A method and system for detecting spoofing jamming using carrier phase

Abstract

The embodiment of the present application discloses a method and system for detecting spoofing interference by carrier phase. The method comprises setting a channel of a receiver as an observed channel and a replica channel, receiving satellite signals by the observed channel and positioning, and stopping the replica channel from receiving satellite signals; after the receiver completes positioning, obtaining a carrier count value and a phase-locked loop phase value of the satellite signals at a current time of the observed channel; taking the carrier count value and the phase-locked loop phase value at the current time as initial carrier count value and initial phase-locked loop phase value of the replica channel; generating a carrier signal according to a clock of the receiver, the initial carrier count value and the initial phase-locked loop phase value by the replica channel, and performing Doppler frequency shift compensation on the carrier signal to obtain a frequency-compensated carrier signal; calculating a phase difference between a phase of the satellite signals received by the observed channel and a phase of the frequency-compensated carrier signal generated by the replica channel, and judging whether there is spoofing interference according to the phase difference.

Description

Technical Field

[0001] This invention relates to the field of satellite navigation signal processing. More specifically, it relates to a method and system for detecting deception interference using carrier phase detection. Background Technology

[0002] Currently, among various types of interference to satellite navigation receivers, spoofing is a relatively well-concealed interference technique. Spoofing interference is divided into generation and relaying types. Both types will cause a time delay in the arrival of the spoofing signal at the target receiver. The carrier phase of the real signal is stable and gradually changes. Relaying spoofing interference will cause a carrier phase delay ΔΦ=2πf·Δτ due to the relay time, where f is the carrier center frequency and Δτ is the relay delay. Generation spoofing interference will show abnormal changes in the carrier phase.

[0003] Carrier phase measurement involves determining the phase change of the carrier signal in the navigation signal as it propagates from the satellite transmitter to the receiver. Carrier phase measurement techniques obtain the propagation time of the received signal based on the integer carrier propagation time and the carrier phase value within that integer cycle. Commonly used detection techniques are generally applicable to cases where the relay delay is greater than 1.5 chips (approximately 43.95 meters). However, the carrier wavelength of the B3 frequency satellite navigation signal in the BeiDou navigation system is approximately 0.23 meters, allowing for millimeter-level accuracy in carrier phase measurement. When a spoofing signal is received, i.e., after the delay occurs, the change in carrier phase can be calculated to detect whether the received signal is a spoofing signal. Furthermore, commonly used detection techniques rely on external antennas or complex algorithms, reducing receiver operating efficiency and the efficiency of detecting spoofing interference. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for deception interference using carrier phase detection, so as to solve at least one of the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of this invention provides a method for deception interference using carrier phase detection, the method comprising: Set the satellite receiving channel of the satellite navigation receiver to the observed channel and the copy channel. Use the observed channel to receive satellite signals and perform positioning, and make the copy channel stop receiving satellite signals. After the satellite navigation receiver completes positioning, it acquires the carrier count value and phase-locked loop phase value of the satellite signal of the observed channel at the current moment. Use the current carrier count value and the current phase-locked loop phase value as the initial carrier count value and the initial phase-locked loop phase value for the replication channel; The carrier signal is generated using the replication channel based on the satellite navigation receiver's clock, initial carrier count value, and initial phase-locked loop phase value. The carrier signal is then subjected to Doppler frequency shift compensation to obtain a frequency-compensated carrier signal. Calculate the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel, and determine whether there is deception interference based on the phase difference.

[0006] Optionally, the process of performing Doppler frequency shift compensation on the carrier signal to obtain the frequency-compensated carrier signal includes: The speed of the satellite navigation receiver is obtained, and the satellite speed is calculated by decoding the satellite signal. Calculate the relative velocity between the satellite and the satellite navigation receiver, and use the relative velocity and the nominal frequency of the carrier signal to calculate the Doppler frequency shift value; The carrier signal is obtained by compensating the nominal frequency of the carrier signal with the Doppler frequency shift value.

[0007] Optionally, the calculation of the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replicated channel includes: The phase of the satellite signal received by the observed channel is obtained by summing the carrier count value of the satellite signal with the phase-locked loop phase value. The sum of the carrier count value and the phase-locked loop phase value of the frequency-compensated carrier signal is calculated to obtain the phase of the frequency-compensated carrier signal generated by the replication channel. The phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replicated channel is obtained by subtracting the phase of the frequency-compensated carrier signal generated by the replicated channel from the phase of the satellite signal received by the observed channel.

[0008] Optionally, determining whether deception interference exists based on the phase difference includes: Determine whether the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replicated channel is less than 0. If it is less than 0, then determine whether the absolute value of the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel is greater than the preset value. If the value exceeds the preset value, it is determined to be a forwarding-type deception interference.

[0009] Optionally, determining whether deception interference exists based on the phase difference includes: Within a preset time after the carrier signal is generated by the replication channel, it is determined whether the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replication channel is greater than 0. If it is greater than 0, then determine whether the absolute value of the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel is greater than the preset value. If the value is greater than the preset value, it is determined to be generative deception interference.

[0010] Optionally, the deception interference delay corresponding to the preset value is greater than 10ns.

[0011] Optionally, the carrier count value corresponding to the preset value is greater than 15.74.

[0012] Optionally, the preset time is 1s to 5s.

[0013] Optionally, the method further includes: using a temperature-compensated crystal oscillator to generate the clock for the satellite navigation receiver.

[0014] A second aspect of the present invention provides a system for deception interference using carrier phase detection, the system comprising: a satellite navigation receiver, the satellite navigation receiver including a processor and a setting unit; The setting unit is used to set the satellite receiving channel of the satellite navigation receiver as the observed channel and the copy channel, use the observed channel to receive satellite signals and perform positioning, and make the copy channel stop receiving satellite signals; The processor is used to acquire the carrier count value and phase-locked loop phase value of the satellite signal of the observed channel at the current moment after the satellite navigation receiver completes positioning; The processor is also used to use the current carrier count value and the current phase-locked loop phase value as the initial carrier count value and the initial phase-locked loop phase value of the replication channel; The processor is also used to generate a carrier signal based on the clock of the satellite navigation receiver, the initial carrier count value, and the initial phase-locked loop phase value using the replication channel, and to perform Doppler frequency shift compensation on the carrier signal to obtain a frequency-compensated carrier signal; The processor is also used to calculate the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel, and to determine whether there is deception interference based on the phase difference.

[0015] The beneficial effects of this invention are as follows: The technical solution described in this invention does not rely on external antennas or complex algorithms, effectively improving receiver operating efficiency and spoofing interference detection efficiency. This solution provides a raw observation method for spoofing detection; utilizing carrier phase detection can rapidly increase detection speed and reduce algorithm complexity, overcoming the problem of increased internal computational complexity in receivers when using spoofing detection algorithms in existing technologies. The solution proposes a method for replicating carrier detection spoofing interference in the observed satellite channel without relying on complex detection algorithms, and this method does not require additional hardware overhead, such as adding antennas. The solution observes the satellite receiving channel based on the existing receiver. This solution is effective against repeater-type interference, generator-type interference, single-antenna transmission interference, and multi-antenna transmission interference. Attached Figure Description

[0016] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0017] Figure 1 A flowchart illustrating a method for deceiving interference using carrier phase detection according to an embodiment of the present invention is shown.

[0018] Figure 2 A flowchart illustrating a method for deceiving interference using carrier phase detection according to another embodiment of the present invention is shown.

[0019] Figure 3 This diagram illustrates a system for deceiving interference using carrier phase detection, according to yet another embodiment of the present invention. Detailed Implementation

[0020] To more clearly illustrate the present invention, the following description, in conjunction with embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0021] Carrier phase measurement involves determining the phase change of the carrier signal in the navigation signal as it propagates from the satellite transmitter to the receiver. Carrier phase measurement techniques obtain the propagation time of the received signal based on the integer carrier propagation time and the carrier phase value within that integer cycle. Commonly used detection techniques are generally applicable to cases where the relay delay is greater than 1.5 chips (approximately 43.95 meters). However, the carrier wavelength of the B3 frequency satellite navigation signal in the BeiDou navigation system is approximately 0.23 meters, allowing for millimeter-level accuracy in carrier phase measurement. When a spoofing signal is received, i.e., after the delay occurs, the change in carrier phase can be calculated to detect whether the received signal is a spoofing signal. Furthermore, commonly used detection techniques rely on external antennas or complex algorithms, reducing receiver operating efficiency and the efficiency of detecting spoofing interference.

[0022] In view of this, such as Figure 1 As shown, one embodiment of the present invention provides a method for detecting deception interference using carrier phase. The method includes: setting a satellite receiving channel of a satellite navigation receiver as an observed channel and a replica channel; using the observed channel to receive satellite signals and perform positioning, and stopping the replica channel from receiving satellite signals; after the satellite navigation receiver completes positioning, acquiring the carrier count value and the phase-locked loop (PLL) phase value of the satellite signal at the current moment of the observed channel; using the carrier count value and the PLL phase value at the current moment as the initial carrier count value and the initial PLL phase value of the replica channel; using the replica channel to generate a carrier signal based on the clock of the satellite navigation receiver, the initial carrier count value, and the initial PLL phase value; performing Doppler frequency shift compensation on the carrier signal to obtain a frequency-compensated carrier signal; calculating the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replica channel; and determining whether deception interference exists based on the phase difference.

[0023] In a specific example, a method for detecting spoofing interference using carrier phase is proposed for a satellite navigation receiver. This method replicates the carrier of the observed channel, maintains the replicated carrier using Doppler compensation, and calculates the difference between the replicated carrier phase and the carrier phase of the observed channel in real time. If the difference exceeds a threshold, spoofing interference is detected.

[0024] In a specific example, under interference-free conditions, the receiver selects a channel to generate a local carrier signal in real time that is the same as the satellite signal received in the observed channel. The local carrier signal is maintained using Doppler compensation. When spoofing occurs, it is generally accompanied by a delay in the received signal. At this time, the local carrier signal is compared with the received signal. When the error exceeds a threshold, spoofing is detected.

[0025] In a specific example, after the satellite navigation receiver is positioned, the observation channel carrier is locally copied, and the phase difference between the locally copied carrier and the observation channel carrier is calculated.

[0026] In a specific example, the method includes setting a satellite receiving channel as the observed channel, then transmitting the carrier count value and phase value in the phase-locked loop of the observed channel to the CPU for storage in real time, selecting a satellite receiving channel as a copy channel of the observed channel, disabling the satellite search function of the channel, no longer searching for and capturing satellites, and waiting for the receiver to locate. Furthermore, assuming the initial time receiver is not spoofed, after the receiver is located, the values ​​of each satellite observation channel of the receiver are available, and the CPU records the carrier count value of the observed satellite channel and the phase value in the phase-locked loop; Furthermore, the CPU writes the carrier count value and the phase value in the phase-locked loop into the channel of the observed satellite, and transmits the two values ​​to the corresponding module of the replication channel for recording. The replication channel uses the carrier count value and the phase value of the phase-locked loop as the initial value, uses a temperature-compensated crystal oscillator as the clock reference to generate a carrier, and maintains the replicated carrier with the Doppler compensation value predicted by the prediction model. Furthermore, the CPU calculates the phase difference between the carrier of the observed satellite channel and the carrier of the replicated observed satellite channel in real time. That is, the difference between the carrier count value and the phase-locked loop phase value of the observed satellite channel and the replicated observed satellite channel. When the carrier phase value of the observed satellite channel is less than the carrier phase of the replicated observed satellite channel, and the difference is greater than the threshold, it is judged that spoofing interference has occurred.

[0027] Furthermore, the above method is used to observe the channel of each receiving satellite to detect in real time whether spoofing interference occurs in all satellite channels. If spoofing occurs in the initial period, the carrier phase value of the observed satellite channel will be greater than the carrier phase of the replicated observed satellite channel. When the absolute value of the difference is greater than a threshold, it is judged that spoofing interference has occurred.

[0028] In a specific example, such as Figure 2 As shown, the method includes: setting one satellite receiving channel as the observed channel and another satellite receiving channel as the replica channel; after the receiver is positioned, recording the carrier count value and phase value in the phase-locked loop of the observed satellite channel; the CPU writes the carrier count value and phase value in the phase-locked loop into the replica observed satellite channel, and the temperature-compensated crystal oscillator and the Doppler compensation value predicted by the prediction model maintain the replica carrier; the CPU calculates the phase difference between the carrier of the observed satellite channel and the carrier of the replica observed satellite channel in real time, and when the difference is greater than a threshold, it is judged that deception interference has occurred.

[0029] The technical solution described in this invention does not rely on external antennas or complex algorithms, effectively improving receiver operating efficiency and spoofing interference detection efficiency. This solution provides a raw observation method for spoofing detection; utilizing carrier phase detection can rapidly increase detection speed and reduce algorithm complexity, overcoming the problem of increased internal computational complexity in receivers when using spoofing detection algorithms in existing technologies. The solution proposes a method for replicating carrier detection spoofing interference in the observed satellite channel without relying on complex detection algorithms, and this method does not require additional hardware overhead, such as adding antennas. The solution observes the satellite receiving channel based on the existing receiver. This solution is effective against repeater-type interference, generator-type interference, single-antenna transmission interference, and multi-antenna transmission interference.

[0030] This embodiment fully reuses the existing multi-channel resources of the satellite navigation receiver, without the need for additional antennas, RF front-ends, or other peripherals, resulting in no new hardware overhead and high integration. The duplicated channel stops receiving satellite signals and independently generates a local carrier, ensuring that the detection benchmark is not affected by external deception signals and has high reliability. The core detection logic consists only of phase difference calculation and threshold comparison, resulting in extremely low algorithm complexity, significantly reducing the receiver's computational burden and improving the real-time response speed of deception detection. Relying on the high-precision measurement characteristics of the carrier phase, it can identify signal delays at the nanosecond level, with detection sensitivity far exceeding that of traditional code phase detection schemes. It can cover attack scenarios that traditional schemes cannot identify, such as small-delay forwarding deception.

[0031] In one possible implementation, the step of performing Doppler frequency shift compensation on the carrier signal to obtain a frequency-compensated carrier signal includes: obtaining the speed of the satellite navigation receiver; calculating the speed of the satellite by processing the satellite signal; calculating the relative motion speed between the satellite and the satellite navigation receiver; calculating the Doppler frequency shift value using the relative motion speed and the nominal frequency of the carrier signal; and compensating the nominal frequency of the carrier signal using the Doppler frequency shift value to obtain a frequency-compensated carrier signal.

[0032] This embodiment calculates the theoretical Doppler frequency shift based on the calculated satellite velocity and receiver velocity, without relying on the measured frequency parameters of the received signal throughout the process. This fundamentally avoids the backlash of deceptive signals on the detection benchmark of the replication channel. By accurately calculating the Doppler frequency shift through relative motion velocity, it can effectively offset the carrier frequency offset caused by the relative motion between the satellite and the receiver, keeping the phase difference between the two carriers within a very small range under interference-free conditions, significantly reducing the probability of false alarms under normal operating conditions. All calculation data sources are the conventional outputs of the receiver positioning calculation, requiring no additional external information collection, and are compatible with the existing receiver software architecture, making implementation easy.

[0033] In one possible implementation, calculating the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replica channel includes: calculating the sum of the carrier count value and the phase-locked loop phase value of the satellite signal to obtain the phase of the satellite signal received by the observed channel; calculating the sum of the carrier count value and the phase-locked loop phase value of the frequency-compensated carrier signal to obtain the phase of the frequency-compensated carrier signal generated by the replica channel; and subtracting the phase of the frequency-compensated carrier signal generated by the replica channel from the phase of the satellite signal received by the observed channel to obtain the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replica channel.

[0034] This embodiment uses the summation of carrier integer count value and phase-locked loop phase value to obtain the total phase, and then performs the difference, which completely eliminates the periodic ambiguity problem of single-cycle phase. It can accurately reflect the true total phase deviation of the two carriers and avoid detection failure caused by integer jump. It directly reuses the original output data of the receiver's original carrier phase counter and phase-locked loop, without the need to add a new phase measurement circuit. It has a high degree of hardware resource reuse and low engineering implementation cost.

[0035] In one possible implementation, determining whether spoofing interference exists based on the phase difference includes: determining whether the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel is less than 0; if it is less than 0, determining whether the absolute value of the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel is greater than a preset value; if it is greater than the preset value, determining it as a forwarding spoofing interference.

[0036] This embodiment accurately matches the physical characteristic of phase lag introduced by the delay of forwarding spoofing signals. The decision logic is highly consistent with the attack characteristics, resulting in high detection accuracy for forwarding spoofing. The decision rules only include sign judgment and absolute value comparison, with extremely low computational load, which can be executed at high speed in embedded processors, resulting in short detection response latency.

[0037] In one possible implementation, determining whether deceptive interference exists based on the phase difference includes: within a preset time after the replica channel generates a carrier signal, determining whether the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replica channel is greater than 0; if it is greater than 0, determining whether the absolute value of the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replica channel is greater than a preset value; if it is greater than the preset value, determining it as generative deceptive interference.

[0038] This embodiment supplements the attack scenario where the phase of the generated spoofing signal is ahead in the early stage of detection, fills the detection blind spot of single hysteresis decision, and greatly improves the detection coverage of all types of spoofing interference; by limiting the effective range of positive decision by preset time window, it avoids the slow phase drift caused by long-term open-loop operation of the replication channel, and effectively controls the false alarm rate of long-term system operation while improving the detection coverage.

[0039] In one possible implementation, the spoofing interference delay corresponding to the preset value is greater than 10 ns.

[0040] This embodiment uses the minimum delay of 10ns achievable by forwarding spoofing in engineering as the lower limit of the threshold. This ensures both the detection coverage of the vast majority of practical forwarding spoofing attacks and that the threshold is greater than the sum of short-term phase fluctuations under normal operating conditions, achieving the optimal balance between detection sensitivity and false alarm suppression.

[0041] In one possible implementation, the preset value corresponds to a carrier count value greater than 15.74.

[0042] In a specific example, the delay of generative spoofing interference is typically in the millisecond range, while the delay of forwarding spoofing interference is in the tens of nanosecond range. Therefore, the threshold can be set to the minimum delay of forwarding spoofing interference, 10 ns, which corresponds to 15.74 carriers.

[0043] This embodiment converts the time-dimensional delay threshold into a carrier period quantity that can be directly counted by the receiver hardware. It is directly compatible with the output format of the carrier phase counter, eliminating the need for additional dimension conversion circuits. The decision logic can be executed directly based on the count value, making the engineering implementation simple and efficient, and the decision execution speed fast.

[0044] In one possible implementation, the preset time is 1s to 5s.

[0045] In this embodiment, the 1s to 5s time window is matched with the phase error accumulation rate predicted by open-loop Doppler under temperature compensated crystal oscillator. This not only fully covers the initial stage where spoofing attacks are common after receiver positioning, but also avoids slow drift misjudgment due to an excessively long window, thus balancing detection effectiveness and system stability.

[0046] In one possible implementation, the method further includes using a temperature-compensated crystal oscillator to generate the clock for the satellite navigation receiver.

[0047] In a specific example, to ensure the accuracy of the replicated carrier phase output of the observed satellite channel, the local sampling clock is generated by a 62MHz temperature-compensated crystal oscillator to produce the replicated carrier. This scheme is not limited to any type of satellite navigation signal; any navigation signal can be used to generate a replicated carrier of the observed satellite channel to detect deception interference.

[0048] This embodiment uses a temperature-compensated crystal oscillator to provide a local clock reference, which can offset the crystal frequency drift caused by changes in ambient temperature, significantly improve the frequency stability of the replicated carrier, reduce the phase accumulation error of open-loop operation, and extend the effective duration of the detection reference; at the same time, it is lower in cost than high-end devices such as temperature-compensated crystal oscillators, balancing performance and economy.

[0049] Another embodiment of the present invention provides a system for detecting deception interference using carrier phase, characterized in that a satellite navigation receiver includes a processor and a setting unit; the setting unit is used to set the satellite receiving channel of the satellite navigation receiver as an observed channel and a replica channel, using the observed channel to receive satellite signals and perform positioning, and causing the replica channel to stop receiving satellite signals; the processor is used to acquire the carrier count value and the phase-locked loop (PLL) phase value of the satellite signal at the current moment of the observed channel after the satellite navigation receiver completes positioning; the processor is also used to use the carrier count value and the PLL phase value at the current moment as the initial carrier count value and the initial PLL phase value of the replica channel; the processor is also used to generate a carrier signal using the replica channel based on the clock of the satellite navigation receiver, the initial carrier count value, and the initial PLL phase value, and to perform Doppler frequency shift compensation on the carrier signal to obtain a frequency-compensated carrier signal; the processor is also used to calculate the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replica channel, and to determine whether deception interference exists based on the phase difference.

[0050] In a specific example, the hardware of this system includes a carrier phase counter, a phase-locked loop (PLL) control circuit, a numerically controlled oscillator (CNC) oscillator, and a temperature-compensated crystal oscillator (TCC). The carrier phase counter and PLL control circuit are used to accumulate and adjust the integer cycles and phase of the carrier signal in the observation channel. The CNC oscillator generates a local carrier signal with precisely adjustable frequency and phase based on the frequency and phase control words provided by the carrier phase counter. The TCC oscillator uses a temperature compensation circuit to offset the influence of ambient temperature changes on the crystal oscillation frequency, outputting a highly stable frequency signal.

[0051] In a specific example, the system is used when a satellite navigation receiver detects spoofing interference. The satellite navigation receiver is equipped with a signal receiving module and a CPU using an ARM Cortex-A53 low-power embedded processor core. The chip has four cores: core one processes radio frequency data reception, core two runs positioning calculations, core three is responsible for data transmission, and core four runs a Doppler compensation prediction model. It also calculates the phase difference between the observed satellite channel and the replicated observed satellite channel, compares the difference with a threshold, increases the computing speed, and reduces the computing time.

[0052] In a specific example, such as Figure 3As shown, the satellite navigation receiver receives satellite signals. The satellite navigation receiver includes an observed satellite channel, other satellite channels, and a copied observed satellite channel. Each satellite channel includes a carrier phase counter and a phase-locked loop. The copied observed satellite channel receives signals from a temperature-compensated crystal oscillator. The CPU reads the carrier phase of the observed satellite channel and writes the carrier phase to the copied observed satellite channel. The CPU interprets and outputs the spoofing detection result.

[0053] The technical solution described in this invention does not rely on external antennas or complex algorithms, effectively improving receiver operating efficiency and spoofing interference detection efficiency. This solution provides a raw observation method for spoofing detection; utilizing carrier phase detection can rapidly increase detection speed and reduce algorithm complexity, overcoming the problem of increased internal computational complexity in receivers when using spoofing detection algorithms in existing technologies. The solution proposes a system for replicating carrier detection spoofing interference in the observed satellite channel without relying on complex detection algorithms, and this system requires no additional hardware overhead, such as adding antennas. The solution observes the satellite receiving channel based on an existing receiver. This solution is effective against repeater-type interference, generator-type interference, single-antenna transmission interference, and multi-antenna transmission interference.

[0054] In this embodiment, the entire detection system is completely embedded within the satellite navigation receiver, requiring no external auxiliary equipment. It has a compact structure, can be directly adapted to various embedded satellite navigation terminals, and has a wide range of applications. It achieves its functions based on the receiver's original processor and channel resources, requiring minimal hardware modifications and ensuring software development compatibility with the original architecture, resulting in low development and deployment costs. The detection function and the receiver's original positioning function operate in parallel without interference, enabling real-time deception interference detection without affecting normal positioning performance.

[0055] In the description of this invention, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0056] It should also be noted that in the description of this invention, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0057] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for deception interference using carrier phase detection, characterized in that, The method includes: Set the satellite receiving channel of the satellite navigation receiver to the observed channel and the copy channel. Use the observed channel to receive satellite signals and perform positioning, and make the copy channel stop receiving satellite signals. After the satellite navigation receiver completes positioning, it acquires the carrier count value and phase-locked loop phase value of the satellite signal of the observed channel at the current moment. Use the current carrier count value and the current phase-locked loop phase value as the initial carrier count value and the initial phase-locked loop phase value for the replication channel; The carrier signal is generated using the replication channel based on the satellite navigation receiver's clock, initial carrier count value, and initial phase-locked loop phase value. The carrier signal is then subjected to Doppler frequency shift compensation to obtain a frequency-compensated carrier signal. Calculate the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel, and determine whether there is deception interference based on the phase difference.

2. The method for deception interference using carrier phase detection according to claim 1, characterized in that, The frequency-compensated carrier signal obtained by performing Doppler frequency shift compensation on the carrier signal includes: The speed of the satellite navigation receiver is obtained, and the satellite speed is calculated by decoding the satellite signal. Calculate the relative velocity between the satellite and the satellite navigation receiver, and use the relative velocity and the nominal frequency of the carrier signal to calculate the Doppler frequency shift value; The carrier signal is obtained by compensating the nominal frequency of the carrier signal with the Doppler frequency shift value.

3. The method for deception interference using carrier phase detection according to claim 2, characterized in that, The phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replicated channel includes: The phase of the satellite signal received by the observed channel is obtained by summing the carrier count value of the satellite signal with the phase-locked loop phase value. The sum of the carrier count value and the phase-locked loop phase value of the frequency-compensated carrier signal is calculated to obtain the phase of the frequency-compensated carrier signal generated by the replication channel. The phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replicated channel is obtained by subtracting the phase of the frequency-compensated carrier signal generated by the replicated channel from the phase of the satellite signal received by the observed channel.

4. The method for deception interference using carrier phase detection according to claim 3, characterized in that, The method of determining whether deceptive interference exists based on phase difference includes: Determine whether the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replicated channel is less than 0. If it is less than 0, then determine whether the absolute value of the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel is greater than the preset value. If the value exceeds the preset value, it is determined to be a forwarding-type deception interference.

5. The method for deception interference using carrier phase detection according to claim 3, characterized in that, The method of determining whether deceptive interference exists based on phase difference includes: Within a preset time after the carrier signal is generated by the replication channel, it is determined whether the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the replication channel is greater than 0. If it is greater than 0, then determine whether the absolute value of the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel is greater than the preset value. If the value is greater than the preset value, it is determined to be generative deception interference.

6. The method for deception interference using carrier phase detection according to claim 4 or 5, characterized in that, The preset value corresponds to a deception interference delay greater than 10ns.

7. The method for deception interference using carrier phase detection according to claim 6, characterized in that, The preset value corresponds to a carrier count value greater than 15.

74.

8. The method for deception interference using carrier phase detection according to claim 5, characterized in that, The preset time is 1s to 5s.

9. The method for deception interference using carrier phase detection according to claim 2, characterized in that, The method also includes: using a temperature-compensated crystal oscillator to generate the clock for the satellite navigation receiver.

10. A system for deception interference using carrier phase detection, characterized in that, The system includes: a satellite navigation receiver, which includes a processor and a settings unit; The setting unit is used to set the satellite receiving channel of the satellite navigation receiver as the observed channel and the copy channel, use the observed channel to receive satellite signals and perform positioning, and make the copy channel stop receiving satellite signals; The processor is used to acquire the carrier count value and phase-locked loop phase value of the satellite signal of the observed channel at the current moment after the satellite navigation receiver completes positioning; The processor is also used to use the current carrier count value and the current phase-locked loop phase value as the initial carrier count value and the initial phase-locked loop phase value of the replication channel; The processor is also used to generate a carrier signal based on the clock of the satellite navigation receiver, the initial carrier count value, and the initial phase-locked loop phase value using the replication channel, and to perform Doppler frequency shift compensation on the carrier signal to obtain a frequency-compensated carrier signal; The processor is also used to calculate the phase difference between the phase of the satellite signal received by the observed channel and the phase of the frequency-compensated carrier signal generated by the copy channel, and to determine whether there is deception interference based on the phase difference.

Images