Joint User Association, Power Allocation and Beamforming for NOMA-Based Integrated Satellite-Terrestrial Networks

Area of Science:

• Wireless communication networks
• Satellite communications
• Resource management

Background:

• Integrated satellite-terrestrial networks (ISTNs) offer extended coverage but face resource allocation challenges.
• Non-orthogonal multiple access (NOMA) enhances spectral efficiency in wireless systems.
• Optimizing user association and power allocation is crucial for ISTN performance.

Purpose of the Study:

• To maximize the achievable sum rate in a NOMA-based ISTN.
• To develop an efficient resource optimization algorithm for dynamic network conditions.
• To analyze user preference and Quality of Service (QoS) provisioning in hybrid networks.

Main Methods:

• A two-stage resource optimization algorithm was proposed.
• User association was determined by preference lists and backhaul capacity.
• Power allocation and receiving beamforming vectors were optimized alternately with closed-form transmit power solutions.

Main Results:

• The proposed algorithm effectively optimizes resource allocation in NOMA-based ISTNs.
• Users prefer terrestrial base stations (BSs) when backhaul capacity is sufficient; otherwise, satellites provide QoS guarantees.
• Optimal system performance is achieved when the number of users matches the number of receive antennas at access points.

Conclusions:

• NOMA significantly benefits ISTN performance.
• Dynamic user association and adaptive resource allocation are key to hybrid network efficiency.
• The proposed algorithm offers a viable solution for enhancing sum rate and QoS in integrated networks.