A concealed measurement and control signal generating device

Abstract

The present invention provides a covert measurement and control signal generating device, comprising a shielding branch, a measurement branch, an accumulator, and a DAC unit. The shielding branch processes a pseudo-random sequence using fixed parameters to obtain a shielding branch signal, which is then sent to an input of the accumulator. The measurement branch processes an input measurement frame using randomized parameters to obtain a measurement branch signal, which is then sent to another input of the accumulator. The accumulator combines the shielding branch signal and the measurement branch signal into one signal, which is then sent to the DAC unit for digital-to-analog conversion to form a baseband analog signal, i.e., the covert measurement and control signal. The present invention randomizes waveform parameters from multiple dimensions, resulting in non-stationary characteristics of the signal, significantly improving anti-interception performance. The addition of a shielding branch further increases the difficulty of detection and interception, enabling covert measurement and control, and ensuring safe and effective aircraft measurement and control.

Description

Technical Field

[0001] The present invention relates to the field of covert communication in the field of wireless communications, and in particular to a covert measurement and control signal generating device. Background Art

[0002] The aerospace tracking and control system is a large electronic system that tracks, measures and controls operating launch vehicles, satellites, missiles and other aircraft. It consists of two parts: a ground tracking and control station and a tracking and control transponder device mounted on the aircraft. The two parts form an uplink tracking and control link and a downlink tracking and control link to achieve tracking and control of the aircraft.

[0003] Ground-based TT&C stations generate uplink TT&C signals, which are wirelessly transmitted to the aircraft. TT&C transponders receive and process the uplink signals, generating downlink TT&C signals that are then sent to the ground-based TT&C stations. Because uplink and downlink TT&C signals travel long distances, they are easily intercepted and intercepted by reconnaissance equipment, potentially compromising the proper functioning of our TT&C systems and potentially generating spoofing signals to take over our aircraft, seriously impacting our space security. Therefore, space TT&C signals require robust anti-detection and anti-interception capabilities to achieve covert TT&C.

[0004] The existing system of aerospace measurement and control systems uses direct sequence spread spectrum and frequency hopping as the main anti-interception means. However, fixed parameters such as the spreading code rate, spreading code period, frequency hopping period, and frequency hopping rate make the TT&C signals' ergodic and cyclostationary characteristics significant. Reconnaissance equipment can still carry out targeted detection and interception by analyzing these characteristics over a period of time. Summary of the Invention

[0005] In response to the problems existing in the existing technology, a covert measurement and control signal generating device is provided. The waveform parameters are randomized to destroy the ergodicity of the spread spectrum / frequency hopping signal, and a fixed parameter spread spectrum waveform is introduced for cover. The combination of the two generates a new aerospace measurement and control signal, which significantly reduces the probability of being detected and intercepted, and realizes covert measurement and control of our aircraft.

[0006] The present invention adopts the following technical solution: a covert measurement and control signal generating device, comprising a shielding branch, a measuring branch, an accumulator, and a DAC unit; the shielding branch processes a pseudo-random sequence using fixed parameters to obtain a shielding branch signal, and transmits the signal to an input of the accumulator; the measuring branch processes an input measurement frame using randomized parameters to obtain a measuring branch signal, and transmits the signal to another input of the accumulator; the accumulator combines the shielding branch signal and the measuring branch signal into one signal, and transmits the combined signal to the DAC unit, where the combined signal is converted into a baseband analog signal, i.e., the covert measurement and control signal.

[0007] Furthermore, the guard branch includes a first rate matching unit, a first spreading unit, a first modulation unit, and a first up-conversion unit connected in sequence. The pseudo-random sequence is input to the first rate matching unit, and rate conversion, spreading processing, modulation, and up-conversion processing are performed in sequence. The first up-conversion unit outputs the guard branch signal.

[0008] Furthermore, the first rate matching unit uses a fixed-rate information clock for rate conversion, the first spreading unit uses a fixed-rate fixed-sequence spreading code for spreading processing, and the first up-conversion unit uses a fixed frequency for up-conversion processing.

[0009] Furthermore, the measurement branch includes a second rate matching unit, a second spread spectrum unit, a second modulation unit, a second up-conversion unit, and a randomization parameter generation unit connected in sequence to the second rate matching unit, the second spread spectrum unit, and the second up-conversion unit respectively. The measurement frame is input to the second rate matching unit, and rate conversion, spread spectrum processing, modulation and up-conversion processing are performed in sequence, and the measurement branch signal is output by the second up-conversion unit; the randomization parameter generation unit generates the randomization parameters required for signal processing of the second rate matching unit, the second spread spectrum unit, and the second up-conversion unit and sends them to the corresponding units.

[0010] Furthermore, the randomization parameter generating unit includes an information clock generating unit, a spread spectrum code generating unit, a frequency hopping code generating unit and a randomization processing unit; the randomization processing unit is composed of a plurality of independent random number generating modules, which generate multiple random numbers and input them into the information clock generating unit, the spread spectrum code generating unit and the frequency hopping code generating unit respectively; the information clock generating unit generates an information clock according to the input random number and inputs it into the second rate matching unit; the spread spectrum code generating unit generates a spread spectrum code according to the input random number and inputs it into the second spread spectrum unit; the frequency hopping code generating unit generates a frequency hopping code according to the input random number and inputs it into the second up-conversion unit.

[0011] Furthermore, the information clock generating unit includes an information clock generator, an information rate control module and an information rate change rate control module. The information rate control module and the information rate change rate control module respectively receive independent random numbers generated by the randomization processing unit, determine the information rate and the information rate change rate according to the random numbers, and send them to the information clock generator, which generates the corresponding information clock.

[0012] Furthermore, the spread spectrum code generating unit includes a spread spectrum code generator, a spread spectrum code clock generator, a spread spectrum code rate control module and a spread spectrum code rate change rate control module; the spread spectrum code generator, the spread spectrum code rate control module and the spread spectrum code rate change rate control module respectively receive independent random numbers generated by the randomization processing unit; the spread spectrum code rate control module and the spread spectrum code rate change rate control module determine the spread spectrum code rate and the spread spectrum code rate change rate according to the random number, and send them to the spread spectrum code clock generator, the spread spectrum code clock generator generates a corresponding spread spectrum code clock, and then sends the spread spectrum code clock to the spread spectrum code generator; the spread spectrum code generator selects a spread spectrum code sequence according to the random number, and generates a corresponding spread spectrum code according to the spread spectrum code clock.

[0013] Furthermore, the frequency hopping code generating unit includes a frequency hopping code generator, a frequency hopping code clock generator, a frequency hopping code rate control module and a frequency hopping code rate change rate control module; the frequency hopping code generator, the frequency hopping code rate control module and the frequency hopping code rate change rate control module respectively receive independent random numbers generated by the randomization processing unit; the frequency hopping code rate control module and the frequency hopping code rate change rate control module determine the frequency hopping code rate and the frequency hopping code rate change rate according to the random number, and send them to the frequency hopping code clock generator, the frequency hopping code clock generator generates a corresponding frequency hopping code clock, and then sends the frequency hopping code clock to the frequency hopping code generator; the frequency hopping code generator selects a frequency hopping code sequence according to the random number, and generates a corresponding frequency hopping code according to the frequency hopping code clock.

[0014] Furthermore, the independent random numbers generated by the randomization processing unit correspond to the preset rates, change rates or code sequence numbers in the information rate control module, the information rate change rate control module, the spread spectrum code generator, the spread spectrum code rate control module, the spread spectrum code rate change rate control module, the frequency hopping code generator, the frequency hopping code rate control module and the frequency hopping code rate change rate control module, and the period of each random number is a different prime number.

[0015] Furthermore, the random number generation module is implemented in a real-time generation method based on a shift register or a non-real-time generation method based on storage.

[0016] Compared with the existing technology, the beneficial effects of adopting the above technical solution are: the present invention randomizes the waveform parameters from multiple dimensions, making the signal exhibit non-stationary characteristics, significantly improving the anti-interception performance, increasing the cover branch, further increasing the difficulty of detection and interception, realizing covert measurement and control, and ensuring the safety and effectiveness of aircraft measurement and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of a covert measurement and control signal generating device proposed in one embodiment of the present invention.

[0018] Reference numerals: 1-protection branch, 2-measurement branch, 3-accumulator, 4-DAC unit, 11-first rate matching unit, 12-first spreading unit, 13-first modulation unit, 14-first up-conversion unit, 21-second rate matching unit, 22-second spreading unit, 23-second modulation unit, 24-second up-conversion unit, 25-randomization parameter generation unit, 251-information clock generation unit, 252-spreading code generation unit, 253-frequency hopping code generation unit, 2 54-Randomization processing unit, 2511-Information clock generator, 2512-Information rate control module, 2513-Information rate change rate control module, 2521-Spread spectrum code generator, 2522-Spread spectrum code clock generator, 2523-Spread spectrum code rate control module, 2524-Spread spectrum code rate change rate control module, 2531-Frequency hopping code generator, 2532-Frequency hopping code clock generator, 2533-Frequency hopping code rate control module, 2534-Frequency hopping code rate change rate control module. DETAILED DESCRIPTION

[0019] The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar modules or modules with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications, and equivalents that fall within the spirit and scope of the appended claims.

[0020] To prevent the tracking and control signals transmitted by aerospace tracking and control systems from being detected and intercepted by reconnaissance equipment, this embodiment proposes a covert tracking and control signal generation device. This device disrupts the ergodicity of spread spectrum / frequency hopping signals by randomizing waveform parameters and introduces a fixed-parameter spread spectrum waveform for masking. The combination of the two generates a new aerospace tracking and control signal, significantly reducing the probability of detection and interception, thereby achieving covert tracking and control of our aircraft. The details are as follows:

[0021] The device includes a shielding branch 1, a measurement branch 2, an accumulator 3, and a DAC unit 4. The shielding branch 1 processes a pseudo-random sequence using fixed parameters to obtain a shielding branch signal, which is sent to the input end of the accumulator 3. The measurement branch 2 processes an input measurement frame using randomized parameters to obtain a measurement branch signal, which is sent to the other input end of the accumulator 3. The accumulator 3 combines the shielding branch signal and the measurement branch signal into one signal, which is then sent to the DAC unit 4. The DAC unit 4 converts the signal into a baseband analog signal, i.e., the covert measurement and control signal.

[0022] Specifically, the cover branch 1 includes a first rate matching unit 11, a first spreading unit 12, a first modulation unit 13, and a first up-conversion unit 14, which are connected in sequence. The pseudo-random sequence is input to the first rate matching unit 11, which sequentially undergoes rate conversion, spreading processing, modulation, and up-conversion processing. The first up-conversion unit 14 then outputs the cover branch signal.

[0023] Among them, the first rate matching unit 11 performs rate conversion on the pseudo-random sequence according to the information clock of the fixed rate; the first spread spectrum unit 12 performs spread spectrum processing on the rate-converted data according to the fixed PN sequence of the fixed rate; the first up-conversion unit 14 performs frequency conversion processing on the modulated signal according to the fixed frequency; the fixed rate, PN sequence and fixed frequency can be preset in the corresponding unit according to demand.

[0024] Furthermore, the measurement branch 2 includes a second rate matching unit 21, a second spread spectrum unit 22, a second modulation unit 23, a second up-conversion unit 24, and a randomization parameter generation unit 25 connected to the second rate matching unit 21, the second spread spectrum unit 22, and the second up-conversion unit 24 in sequence. The measurement frame is input to the second rate matching unit 21, and rate conversion, spread spectrum processing, modulation and up-conversion processing are performed in sequence, and the measurement branch signal is output by the second up-conversion unit 24; the randomization parameter generation unit 25 generates the randomization parameters required for signal processing of the second rate matching unit 21, the second spread spectrum unit 22, and the second up-conversion unit 24 and sends them to the corresponding units.

[0025] In this embodiment, the randomization parameter generation unit 25 includes an information clock generation unit 251, a spread spectrum code generation unit 252, a frequency hopping code generation unit 253, and a randomization processing unit 254; the randomization processing unit 254 is composed of a plurality of independent random number generation modules, which generate multiple random numbers and input them into the information clock generation unit 251, the spread spectrum code generation unit 252, and the frequency hopping code generation unit 253 respectively; the information clock generation unit 251 generates an information clock according to the input random number and inputs it into the second rate matching unit 21; the spread spectrum code generation unit 252 generates a spread spectrum code according to the input random number and inputs it into the second spread spectrum unit 22; the frequency hopping code generation unit 253 generates a frequency hopping code according to the input random number and inputs it into the second up-conversion unit 24.

[0026] In this embodiment, the specific components of the information clock generating unit 251, the spread spectrum code generating unit 252, and the frequency hopping code generating unit 253 are proposed:

[0027] The information clock generating unit 251 includes an information clock generator 2511, an information rate control module 2512 and an information rate change rate control module 2513. The information rate control module 2512 and the information rate change rate control module 2513 respectively receive independent random numbers generated by the randomization processing unit 254, determine the information rate and the information rate change rate according to the random numbers, and send them to the information clock generator 2511, which generates the corresponding information clock.

[0028] The spreading code generation unit 252 includes a spreading code generator 2521, a spreading code clock generator 2522, a spreading code rate control module 2523, and a spreading code rate change rate control module 2524. The spreading code generator 2521, the spreading code rate control module 2523, and the spreading code rate change rate control module 2524 each receive an independent random number generated by the randomization processing unit 254. The spreading code rate control module 2523 and the spreading code rate change rate control module 2524 determine the spreading code rate and spreading code rate change rate based on the random number and send them to the spreading code clock generator 2522. The spreading code clock generator 2522 generates a corresponding spreading code clock and then sends the spreading code clock to the spreading code generator 2521. The spreading code generator 2521 selects a spreading code sequence based on the random number and generates the corresponding spreading code according to the spreading code clock.

[0029] The frequency hopping code generation unit 253 includes a frequency hopping code generator 2531, a frequency hopping code clock generator 2532, a frequency hopping code rate control module 2533, and a frequency hopping code rate change rate control module 2534. The frequency hopping code generator 2531, the frequency hopping code rate control module 2533, and the frequency hopping code rate change rate control module 2534 each receive an independent random number generated by the randomization processing unit 254. The frequency hopping code rate control module 2533 and the frequency hopping code rate change rate control module 2534 determine the frequency hopping code rate and the frequency hopping code rate change rate based on the random number and send them to the frequency hopping code clock generator 2532. The frequency hopping code clock generator 2532 generates a corresponding frequency hopping code clock and then sends the frequency hopping code clock to the frequency hopping code generator 2531. The frequency hopping code generator 2531 selects a frequency hopping code sequence based on the random number and generates a corresponding frequency hopping code according to the frequency hopping code clock.

[0030] Accordingly, in this embodiment, the randomization processing unit 254 is composed of 8 independent random number generation modules. The 8 random numbers generated correspond to the numbers of the rates, change rates or code sequences preset in the information rate control module 2512, the information rate change rate control module 2513, the spread spectrum code generator 2521, the spread spectrum code rate control module 2523, the spread spectrum code rate change rate control module 2524, the frequency hopping code generator 2531, the frequency hopping code rate control module 2533, and the frequency hopping code rate change rate control module 2534. Each unit can select the corresponding rate, change rate or code sequence according to the number corresponding to the random number.

[0031] It should be noted that the periods of the random numbers in each channel in this embodiment are different prime numbers.

[0032] In a preferred embodiment, the random number generation module is implemented using a real-time generation method based on a shift register or a non-real-time generation method based on storage.

[0033] The covert measurement and control signals generated by the device proposed in this embodiment can be divided into uplink measurement and control signals and downlink measurement and control signals. Among them, the measurement frames of the uplink measurement and control signals include three types of data frames: synchronization frames, remote control frames and idle frames. The synchronization frames are sent periodically, the remote control frames are sent on demand, and the idle frames are sent at the rest of the time; the measurement frames of the downlink measurement and control signals include three types of data frames: synchronization frames, telemetry frames and idle frames. The synchronization frames are sent periodically, the telemetry frames are sent on demand, and the idle frames are sent at the rest of the time.

[0034] It should be noted that in the description of the embodiments of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances; the drawings in the embodiments are used to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations.

[0035] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A concealed measurement and control signal generating device, characterized in that: The system includes a protection branch, a measurement branch, an accumulator, and a DAC unit. The protection branch processes a pseudo-random sequence using fixed parameters to obtain a protection branch signal, which is then sent to the input of the accumulator. The measurement branch processes an input measurement frame using randomized parameters to obtain a measurement branch signal, which is then sent to the other input of the accumulator. The accumulator combines the protection branch signal and the measurement branch signal into one signal, which is then sent to the DAC unit for digital-to-analog conversion to form a baseband analog signal, i.e., the covert measurement and control signal. The protection branch includes a first rate matching unit, a first spreading unit, a first modulation unit, and a first up-conversion unit connected in sequence. The pseudo-random sequence is input to the first rate matching unit, and is sequentially subjected to rate conversion, spreading processing, modulation, and up-conversion processing. The first up-conversion unit outputs a protection branch signal. The first rate matching unit uses a fixed-rate information clock to perform rate conversion, the first spreading unit uses a fixed-rate fixed-sequence spreading code to perform spreading processing, and the first up-conversion unit uses a fixed frequency to perform up-conversion processing; The measurement branch includes a second rate matching unit, a second spreading unit, a second modulation unit, a second up-conversion unit, and a randomization parameter generation unit connected in sequence to the second rate matching unit, the second spreading unit, and the second up-conversion unit, respectively. The measurement frame is input to the second rate matching unit, and is sequentially subjected to rate conversion, spreading processing, modulation, and up-conversion processing, and the second up-conversion unit outputs a measurement branch signal; the randomization parameter generation unit generates randomization parameters required for signal processing by the second rate matching unit, the second spreading unit, and the second up-conversion unit and sends them to corresponding units; The randomization parameter generation unit includes an information clock generation unit, a spread spectrum code generation unit, a frequency hopping code generation unit, and a randomization processing unit; the randomization processing unit is composed of a plurality of independent random number generation modules, which generate multiple random numbers and input them into the information clock generation unit, the spread spectrum code generation unit, and the frequency hopping code generation unit respectively; the information clock generation unit generates an information clock based on the input random number and inputs it into the second rate matching unit; the spread spectrum code generation unit generates a spread spectrum code based on the input random number and inputs it into the second spread spectrum unit; The frequency hopping code generating unit generates a frequency hopping code according to the input random number and inputs the frequency hopping code to the second up-conversion unit.

2. The covert measurement and control signal generating device according to claim 1, characterized in that: The information clock generating unit includes an information clock generator, an information rate control module and an information rate change rate control module. The information rate control module and the information rate change rate control module respectively receive independent random numbers generated by the randomization processing unit, determine the information rate and the information rate change rate according to the random numbers, and send them to the information clock generator, which generates a corresponding information clock.

3. The covert measurement and control signal generating device according to claim 2, characterized in that: The spreading code generation unit includes a spreading code generator, a spreading code clock generator, a spreading code rate control module, and a spreading code rate change rate control module; the spreading code generator, the spreading code rate control module, and the spreading code rate change rate control module respectively receive independent random numbers generated by the randomization processing unit; the spreading code rate control module and the spreading code rate change rate control module determine the spreading code rate and the spreading code rate change rate based on the random numbers, and send them to the spreading code clock generator, which generates a corresponding spreading code clock and then sends the spreading code clock to the spreading code generator; the spreading code generator selects a spreading code sequence based on the random numbers and generates a corresponding spreading code according to the spreading code clock.

4. The covert measurement and control signal generating device according to claim 3, characterized in that: The frequency hopping code generation unit includes a frequency hopping code generator, a frequency hopping code clock generator, a frequency hopping code rate control module, and a frequency hopping code rate change rate control module; the frequency hopping code generator, the frequency hopping code rate control module, and the frequency hopping code rate change rate control module respectively receive independent random numbers generated by the randomization processing unit; the frequency hopping code rate control module and the frequency hopping code rate change rate control module determine the frequency hopping code rate and the frequency hopping code rate change rate based on the random numbers, and send them to the frequency hopping code clock generator, which generates a corresponding frequency hopping code clock and then sends the frequency hopping code clock to the frequency hopping code generator; The frequency hopping code generator selects a frequency hopping code sequence according to a random number and generates a corresponding frequency hopping code according to a frequency hopping code clock.

5. The covert measurement and control signal generating device according to claim 4, characterized in that: The independent random numbers generated by the randomization processing unit correspond to the preset rates, change rates or code sequence numbers in the information rate control module, the information rate change rate control module, the spread spectrum code generator, the spread spectrum code rate control module, the spread spectrum code rate change rate control module, the frequency hopping code generator, the frequency hopping code rate control module and the frequency hopping code rate change rate control module, and the period of each random number is a different prime number.

6. The covert measurement and control signal generating device according to claim 1, characterized in that: The random number generation module is implemented in a real-time generation mode based on a shift register or a non-real-time generation mode based on storage.

Images