A Flexible OFDM-like DFT-s-OFDM Reference Symbol

With many high throughput satellites (HTS) in space, the satellite industry is now able to provide flexible services at costs that tend to become competitive. Satellite networks may ultimately play a significant role in the global telecommunication market. As an illustration of this trend, satellite stakeholders are pushing with some success for a satellite component in the global 5G system. With power fluctuations similar to those of single carrier waveforms, the discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) modulation appears as a relevant waveform for some satellite applications such as backhauling. Despite its many advantages, DFT-s-OFDM still lacks of reference signals (RS) showing low-power fluctuations for whatever length. In this paper, we propose a new RS that consists in inserting an OFDM pilot with its own cyclic prefix within a DFT-s-OFDM symbol. The novelty is here to modulate specific samples that are computed to closely match - after modulation - the OFDM pilot thus minimizing the interference resulting from the insertion. Performance evaluations assess the relevance of the proposed scheme that brings the flexibility of OFDM RS to DFT-s-OFDM systems.