Multibeam Satellite Frequency/Time Duality Study and Capacity Optimization

TL;DR

This paper compares two satellite transmission schemes, NOFR and BH, analyzing their performance, capacity optimization, and technological constraints to determine which domain offers better overall efficiency.

Contribution

It introduces a novel SINR formulation demonstrating frequency/time duality and proposes capacity optimization methods considering realistic technological constraints.

Findings

BH outperforms NOFR in non-real-time services.

Significant power and spectral efficiency gains are achieved.

Technological constraints create a gap in the ideal duality.

Abstract

In this paper, we investigate two new candidate transmission schemes, Non-Orthogonal Frequency Reuse (NOFR) and Beam-Hoping (BH). They operate in different domains (frequency and time/space, respectively), and we want to know which domain shows overall best performance. We propose a novel formulation of the Signal-to-Interference plus Noise Ratio (SINR) which allows us to prove the frequency/time duality of these schemes. Further, we propose two novel capacity optimization approaches assuming per-beam SINR constraints in order to use the satellite resources (e.g. power and bandwidth) more efficiently. Moreover, we develop a general methodology to include technological constraints due to realistic implementations, and obtain the main factors that prevent the two technologies dual of each other in practice, and formulate the technological gap between them. The Shannon capacity (upper bound) and current state-of-the-art coding and modulations are analyzed in order to quantify the gap and to evaluate the performance of the two candidate schemes. Simulation results show significant improvements in terms of power gain, spectral efficiency and traffic matching ratio when comparing with conventional systems, which are designed based on uniform bandwidth and power allocation. The results also show that BH system turns out to show a less complex design and performs better than NOFR system specially for non-real time services.