![]() Yalcin, Baris Can ![]() ![]() ![]() in Frontiers in Space Technologies (2022) Space debris is positioned as a fatal problem for current and future space missions. Many e ective space debris removal methods have been proposed in the past decade, and several techniques have been ... [more ▼] Space debris is positioned as a fatal problem for current and future space missions. Many e ective space debris removal methods have been proposed in the past decade, and several techniques have been either tested on the ground or in parabolic ight experiments. Nevertheless, no uncooperative debris has been removed from any orbit until this moment. Therefore, to expand this research eld and progress the development of space debris removal technologies, this paper reviews and compares the existing technologies with past, present, and future methods and missions. Moreover, since one of the critical problems when designing space debris removal solutions is how to transfer the energy between the chaser/de-orbiting kit and target during the rst interaction, this paper proposes a novel classi cation approach, named ET-Class (Energy Transfer Class). This classi cation approach provides an energy-based perspective to the space debris phenomenon by classifying how existing methods dissipate or store energy during rst contact. [less ▲] Detailed reference viewed: 144 (38 UL)![]() Lagunas, Eva ![]() in Frontiers in Space Technologies (2021) Zero-Forcing (ZF) and Regularized Zero-Forcing (RZF) precoding are low-complexity sub-optimal solutions widely accepted in the satellite communications community to mitigate the resulting co-channel ... [more ▼] Zero-Forcing (ZF) and Regularized Zero-Forcing (RZF) precoding are low-complexity sub-optimal solutions widely accepted in the satellite communications community to mitigate the resulting co-channel interference caused by aggressive frequency reuse. However, both are sensitive to the conditioning of the channel matrix, which can greatly reduce the achievable gains. This paper brings the attention to the benefits of a design that allows some residual received interference power at the co-channel users. The motivation behind this approach is to relax the dependence on the matrix inversion procedure involved in conventional precoding schemes. In particular, the proposed scheme aims to be less sensitive to the user scheduling, which is one of the key limiting factors for the practical implementation of precoding. Furthermore, the proposed technique can also cope with more users than satellite beams. In fact, the proposed precoder can be tuned to control the interference towards the co-channel beams, which is a desirable feature that is not met by the existing RZF solutions. The design is formulated as a non-convex optimization and we study various algorithms in order to obtain a practical solution. Supporting results based on numerical simulations show that the proposed precoding implementations are able to outperform the conventional ZF and RZF schemes. [less ▲] Detailed reference viewed: 101 (23 UL) |
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