, while monitoring... The amplitude, when the phase is adjusted to 120° Minimum amplitude; fix the phase, then adjust. The power is adjusted from -50dBm to 0dBm in 1dBm increments. When the power is adjusted to -25dBm... The amplitude is at its minimum again at this point. To achieve optimal cancellation, the local oscillator control module sets the local oscillator signal of the local oscillator microwave module to... ,in The original 10GHz oscillator signal was used; the receiver continued to operate, and the interference was effectively canceled out.

Claims

1. A method for active anti-interference of a Rydberg atom receiver, characterized in that, Includes the following processes: (1) Construct an active anti-interference system for a Rydberg atom receiver, including a Rydberg atom receiver and a local oscillator control module. The Rydberg atom receiver includes a laser system, an atomic gas cell, a photodetector, an ADC, a receiving signal processing module, and a local oscillator microwave module. (2) The atomic gas cell mixes the signal microwave and the signal output from the local oscillator microwave module. The probe light output by the laser system is modulated according to the change in the transmittance of the atomic gas cell. After processing by the photodetector and ADC, it is output to the receiving signal processing module. When the receiving signal processing module detects that the signal-to-noise ratio of the receiver drops to the set threshold, it controls the local oscillator microwave module to start scanning through the local oscillator control module, and at each scanning frequency point... f n Waiting time set t 0 ; (3) At each radio frequency scanning point f n Waiting time t 0 If the receiving signal processing module detects a single-tone intermediate frequency (IF) signal for the first time, it calculates the interfering radio frequency (RF) frequency. f 2 Then the receiving signal processing module controls the local oscillator microwave module to end the scan through the local oscillator control module and executes step (4); if no single-tone intermediate frequency signal is detected, the scan continues; (4) For the detected single-tone intermediate frequency signal, the local oscillator control module sets the local oscillator signal of the local oscillator microwave module to a dual-frequency signal. , The frequency contained is signal At this time, the receiving signal processing module detects a single-tone intermediate frequency signal as... S IF2 ; (5) The local oscillator control module adjusts the phase of the transmitted signal of the local oscillator microwave module until the single-tone intermediate frequency signal detected by the receiving signal processing module is reached. S IF2 Minimum amplitude, then fix the local oscillator microwave module to transmit dual-frequency signals. The phase, and adjust The power, until the single-tone intermediate frequency signal detected by the receiving signal processing module. S IF2 The amplitude reaches its minimum again at this point. In order to achieve the optimal power and phase to cancel out interference, the local oscillator signal of the local oscillator microwave module is then set. In step (4), the dual-frequency signal for: ； in, Frequency is , Frequency is , and The frequency difference does not exceed the intermediate frequency range detectable by the Rydberg receiver; at this time, the receiving signal processing module is at the intermediate frequency. A single-tone intermediate frequency signal of S can be detected at this location. IF2。 2. The active anti-interference method for a Rydberg atom receiver according to claim 1, characterized in that, In step (2), the scanning range is: The scan proceeds from smallest to largest, with a single-frequency scanning signal; among which... The scanning frequency step can be adjusted according to requirements. It is relative frequency offset, This is the normal operating frequency of the Rydberg atomic receiver.

3. The active anti-interference method for a Rydberg atom receiver according to claim 1, characterized in that, In step (3), the interfering radio frequency f 2 The calculation method is as follows: f 2 = f n +IF 1； Wherein, IF1 is the frequency of the single-tone intermediate frequency signal.

4. The active anti-interference method for a Rydberg atom receiver according to claim 1, characterized in that, In step (5), the local oscillator signal of the local oscillator microwave module is set to: ； in, The local oscillator used during the original operation of the Rydberg atomic receiver. Frequency is This refers to step (4). Signals in After phase and power adjustment, the component that can cancel out the interference is obtained.

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