Rate Splitting Multiple Access for Cognitive Radio GEO-LEO Co-Existing Satellite Networks

Abstract

Low Earth orbit (LEO) satellite communication has drawn particular attention recently due to its high data rate services and low round-trip latency. It is low-cost to launch and can provide global coverage. However, the spectrum scarcity might be one of the critical challenges in the growth of LEO satellites, impacting severe restrictions on the development of ground-space integrated networks. To address this issue, we propose rate splitting multiple access (RSMA) for cognitive radio (CR) enabled nongeostationary orbit (GEO)-LEO coexisting satellite network. In particular, this work aims to maximize the system's sum rate by simultaneously optimizing the power allocation and subcarrier beam assignment of LEO satellite communication while restricting the interference temperature to GEO satellite users. The problem of sum rate maximization is formulated as non-convex and a Global optimal solution is challenging to obtain. Therefore, we first employ the successive convex approximation technique to reduce the complexity and make the problem more tractable. Then for the power allocation, we exploit Karush-Kuhn-Tucker (KKT) condition and adopt an efficient algorithm based on the greedy approach for subcarrier beam assignment. We also propose two suboptimal schemes with fixed power allocation and random subcarrier beam assignment as the benchmark. Results demonstrate the benefits of the proposed scheme compared to the benchmark schemes.

Cooperative Downloading for LEO Satellite Networks: A DRL-Based Approach

“…Meanwhile, ref. [13][14][15] investigated sum rate maximization problems. Dong et al [13] considered an integrated terrestrial-satellite network aided by an intelligent reflecting surface (IRS), which is a promising technology for satellite communications in terms of security [16], energy saving [17], and performance improvement [18] by making incoming signals constructive or destructive by shifting phases.…”

“…They proposed an iterative algorithm with the objective to maximize the weighted sum rate of all users. Khan et al [14,15] tackled the spectrum scarcity issue in LEO satellites, and they proposed a cognitive-radio (CR)-enabled satellite network using the rate splitting multiple access (RSMA) technology, where GEO and LEO satellites work as primary and secondary nodes, respectively. They also formulated a joint problem of user association and beam resource management for LEO satellites and proposed a greedy algorithm with relaxation techniques.…”

“…For every B steps, use soft update for the target critic networks based on Equation (14) 19: end for 20: end for Now the algorithm enters into the parameter update phase. To this end, the algorithm randomly samples a mini-batch D of a few experiences from the buffer D (see line 13 in Algorithm 1).…”

Automatic Modulation Recognition Based on the Optimized Linear Combination of Higher-Order Cumulants

“…A typical heterogeneous network consists of different systems and technologies [ 8 , 9 ]. Some of the potential systems and technologies are device-to-device communication [ 10 ], cognitive radio communication [ 11 ], intelligent transportation [ 12 ], unmanned aerial vehicles [ 13 ], intelligent reflecting surfaces [ 14 ], artificial intelligence [ 15 ], and satellite communications [ 16 , 17 ]. In a heterogeneous network environment, IoT devices face some common security concerns, such as privacy, authentication, administration, information storage, and so on, which may lead to quality-of-service (QoS) degradation [ 18 , 19 ].…”