Channel control simulation system and method in navigation interference scene

Abstract

The invention relates to a channel control simulation system and method in a navigation interference scene, the system comprises a navigation control system, a wireless channel simulation instrument, an array antenna and a receiver, the navigation control system, the wireless channel simulation instrument, the array antenna and the receiver are connected in sequence, the navigation control system is used for giving a channel control strategy, and the wireless channel simulation instrument is used for receiving the channel control strategy. And a channel control strategy is input to the wireless channel simulator, the wireless channel simulator is used for carrying out phase difference simulation on the input interference signals and issuing wavefront characteristic simulation parameters to the wireless channel simulator, the array antenna and the receiver through the navigation control system for carrying out corresponding phase control. According to the invention, a navigation control system is supported to carry out logic topology design on 128 logic channels (two frequency channels, each having 8 inputs and 8 outputs) wireless channels, an instant control strategy is implemented in a navigation interference scene, high-fidelity interference signal propagation effect simulation is realized, and the navigation control system is combined to carry out bottom noise compensation.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite navigation jamming, and in particular to a channel control simulation system and method under a navigation jamming scenario. Background Art

[0002] A wireless channel simulator is mainly used to provide an accurate and sufficient simulated wireless channel environment for a receiving system. The propagation of radio waves is affected by many factors, such as multipath effect, Doppler effect, noise and interference, etc. In an ideal free space, the radio propagation model is a simple path loss or free space fading model. However, in a navigation jamming scenario, the front end of the wireless channel simulator is a jamming signal, and the back end is a satellite navigation terminal. The simulation of the wireless channel environment needs to consider the characteristics of the jamming signal, including jamming frequency, jamming pattern, jamming power, etc. For a dynamic navigation jamming scenario, an upper-level navigation control system is required to implement appropriate simulation and control strategies for the wireless channel to cope with different types of jamming signal inputs under different space-time conditions and meet the scenario requirements.

[0003] In addition, since the wireless channel simulator itself has a floor noise signal, which has a similar interference effect on the satellite navigation signal after leaking to the satellite navigation terminal, reducing the carrier-to-noise ratio of the signal received by the satellite navigation terminal. Therefore, in a navigation jamming scenario, a compensation scheme for the floor noise problem of the wireless channel simulator needs to be proposed. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and propose a channel control simulation system and method under a navigation jamming scenario, which can support the navigation control system to perform logical topology design on a 128-logical-channel (two frequency channels, each with 8 inputs and 8 outputs) wireless channel, implement an instant control strategy under a navigation jamming scenario, realize a highly realistic simulation of the propagation effect of jamming signals, and perform floor noise compensation in combination with the navigation control system.

[0005] The present invention solves its technical problems by adopting the following technical solutions:

[0006] A channel control simulation system under a navigation jamming scenario includes a navigation control system, a wireless channel simulator, and an array antenna and receiver. Among them, the navigation control system, the wireless channel simulator, and the array antenna and receiver are connected in sequence. The navigation control system is used to give a channel control strategy and input the channel control strategy into the wireless channel simulator. The wireless channel simulator is used to simulate the phase difference of the input jamming signal, and transmit the wavefront characteristic simulation parameters to the wireless channel simulator through the navigation control system and then to the array antenna and receiver. The array antenna and receiver are used to perform corresponding phase control.

[0007] Moreover, the channel control strategy includes topology scheme design, channel model selection, wavefront simulation control strategy, and parameters for configuring a wireless channel instrument. According to the control strategy, the wireless channel instrument makes corresponding responses and hardware feedback to the topology scheme and channel model, and performs wavefront simulation on the input interference signal.

[0008] Moreover, the parameters for configuring the wireless channel instrument include input / output power, operating frequency, multipath information, fading type, Doppler, delay, and interference mode.

[0009] Moreover, the wireless channel simulator includes two fully connected topologies, each containing 8 input ports and 8 output ports.

[0010] Moreover, the wireless channel simulator uses a digital channelization method based on a DFT modulated filter bank to implement the allocation of logical channels, and at the same time, by changing the rules for reconstructing each sub-channel, it meets the dynamic changes of the navigation interference scenario.

[0011] A simulation method for a channel control simulation system under a navigation interference scenario includes the following steps:

[0012] Step 1: The navigation control system gives the channel control strategy and inputs the channel control strategy into the wireless channel simulator.

[0013] Step 2: The wireless channel instrument simulates the phase difference of the input interference signal according to the channel control strategy, and sends the wavefront characteristic simulation parameters to the wireless channel simulator through the navigation control system.

[0014] Step 3: The array antenna and receiver are used for corresponding phase control.

[0015] Moreover, the specific implementation method of the phase difference simulation in Step 2 includes: interference signal propagation model simulation, interference signal wavefront simulation real-time control strategy, and background noise compensation strategy.

[0016] Moreover, the specific implementation method of the interference signal propagation model simulation is: in the process of channel modeling implementation, the relative path delay and multipath fading are implemented by the baseband processing board FPGA, and the shadow fading and path loss are jointly implemented by the baseband processing board FPGA and a controllable analog attenuator for real-time configuration of the RF output.

[0017] Moreover, the interference signal wavefront simulation real-time control strategy includes analog attenuation amount setting, Doppler parameter calculation, weather type setting, terrain type setting, and multipath parameter setting.

[0018] Moreover, the background noise compensation strategy is to achieve the same carrier-to-noise ratio of the receiver before and after the wireless channel instrument accesses the system by increasing the actual transmission power of the navigation signal.

[0019] The advantages and positive effects of the present invention are as follows:

[0020] The present invention includes a navigation control system, a wireless channel simulator, an array antenna and a receiver. The navigation control system, the wireless channel simulator, and the array antenna and the receiver are connected in sequence. The navigation control system is used to give a channel control strategy and input the channel control strategy into the wireless channel simulator. The wireless channel instrument is used to simulate the phase difference of the input interference signal and send the wavefront characteristic simulation parameters to the wireless channel simulator through the navigation control system and then transmit them to the array antenna and the receiver. The array antenna and the receiver are used to perform corresponding phase control. The present invention supports the navigation control system to perform logical topology design on a 128-logical-channel (two frequency channels, each with 8 inputs and 8 outputs) wireless channel, implement an immediate control strategy in a navigation interference scenario, realize a highly realistic simulation of the interference signal propagation effect, and perform background noise compensation in combination with the navigation control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a block diagram of the system connection of the present invention;

[0022] Figure 2 is a schematic diagram of constructing the logical topology of the present invention;

[0023] Figure 3 is a schematic diagram of the logical channel allocation of the present invention;

[0024] Figure 4 is a schematic diagram of the implementation structure of digital channelization of the present invention;

[0025] Figure 5 is a block diagram of the implementation of channel modeling of the present invention;

[0026] Figure 6 is a schematic diagram of the classification of the fading channel of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings.

[0028] A channel control simulation system under a navigation interference scenario, as Figure 1 shown, includes a navigation control system, a wireless channel simulator, an array antenna and a receiver. The navigation control system, the wireless channel simulator, and the array antenna and the receiver are connected in sequence. The navigation control system is used to give a channel control strategy and input the channel control strategy into the wireless channel simulator. The wireless channel instrument is used to simulate the phase difference of the input interference signal and send the wavefront characteristic simulation parameters to the wireless channel simulator through the navigation control system and then transmit them to the array antenna and the receiver. The array antenna and the receiver are used to perform corresponding phase control.

[0029] The channel control strategy includes topology scheme design, channel model selection, wavefront simulation control strategy, and parameter configuration of the wireless channel instrument. The wireless channel instrument makes corresponding responses and hardware feedback to the topology scheme and channel model according to the control strategy, and conducts wavefront simulation on the input interference signal. The parameters configured for the wireless channel instrument include input and output power, operating frequency, multipath information, fading type, Doppler, delay, and interference mode.

[0030] According to the correspondence between the navigation interference scenario and the number of hardware channels, the wireless channel instrument can simulate an 8-in-8-out wireless channel environment with two frequency points. As Figure 2 shown, the wireless channel simulator contains two fully connected topologies, each containing 8 input ports and 8 output ports.

[0031] As Figure 3 shown, taking the first frequency point as an example, the 8 channels on the left side of the fully connected topology are input channels (corresponding to up to 8 interference sources), and the 8 channels on the right side are output channels (corresponding to up to 8 antenna array elements).

[0032] The wireless channel simulator uses a digital channelization method based on DFT modulated filter banks to implement the allocation of logical channels, and at the same time, by changing the rules for reconstructing each sub-channel, it meets the dynamic changes of the navigation interference scenario.

[0033] As Figure 4 shown, after the interference signal is input into the wireless channel simulator, first, the input signal is evenly channelized and analyzed through an analysis filter bank, and each input signal is evenly divided into 8 logical channels. Then, according to the position of each input signal in the frequency spectrum, the polyphase components after its uniform channel division are exchanged. Finally, the exchanged polyphase components are sent into a synthesis filter bank to re-synthesize a frequency division multiplexed signal, which respectively forms 8 output signals.

[0034] A simulation method for a channel control simulation system under a navigation interference scenario includes the following steps:

[0035] Step 1: The navigation control system gives a channel control strategy and inputs the channel control strategy into the wireless channel simulator.

[0036] Step 2: The wireless channel instrument simulates the phase difference of the input interference signal according to the channel control strategy, and sends the wavefront characteristic simulation parameters to the wireless channel simulator through the navigation control system.

[0037] The specific implementation method of the phase difference simulation includes: interference signal propagation model simulation, interference signal wavefront simulation real-time control strategy, and background noise compensation strategy.

[0038] Interference signal propagation model simulation:

[0039] In the process of channel modeling implementation, the relative path delay and multipath fading are implemented by the FPGA on the baseband processing board, and the shadow fading and path loss are jointly implemented by the FPGA on the baseband processing board and a controllable analog attenuator that can be configured in real time for RF output. The total number of channels to be processed and the channel model and parameters corresponding to each channel can be configured inside the FPGA on the baseband processing board. For example Figure 5 The following figure shows the implementation block diagram of channel modeling inside the FPGA on the baseband processing board.

[0040] The most significant effects of the channel are path loss and multipath propagation. The power of the received signal changes due to two effects: large-scale propagation path loss and small-scale fading. The large-scale propagation model describes the field strength variation over a long distance between the transmitter and the receiver; the small-scale fading model describes the propagation model of the rapid fluctuation of the field strength over a short distance (several wavelengths) or a short time (in seconds). The average propagation loss is related to the distance and is caused by the absorption of water and plants and the reflection effect of the ground. Small-scale fading may be slow fading caused by the shadow effect of buildings and natural terrain, or fast fading caused by the constructive and destructive combination of multipaths. For example Figure 6 The following figure shows the classification of fading channels.

[0041] The wireless channel simulator conducts theoretical analysis and simulation modeling for the above-mentioned fading, and uses the ray-tracing method to establish a method for predicting and analyzing the electromagnetic environment of interference signals in the electromagnetic environment of regular areas such as the site corresponding to the constructed navigation interference scenario, irregular terrains such as mountains and vegetation areas, and complex platforms such as airports and large ships, and highly realistically restores the interference signal propagation model.

[0042] The wireless channel simulator incorporates a variety of propagation models. For example, the cost207 model can simulate parameters such as the power, Doppler, multipath, and delay of interference signals in scenarios such as suburban areas, typical urban areas, harsh areas, and hilly areas; the ITU-R P.840-8 model can simulate the channel model under cloudy and foggy weather; the ITU-R P618-12 can simulate the channel model under rainy and snowy weather; the ITU-RP.676-12 can simulate the attenuation and related effects of interference signals in the atmosphere. In addition, Rayleigh fading, multipath fading, and Rice fading modeling are carried out for the small-scale propagation model.

[0043] Immediate control strategy for simulating the wavefront of interference signals

[0044] In the navigation interference scenario, the navigation control system implements an immediate control strategy for the wireless channel simulator, and issues the wavefront characteristic simulation parameters to the wireless channel simulator at a certain frequency to achieve the simulation of the wavefront characteristics of interference signals. The core control strategies include analog attenuation amount setting, Doppler parameter calculation, weather type setting, terrain type setting, and multipath parameter setting. As shown in Table 1:

[0045] Table 1 Core Control Strategy

[0046]

[0047]

[0048] Noise Floor Compensation Strategy

[0049] When the wireless channel simulator performs signal attenuation, it includes two parts: fixed attenuation (analog attenuation) and digital attenuation. They jointly form an attenuation amount, and the power of the noise floor signal is mainly determined by the fixed attenuation. In the navigation interference scenario, when the target approaches the interference source, the interference signal to be simulated is large. With the interference source position fixed, the attenuation amount that the infinite channel simulator needs to complete decreases, the fixed attenuation is relatively small, and the attenuation of the noise floor is also small at this time, so it causes excessive noise floor output and reduces the carrier-to-noise ratio.

[0050] To minimize the above impacts, a noise floor compensation strategy based on enhancing the navigation signal power is proposed. By increasing the actual broadcast power of the navigation signal, the carrier-to-noise ratio of the receiver before and after the wireless channel instrument accesses the system is made consistent. Specifically as follows:

[0051] The noise floor of the wireless channel instrument is determined by the port output power. Therefore, by manually setting the port output power to traverse from 0 dBm to -60 dBm in steps of 1 dBm, the noise floor under different output powers is measured.

[0052] 1) In the navigation interference scenario, set the navigation control system to broadcast a satellite navigation signal of -130 dBm, turn off the wireless channel instrument, and record the average carrier-to-noise ratio CN0-A of the receiver at this time;

[0053] 2) In the same navigation source scenario, turn on the wireless channel instrument, set the wireless channel port output power, and record the average carrier-to-noise ratio CN0-B of the receiver at this time;

[0054] 3) Increase the broadcast power of the navigation control system so that CN0-A = CN0-B, and the increased value is the noise floor compensation value.

[0055] 4) Change the wireless channel port output power, calculate the corresponding noise floor compensation value according to 3), and record it in the following table.

[0056] 5) Obtain the noise floor situation investigation table to prepare for subsequent noise floor compensation.

[0057] Taking the center frequency of 1575.42 MHz as an example, the following table gives the noise floor situation investigation table of the wireless channel.

[0058] Table 2 Noise Floor Situation Investigation Table of 1575.42 MHz Wireless Channel

[0059]

[0060]

[0061]

[0062] The power of the background noise signal is mainly determined by the fixed attenuation. The minimum step size of the fixed attenuation is 3 dB, and the set delay for the hardware response is about 2 - 3 seconds. Therefore, real-time adjustment can achieve flexible compensation of the background noise by setting the output power of the wireless channel port through gradients.

[0063] In the navigation interference scenario, when the target is far from the interference source, the interference signal to be simulated is small. With the interference source position fixed, the attenuation amount that the wireless channel simulator needs to complete is large, and the fixed attenuation is relatively large. At this time, the attenuation of the background noise is large, the power of the background noise signal is low, and the carrier-to-noise ratio of the satellite signal to be compensated is small.

[0064] When the target approaches the interference source, the interference signal to be simulated is large. With the interference source position fixed, the attenuation amount that the wireless channel simulator needs to complete decreases, and the fixed attenuation is relatively small. At this time, the attenuation of the background noise is also small, so it causes excessive background noise output, and the carrier-to-noise ratio of the satellite signal to be compensated is large.

[0065] After testing, when the fixed attenuation of the wireless channel simulator is set to -60 dBm or below, the intensity of the background noise signal remains basically unchanged. Therefore, the fixed attenuation range for background noise compensation is -60 dBm to 0 dBm. According to the measured data, with a compensation value step of about 4 dB, the fixed attenuation levels for background noise compensation of the wireless channel are set to 0, -15, -18, -24, -30, -60 dBm respectively, and the corresponding navigation signal power for compensation is set. The specific scheme is shown in the following table:

[0066] Table 3 Background Noise Compensation Scheme

[0067]

[0068] Step 3: The array antenna and the receiver are used to perform corresponding phase control.

[0069] The present invention supports the navigation control system to perform logical topology design on the wireless channels of 128 logical channels (two frequency channels, each with 8 inputs and 8 outputs), implement an immediate control strategy in the navigation interference scenario, achieve a highly realistic simulation of the interference signal propagation effect, and perform background noise compensation in combination with the navigation control system.

[0070] It should be emphasized that the embodiments described in the present invention are illustrative rather than restrictive. Therefore, the present invention includes, but is not limited to, the embodiments described in the specific implementation manners. Any other implementation manners obtained by those skilled in the art based on the technical solutions of the present invention also fall within the scope of protection of the present invention.

Claims

1. A channel control simulation system in a navigation interference scenario, characterized in that: It includes a navigation control system, a wireless channel emulator, an array antenna and a receiver, wherein the navigation control system, the wireless channel emulator, the array antenna and the receiver are connected in sequence, the navigation control system is used to provide a channel control strategy, and input the channel control strategy to the wireless channel emulator, the wireless channel instrument is used to simulate the phase difference of the input interference signal, and send the wavefront characteristic simulation parameters to the wireless channel emulator through the navigation control system and transmit them to the array antenna and the receiver, the array antenna and the receiver are used to perform corresponding phase control.

2. The channel control simulation system in a navigation interference scenario according to claim 1, characterized in that: The channel control strategy includes topology scheme design, channel model selection, wavefront simulation control strategy and configuration of wireless channel meter parameters. The wireless channel meter responds to the topology scheme and channel model and provides hardware feedback according to the control strategy, and performs wavefront simulation on the input interference signal.

3. The channel control simulation system in a navigation interference scenario according to claim 2, characterized in that: The parameters for configuring the wireless channel meter include input and output power, operating frequency, multipath information, fading type, Doppler, delay and interference mode.

4. The channel control simulation system in a navigation interference scenario according to claim 1, characterized in that: The wireless channel emulator comprises two fully connected topologies, each comprising 8 input ports and 8 output ports.

5. The channel control simulation system in a navigation interference scenario according to claim 1, characterized in that: The wireless channel simulator adopts a digital channelization method based on a DFT modulation filter group to realize the allocation of logical channels, and at the same time satisfies the dynamic changes of navigation interference scenarios by changing the rules for reconstructing each sub-channel.

6. A simulation method for a channel control simulation system in a navigation interference scenario according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: The navigation control system provides a channel control strategy and inputs the channel control strategy into a wireless channel simulator; Step 2: The wireless channel simulator simulates the phase difference of the input interference signal according to the channel control strategy, and sends the wavefront characteristic simulation parameters to the wireless channel simulator through the navigation control system; Step 3: The array antenna and the receiver are used to perform corresponding phase control.

7. The simulation method of a channel control simulation system in a navigation interference scenario according to claim 6, characterized in that: The specific implementation method of the phase difference simulation in step 2 includes: interference signal propagation model simulation, interference signal wavefront simulation real-time control strategy and background noise compensation strategy.

8. The simulation method of a channel control simulation system in a navigation interference scenario according to claim 7, characterized in that: The specific implementation method of the interference signal propagation model simulation is as follows: in the channel modeling implementation process, the relative path delay and multipath fading are implemented by the baseband processing board FPGA, and the shadow fading and path loss are implemented by the baseband processing board FPGA and the controllable analog attenuator that configures the RF output in real time.

9. The simulation method of a channel control simulation system in a navigation interference scenario according to claim 7, characterized in that: The interference signal wavefront simulation instant control strategy includes simulation attenuation amount setting, Doppler parameter calculation, weather type setting, terrain type setting and multipath parameter setting.

10. The simulation method of a channel control simulation system in a navigation interference scenario according to claim 7, characterized in that: The noise floor compensation strategy is to achieve a consistent receiver carrier-to-noise ratio before and after the wireless channel meter is connected to the system by increasing the actual broadcast power of the navigation signal.

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