Spread spectrum TT&C signal processing method and related device

Abstract

The application discloses a spread spectrum measurement and control signal processing method and related equipment. The method comprises the following steps: for the downlink direction from a satellite to the ground, completing the downlink front-stage processing which does not depend on pseudo code parameters at a ground station side, and transmitting downlink chip-level data which retains spread spectrum characteristics to a secure processing domain, and calling the pseudo code parameters by the secure processing domain to complete despreading processing; for the uplink direction from the ground to the satellite, calling the pseudo code parameters by the secure processing domain to complete spreading processing, and transmitting formed uplink chip-level data to the ground station side, and completing uplink rear-stage processing and emission by the ground station side without calling the pseudo code parameters. The method can solve the problem that the ground station cannot support the satellite with controlled pseudo code in the traditional spread spectrum measurement and control scheme, and seriously limits the flexibility of satellite measurement and control.

Description

Technical Field

[0001] The embodiments of this application relate to the aerospace field, and more specifically, the present invention relates to a spread spectrum telemetry and control signal processing method and related equipment. Background Technology

[0002] Currently, satellite telemetry, tracking, and command (TT&C) communication widely adopts the spread spectrum TT&C system. The spread spectrum TT&C system uses pseudo-random codes to spread the spectral density of TT&C signals, which has advantages such as anti-interference, low probability of interception, and high ranging accuracy, and has become the mainstream system for satellite TT&C.

[0003] The basic modulation method for spread spectrum telemetry and control signals is BPSK (Binary Phase Shift Keying), with a chip rate of N × 1.023 Mcps (N being an integer from 1 to 10), and a pseudo-code length typically of 1023 chips (Gold code). The signal operates in frequency bands covering S-band, X-band, and other frequency bands.

[0004] In a spread spectrum telemetry and control system, the ground station's telemetry and control baseband needs to complete processes such as pseudo-code acquisition, pseudo-code tracking, carrier recovery, despreading, bit synchronization, and channel decoding. Among these, despreading is the core process. The ground station must master the pseudo-code used by the satellite (including parameters such as code polynomial, code length, and initial phase) in order to restore the spread spectrum signal to a narrowband data signal through relevant calculations.

[0005] However, in many application scenarios, the spreading polynomials and pseudocodes used by satellites are controlled and cannot be exported; only authorized users can obtain them in specific secure environments. In such cases, the ground station's telemetry and control baseband cannot obtain the pseudocode parameters, thus preventing despreading and consequently hindering the demodulation of telemetry signals and the modulation of transmitted spread-spectrum remote control signals. This prevents ground stations from providing telemetry and control support for satellites using controlled pseudocodes, severely limiting the flexibility of satellite telemetry and control. Summary of the Invention

[0006] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. The summary section of this invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0007] To address the problem in traditional spread spectrum telemetry and control schemes where ground stations cannot provide telemetry and control support for satellites using controlled pseudocodes, severely limiting the flexibility of satellite telemetry and control, this invention proposes, in a first aspect, a spread spectrum telemetry and control signal processing method, comprising: The system receives the spread spectrum telemetry and control downlink signal transmitted by the satellite, performs downlink pre-processing on the spread spectrum telemetry and control downlink signal on the ground station side without relying on the pseudocode parameters corresponding to the satellite, obtains downlink chip-level data that retains the spread spectrum characteristics, and transmits the downlink chip-level data to the secure processing domain. Within the security processing domain, the pseudocode parameters corresponding to the satellite are invoked to perform downlink security processing, including despreading, on the downlink chip-level data to obtain telemetry data. Within the security processing domain, remote control data is acquired, and the pseudocode parameters corresponding to the satellite are called to perform uplink security processing on the remote control data, including spread processing, to obtain uplink chip-level data. The uplink chip-level data is transmitted to the ground station. The ground station performs uplink post-processing on the uplink chip-level data, which is independent of the pseudo-code parameters, to generate a spread spectrum telemetry and control uplink signal, which is then transmitted to the satellite.

[0008] Secondly, the present invention also proposes a spread spectrum measurement and control signal processing device, comprising: The downlink signal receiving unit is used to receive the spread spectrum telemetry and control downlink signal transmitted by the satellite, and to perform downlink pre-processing on the spread spectrum telemetry and control downlink signal on the ground station side without relying on the pseudocode parameters corresponding to the satellite to obtain downlink chip-level data that retains the spread spectrum characteristics, so as to transmit the downlink chip-level data to the secure processing domain. The telemetry data acquisition unit is used to call the pseudocode parameters corresponding to the satellite within the security processing domain, perform downlink security processing including despreading on the downlink chip-level data, and obtain telemetry data. The remote control data acquisition unit is used to acquire remote control data within the security processing domain, call the pseudocode parameters corresponding to the satellite to perform uplink security processing on the remote control data, including spread processing, to obtain uplink chip-level data. An uplink signal transmission unit is used to transmit the uplink chip-level data to the ground station, and to perform uplink post-processing on the uplink chip-level data on the ground station that is independent of the pseudo-code parameters to generate a spread spectrum telemetry and control uplink signal for transmission to the satellite.

[0009] Thirdly, an electronic device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program stored in the memory to implement the steps of the spread spectrum measurement and control signal processing method as described in any of the first aspects above.

[0010] Fourthly, the present invention also proposes a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the spread spectrum measurement and control signal processing method of any of the above claims in the first aspect.

[0011] In summary, the spread spectrum telemetry and control signal processing method proposed in this application redefines the processing boundary between the ground station and the secure processing domain based on whether a certain signal processing step requires the actual invocation of pseudo-code parameters. For the downlink direction from satellite to ground, the satellite transmits a spread spectrum telemetry and control downlink signal that has already undergone spread spectrum processing. After receiving this signal, the ground station does not perform despreading, which requires the invocation of pseudo-code parameters, on the ground station side. Instead, it first performs downlink pre-processing independent of pseudo-code parameters, converting the received spread spectrum telemetry and control downlink signal into downlink chip-level data suitable for further processing and transmission, while still retaining the spread spectrum characteristics. Subsequently, the downlink chip-level data is transmitted to the secure processing domain. Since the spread spectrum characteristics are still retained, after obtaining this data, the secure processing domain can call the corresponding satellite's pseudo-code parameters for despreading within the secure processing domain and further obtain telemetry data. For the uplink direction from ground to satellite, the data processing direction corresponds to the downlink direction described above. The secure processing domain first obtains the remote control data to be sent to the satellite, and then calls the corresponding pseudo-code parameters of the satellite within the secure processing domain to spread the remote control data, obtaining uplink chip-level data that already contains the pseudo-code spread spectrum relationship. The uplink chip-level data is then transmitted to the ground station. The ground station no longer receives the raw remote control data awaiting spread spectrum using pseudo-code parameters, but rather the already spread chip-level data. Therefore, the ground station can complete subsequent uplink post-processing without obtaining the pseudo-code parameters, generating a spread spectrum telemetry and control uplink signal ready for actual transmission. Thus, although the downlink and uplink signals flow in opposite directions, the processing boundaries regarding pseudo-code parameters are consistent. In the downlink direction, the data first passes through the ground station before entering the secure processing domain; therefore, despreading is postponed to the secure processing domain. In the uplink direction, the data first passes through the secure processing domain before reaching the ground station; therefore, spread spectrum is completed earlier in the secure processing domain. This ensures that all core spread spectrum processing in both directions that relies on satellite pseudo-code parameters is located in the secure processing domain, while the ground station handles signal pre-processing or post-processing that can be completed without obtaining the pseudo-code parameters. Attached Figure Description

[0012] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit this specification. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic flowchart of a spread spectrum measurement and control signal processing method provided in an embodiment of this application; Figure 2 This is a schematic diagram of a spread spectrum measurement and control signal processing device provided in an embodiment of this application; Figure 3 This is a schematic diagram of a spread spectrum measurement and control signal processing electronic device provided in an embodiment of this application. Detailed Implementation

[0013] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. The technical solutions of the embodiments of this application will now be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0014] Understandably, the despreading function of traditional telemetry, tracking, and command (TT&C) baseband must be completed within the baseband equipment, requiring the baseband equipment to store and use the satellite's pseudocode parameters. When the satellite pseudocode is controlled, the ground station cannot obtain the pseudocode, resulting in the TT&C baseband being unable to demodulate, and the ground station being unable to support the TT&C mission for that satellite. In existing solutions, pseudocode processing (despreading / addition) and signal processing (carrier recovery, bit synchronization, etc.) are completed in the same baseband equipment, making it impossible to isolate pseudocode operations to an independent secure environment. The pseudocode must be sent to the ground station equipment, increasing the risk of security management. Different satellites may use different spreading schemes and different pseudocode parameters. Existing solutions require the ground station to configure a corresponding TT&C baseband or load a corresponding pseudocode for each type of satellite, making it difficult to achieve universality. Although existing SDR solutions achieve physical separation of the RF front-end and back-end, the back-end still needs to complete despreading, and the pseudocode still needs to enter the ground station's back-end processing equipment, failing to fundamentally resolve the contradiction between pseudocode control and ground station compatibility. LEO satellites are characterized by low orbital altitude, short overpass time (typically 8-15 minutes), and large Doppler dynamics. Existing solutions do not address these characteristics with Doppler pre-compensation and rapid acquisition optimization, resulting in low utilization of the LEO satellite telemetry and control arc.

[0015] To address the problem in traditional spread spectrum telemetry and control schemes where ground stations cannot provide telemetry and control support for satellites using controlled pseudocodes, severely limiting the flexibility of satellite telemetry and control. Please refer to... Figures 1 to 3 As shown, Figure 1 This application provides a schematic flowchart of a spread spectrum telemetry and control signal processing method, which specifically includes the following in the telemetry process: S110: Receive the spread spectrum telemetry and control downlink signal transmitted by the satellite, and perform downlink pre-processing on the spread spectrum telemetry and control downlink signal on the ground station side without relying on the pseudocode parameters corresponding to the satellite to obtain downlink chip-level data that retains the spread spectrum characteristics, so as to transmit the downlink chip-level data to the secure processing domain.

[0016] S120, within the security processing domain, the pseudocode parameters corresponding to the satellite are called to perform downlink security processing, including despreading, on the downlink chip-level data to obtain telemetry data.

[0017] Specifically, the remote control process may include: S230, remote control data is obtained within the security processing domain, and the pseudocode parameters corresponding to the satellite are called to perform uplink security processing on the remote control data, including spread processing, to obtain uplink chip-level data.

[0018] S240, the uplink chip-level data is transmitted to the ground station, and the uplink chip-level data is processed at the ground station without relying on the pseudo-code parameters to generate a spread spectrum telemetry and control uplink signal, which is then transmitted to the satellite.

[0019] Understandably, in traditional spread spectrum telemetry and control signal processing, to complete the despreading of satellite downlink signals, the ground station responsible for receiving signal processing usually needs to obtain the corresponding satellite pseudocode parameters. Similarly, to generate uplink remote control signals that the satellite can correctly receive and despread, the ground station responsible for transmitting signals also often needs to obtain the corresponding pseudocode parameters. Thus, every ground station that needs to perform satellite telemetry and control tasks may become a location where pseudocode parameters are used. When the telemetry and control network includes multiple ground stations or needs to dynamically select different ground stations to undertake tasks, the distribution range of pseudocode parameters expands accordingly. Therefore, this paper uses chip-level data as the bidirectional signal processing interface between the ground station side and the secure processing domain. Based on the dependency relationship between despreading and augmentation on pseudocode parameters, in the downlink direction, despreading is set after the chip-level data enters the secure processing domain, and in the uplink direction, augmentation is set before the chip-level data leaves the secure processing domain. This maintains bidirectional spread spectrum telemetry and control capabilities while ensuring that the pseudocode parameters required for both telemetry and remote control can be used within the secure processing domain.

[0020] For example, the system as a whole is divided into two functional domains, separated by controlled boundaries: Uncontrolled area (ground station): includes antenna and RF front end, data transmission baseband (receive transparent mode), data transmission baseband (transmit modulation mode) and network interface; Controlled area (security processing domain): includes network interface, despreading module, telemetry decoding module, remote control encoding module, spread-through module and pseudocode parameter library.

[0021] For example, in S110, when the spread spectrum telemetry and control downlink signal transmitted by the satellite reaches the ground station, the signal already contains the spread spectrum relationship formed between telemetry information and pseudocode. This step does not require the ground station to directly recover the telemetry information from it, but rather requires the ground station to process the received signal to a degree suitable for further processing in the secure processing domain. Therefore, downlink pre-processing is significantly different from traditional complete telemetry demodulation. Its processing endpoint is not the recovered telemetry data, but downlink chip-level data that still retains the spread spectrum characteristics. That is to say, downlink pre-processing can change the signal's representation suitable for digital processing and transmission, but should not prematurely eliminate the spread spectrum relationship required for subsequent despreading in the secure processing domain. The phrase "not dependent on the pseudocode parameters corresponding to the satellite" emphasizes that when the ground station performs this stage of processing, it does not need to perform matching despreading based on the specific pseudocode content of the target satellite. Therefore, the ground station can complete those processes related to signal reception itself, but which do not require knowledge of the specific spread spectrum sequence. After the actual telemetry and control mission begins, the target satellite transmits the spread spectrum telemetry and control downlink signal to the ground. The ground station receives the signal through its own receiving equipment and completes downlink pre-processing at the ground station side. After downlink pre-processing, the spread spectrum telemetry and control downlink signal, originally suitable for wireless transmission, is converted into downlink chip-level data suitable for digital processing and transmission to the secure processing domain. An important control principle in this process is that the formation of chip-level data should not be interpreted as the complete recovery of all telemetry bits represented by the chips. The chip-level data still carries the spread spectrum structure of the satellite's transmitted signal, and the secure processing domain still needs to rely on the corresponding pseudocode parameters to complete despreading. For example, satellite A is transmitting a spread spectrum telemetry signal. After receiving this signal, ground station A can convert it into downlink chip-level data. At this point, although ground station A has completed the pre-processing of the signal, it does not know the specific pseudocode sequence used by satellite A, and therefore cannot recover the final telemetry content based on the pseudocode in this step. The formed chip-level data is then passed to the secure processing domain, which continues to perform processing dependent on the pseudocode parameters. For example, when another ground station B undertakes the telemetry and control mission for the same satellite, ground station B can still obtain chip-level data that retains the spread spectrum characteristics according to the same processing boundaries, without having to configure the satellite's pseudo-code parameters to ground station B at the same time just because the telemetry and control mission is transferred to ground station B.

[0022] For example, the satellite transmits spread-spectrum BPSK telemetry and control signals. The ground station antenna and RF front-end receive the signals, amplify them with low noise, down-convert them to intermediate frequency (IF), and send them to the data transmission baseband. The data transmission baseband performs A / D sampling on the IF signal, with a sampling rate of not less than twice the signal bandwidth. For a signal with a chip rate of N×1.023 Mcps (N=1~10), the zero-to-zero bandwidth is 2×N×1.023 MHz. Considering that the LEO satellite has a maximum Doppler shift of ±57 kHz in the S-band (500km orbit) and a maximum Doppler shift of ±213 kHz in the X-band, the A / D sampling bandwidth should meet the following requirements: B_sample ≥ 2 × N × 1.023 MHz + 0.426 MHz (X-band Doppler margin) Where B_sample is the sampling bandwidth in MHz. For N=10, 2 × 10 × 1.023 MHz + 0.426 MHz = 20.886 MHz, which is approximately 21 MHz. Therefore, the sampling bandwidth should not be less than 21 MHz.

[0023] For example, the secure processing domain can employ a hardware cryptographic module. Integrated within the ground station cabinet (PCIe cryptographic card / national cryptographic security chip / FPGA cryptographic coprocessor), it is directly connected via PCIe or SRIO (Serial RapidIO) bus, with transmission latency in the microsecond range. This is suitable for LEO satellite telemetry and control scenarios requiring rapid deployment, such as mobile stations and portable stations. Alternatively, a physically isolated secure device can be used. Located in a dedicated equipment room / secure cabinet, it is connected via encrypted fiber optic cable, with transmission latency in the millisecond range. Pseudo-code does not extend beyond physical boundaries, providing the highest level of security. This is suitable for long-term LEO satellite telemetry and control scenarios such as fixed stations and master stations.

[0024] For example, in S120, after processing, the downlink chip-level data still retains the spread spectrum characteristics of the satellite's transmitted signal, and therefore cannot be directly used as the final telemetry data. After obtaining the downlink chip-level data, the secure processing domain forms a processing basis corresponding to the received spread spectrum structure based on the pseudo-code parameters corresponding to the current satellite, and uses these pseudo-code parameters to complete despreading, thus recovering the telemetry information spread in the chip sequence. The key is not placing the telemetry data in the secure processing domain, but rather that the act of calling the pseudo-code parameters to perform despreading occurs within the secure processing domain. For example, ground station A transmits the downlink chip-level data corresponding to satellite A to the secure processing domain. After identifying that the data belongs to the telemetry and control mission corresponding to satellite A, the secure processing domain calls the pseudo-code parameters corresponding to satellite A. Subsequently, the secure processing domain uses the spread spectrum correspondence between these pseudo-code parameters and the received chip-level data to perform despreading, recovering the telemetry information originally distributed in the spread spectrum chips, and finally obtaining the telemetry data. Assume the system also simultaneously undertakes the telemetry and control mission for satellite B. Satellite B may use different pseudo-code parameters than satellite A. Accordingly, it is not necessary to provide the pseudocode parameters of satellite A and satellite B separately to different ground stations undertaking the receiving task. Instead, these ground stations can all generate downlink chip-level data that retains the spread spectrum characteristics, and then the security processing domain can call the corresponding pseudocode parameters for different satellites.

[0025] For example, the data transmission baseband transmits chip-level I / Q data streams to the network interface 105 of the secure processing domain via network interface 104. The transmission uses UDP or RDMA (Remote Direct Memory Access) protocols to reduce latency. A jitter buffer (FIFO) is set up on the secure processing domain side, with a depth configured according to network jitter statistics (typically 1~5ms), to eliminate the impact of network latency jitter on despreading processing. Total transmission latency: approximately 1~2ms for in-site deployment, and approximately 2~7ms for remote deployment.

[0026] For example, in S230, if only downlink despreading is set in the secure processing domain, while uplink is still respread by obtaining pseudocode parameters from the ground station, then the pseudocode parameters still need to enter the ground station, and the bidirectional processing boundary that this scheme aims to achieve cannot be established. Therefore, the uplink direction adopts a division method corresponding to the downlink direction. The only difference is that the signal flow direction changes. Downlink data retains its spreading characteristics before entering the secure processing domain and is despread within the secure processing domain; uplink remote control data is respread before leaving the secure processing domain, so that the data leaving the secure processing domain has become uplink chip-level data with the corresponding spreading relationship. For example, when a set of remote control data needs to be sent to satellite A, the remote control data first enters the secure processing domain. After the secure processing domain determines its corresponding satellite, it calls the pseudocode parameters corresponding to satellite A and uses these pseudocode parameters to perform respreading processing on the remote control data. Assuming that a remote control data unit represents control information to be transmitted to the satellite before respreading, then after respreading, its information has been distributed into the corresponding chip sequence according to the spreading relationship adopted by satellite A. The data output to the ground station is this uplink chip-level data, not the remote control data that requires the ground station to retrieve the pseudo-code parameters of satellite A for spread spectrum processing. For example, ground station A is currently responsible for the uplink mission of satellite A, and subsequently, due to changes in telemetry and control conditions, the transmission mission is taken over by ground station B. As long as the security processing domain still generates the corresponding uplink chip-level data for satellite A, ground station B's task remains the subsequent processing after obtaining the uplink chip-level data, without needing to obtain the pseudo-code parameters of satellite A.

[0027] For example, in S240, after the security processing domain completes the spread spectrum, the spreading relationship between the remote control information and the target satellite pseudocode has been determined. However, the uplink chip-level data itself still needs to undergo subsequent processing suitable for ground station transmission before it can become a spread spectrum telemetry and control uplink signal that can be actually transmitted to the satellite via the wireless link. Therefore, this step leaves this part of the processing, which does not need to call the pseudocode parameters again, to be completed on the ground station side. This actually utilizes the characteristics of the logical order of spread spectrum signal processing: as long as the spread process related to the pseudocode has been completed in the security processing domain, the subsequent processing to form the actual transmission signal can use the already formed uplink chip-level data as input, without needing to know again what pseudocode parameters were used when these chips were generated. After the security processing domain completes the remote control data spread for satellite A, it transmits the formed uplink chip-level data to the ground station currently undertaking the mission of transmitting satellite A. The ground station receives the uplink chip-level data, performs subsequent processing according to the processing method required for uplink signal transmission, and generates a spread spectrum telemetry and control uplink signal. The generated signal is finally transmitted to satellite A through the ground station's transmission link. Throughout the process, the ground station can see the chip-level data to be transmitted, but it does not need to obtain the satellite A pseudocode parameters used by the secure processing domain to form these chips. For example, when multiple ground stations are assigned to different telemetry and control (TT&C) arcs based on the satellite's transit position, the secure processing domain can always handle the amplification of remote control data, while different ground stations receive the corresponding uplink chip-level data and generate uplink signals during their respective missions. When the TT&C geographical location changes, the pseudocode parameters do not need to migrate with the ground station undertaking the transmission mission.

[0028] For example, the despreading module within the secure processing domain performs the following processing on the chip-level I / Q data stream received from the network. The received signal model is: r(n) = A · PN(n τ) · D(n) · exp(j(2π·Δf·n·T_s + φ)) + w(n) Where A is the signal amplitude, PN(·) is the pseudocode sequence, τ is the code phase offset (chip), D(·) is the data bit (±1), Δf is the residual frequency offset (Hz), T_s is the sampling interval (s), φ is the carrier initial phase (rad), w(n) is the complex Gaussian white noise, n is the discrete sampling point number n=0,1,2……, and j is the imaginary unit.

[0029] a) Pseudo-code Acquisition: A parallel acquisition method using FFT (Fast Fourier Transform) is employed. The received signal is cyclically correlated with the local pseudo-code (implemented via FFT / IFFT), covering all 1023 code phases in a single operation. The correlation result is squared modulo-based and incoherently accumulated. Peak detection is used to determine the pseudo-code phase τ0 and coarse frequency offset Δf0. For a 7.3 m aperture antenna ground station, the G / T value in the S-band is approximately 19.9 dB / K, and the G / T value in the X-band is approximately 30.9 dB / K. Under typical satellite EIRP conditions of approximately 20 dBm, the C / N0 range is 64–84 dB-Hz, and the acquisition time is less than 10 ms.

[0030] b) Tracking Loop: After acquisition, the tracking phase begins, employing a combined carrier loop and code loop for tracking. The carrier loop uses a Costas loop with a bandwidth of 5~50 Hz. The code loop uses a delay-locked loop (DLL) with an early-code to late-code interval of 0.5 chips and a loop bandwidth of 1~10 Hz. The code loop also has sampling clock deviation compensation capability: when there is an accuracy deviation δ (typically 10 ppm) between the data transmission baseband and the security processing domain processing clock, the code phase drift rate is δ × R_chip. For N=3 and δ=10 ppm, the drift rate is 30.7 chips / s, which is well within the DLL tracking capability range.

[0031] c) Despreading and Decoding: After tracking stabilizes, the local pseudocode and the received signal are aligned using precise code phase, and correlation operations are performed to complete despreading. After bit synchronization and decision, channel decoding is selectively performed according to the satellite telemetry and control system (channel coding is optional, including no coding, convolutional coding, etc.), and plaintext telemetry frame data is output.

[0032] In summary, based on the above scheme, the security processing requirements of pseudo-code parameters are integrated with the actual spread spectrum telemetry and control signal processing flow. This scheme limits the actual data boundary location where the ground station obtains pseudo-code parameters: downlink selects downlink chip-level data retaining spread spectrum characteristics as data entering the secure processing domain, and uplink selects uplink chip-level data that has already undergone spread as data leaving the secure processing domain. Therefore, even if the ground station does not obtain pseudo-code parameters, the entire telemetry and remote control processing flow can still continue. Furthermore, it simultaneously solves the dependency problem of pseudo-code parameters in both downlink despreading and uplink spread. If only the downlink processing method is changed, it may still be necessary to configure pseudo-code parameters to the ground station when performing uplink remote control tasks. This scheme further arranges uplink spread in the secure processing domain, so that the processing requiring pseudo-code parameters in both uplink and downlink directions can be concentrated in the same controlled area. It also reduces the correlation between changes in the ground station and the scope of pseudo-code parameter usage. When a task is transferred from one ground station to another, only the ground station responsible for the front-end reception or back-end transmission processing needs to change, rather than necessarily changing the location where pseudo-code parameters are used. Therefore, the telemetry, tracking, and command (TT&C) system can organize satellite missions across different ground stations without distributing sensitive pseudocode parameters along with the missions to each mission's ground station. Furthermore, it retains the original physical receiving and transmitting functions of the ground stations while restricting the location of sensitive parameters. Since satellite radio signals are still directly received and transmitted by the ground stations, this solution does not require changing the basic function of the ground stations as wireless TT&C nodes. What is changed is the division of signal processing responsibilities between the ground stations and the security processing domain, making it more adaptable to distributed TT&C scenarios.

[0033] In some examples, the security processing domain is equipped with a pseudocode parameter library, which stores pseudocode parameters corresponding to multiple satellites, indexed by satellite mission identifiers. These pseudocode parameters include code polynomial, code length, chip rate, initial phase, and spreading scheme type. The method further includes: In response to the satellite mission identifier corresponding to the target satellite issued by the mission scheduling system, the ground station configures the corresponding signal sampling parameters according to the satellite mission identifier, and retrieves the corresponding pseudocode parameters from the pseudocode parameter library according to the satellite mission identifier in the security processing domain to configure the downlink security processing and the uplink security processing. The pseudo-code parameters are injected into the secure processing domain through a secure channel without passing through the ground station. The acquisition, storage, and retrieval of the pseudo-code parameters are restricted to the secure processing domain, so that both the downlink secure processing and the uplink secure processing are completed by calling the pseudo-code parameters within the secure processing domain. The ground station completes the downlink pre-processing and the uplink post-processing respectively without acquiring the pseudo-code parameters.

[0034] For example, before mission execution, a pseudo-code parameter library can be established in the security processing domain. For satellite A, the corresponding record stores satellite A's code polynomial, code length, chip rate, initial phase, and spreading scheme type; for satellite B, another set of parameter records is also established. Different records are distinguished by their corresponding satellite mission identifiers. When the mission scheduling system determines that the target of the next telemetry and control mission is satellite A, it sends the satellite mission identifier corresponding to satellite A to the relevant processing section. After receiving the identifier, the ground station configures the corresponding signal sampling parameters according to the current satellite mission, enabling the receiving link to process satellite A's downlink signals, but it does not need to read satellite A's code polynomial or initial phase during this process. At the same time, the security processing domain searches the pseudo-code parameter library based on the same satellite mission identifier. When the search result points to the parameter record of satellite A, the security processing domain obtains the code polynomial, code length, chip rate, initial phase, and spreading scheme type from that record, and configures the subsequent downlink security processing accordingly. When it is necessary to send remote control data to satellite A, the security processing domain still uses the corresponding parameters to complete the uplink spreading. When the mission switches to Satellite B, the ground station changes the signal sampling parameters to adapt to the Satellite B mission, while the security processing domain uses the Satellite B mission identifier to retrieve the pseudo-code parameters of Satellite B. The pseudo-code parameters themselves do not flow between the security processing domain and the ground station due to the change in the target satellite.

[0035] In some examples, the downlink preprocessing of the spread spectrum telemetry and control downlink signal at the ground station side, independent of the pseudocode parameters corresponding to the satellite, to obtain downlink chip-level data that retains the spread spectrum characteristics, includes: The spread spectrum telemetry and control downlink signal is sampled by analog and digital signals at the ground station, and the digital intermediate frequency signal obtained by analog and digital sampling is digitally downconverted to the baseband. The baseband signal obtained by digital downconversion is low-pass filtered and decimated, and the processed in-phase and quadrature components are quantized to obtain a chip-level in-phase and quadrature data stream as the downlink chip-level data. In the process of forming the chip-level in-phase and quadrature data stream on the ground station side, the spread spectrum telemetry and control downlink signal is not despread.

[0036] For example, after receiving the analog spread spectrum telemetry and control downlink signal from the target satellite, the ground station performs analog-to-digital sampling on the signal to obtain a digital intermediate frequency (IF) signal. The digital IF signal is still located at the corresponding IF position and is not suitable for direct use as data for subsequent chip-level processing. Therefore, it is digitally down-converted to the baseband. After digital down-conversion, the corresponding in-phase and quadrature components are obtained. These baseband signals are low-pass filtered to preserve the frequency band of the target spread spectrum signal and suppress unwanted frequency components. Subsequently, decimation is performed to adapt the data sampling scale to the requirements of subsequent chip-level processing. The processed in-phase and quadrature components are further quantized, ultimately forming a chip-level in-phase and quadrature data stream that can be represented digitally. It is important to note that the ground station does not perform correlation operations with this data using the target satellite pseudocode; therefore, what is obtained is not the recovered telemetry bits, but still chip-level data containing spread spectrum characteristics.

[0037] In some examples, transmitting the downlink chip-level data to the secure processing domain includes: The chip-level in-phase orthogonal data stream is transmitted in real time to the secure processing domain via a network link, wherein the network link uses User Datagram Protocol or Remote Direct Memory Access Protocol to transmit the chip-level in-phase orthogonal data stream. A jitter buffer is set on the secure processing domain side, and the received chip-level in-phase quadrature data stream is written into the jitter buffer; The jitter buffer is used to compensate for the delay jitter caused by network transmission.

[0038] For example, when chip-level signal processing is divided between the ground station and the secure processing domain from within a single device, an easily overlooked problem arises: data that might have flowed continuously within the same signal processing device now needs to be transmitted via a network link. The latency introduced by the network link is typically not strictly constant. Even if chip-level in-phase quadrature data is generated sequentially, the time interval between different data arrivals at the secure processing domain can fluctuate. However, subsequent carrier recovery, pseudocode acquisition, and pseudocode tracking deal with chip-level signals that are time-continuous. Therefore, this example does not simply send the chip data over the network, but instead sets up a jitter buffer at the secure processing domain. Received data first enters the jitter buffer, using the buffering effect to absorb short-term variations in network transmission latency, thereby reducing the direct impact of network transmission inhomogeneity on subsequent continuous signal processing. After the ground station forms a chip-level in-phase quadrature data stream, it sends it to the secure processing domain in real time via the network link. The network link can use either the User Datagram Protocol (UDP) or the Remote Direct Memory Access Protocol (RDP). After receiving in-phase orthogonal chip-level data, the security processing domain does not immediately pass each arriving data to subsequent despreading processing. Instead, it first writes it to a jitter buffer. Suppose that several consecutive chip data sets are generated at a relatively stable pace at the ground station, but one set arrives slightly later due to changes in network transmission status, while another set arrives faster. If subsequent processing operates entirely based on the arrival times of the network data, these transmission time variations could manifest as uneven input data. By setting up a jitter buffer, the buffered data can absorb these short-term transmission time variations, making the data provided to subsequent security processing more stable in terms of temporal continuity.

[0039] In some examples, the step of invoking the pseudocode parameters corresponding to the satellite within the security processing domain to perform downlink security processing, including despreading, on the downlink chip-level data to obtain telemetry data includes: A local pseudocode is generated based on the pseudocode parameters, and carrier recovery and pseudocode acquisition are performed on the chip-level in-phase quadrature data stream to determine the pseudocode phase and residual frequency offset of the received signal. After the pseudocode acquisition is completed, carrier tracking and pseudocode tracking are performed on the received signal; The local pseudocode is aligned with the received signal based on the tracked code phase, and despreading is completed through correlation operations. Bit synchronization and decision-making are performed on the despread data, and channel decoding is selectively performed according to the spread spectrum telemetry and control system corresponding to the satellite to obtain the telemetry data.

[0040] For example, assume the secure processing domain receives a chip-level in-phase orthogonal data stream belonging to satellite A. First, a local pseudocode is generated based on the pseudocode parameters corresponding to satellite A. Since the actual received signal is affected by factors such as satellite motion, the receiving link, and timing, the locally generated processing reference cannot be naturally perfectly aligned with the received signal simply by the parameter generation action; therefore, carrier recovery and pseudocode acquisition are performed. Pseudocode acquisition determines the pseudocode phase corresponding to the received signal, and carrier recovery obtains the carrier state required for subsequent processing and determines the residual frequency offset. After acquisition, the continuous tracking phase begins. Carrier tracking maintains the following of the received signal's carrier state, while pseudocode tracking ensures the local pseudocode maintains the correct phase relationship with the received chip. Based on this, correlation operations are performed between the aligned local pseudocode and the received signal to obtain the despread data. Subsequently, the bit timing relationship in the despread data is identified, bit synchronization is completed, and the data is judged. If the current satellite's telemetry and control system requires channel decoding of the received data, then the corresponding channel decoding continues; otherwise, telemetry data is directly generated according to the corresponding system.

[0041] In some examples, the step of acquiring remote control data within the security processing domain and performing uplink security processing on the remote control data, including spread processing, by calling the pseudocode parameters corresponding to the satellite, includes: Within the security processing domain, remote control commands are acquired, and the remote control commands are either channel-coded or the un-channel-coded remote control commands are formed into a remote control data bit stream. The pseudocode parameters corresponding to the satellite are obtained from the pseudocode parameter library. A local pseudocode is generated based on the obtained pseudocode parameters. The local pseudocode is then used to spread spectrum modulate the remote control data bit stream to generate a spread spectrum chip stream as the uplink chip-level data. The spread spectrum chip stream is transmitted to the ground station, where the ground station performs binary phase shift keying modulation, up-conversion, and power amplification on the spread spectrum chip stream to generate and transmit the spread spectrum telemetry and control uplink signal.

[0042] For example, in the downlink direction, the signal transmitted by the satellite has already been spread, so despreading needs to be performed in the secure processing domain. Conversely, in the uplink direction, the original remote control data does not yet have the spreading relationship required by the target satellite, so upspreading needs to be performed within the secure processing domain. After the secure processing domain obtains the remote control command, it can first perform channel coding, or directly form a remote control data bitstream from the un-channel-coded remote control command, depending on the current telemetry and control system. Then, it obtains the pseudo-code parameters of the target satellite from the pseudo-code parameter library, generates the corresponding local pseudo-code, and uses this local pseudo-code to perform spread spectrum modulation on the remote control data bitstream. The resulting spread spectrum chip stream already contains the spreading relationship required by the target satellite. Therefore, after the spread spectrum chip stream leaves the secure processing domain and enters the ground station, the ground station does not need to obtain the pseudo-code parameters again, but can continue to perform binary phase-shift keying modulation, up-conversion, and power amplification, ultimately forming a spread spectrum telemetry and control uplink signal that can be transmitted to the satellite. For example, the control system generates a remote control command that needs to be sent to satellite A. This remote control command enters the secure processing domain. Based on the telemetry and control (TT&C) method used by satellite A, if channel coding is required for the corresponding processing, the remote control commands are first channel coded; if channel coding is not required, the corresponding remote control data bitstream is directly generated. The security processing domain then retrieves the pseudocode parameters corresponding to satellite A from the pseudocode parameter library and generates local pseudocode accordingly. After performing spread spectrum modulation on the remote control data bitstream using this local pseudocode, a spread spectrum chip stream is formed. This spread spectrum chip stream is then transmitted from the security processing domain to the ground station undertaking the current task. Since the spread spectrum has been completed, the ground station does not need to reacquire the code polynomial, code length, or initial phase of satellite A. Instead, it directly performs binary phase shift keying modulation on the received spread spectrum chip stream, then performs up-conversion and power amplification to generate a spread spectrum TT&C uplink signal suitable for wireless transmission, and sends it to satellite A.

[0043] In some examples, it also includes: Based on the satellite's orbital prediction parameters and the ground station's position coordinates, the radial velocity of the satellite relative to the ground station within the telemetry and control arc is determined, and the Doppler frequency shift at the corresponding moment is determined based on the radial velocity and the carrier frequency. In the downlink direction, the frequency of the digitally controlled oscillator used for digital downconversion is preset according to the Doppler frequency shift, so that the residual frequency offset corresponding to the downlink chip-level data after digital downconversion is reduced; In the uplink direction, the transmit carrier frequency used to generate the spread spectrum telemetry and control uplink signal is set according to the Doppler frequency shift, so as to perform Doppler pre-compensation on the spread spectrum telemetry and control uplink signal.

[0044] For example, there is usually significant relative motion between the satellite and the ground station. The radial velocity along the line connecting the ground station and the satellite causes a Doppler shift in the actual received carrier frequency relative to the nominal carrier, thus affecting the uplink carrier frequency actually received by the satellite. This example uses orbit prediction parameters and the ground station's position coordinates to pre-determine the satellite's radial velocity relative to the ground station within the telemetry and control arc, and then combines this with the carrier frequency to obtain the Doppler frequency shift at each corresponding moment. In downlink processing, the predicted Doppler frequency shift is used to preset the frequency of the digitally controlled oscillator used for digital downconversion. In this way, while the intermediate frequency signal is shifted to the baseband, a large portion of the predictable Doppler frequency change has already been pre-compensated, reducing the residual frequency offset corresponding to the resulting downlink chip-level data. In uplink processing, the transmit carrier frequency used to generate the spread spectrum telemetry and control uplink signal is set according to the predicted Doppler frequency shift, so that the transmitted signal has pre-compliance with frequency compensation for the relative motion of the satellite. Before or during a satellite tracking and control (TT&C) segment, the satellite's position and motion at different times are determined based on predicted satellite orbit parameters. This, combined with the known coordinates of the ground station, determines the satellite's radial velocity relative to that ground station. The Doppler shift at that moment is calculated based on the radial velocity and the corresponding carrier frequency. During the phase where the satellite rapidly approaches the ground station, after predicting the corresponding Doppler shift, the numerically controlled oscillator (CCO) in the digital down-conversion process is preset accordingly. This ensures that the downlink signal actually received by the ground station, after digital down-conversion, has a frequency position closer to the desired state for subsequent safety processing. As the satellite passes its designated position and gradually moves away from the ground station, its radial velocity changes, and the Doppler shift changes accordingly. Therefore, the CCO frequency can be adjusted based on the predicted results at the corresponding moment. The same principle applies to the uplink direction. When generating the actual spread spectrum TT&C uplink signal, the transmit carrier frequency is set according to the predicted Doppler shift at that moment. This ensures that after the Doppler effect caused by the relative motion between the satellite and the ground station, the signal is closer to the carrier frequency that the satellite is expected to receive.

[0045] For example, an NCO (Numerically Controlled Oscillator) can be used to shift the digital intermediate frequency signal to baseband. The NCO frequency is preset according to the satellite orbit prediction parameters (ephemeris) for Doppler pre-compensation. The residual frequency offset Δf_residual after pre-compensation satisfies: Δf_residual = f_carrier × Δv / c Where f_carrier is the carrier frequency (Hz), Δv is the satellite velocity prediction error (m / s), and c is the speed of light (3×10⁻⁶). 8m / s). Based on TLE (Two-Line Element) ephemeris prediction, the typical satellite velocity error is approximately 1 m / s, with a residual frequency offset of approximately ±7.5 Hz in the S-band (2.25 GHz) and approximately ±28 Hz in the X-band (8.4 GHz). Based on precise ephemeris, the velocity error is approximately 0.1 m / s, and the residual frequency offset can be reduced to within ±1 Hz. Low-pass filtering and decimation: The DDC output signal is low-pass filtered to remove out-of-band noise and image components, and decimated by integer multiples to reduce the data rate. The filtered I / Q baseband signal is output as a chip-level I / Q data stream with 4-bit or 8-bit quantization precision. The output data rate D_out is: D_out = R_chip × Q × 2 Where R_chip is the chip rate (cps), Q is the quantization bit depth (bits), and the coefficient 2 corresponds to both I and Q channels. For N=10 and 8-bit quantization, the output data rate is 163.7 Mbps; for 4-bit quantization, it is 81.8 Mbps. A network bandwidth of 500 Mbps can meet the real-time transmission requirements for all N values.

[0046] In some examples, when performing pseudocode tracking on the downlink chip-level data within the secure processing domain, a delay phase-locked loop is used to track the code phase, and the clock frequency deviation between the sampling clock on which the ground station uses to form the downlink chip-level data and the processing clock of the secure processing domain is compensated based on the code phase change obtained by the delay phase-locked loop tracking.

[0047] For example, downlink chip-level data is generated at the ground station based on the ground station's sampling clock, while despreading and pseudocode tracking occur in the secure processing domain. The ground station's sampling clock and the secure processing domain's processing clock do not inherently have the same actual frequency. Even if the nominal frequencies of the two clocks are the same, there may be a small frequency deviation in actual operation. When the data duration is short, this deviation may not be noticeable; however, over a longer telemetry and control period, small clock frequency differences may accumulate over processing time, eventually manifesting as a continuous change in code phase relative to the local processing reference in the secure processing domain. This example uses the code phase change obtained from delay-locked loop tracking to characterize this accumulated deviation. If the code phase change is not merely a short-term fluctuation but continuously evolves in a certain direction during a certain processing process, it indicates that there may be a frequency difference between the sampling time reference used by the ground station to generate the data and the processing time reference in the secure processing domain. Therefore, compensating for the clock frequency deviation based on the code phase change obtained from the delay-locked loop allows the secure processing domain to adapt to changes in chip timing relationships caused by cross-regional clock differences. When the secure processing domain performs pseudocode tracking on the received downlink chip-level data, it uses a delay-locked loop (PLL) to continuously obtain the code phase state. It is assumed that in the initial tracking phase, the local pseudocode is already aligned with the received signal. However, as the processing time increases, the PLL continuously indicates that the local pseudocode needs to be corrected in the same direction for its code phase. At this point, based on the code phase changes obtained during this period, a clock frequency deviation between the ground station's sampling clock and the secure processing domain's processing clock can be determined, and compensation can be performed accordingly. After compensation, the timing relationship used by the secure processing domain to process chip data is more adapted to the sampling timing relationship used by the ground station when actually generating this data, thereby reducing the continuous code phase drift caused by the long-term accumulated deviation between the two independent clocks.

[0048] In some examples, the spread spectrum telemetry and control systems corresponding to the multiple satellites include the Space Data Systems Advisory Committee spread spectrum telemetry and control system and the standard spread spectrum telemetry and control system; For different spread spectrum telemetry and control systems, the ground station performs the downlink pre-processing and the uplink post-processing without calling the corresponding pseudocode parameters. The security processing domain configures corresponding despreading and spreading processing based on the spread spectrum system type and pseudocode parameters corresponding to the current satellite mission identifier, so as to process the telemetry and control signals of satellites with different spread spectrum telemetry and control systems without changing the ground station-side processing architecture.

[0049] For example, suppose the telemetry, tracking, and command (TT&C) system first executes the mission for satellite A, which uses the Space Data Systems Advisory Committee (SDSAC) spread spectrum TT&C scheme. In the downlink direction, the ground station processes the received signal from satellite A into chip-level data that retains the spread spectrum characteristics, as described above. The security processing domain determines the spread spectrum scheme type based on satellite A's mission identifier and calls the corresponding pseudocode parameters for satellite A, then configures despreading processing suitable for that scheme. In the uplink direction, the security processing domain similarly performs upspreading based on the spread spectrum scheme and pseudocode parameters corresponding to satellite A, then sends the spread spectrum chip stream to the ground station for further processing. Subsequently, the system executes the mission for satellite B, which uses a certain standard spread spectrum TT&C scheme. The ground station still handles both downlink pre-processing and uplink post-processing according to the principle of not directly calling the corresponding pseudocode parameters. The main change is in the scheme configuration within the security processing domain: the security processing domain obtains the corresponding spread spectrum scheme type and pseudocode parameters based on the satellite mission identifier corresponding to satellite B, and configures despreading and upspreading processing for satellite B accordingly.

[0050] In some cases, considering the process of transmitting chip-level in-phase orthogonal data from the ground station to the secure processing domain, the data is typically divided into multiple data groups or packets according to the sequential sampling order. Ideally, adjacent data groups are consecutive at the sampling positions, and the secure processing domain can recover the complete sampling sequence based on the receiving order, and perform pseudocode capture and pseudocode tracking using this sampling sequence. However, network packet loss, transmission congestion, device buffering anomalies, or packet verification failures can all cause some chip-level in-phase orthogonal data to be missing. If the secure processing domain simply concatenates the subsequently received data directly after the data before the missing data, the position of the subsequent data in the processing sequence will be advanced relative to its actual sampling position. Since the local pseudocode is generated consecutively according to the sampling positions, a phase misalignment will occur between the subsequently received data and the local pseudocode due to non-propagation reasons. For example, one pseudocode period corresponds to one million sampling positions. The last valid sample point before the data loss is located at the 999,800th sampling position, followed by a loss of 500 samples. The first actual sample point after the loss is already located near the 300th sampling position of the next pseudocode period. If the secure processing domain directly connects the missing sample to the sample before it was missing, it will be treated as data from the 999,801st sampling position, thus misaligning the local pseudocode with the received signal by 500 sampling positions. On the other hand, simply filling the missing position with in-phase and quadrature components of zero value can maintain the absolute position of subsequent samples, but these zero-value samples may still be treated as ordinary received samples in the correlation energy calculation. Different candidate code phases may contain different proportions of zero-value samples, meaning the correlation result depends not only on the degree of matching between the received signal and the local pseudocode, but also on the number of missing data points within each candidate correlation window. This reduces the comparability between different candidate code phases. Based on this, in some examples, the ground station serves as a continuous sampling position identifier for each group of chip-level in-phase orthogonal data associations; the secure processing domain identifies data missing intervals based on positional changes between adjacent continuous sampling position identifiers, sets invalid sample mark at the relevant operation position corresponding to the data missing interval, and determines the normalized correlation detection quantity based on the correlation energy of the effective sample points corresponding to each candidate code phase and the number of effective samples; when the data missing interval crosses the pseudocode period boundary, the local pseudocode is continued according to multiple candidate pseudocode period positions, the correlation energy persistence corresponding to each candidate pseudocode period position is determined based on the continuous data after the data missing interval, and the pseudocode period position after the data missing interval is determined based on the correlation energy persistence.

[0051] Understandably, continuous sampling position identifiers can be associated with each group of chip-level in-phase orthogonal data. These continuous sampling position identifiers do not represent the order in which data packets arrive at the secure processing domain, but rather the actual position of that data group within the continuous sampling sequence at the ground station. By comparing the continuous sampling position identifiers of adjacent data groups, the secure processing domain can determine whether there is a sampling position jump between two data groups, and accordingly determine the start and end positions of the missing intervals, as well as the number of missing samples. For identified missing data intervals, the secure processing domain retains the time positions that these samples should occupy, but sets invalid sample markers at the corresponding correlation operation positions. Invalid samples do not contribute received amplitude to the correlation operation, nor are they counted in the number of valid samples. Thus, subsequent samples remain in their true sampling positions, while missing samples do not participate in correlation statistics as fictitious zero-amplitude received signals. For any candidate code phase, the secure processing domain determines the correlation energy and the number of valid samples, and normalizes the correlation energy based on the number of valid samples. The basic meaning is that correlation results need to be recalculated based on the actual amount of data involved in the calculation, so that candidate correlation windows with different missing proportions still have comparable statistical scales. When the missing data interval crosses the pseudocode period boundary, simply maintaining the sampling position may not be sufficient to determine which pseudocode period the missing data belongs to. This is because periodic pseudocodes have the same chip arrangement in different periods, and short-term correlation results may only determine the code phase within a period, but not the absolute pseudocode period position.

[0052] For example, the ground station sets an initial sampling position identifier and the number of sampling points contained in each group of chip-level in-phase orthogonal data. The initial sampling position identifier can be generated by a freely running sampling counter of the ground station. The sampling counter continuously increments with analog-to-digital conversion sampling and does not recount due to data packet fragmentation, network retransmission, or task processing delay. After receiving two adjacent groups of data, the secure processing domain calculates the expected initial sampling position of the next group of data based on the initial sampling position and the number of sampling points of the previous group. If the actual initial sampling position of the next group of data is greater than the expected initial sampling position, the sampling range corresponding to the difference between the two is identified as the data missing interval. When identifying whether the data missing interval crosses the pseudo-code period boundary, the secure processing domain can estimate the possible pseudo-code period range after the missing interval based on the pseudo-code period position determined before the missing interval, the length of the missing interval, and the current code rate adjustment. If the sampling clock deviation, network missing length measurement error, or original code phase estimation error makes the period position not uniquely determined, multiple candidate pseudo-code period positions are retained. For example, the processing state before the missing data indicates that the local pseudocode has reached the end of the current cycle. However, due to the long missing interval, the data after the missing data may correspond to the next pseudocode cycle or the one after that. The secure processing domain generates local pseudocode according to these two candidate positions and performs correlation operations using the continuous data after the missing data. For each candidate hypothesis, the secure processing domain can record correlation peaks in multiple continuous correlation intervals. If the first candidate hypothesis forms correlation peaks with continuous positions and stable energy in multiple consecutive intervals, while the second candidate hypothesis only forms an occasional peak in the first interval, and then the correlation energy rapidly decreases, then the first candidate hypothesis is determined as the position of the pseudocode cycle after the missing data. When the signal is weak or the length of the continuous data after the missing data is short, the secure processing domain can temporarily retain multiple candidate hypotheses instead of immediately discarding them, until one of the candidate results shows sufficiently stable correlation energy persistence. This avoids prematurely determining the wrong cycle position based on a single noise peak.

[0053] In some cases, when ground stations perform digital down-conversion on received satellite RF signals, they typically use a numerically controlled oscillator (CNC) to generate a digital local carrier and mix the received signal with the digital local carrier to obtain chip-level in-phase quadrature data. Due to the relative motion between the satellite and the ground station, the Doppler shift of the received signal changes continuously with the telemetry and control (TT&C) arc. The ground station needs to update the CNC's frequency parameters based on orbit predictions or frequency compensation trajectories to keep the residual frequency offset after digital down-conversion within a manageable range. If the CNC's phase accumulator is reinitialized during frequency parameter updates, the new frequency parameters, while closer to the actual Doppler shift, may result in a discontinuity in the local carrier phase generated by the CNC at the switching moment compared to before the switch. This discontinuity is directly reflected in a phase abrupt change in the chip-level in-phase quadrature data. This phase abrupt change is not caused by satellite motion, propagation path, or satellite transmitter status, but rather by the switching of digital processing parameters at the ground station. If the security processing domain is unaware that a frequency parameter update has occurred at a given moment, it may interpret a phase abrupt change as a sudden change in the satellite carrier state, causing the carrier tracker to make excessively large frequency or phase adjustments. Therefore, in some examples, when updating the frequency parameters of the numerically controlled oscillator (CNC) used for digital down-conversion, the ground station acquires the switching sampling position of the frequency parameters and the phase accumulation state of the CNC oscillator at that switching sampling position. The phase accumulation state is used as the starting phase corresponding to the updated frequency parameters, and the frequency configuration generation identifier and the switching sampling position are associated with the chip-level in-phase quadrature data stream. The security processing domain identifies the frequency parameter switching based on the frequency configuration generation identifier and differentiates the phase change caused by the frequency parameter switching from the phase change caused by satellite carrier dynamics during carrier recovery.

[0054] Understandably, when updating the frequency parameters of the numerically controlled oscillator, the switching sampling position and the corresponding phase accumulation state can be obtained. The old frequency parameters have already accumulated to a definite phase at the switching position, and this scheme uses this phase as the starting phase of the updated frequency parameters. In this way, the phase change between the last sampling position before the parameter switch and the first sampling position after the parameter switch is still determined by continuous time progression and the new frequency value, without any additional jumps caused by clearing the phase accumulator. In other words, this scheme allows the phase change rate of the local carrier to be adjusted, but maintains the continuity of the local carrier phase itself at the switching position. The frequency parameters determine the rate at which the phase changes with the sampling position, while the phase accumulation state determines the phase position already reached at the switching time; the two play different roles. This scheme also associates the frequency configuration generation identifier and the switching sampling position with the chip-level in-phase orthogonal data stream. The frequency configuration generation identifier is used to indicate which frequency configuration generated a certain set of data, and the switching sampling position is used to indicate from which sampling position the new configuration takes effect. The security processing domain can use this to identify whether the observed carrier state change corresponds to the ground station configuration change in time. The distinction between phase changes caused by parameter switching and those caused by satellite carrier dynamics means that the security processing domain does not directly input all phase differences at the moment of configuration switching into the satellite carrier dynamic estimation process. For ideal continuous phase switching, the security processing domain mainly adjusts the prediction basis for carrier tracking based on the generational changes in frequency configuration; for cases where hardware still generates deterministic phase changes, these deterministic changes can be eliminated before carrier recovery.

[0055] For example, the ground station obtains time-varying downlink Doppler compensation parameters based on orbit predictions and generates a new numerically controlled oscillator (CNC) frequency control word according to a predetermined update cycle. Before each frequency control word switch, the ground station records the new frequency parameter to be effective, the corresponding switching sampling position, and the phase accumulation state of the CNC at that position. The frequency parameter does not take effect immediately at any time when the control command arrives at the device, but rather at a specific sampling position, thereby enabling the parameter switch to correspond to the sampling position in the output data. For example, the CNC originally operated according to the first frequency parameter. When the sampling count reaches the 50 millionth sampling position, it needs to switch to the second frequency parameter. The ground station first calculates the phase accumulation value of the CNC at the 50 millionth sampling position based on the first frequency parameter, then sets the second frequency parameter as the subsequent phase increment, and uses the phase accumulation value as the starting phase of the second frequency parameter. After the switch is completed, the ground station updates the frequency configuration generation from the first generation to the second generation and associates the second generation identifier with the chip-level in-phase orthogonal data formed starting from the 50 millionth sampling position. After receiving the data, the secure processing domain can determine that the 50 millionth sampling position is a frequency configuration change location. In an ideal implementation, the numerically controlled oscillator (CNC) uses a continuously running phase accumulator, updating only the phase increment added in each sampling period. Since the accumulator's current value is not cleared, the digital local carrier naturally maintains phase continuity before and after frequency switching. In another implementation, the CNC hardware needs to reload the phase parameters when updating the frequency. In this case, the ground station reads or calculates the old phase accumulation value at the time of switching and writes this value into the newly configured start phase register, thereby minimizing phase discontinuities caused by configuration updates. If the equipment architecture still produces a known deterministic phase change during frequency switching, the ground station can record this phase change and associate it as phase correction information without pseudocode content with the frequency configuration generation and the switching sampling position. The secure processing domain corrects for this deterministic phase change when processing the data at the corresponding sampling position. After detecting a frequency configuration generation change, the secure processing domain can adjust the frequency prediction value for the carrier recovery process based on the difference between the old and new digital down-conversion frequencies. In this way, the safety processing domain will not attribute all residual frequency changes resulting from a ground station's active change of the down-conversion frequency to a change in satellite motion. For example, if the ground station increases the digital down-conversion frequency by 100 Hz, the residual frequency observed in the safety processing domain will theoretically decrease accordingly. Based on the frequency configuration generation and handover location, the safety processing domain can consider this known configuration change in carrier frequency estimation, rather than misinterpreting the residual frequency change as a sudden change in satellite radial velocity.

[0056] In some cases, during uplink spread spectrum telemetry and control, the security processing domain performs spread processing based on the data to be transmitted and protected pseudocode parameters to form uplink chip data, which is then transmitted to the ground station via the network. The ground station then converts the uplink chip data into the actual transmitted waveform. The arrival time of data packets in network transmission is typically not uniform. Even if the security processing domain generates data according to a uniform chip period, data packets may arrive at the ground station earlier or later due to queuing, routing changes, or network resource contention. If the ground station directly reads and transmits chips according to the actual arrival rhythm of the data packets, network jitter will translate into variations in chip width or time intervals between adjacent chips. For downlink data, network jitter mainly changes the time when the security processing domain obtains the data; as long as the data order and sampling position can be recovered, it usually does not change the radio frequency signal already transmitted by the satellite. However, for uplink data, the ground station has not yet completed radio frequency transmission. If transmission is controlled directly based on the network arrival time, network jitter will be actually written into the uplink waveform and observed by the satellite receiver. Based on this, in some examples, the security processing domain associates the uplink chip data obtained after spread processing with the chip period number and the predetermined transmission time position, and transmits the uplink chip data associated with the chip period number and the predetermined transmission time position to the ground station; the ground station writes the received uplink chip data into the transmission buffer, and reads and outputs the uplink chip data from the transmission buffer according to the chip period number and the predetermined transmission time position using a local transmission clock independent of the network arrival time of the uplink chip data; when it is necessary to correct the cumulative deviation between the local transmission clock and the time scale of the uplink chip data, time correction is performed at a pre-defined allowable adjustment position.

[0057] For example, after the secure processing domain completes the spread processing, it divides the continuous uplink chip data into multiple transmission units. Each transmission unit includes a corresponding starting chip period number and a predetermined transmission time position. Upon receiving a transmission unit, the ground station first checks its chip period number and writes the data into the corresponding position in the transmission buffer according to the chip period number. Even if a later transmission unit arrives before the previous one, the ground station can restore the correct order based on the chip period number, instead of directly using the network arrival order as the transmission order. Before the mission begins transmission, the ground station can wait for the transmission buffer to reach a predetermined occupancy level. This pre-stored data is used to absorb network arrival time variations within the normal range. After the predetermined conditions are met, the local transmission clock reads the data according to a fixed chip time scale and outputs it to the subsequent modulation and RF transmission links. For example, each transmission unit generated by the secure processing domain contains ten thousand chips. If a transmission unit arrives two milliseconds later than expected, the transmission buffer still contains enough data to support five milliseconds of continuous transmission. Because the local transmission clock continues to read existing data at a predetermined rhythm, these two milliseconds of network delay will not manifest as actual chip jitter. The ground station can continuously monitor changes in the occupancy of the transmit buffer. If the occupancy increases slowly over a longer period, it indicates that the uplink chip timescale corresponding to the security processing domain is slightly ahead of the ground station's local transmit clock; if the occupancy decreases slowly, it indicates that the ground station's read speed is relatively fast. When cumulative deviation correction is needed, the ground station determines the upcoming pre-defined allowable adjustment position and performs a minor time correction at that position. The correction process can be applied to the read timescale or the time interval at the allowable adjustment position, but it does not arbitrarily change the width of ordinary service chips. For example, if the ground station detects a continuous increase in transmit buffer occupancy, it indicates that the read rate needs to be appropriately increased. The ground station does not immediately compress the currently transmitted single chip, but waits to reach the predetermined pseudo-code period boundary and performs time correction near that boundary to make the subsequent read timescale more consistent with the input data timescale. When network anomalies cause insufficient buffer data, the ground station cannot simply repeat the last chip, because repeating the chip will change the spreading sequence generated by the security processing domain. The ground station should suspend transmission or switch to a predetermined idle waveform according to the anomaly handling instructions provided in advance by the security processing domain. This process does not require the ground station to generate the missing pseudocode itself, thus maintaining the processing boundary that the pseudocode parameters are only used in the secure processing domain.

[0058] In some cases, considering that processing nodes in the secure processing domain are responsible for carrier recovery, pseudocode acquisition, pseudocode tracking, despreading, and bit synchronization, for ongoing satellite telemetry and control missions, processing nodes not only hold pseudocode parameters but also generate a large number of operational states related to the current signal state and data processing progress. These operational states include the current carrier frequency estimate, carrier phase accumulation status, pseudocode period position, code phase subdivision value, code rate adjustment, input data read position, jitter buffer read position, and current acquisition or tracking status. If the original processing node needs to migrate the task to a new processing node due to failure, maintenance, or resource overload, and the new processing node only obtains static pseudocode parameters, then the new processing node does not know which chip position the original processing node has processed to, nor does it know the current carrier frequency, carrier phase, and code phase. In this case, the new processing node usually needs to perform carrier search and pseudocode acquisition from scratch, which may cause a long period of telemetry data interruption. Based on this, in some examples, when migrating a satellite telemetry and control task from the original processing node in the secure processing domain to a new processing node, a protected processing state record formed by the original processing node is obtained. The protected processing state record includes the current carrier frequency estimate, carrier phase accumulation state, pseudocode period position, code phase subdivision value, code rate adjustment amount, input data reading position, jitter buffer reading position, and current acquisition or tracking state. The new processing node reads chip-level in-phase orthogonal data from the same chip position as the original processing node, and continues to generate local carriers and local pseudocodes according to the protected processing state record. Within a predetermined overlap time, the original processing node and the new processing node process the same segment of chip-level in-phase orthogonal data. After the code phase changes, carrier frequency changes, and telemetry decision results of the two nodes meet predetermined consistency conditions, the new processing node continues to process the satellite telemetry and control task.

[0059] For example, during satellite telemetry and control missions, the original processing node generates a protected processing status record according to predetermined update conditions. This record can be associated with the corresponding input data read position, enabling each status record to clearly represent the operational state formed after processing a certain sampling position. When the secure processing domain determines that a mission migration is necessary, the most recently formed and complete protected processing status record of the original processing node is selected first. Simultaneously, a segment of chip-level in-phase orthogonal data starting from the corresponding position of this status record is provided to the new processing node. The new processing node reads the current carrier frequency estimate and sets the local carrier frequency accordingly; reads the carrier phase accumulation state and sets the starting phase of the local carrier accordingly; reads the pseudocode period position and code phase subdivision value and sets the starting position of the local pseudocode accordingly; reads the code rate adjustment amount and advances the local pseudocode according to the code rate correction relationship already formed by the original node. Subsequently, the new processing node acquires the corresponding data according to the input data read position and jitter buffer read position. If the original processing node is processing a certain incoherent accumulation interval, the current acquisition or tracking state can allow the new processing node to determine whether to continue the corresponding processing state, avoiding unconditional re-execution of the complete search. During the predetermined overlap time, the original processing node and the new processing node process the same data segment respectively. The secure processing domain compares the code phase changes of the two nodes. For example, it can determine whether the code phase difference output by the two nodes is within a predetermined allowable range, and whether the trend of code phase change over time is consistent. The secure processing domain also compares the carrier frequency changes of the two nodes. Here, it can compare not only the frequency estimate at a certain moment, but also the direction and magnitude of frequency change during the overlap time. If both nodes process the same input data from the same initial state, they should normally produce similar carrier frequency change results. In addition, the secure processing domain compares the telemetry decision results output by the two nodes. Only when the code phase change, carrier frequency change, and telemetry decision results all meet the predetermined consistency conditions is it determined that the new processing node has correctly inherited the processing state of the original processing node. For example, if the original processing node needs to migrate its task due to excessive computing resource consumption, the secure processing domain obtains the protected processing state record formed by the original processing node at a certain input data position and enables the new processing node to start processing from that position. The two nodes simultaneously output telemetry decision results for a subsequent period of time. When the code phase changes of the two data points are consistent, the carrier frequency estimation difference remains within the allowable range, and the continuous telemetry decision results are consistent, the secure processing domain will hand over subsequent input data to a new processing node for further processing. If the consistency condition is not met, the task will not be immediately taken over by a new processing node. The secure processing domain may continue to extend the overlap processing time or reselect an earlier state record and input data position for inheritance verification. The above process always occurs within the secure processing domain, and the protected processing state record is not transmitted to the ground station.

[0060] In some cases, considering that the pseudocode parameters actually used by the satellite may be updated during satellite telemetry and control missions, the pseudocode parameter library in the security processing domain will also receive corresponding parameter update information. However, there may be a discrepancy between the nominal effective time specified by the management system and the actual time the satellite performs the switchover. If the security processing domain immediately replaces the current pseudocode parameters with the pseudocode parameters to be effective at the nominal effective time, but the satellite has not yet switched over, the local pseudocode generated by the security processing domain will not match the received signal. Conversely, if the satellite switches over prematurely, and the security processing domain continues to use the current pseudocode parameters, it will also cause the relevant peak values ​​to disappear and despreading to fail. Based on this, in some examples, the pseudocode parameter library in the security processing domain stores the current pseudocode parameter record and the pseudocode parameter record to be activated for the same satellite mission identifier, and sets the activation conditions for the pseudocode parameter record to be activated, which are resolved by the security processing domain; within the expected parameter switching interval, the current pseudocode parameter record and the pseudocode parameter record to be activated are used to perform correlation processing on the same chip-level in-phase orthogonal data respectively to obtain two sets of candidate correlation results. Based on the persistence of the correlation peak of each of the two sets of candidate correlation results, the pseudocode parameter record actually used by the satellite and its actual switching sampling position are determined, and the pseudocode parameter record that does not match the received signal is stopped from being used from the actual switching sampling position.

[0061] Understandably, both the current pseudocode parameter record and the pending pseudocode parameter record can be saved simultaneously for the same satellite mission identifier. The current pseudocode parameter record corresponds to the parameters currently used by the security processing domain to process the received signal, while the pending pseudocode parameter record corresponds to the parameters planned for subsequent use. Effective conditions are set for the pending pseudocode parameter record, resolved by the security processing domain, ensuring that parameter switching decisions remain within the area accessible to the pseudocode parameters. The ground station does not need to obtain the content of the pseudocode parameters, nor does it need to know the differences between the two parameter records. Within the expected parameter switching interval, the security processing domain processes the same chip-level in-phase orthogonal data using both the current pseudocode parameter record and the pending pseudocode parameter record, forming two sets of candidate correlation results. This is equivalent to simultaneously verifying whether the satellite is still using the current parameters and whether it has started using the pending parameters within a time range where the switching time is uncertain. The security processing domain does not directly complete the switching based on the instantaneous correlation peak at a certain sampling position, but rather compares the persistence of the correlation peaks of the two sets of candidate correlation results. If the correlation peak corresponding to the current parameter gradually weakens or disappears, while the correlation peak corresponding to the pending parameters appears stably in multiple consecutive processing intervals, it indicates that the satellite has actually switched to the pending parameters. After the handover is confirmed, the security processing domain records the actual handover sampling position. This position reflects the actual parameter change location confirmed from the received signal, not just the planned time given by the management system. From this actual handover sampling position onwards, the security processing domain stops using parameter records that do not match the received signal.

[0062] For example, the pseudocode parameter library uses the satellite mission identifier as an index to simultaneously store the current pseudocode parameter record and the pseudocode parameter record to be activated for the same satellite mission. The pseudocode parameter record to be activated is associated with the expected activation time range or other activation conditions used by the security processing domain. Before the expected parameter switching interval arrives, the security processing domain still performs normal acquisition, tracking, and despreading processing using the current pseudocode parameter record. After entering the expected parameter switching interval, the security processing domain establishes candidate processing procedures corresponding to the parameters to be activated while maintaining the current parameter processing channel. The two candidate processing procedures read the same chip-level in-phase orthogonal data, but generate local pseudocodes based on the current pseudocode parameter record and the pseudocode parameter record to be activated respectively, and calculate the correlation results separately. Since the input data is the same, the two sets of candidate correlation results can reflect the degree of matching between the two parameter records and the actual received signals. For example, the management system expects the satellite to complete the pseudocode parameter switching around a certain time. The security processing domain can enter the expected parameter switching interval before that time. In the initial stage, the correlation peak corresponding to the current parameter remains stable, and the correlation result corresponding to the parameter to be activated is close to the noise level, indicating that the satellite has not yet switched. As processing continues, if, starting from a certain sampling position, the correlation peak corresponding to the current parameter no longer persists, while the correlation peak corresponding to the parameter to be activated appears continuously and remains stable, the security processing domain determines the vicinity of that sampling position as the actual switching position. To reduce erroneous judgments caused by short-term interference, the security processing domain can assess the persistence of correlation peaks based on multiple consecutive correlation processing intervals. If the parameter to be activated only forms an occasional peak in one interval, and cannot be maintained in subsequent intervals, the switch is not immediately confirmed. Only when the correlation peak of the parameter to be activated continuously meets predetermined conditions, and the current parameter no longer stably matches the received signal, is it determined that the satellite has actually adopted the parameter to be activated. After determining the actual switching sampling position, the security processing domain uses the pseudocode parameter record to be activated as the subsequent current parameter record and stops using the mismatched original current parameter record to process data after the actual switching position. The actual switching sampling position can also be used to distinguish the telemetry recovery results before and after the switch, avoiding the use of data obtained by processing with incorrect parameters as valid telemetry data. Throughout the process, the ground station continues to perform sampling, digital down-conversion, and chip-level in-phase orthogonal data transmission according to the satellite mission identifier. The ground station does not need to receive the current pseudocode parameters, the pseudocode parameters to be effective, or the version differences between the two, nor does it participate in determining which set of pseudocode parameters the satellite actually uses.

[0063] Please see Figure 2 One embodiment of the spread spectrum telemetry and control signal processing device in this application includes: Downlink signal receiving unit 21 is used to receive the spread spectrum telemetry and control downlink signal transmitted by the satellite, and to perform downlink pre-processing on the spread spectrum telemetry and control downlink signal on the ground station side without relying on the pseudocode parameters corresponding to the satellite to obtain downlink chip-level data that retains the spread spectrum characteristics, so as to transmit the downlink chip-level data to the secure processing domain. The telemetry data acquisition unit 22 is used to call the pseudocode parameters corresponding to the satellite in the security processing domain, perform downlink security processing including despreading on the downlink chip-level data, and obtain telemetry data. The remote control data acquisition unit 23 is used to acquire remote control data in the security processing domain, call the pseudocode parameters corresponding to the satellite to perform uplink security processing on the remote control data including spread processing, and obtain uplink chip-level data. The uplink signal transmission unit 24 is used to transmit the uplink chip-level data to the ground station side, and perform uplink post-processing on the uplink chip-level data on the ground station side without relying on the pseudo-code parameters to generate a spread spectrum telemetry and control uplink signal, so as to transmit the spread spectrum telemetry and control uplink signal to the satellite.

[0064] like Figure 3 As shown, this application embodiment also provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor. When the processor 320 executes the computer program 311, it implements the steps of any of the above-mentioned spread spectrum measurement and control signal processing methods.

[0065] Since the electronic device described in this embodiment is the device used to implement the spread spectrum measurement and control signal processing device in the embodiments of this application, those skilled in the art can understand the specific implementation method and various variations of the electronic device in this embodiment based on the method described in the embodiments of this application. Therefore, how the electronic device implements the method in the embodiments of this application will not be described in detail here. Any device used by those skilled in the art to implement the method in the embodiments of this application is within the scope of protection of this application.

[0066] In practical implementation, when the computer program 311 is executed by the processor, it can achieve the following: Figure 1 Any of the corresponding implementation methods in the embodiments.

[0067] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

Claims

1. A spread spectrum measurement and control signal processing method, characterized in that, include: The system receives the spread spectrum telemetry and control downlink signal transmitted by the satellite, performs downlink pre-processing on the spread spectrum telemetry and control downlink signal on the ground station side without relying on the pseudocode parameters corresponding to the satellite, obtains downlink chip-level data that retains the spread spectrum characteristics, and transmits the downlink chip-level data to the secure processing domain. Within the security processing domain, the pseudocode parameters corresponding to the satellite are invoked to perform downlink security processing, including despreading, on the downlink chip-level data to obtain telemetry data. Within the security processing domain, remote control data is acquired, and the pseudocode parameters corresponding to the satellite are called to perform uplink security processing on the remote control data, including spread processing, to obtain uplink chip-level data. The uplink chip-level data is transmitted to the ground station. The ground station performs uplink post-processing on the uplink chip-level data, which is independent of the pseudo-code parameters, to generate a spread spectrum telemetry and control uplink signal, which is then transmitted to the satellite.

2. The method as described in claim 1, characterized in that, The security processing domain is equipped with a pseudo-code parameter library. This library stores pseudo-code parameters corresponding to multiple satellites, indexed by satellite mission identifiers. The pseudo-code parameters include code polynomial, code length, chip rate, initial phase, and spreading scheme type. The method further includes: In response to the satellite mission identifier corresponding to the target satellite issued by the mission scheduling system, the ground station configures the corresponding signal sampling parameters according to the satellite mission identifier, and retrieves the corresponding pseudocode parameters from the pseudocode parameter library according to the satellite mission identifier in the security processing domain to configure the downlink security processing and the uplink security processing. The pseudo-code parameters are injected into the secure processing domain through a secure channel without passing through the ground station. The acquisition, storage, and retrieval of the pseudo-code parameters are restricted to the secure processing domain, so that both the downlink secure processing and the uplink secure processing are completed by calling the pseudo-code parameters within the secure processing domain. The ground station completes the downlink pre-processing and the uplink post-processing respectively without acquiring the pseudo-code parameters.

3. The method as described in claim 1, characterized in that, The step of performing downlink pre-processing on the spread spectrum telemetry and control downlink signal at the ground station, independent of the pseudocode parameters corresponding to the satellite, to obtain downlink chip-level data that retains the spread spectrum characteristics, includes: The spread spectrum telemetry and control downlink signal is sampled by analog and digital signals at the ground station, and the digital intermediate frequency signal obtained by analog and digital sampling is digitally downconverted to the baseband. The baseband signal obtained by digital downconversion is low-pass filtered and decimated, and the processed in-phase and quadrature components are quantized to obtain a chip-level in-phase and quadrature data stream as the downlink chip-level data. In the process of forming the chip-level in-phase and quadrature data stream on the ground station side, the spread spectrum telemetry and control downlink signal is not despread.

4. The method as described in claim 1, characterized in that, The step of transmitting the downlink chip-level data to the secure processing domain includes: The chip-level in-phase orthogonal data stream is transmitted in real time to the secure processing domain via a network link, wherein the network link uses User Datagram Protocol or Remote Direct Memory Access Protocol to transmit the chip-level in-phase orthogonal data stream. A jitter buffer is set on the secure processing domain side, and the received chip-level in-phase quadrature data stream is written into the jitter buffer; The jitter buffer is used to compensate for the delay jitter caused by network transmission.

5. The method as described in claim 1, characterized in that, The process of calling the pseudocode parameters corresponding to the satellite within the security processing domain to perform downlink security processing, including despreading, on the downlink chip-level data to obtain telemetry data includes: A local pseudocode is generated based on the pseudocode parameters, and carrier recovery and pseudocode acquisition are performed on the chip-level in-phase quadrature data stream to determine the pseudocode phase and residual frequency offset of the received signal. After the pseudocode acquisition is completed, carrier tracking and pseudocode tracking are performed on the received signal; The local pseudocode is aligned with the received signal based on the tracked code phase, and despreading is completed through correlation operations. Bit synchronization and decision-making are performed on the despread data, and channel decoding is selectively performed according to the spread spectrum telemetry and control system corresponding to the satellite to obtain the telemetry data.

6. The method as described in claim 1, characterized in that, The process of acquiring remote control data within the security processing domain and then performing uplink security processing on the remote control data, including spread processing, by calling the pseudocode parameters corresponding to the satellite, includes: Within the security processing domain, remote control commands are acquired, and the remote control commands are either channel-coded or the un-channel-coded remote control commands are formed into a remote control data bit stream. The pseudocode parameters corresponding to the satellite are obtained from the pseudocode parameter library. A local pseudocode is generated based on the obtained pseudocode parameters. The local pseudocode is then used to spread spectrum modulate the remote control data bit stream to generate a spread spectrum chip stream as the uplink chip-level data. The spread spectrum chip stream is transmitted to the ground station, where the ground station performs binary phase shift keying modulation, up-conversion, and power amplification on the spread spectrum chip stream to generate and transmit the spread spectrum telemetry and control uplink signal.

7. The method as described in claim 3 or 6, characterized in that, Also includes: Based on the satellite's orbital prediction parameters and the ground station's position coordinates, the radial velocity of the satellite relative to the ground station within the telemetry and control arc is determined, and the Doppler frequency shift at the corresponding moment is determined based on the radial velocity and the carrier frequency. In the downlink direction, the frequency of the digitally controlled oscillator used for digital downconversion is preset according to the Doppler frequency shift, so that the residual frequency offset corresponding to the downlink chip-level data after digital downconversion is reduced; In the uplink direction, the transmit carrier frequency used to generate the spread spectrum telemetry and control uplink signal is set according to the Doppler frequency shift, so as to perform Doppler pre-compensation on the spread spectrum telemetry and control uplink signal.

8. A spread spectrum measurement and control signal processing device, characterized in that, include: The downlink signal receiving unit is used to receive the spread spectrum telemetry and control downlink signal transmitted by the satellite, and to perform downlink pre-processing on the spread spectrum telemetry and control downlink signal on the ground station side without relying on the pseudocode parameters corresponding to the satellite to obtain downlink chip-level data that retains the spread spectrum characteristics, so as to transmit the downlink chip-level data to the secure processing domain. The telemetry data acquisition unit is used to call the pseudocode parameters corresponding to the satellite within the security processing domain, perform downlink security processing including despreading on the downlink chip-level data, and obtain telemetry data. The remote control data acquisition unit is used to acquire remote control data within the security processing domain, call the pseudocode parameters corresponding to the satellite to perform uplink security processing on the remote control data, including spread processing, to obtain uplink chip-level data. An uplink signal transmission unit is used to transmit the uplink chip-level data to the ground station, and to perform uplink post-processing on the uplink chip-level data on the ground station that is independent of the pseudo-code parameters to generate a spread spectrum telemetry and control uplink signal for transmission to the satellite.

9. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor, when executing the computer program stored in the memory, implements the steps of the spread spectrum measurement and control signal processing method as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the spread spectrum measurement and control signal processing method as described in any one of claims 1-7.

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