Dual-channel Roland C magnetic antenna simulator and use method thereof

Abstract

The invention discloses a dual-channel Roland C magnetic antenna simulator, which comprises a clock module and a dual-channel signal processing system, the clock module provides a clock source to control the dual-channel signal processing system, and the dual-channel signal processing system comprises two groups of signal generation modules, two groups of signal attenuation modules and two groups of signal conversion modules. The signal generation module is used for generating Rowland C signals and outputting multiple paths of analog signals, the signal attenuation module is used for attenuating the multiple paths of analog signals to reach target signal field intensity and form combined signals, and the signal conversion module is used for converting the combined signals into differential signals. Two independent channels are adopted, four station chain signals can be output respectively, parameters such as the field intensity and the packet cycle difference of each channel can be set at will, mutual matched output or independent output is achieved, mutual influence is avoided, and the flexibility and practicability of the simulator are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic antenna signal simulation, and in particular relates to a dual-channel Roland C magnetic antenna simulator and a use method thereof. Background Art

[0002] At present, the performance of dual-channel long-wave magnetic antenna receivers is evaluated by only receiving the signals broadcast by the station through the magnetic antenna. There is no special instrument to simulate the signal of the dual-channel long-wave magnetic antenna to fully evaluate the quality of the dual-channel long-wave magnetic antenna receiver. The dual-channel long-wave magnetic antenna outputs 2 channels and differential signals. The current Roland C simulator technology can only output a single channel and single-ended signal, which cannot meet the test requirements. The functions that cannot be completed are mainly the following:

[0003] (1) Unable to output differential signals;

[0004] (2) It is not possible to simulate two channel signals at the same time;

[0005] (3) It is not possible to simulate the simultaneous output of two channels of the same station signal with different field strengths;

[0006] (4) It cannot simulate the simultaneous output of two channels with different field strengths at different angles from the same station;

[0007] (5) It cannot simulate different stations with different output angles and different field strengths;

[0008] (6) It cannot simulate the different field strength outputs of the two channels during circular motion;

[0009] (7) It is not possible to simulate the output of signals with different packet difference between two channels. Summary of the invention

[0010] The object of the present invention is to provide a dual-channel Loran C magnetic antenna simulator to solve the problems pointed out in the background technology.

[0011] In order to solve the above problems, the present invention discloses a dual-channel Roland C magnetic antenna simulator, comprising: a clock module and a dual-channel signal processing system, the clock module provides a clock source to control the dual-channel signal processing system, the dual-channel signal processing system comprises two groups of signal generation modules, two groups of signal attenuation modules and two groups of signal conversion modules, the signal generation module is used to generate Roland C signals and output multi-channel analog signals, the signal attenuation module is used to attenuate the multi-channel analog signals to achieve the target signal field strength and form a combined signal, and the signal conversion module is used to convert the combined signal into a differential signal.

[0012] Preferably, the signal generating module comprises a signal processing unit, a DAC conversion unit, an amplifier and a signal buffer.

[0013] Preferably, the signal attenuation module includes a single-channel attenuator, a signal adder and a combining attenuator.

[0014] Preferably, the single-channel attenuator includes two signal attenuators.

[0015] Preferably, the combining attenuator includes two signal attenuators.

[0016] Preferably, the signal conversion module includes a signal buffer, a single-ended to differential unit and a DC block.

[0017] Preferably, there are two signal buffers, which are arranged at both ends of the single-ended to differential unit.

[0018] Preferably, the clock module includes a clock selector and a clock distributor, the clock selector is used to select an external clock and an internal clock, the internal clock is connected to a satellite guide module, and the external clock is connected to a clock buffer.

[0019] The present invention also discloses a method for using a dual-channel Roland C magnetic antenna simulator, comprising:

[0020] The user sets the waveform output parameters or the user changes the waveform output parameters;

[0021] Determine whether it is motion simulation, if so, calculate the dynamic angle, if not, determine whether the angle has been calculated, if not, calculate the static angle;

[0022] Calculate two channel decomposition coefficients;

[0023] The two channels are multiplied by the decomposition coefficient respectively;

[0024] The waveforms are output through two DACs respectively.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] Independent dual-channel design: The dual-channel Roland C magnetic antenna simulator uses two independent channels, which can output 4 station chain signals (or 3 station chains + noise) respectively. The field strength, packet difference and other parameters of each channel can be set arbitrarily to achieve mutual coordinated output or separate output without affecting each other, which improves the flexibility and practicality of the simulator.

[0027] High signal-to-noise ratio output: avoids the problem of signal-to-noise ratio reduction caused by the use of distributors and attenuators, and improves the quality of the output signal.

[0028] Vector decomposition simulation: According to the parameters set by the user, the decomposition coefficients of the two channels are calculated through vector decomposition to achieve simulation of different angles and field strengths, making the simulator closer to the actual application scenario.

[0029] Flexible signal generation: The simulator can dynamically adjust the output waveform according to user needs to meet the needs of motion signal simulation and static signal simulation.

[0030] High-precision clock control: Use high-precision clock module to ensure the synchronization of the two channel signal processing units and improve the overall performance of the simulator.

[0031] Easy to operate: Users can easily set and change waveform output parameters through the software interface to achieve rapid configuration and adjustment of the simulator.

[0032] Wide application: The present invention is suitable for the fields of Roland C magnetic antenna signal simulation, performance testing, teaching demonstration, etc., and has high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a diagram of the overall structure of the present invention;

[0034] Figure 2 It is a structural composition diagram of the signal generation module of the present invention;

[0035] Figure 3 It is a structural diagram of the signal attenuation module of the present invention;

[0036] Figure 4 It is a structural diagram of the signal conversion module of the present invention;

[0037] Figure 5 It is a structural diagram of the clock module of the present invention;

[0038] Figure 6 It is a flow chart of the method of using the present invention. DETAILED DESCRIPTION

[0039] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0040] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The present invention provides a dual-channel Roland C magnetic antenna simulator, which simulates the signal of the dual-channel Roland C magnetic antenna and simulates the signal receiving situation of the magnetic antenna in various environments. The main ideas are as follows:

[0044] (1) Each channel output of the simulator must contain 4 station chain signals (or 3 station chains + noise). The signals of the 4 station chains are physically superimposed to form a channel signal output. If a channel signal is passed through a distributor, the signal can also be divided into 2 channel signals, and then the 2 channels are controlled by an attenuator to output different field strengths. However, the output signals are at the same time, and it is impossible to simulate the different packet cycle differences of the 2 channels. In addition, adding processing circuits also increases the complexity of the circuits, and will also introduce more noise, resulting in a lower signal-to-noise ratio of the final output signal. Therefore, the dual-channel Roland C magnetic antenna simulator is designed with 2 independent channels, which can output 4 station chain signals (or 3 station chains + noise) respectively. The field strength, packet cycle difference, etc. of each channel can be arbitrarily set, and they can cooperate with each other for output, or they can be output separately without affecting each other.

[0045] (2) If two channels are output in coordination, such as simulating different field strengths of two channels at different angles of the same station, the field strength of the two channels needs to be calculated according to the angle, and the packet cycle difference needs to be set. Because the two signals are output from different paths, the output delay of the two signals will be inconsistent due to differences in components and non-real-time software operation. This can be solved by calibrating the delay method. The impact caused by non-real-time software operation can be compensated by the FPGA processor. In this way, the difference between the two channels can be solved, ensuring accurate control of the signal delay.

[0046] (3) The simulator outputs the signal waveform through the DAC. The DAC is controlled by the DSP, and the standard Loran C waveform is stored inside the DSP. According to the parameters set by the user, the angle of each station is calculated, and the angle is used for vector decomposition to obtain the decomposition coefficients of two different channels. Based on the standard Loran C data, each channel is multiplied by its decomposition coefficient to obtain the data of the output waveform of the two channels, and the DAC is controlled to output the corresponding waveform.

[0047] like Figure 1 As shown, the dual-channel Roland C magnetic antenna simulator of this embodiment includes: a clock module and a dual-channel signal processing system. The clock module provides a clock source to control the dual-channel signal processing system. The dual-channel signal processing system includes two groups of signal generation modules, two groups of signal attenuation modules and two groups of signal conversion modules. The signal generation module is used to generate Roland C signals and output multi-channel analog signals. The signal attenuation module is used to attenuate the multi-channel analog signals to achieve the target signal field strength and form a combined signal. The signal conversion module is used to convert the combined signal into a differential signal.

[0048] Specifically, Figure 1 As shown in the figure, the dual-channel Roland C magnetic antenna simulator is mainly composed of 7 modules. Two signal generation modules can generate two Roland C signals at the same time, two signal attenuation modules are used for signal attenuation and output of target signal field strength, two signal conversion modules convert single-ended signals into differential signals, and the clock module provides a clock source. Using the same clock source is conducive to the synchronous control of system operation.

[0049] like Figure 2 As shown, the signal generation module includes a signal processing unit, a DAC conversion unit, an amplifier and a signal buffer. The function of the signal generation module is to generate a Roland C signal, which also determines the maximum signal field strength output by the simulator. The signal processing unit 1 generates a 4-way digital Roland C signal of 1 channel through signal modulation; the DAC conversion unit converts the digital Roland C signal into an analog single-ended Roland C signal; the amplifier amplifies the signal to reach the specified peak-to-peak value of the output voltage, because the peak-to-peak value of the voltage of the DAC conversion unit is low and cannot meet the requirements. The amplifier can adjust the amplifier multiple and the output voltage arbitrarily according to the output needs; the signal buffer is to match the characteristic impedance of the front and rear circuits to ensure signal integrity; the signal generation module 2 also has the same processing flow, generating 4-way digital Roland C signals of 2 channels.

[0050] like Figure 3As shown, the signal attenuation module includes a single-channel attenuator, a signal superimposer and a combined attenuator. The signal attenuation module attenuates 4 analog signals (digital Roland C signals) to achieve the target signal field strength (peak-to-peak voltage). Two signal attenuators form a group of single-channel attenuators. Because the attenuation value of a single signal attenuator is not enough, two signal attenuators are required here. If the maximum output field strength is strong, the number of attenuators can be increased to meet the attenuation requirements. The signal superimposer combines 4 signals into 1 signal. Two signal attenuators form a group of combined attenuators. Because the attenuation value of a single signal attenuator is not enough, two attenuators are required here. If the maximum output field strength is strong, the number of attenuators can be increased to meet the attenuation requirements.

[0051] like Figure 4 As shown, the main function of the signal conversion module is to convert a single-ended signal into a differential signal. It includes a signal buffer, a single-ended to differential unit and a DC block. There are two signal buffers, which are set at both ends of the single-ended to differential unit. The signal buffer is used to match the characteristic impedance of the front and rear circuits to ensure signal integrity; the single-ended to differential unit converts the single-ended signal into a differential signal; the DC block makes the final output signal an AC signal, and the DC signals of the internal and external circuits do not interfere with each other.

[0052] like Figure 5 As shown, the clock module includes a clock selector and a clock distributor. The clock selector is used to select an external clock and an internal clock. The internal clock is connected to the satellite navigation module, and the external clock is connected to the clock buffer. In order to accurately control the delay of the two channel signals, the two signal processing units run synchronously and use the same clock source. The clock source can select an external clock or an internal clock. When the external clock is connected, the system automatically switches to the external clock. The satellite navigation module can be connected to the satellite navigation antenna, receive Beidou or GPS signals, tame the internal crystal oscillator, and output a high-precision clock. If there is a more accurate clock source outside, it can also receive an external clock; the clock distributor divides the clock into two identical clocks for use by the two signal processing units.

[0053] like Figure 6 As shown, the method for using the dual-channel Roland C magnetic antenna simulator of this embodiment includes:

[0054] First, the user sets or modifies the parameters, then determines whether it simulates the motion state, and further calculates the decomposition coefficients corresponding to the two channels according to the set angle or the dynamic angle calculated in real time. The two channels are multiplied by the synthesis coefficient to synthesize the output signal and output it through the DAC.

[0055] Specifically: the user sets the waveform output parameters or the user changes the waveform output parameters;

[0056] Determine whether it is motion simulation, if so, calculate the dynamic angle, if not, determine whether the angle has been calculated, if not, calculate the static angle;

[0057] Calculate two channel decomposition coefficients;

[0058] The two channels are multiplied by the decomposition coefficient respectively;

[0059] The waveforms are output through two DACs respectively.

[0060] The dual-channel Roland C magnetic antenna simulator of the present invention adopts two independent channels, which can output four station chain signals respectively. The parameters such as field strength and packet cycle difference of each channel can be set arbitrarily to achieve coordinated output or separate output without affecting each other, thereby improving the flexibility and practicality of the simulator.

[0061] The above is only an embodiment of the present invention, and the common sense such as the known specific structure and characteristics in the scheme is not described in detail here. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

Claims

1. A dual-channel Loran C magnetic antenna simulator, characterized in that: include: A clock module and a dual-channel signal processing system, wherein the clock module provides a clock source to control the dual-channel signal processing system, wherein the dual-channel signal processing system comprises two groups of signal generation modules, two groups of signal attenuation modules and two groups of signal conversion modules, wherein the signal generation module is used to generate Roland C signals and output multi-channel analog signals, the signal attenuation module is used to attenuate the multi-channel analog signals to achieve the target signal field strength and form a combined signal, and the signal conversion module is used to convert the combined signal into a differential signal.

2. The dual-channel Loran C magnetic antenna simulator according to claim 1, characterized in that: The signal generating module includes a signal processing unit, a DAC conversion unit, an amplifier and a signal buffer.

3. The dual-channel Loran C magnetic antenna simulator according to claim 1, characterized in that: The signal attenuation module includes a single-channel attenuator, a signal superimposer and a combining attenuator.

4. The dual-channel Loran C magnetic antenna simulator according to claim 3, characterized in that: The single-channel attenuator includes two signal attenuators.

5. The dual-channel Loran C magnetic antenna simulator according to claim 4, characterized in that: The combining attenuator includes two signal attenuators.

6. The dual-channel Loran C magnetic antenna simulator according to claim 1, characterized in that: The signal conversion module includes a signal buffer, a single-ended to differential unit and a DC block.

7. The dual-channel Loran C magnetic antenna simulator according to claim 6, characterized in that: There are two signal buffers, which are arranged at two ends of the single-ended to differential unit.

8. The dual-channel Loran C magnetic antenna simulator according to claim 1, characterized in that: The clock module includes a clock selector and a clock distributor. The clock selector is used to select an external clock and an internal clock. The internal clock is connected to a satellite guide module, and the external clock is connected to a clock buffer.

9. A method for using a dual-channel Loran C magnetic antenna simulator, characterized in that: include: The user sets the waveform output parameters or the user changes the waveform output parameters; Determine whether it is motion simulation, if so, calculate the dynamic angle, if not, determine whether the angle has been calculated, if not, calculate the static angle; Calculate two channel decomposition coefficients; The two channels are multiplied by the decomposition coefficient respectively; The waveforms are output through two DACs respectively.

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