With the continuous progress of satellite internet and China's aerospace TT&C technology, aerospace TT&C networks are developing towards intelligence and integration, making great progress in autonomous TT&C, resource allocation, and other aspects. Therefore, establishing an intelligent space-ground integrated network is an important goal for the future development of China's aerospace industry. In this paper, the relevant principles and technologies of tracking orbit, telemetry, and telecommand in intelligent space TT&C network are introduced. At the same time, combined with the space data link standard protocol proposed by CCSDS, TM, TC, AOS, Proximity-1, and USLP standards are introduced in detail, and the technology and practical application of different standards are analyzed. This paper introduces the working principle and technical requirements of space TT&C system from the view of the data link layer and physical layer, and provides reference and prospects for the research of the intelligent space-ground integrated satellite TT&C communication network in China.

Phased array calibration is crucial to ensure accurate array beam direction and radiation pattern. The calibration method can be divided into farfield calibration and near-field calibration according to the measurement distance. With the development trend of largescale array antennas, it is increasingly difficult for the anechoic chambers to meet the far-field requirements of array antennas. The applicability of far-field calibration methods gradually weakens, while the demand for nearfield calibration methods gradually increases. This article combs traditional near-field calibration methods and discusses the latest near-field calibration methods. The principles and features of different calibration methods are analyzed and compared, and finally an outlook for future development directions is proposed.

Digital beam forming technology is a key in the field of communication countermeasures. By controlling the signal amplitude and phase in the digital domain, multiple independent and controllable beams can be formed, with high precision and flexibility in beam pointing, and theoretically not limited by the number of beam forming. The article focuses on the requirements of large phased arrays, utilizes the principle of digital beam forming, and combines large-scale arrays signal synchronization technology and phased arrays amplitude-phase calibration technique, implements a multi-wave position beam search system that can simultaneously generate 180 biased beams. It can utilize the real-time scanning function of the beam group to achieve large-scale beam search and faster target angle positioning. The system has been applied in engineering and successfully executed a large-scale measurement and control task, achieves complete success.

With the increasing demand for multi-function and multiband operation, more antennas have been employed in different electronic systems, which inevitably results in difficulties in antenna arrangement and severe interference. As a key technique of radio-frequency aperture integration, ultrawideband (UWB) antennas provide an effective solution to this problem. A novel miniaturized UWB H-plane ridged horn antenna with end-fire radiation property is proposed in this paper. In order to broaden the operating bandwidth, an exponential ridge is employed and the cutting-off frequency of the rectangle waveguide is significantly reduced. By extending a hyperbola-shaped dielectric lens from the horn aperture, nearly uniform aperture phase distribution is achieved along the Hplane, which leads to a significant enhancement of the end-fire gain. This antenna has a compact form factor of only 0.57 λ_L×0.45 λ_L×0.11 λ_L and it maintains a wide operating bandwidth ranging from 0.8 GHz to 18 GHz. Moreover, the simulated cross polarization discrimination across the operating bandwidth is better than 30 dB. The antenna structure features a low profile, good stability, and easy fabrication, which can greatly facilitate its integration with metallic structures and missiles. Compared with other reported end-fire antennas, the proposed design shows remarkable superiority in terms of its electrical size and performance.

In order to ensure the communication security of users and improve the high latency of traditional solutions in the integrated network of space and ground. In this paper, we propose a lightweight certificateless key agreement scheme. Firstly, we analyze the certificateless key agreement protocol system model. Based on the characteristics of the integrated network of space and ground, it is proposed that the protocol needs to satisfy some security requirements such as two-way authentication, anti-replay, and integrity. Then, we choose a lightweight certificateless encryption scheme. Base on the encryption scheme, we propose a key agreement protocol to meet the resource and security requirements of the integrated network of space and earth. Finally, we prove the proposed key agreement protocol security conducted on the BAN logical analysis, and compare the protocol performance with software simulation. The results show that the solution not only meets the network security requirements, but also provides fast and efficient negotiation.

For the quadrotor UAV attitude adjustment process, the existence of parameter uncertainty and external environmental interference often cause certain difficulties to the attitude control. This paper studies and proposes a quadrotor attitude control method based on cascade linear active disturbance rejection. First, the dynamic attitude model of the quadrotor UAV was established, and a cascade PID dualloop control architecture was proposed to decompose the attitude control task into two internal and external loops. The Levant differentiator is used to extract control parameters to enhance tracking capabilities. In addition, the original linear active disturbance rejection controller is optimized to better eliminate the impact of external random disturbances on the system. The MATLAB Simulink environment was used to simulate the proposed control method. The results show that compared with traditional method, this method can better suppress the influence of the system caused by perturbations and enhance the tracking ability of the system to the desired signals, which significantly improves the precision and stability of the attitude adjustment of the quadcopter UAV, and improves the precision and robustness of the attitude control of the quadcopter UAV.

Addressing the airsea information collaboration and sharing requirements for UAVs in distant maritime operations, a dynamic priority-based transmission protocol is proposed for random access. Firstly, this protocol is designed to ensure stable telemetry and remote control information transmission within the cluster measurement and control communication adhoc network through efficient cluster networking signaling. Secondly, combines an improved TDMA network timeslot structure for fast node enrollment and dynamic time slot allocation. Finally, an OPNET network simulation is used to analyze the random access, low latency,high throughput, and low end-to-end latency performance of the designed cluster airsea self-organizing network system. The results indicate that the network establishment time under this signaling scheme requires only 2-3 flight control cycles. In a scenario with 32 nodes, the average delay for nodes to complete random Aloha network access is less than 0.6 seconds. Additionally, the improved TDMA protocol reduces end-to-end latency by 1/3 compared to traditional TDMA protocols.

The traditional satellite navigation antijamming high-precision algorithm is only suitable for processing stable interference signals, which is difficult to adapt to the multiple disordered pulsed flicker interferences environment. Based on the idea of interference covariance matrix reconstruction, this paper proposes a new highprecision antiinterference algorithm that is suitable for multiple flicker interferences environment and carries out simulation analysis. Firstly, the direction of interferences is calculated by using compress sensing with one snapshot. Secondly, the interference plus noise covariance matrix is reconstructed. Thirdly, antenna array beamforming with one snapshot is realized by using an adaptive beam constraint algorithm. Finally, the new algorithm forms nulls in the direction of interferences and forms a beam in the direction of satellite navigation signals. Compared with the traditional algorithm, the new algorithm calculates antiinterference weight with only one snapshot and is suitable for fast timevarying multiple flicker interferences environment. The simulation results show that the new algorithm can effectively reduce multiple flicker interferences and maintain a beam in the direction of satellite navigation signals to ensure the observation accuracy meets the requirements of highprecision satellite navigation.

Doppler estimation is a key link in the synchronization process of GMSK spread spectrum communication system receivers in the context of burst transmission. Given the extremely short information transmission time associated with short-duration burst GMSK spread spectrum communication systems, the synchronization segment structure of the system receiver is built. Based on this, a Doppler estimation algorithm adapted to the short-time burst synchronization segment structure is designed. The short-time burst Doppler estimation algorithm model is established. The algorithm formula is derived and the algorithm model is theoretically analyzed. The implementation process of the algorithm for Doppler estimation is described in detail, and the algorithm is simulated. The experimental results demonstrate that the Doppler estimation accuracy of the algorithm can reach 97.2% when the signal-to-noise ratio is 1 dB, and it exceeds 99% when the signal-to-noise ratio is greater than or equal to 3 dB. These findings validate the effectiveness and feasibility of the algorithm in GMSK spread spectrum communication systems within the context of burst transmission. It also shows that the Doppler estimation algorithm can still achieve superior accuracy even under weak signal conditions within the communication system.

Top hypersonic aerodynamic heat simulation technology is one of the important supports for improving the heat protection capability of antennas. To further shorten the development cycle and save costs, this article proposes an engineering algorithm that uses cold wall heat flux and wall surface recovery enthalpy as input conditions, and utilizes MATLAB and CFD joint iterative rapid solution method to quickly solve the antenna temperature field in high-speed airflow. After confirming the high consistency between simulation results and experimental data through aerodynamic heat tests, this simulation method was used to perform heat insulation optimization design for an antenna with a high-speed aerodynamic heating duration of 500 seconds. Based on the primary and secondary factors identified through simulation that cause temperature rise of the core device, targeted improvement measures were proposed. The final target printed circuit board temperature was reduced from 320 ℃ to 142 ℃ with significant thermal control effects.