Cooperative localization is widely used to solve the network localization problem in global navigation satellite system (GNSS) denied environments. In particular, gathering the measurement results of all nodes on a specific node requires substantial time for aircraft networks. Therefore, methods simultaneously calculating all the target node positions are challenging to apply due to information delay. This study uses only two hops measurements information relying on the time of arrival (TOA) and angle of arrival (AOA) to propose a weighted least squares (WLS) method that decentralizes the calculation of a specific single target node position in a 3D environment. Moreover, the effect of TOA and AOA measurement errors on localization accuracy is analyzed based on the geometric relationship. Consequently, a novel weight-factor calculation method is designed. The simulation results show that the proposed cooperative localization method can improve localization accuracy compared with the decentralized non-cooperative method. Furthermore, the proposed hybrid approach provides superior localization accuracy than the weight-factor calculation method which only considers the distance.

Satellite networks play important roles in fields such as communication, meteorology, and the Internet of Things. However, in highly dynamic multilayer heterogeneous satellite networks, the diverse satellite transmission demands pose challenges for network management. In large-scale satellite networks, conventional centralized network management methods have various adverse effects, such as high latency, high communication overhead, and high computational complexity. In this article, to overcome these challenges, we propose a distributed scheme for allocating intersatellite links between satellites at different orbital heights considering their different transmission demands. Specifically, we model the distributed link allocation framework as a Stackelberg game. Low Earth orbit (LEO) satellites, as leaders, apply for access to medium Earth orbit (MEO) satellites using a proposed link selection algorithm based on a stochastic best response strategy. The MEO satellites, as followers, allocate link resources using a proposed heuristic-based time slot resource allocation algorithm in accordance with the accessing applications. Simulation results show that the proposed algorithm outperforms benchmark algorithms in terms of the degree of matching between the transmission capacity and transmission requirements.

Aircraft network has a wide range of applications and plays an important role in various fields. However, the wide distribution and high-dynamic motion of aircraft pose challenges to the multiple access management in aircraft networks. On the one hand, different relative distance of aircraft lead to different channel delays, and when the distance between aircraft is far, time-domain multiple access protocols require large guard intervals; On the other hand, the high-speed movement of aircraft leads to Doppler frequency shift on the received signal, resulting in inter carrier interference in frequency domain multiple access methods. These disadvantages extremely reduce the overall performance of the network. In this article, we use delay doppler (DD) communication technology to provide multiple access for dynamic aircraft networks. Specifically, in the uplink channel of the aircraft network, we distinguish aircraft with different relative distances and velocities on the DD domain, and proposed a heuristic-based resource allocation algorithm to allocate DD domain resources to each aircraft, thereby reducing the interference between aircraft. The simulation results show that compared to the benchmarking algorithm, the proposed algorithm can effectively improve the transmission rate of the aircraft network.

Orthogonal time frequency space (OTFS) modulation has gained significant attention due to its robustness against severe Doppler effects in dual-dispersion channels. However, conventional OTFS channel estimation algorithms are tailored for scenarios with constant Doppler shifts within the OTFS frame, struggling to address rapidly changing Doppler conditions, such as satellite maneuvering and adjacent space vehicles. This letter presents a pilot-aided channel estimation algorithm based on modified discrete Chirp Fourier transform (MDCFT) specifically tailored for high -dynamic environments characterized by uniform Doppler variations. We first establish the OTFS input-output relationship under high dynamic environments. Subsequently, we propose a channel estimation algorithm based on MDCFT, estimating the channel parameters by correlating the channel impulse response of the received pilot in the delay Doppler (DD) domain with our proposed algorithm. Simulation results show that the bit error rate (BER) performance of OTFS detection using our proposed algorithm outperforms that of conventional methods in high dynamic environments.