Robust precoding method suitable for safe transmission of high-orbit satellites

Abstract

The invention provides a robust pre-coding method suitable for high-orbit satellite safety communication, which comprises the following steps of: firstly, considering the long delay characteristic of channel propagation in a satellite communication system and the condition that the position of an eavesdropper is unknown, and respectively representing the phase uncertainty of a user channel and the position uncertainty of the eavesdropper by using random variables; modeling a robust precoding design problem as a high-orbit satellite system safety and rate maximization problem under power constraint; and then, the initial non-convex problem is converted into a series of convex optimization sub-problems capable of being iteratively solved through methods of positive semi-definite relaxation, sequential optimization, S-Procedure and first-order Taylor expansion to be solved, and an optimal precoding vector or a suboptimal precoding vector of each user group is obtained. According to the high-orbit satellite robust precoding method provided by the invention, the safety of a high-orbit satellite system can be guaranteed, the robustness of the system is improved, and meanwhile, the implementation complexity is reduced.

Description

technical field [0001] The invention relates to a satellite communication system precoding method, in particular to a robust precoding method suitable for safe transmission of high-orbit satellites. Background technique [0002] With the continuous development of 6G, satellite communication with wide coverage, low latency, and reliable service has become one of the research hotspots. High-orbit satellites usually adopt a multi-beam system framework, and multiple beams provide services for terminals in a wide coverage area to meet the high-throughput data rate requirements of the next-generation satellite mobile communication system. Compared with single-beam systems, multi-beam mobile satellite communication systems have greater throughput and higher spectrum utilization, but this causes severe inter-beam interference. Multi-beam joint precoding is a multi-beam joint transmission scheme at the transmitting end that preprocesses signals at the transmitting end to offset inte...

AI Technical Summary

Problems solved by technology

[0004] In practical applications, traditional secure transmission methods are subject to various limitations: First, in current satellite standards such as DVB-S2 and DVB-S2X, a precoding vector in the precoding matrix corresponds to a user group, and the satellite transmits The data of multiple users for this user group is encapsulated in the same frame, so the precoding design problem can be converted into a multi-group multicast precoding optimization problem; secondly, in the satellite mobile communication system, the high propagation delay caused by The user channel phase uncertainty makes it difficult for the transmitter to obtain the actual user channel state information

In addition, since the eavesdropper is always hidden, it is difficult to obtain perfect channel state information of the eavesdropper

Traditional terrestrial security transmission methods are no longer suitable for satellite communications

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