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Relay Satellite Assisted LEO Constellation NOMA Communication System

Xuyang Zhang, Xinwei Yue, Zhihao Han, Tian Li, Xia Shen, Yafei Wang, Rongke Liu

Abstract

This paper proposes a relay satellite assisted low earth orbit (LEO) constellation non-orthogonal multiple access combined beamforming (R-NOMA-BF) communication system, where multiple antenna LEO satellites deliver information to ground non-orthogonal users. To measure the service quality, we formulate a resource allocation problem to minimize the second-order difference between the achievable capacity and user request traffic. Based on the above problem, joint optimization for LEO satellite-cell assignment factor, NOMA power and BF vector is taken into account. The optimization variables are analyzed with respect to feasibility and non-convexity. Additionally, we provide a pair of effective algorithms, i.e., doppler shift LEO satellite-cell assisted monotonic programming of NOMA with BF vector (D-mNOMA-BF) and ant colony pathfinding based NOMA exponential cone programming with BF vector (A-eNOMA-BF). Two compromise algorithms regarding the above are also presented. Numerical results show that: 1) D-mNOMA-BF and A-eNOMA-BF algorithms are superior to that of orthogonal multiple access based BF (OMA-BF) and polarization multiplexing schemes; 2) With the increasing number of antennas and single satellite power, R-NOMA-BF system is able to expand users satisfaction; and 3) By comparing various imperfect successive interference cancellation, the performance of A-mNOMA-BF algorithm exceeds D-mNOMA-BF.

Relay Satellite Assisted LEO Constellation NOMA Communication System

Abstract

This paper proposes a relay satellite assisted low earth orbit (LEO) constellation non-orthogonal multiple access combined beamforming (R-NOMA-BF) communication system, where multiple antenna LEO satellites deliver information to ground non-orthogonal users. To measure the service quality, we formulate a resource allocation problem to minimize the second-order difference between the achievable capacity and user request traffic. Based on the above problem, joint optimization for LEO satellite-cell assignment factor, NOMA power and BF vector is taken into account. The optimization variables are analyzed with respect to feasibility and non-convexity. Additionally, we provide a pair of effective algorithms, i.e., doppler shift LEO satellite-cell assisted monotonic programming of NOMA with BF vector (D-mNOMA-BF) and ant colony pathfinding based NOMA exponential cone programming with BF vector (A-eNOMA-BF). Two compromise algorithms regarding the above are also presented. Numerical results show that: 1) D-mNOMA-BF and A-eNOMA-BF algorithms are superior to that of orthogonal multiple access based BF (OMA-BF) and polarization multiplexing schemes; 2) With the increasing number of antennas and single satellite power, R-NOMA-BF system is able to expand users satisfaction; and 3) By comparing various imperfect successive interference cancellation, the performance of A-mNOMA-BF algorithm exceeds D-mNOMA-BF.

Paper Structure

This paper contains 18 sections, 2 theorems, 25 equations, 21 figures, 2 tables, 2 algorithms.

Table of Contents

  1. Introduction
  2. Motivations and Contributions
  3. Organization and Notations
  4. System Model
  5. PROBLEM FORMULATION AND ANALYSIS
  6. Problem Formulation
  7. Complexity analysis of ${{\cal P}_0}$
  8. An effective joint optimization algorithm proposed
  9. Doppler shift-based LEO satellite-cell matching strategy
  10. Monotonic programming of power allocation
  11. BF vector design
  12. Exponential optimization of NOMA assisted ant colony satellite cooperative algorithm
  13. Ant colony algorithm with LEO satellite path planning
  14. Exponential Cone Programming for NOMA
  15. NUMERICAL RESULTS
  16. ...and 3 more sections

Key Result

Proposition 1

The feasibility check problem for ${{\cal P}_0}$ is NP-complete.

Figures (21)

  • Figure 1: A relay satellite assisted LEO constellation NOMA and BF communication system.
  • Figure : Fig. 2: Objective gap versus average demand traffic with various comparative algorithms in R-NOMA-BF system.
  • Figure : Fig. 3: User ID versus achievable capacity for Doppler frequency shift LEO satellite-cell assignment strategy.
  • Figure : Fig. 4: User ID versus achievable capacity for modified ant colony algorithm.
  • Figure : Fig. 5: Simulation results for user satisfaction and satellite transmission power.
  • ...and 16 more figures

Theorems & Definitions (4)

  • Proposition 1
  • proof
  • Corollary 1
  • Remark 1