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Spectrally efficient frequency division multiplexing for improving photonics-aided terahertz wireless transmission
Optics Express
|December 19, 2025
Summary
Photonics-aided terahertz transmission using non-orthogonal discrete Fourier transform spread spectrally efficient frequency division multiplexing (NO-DFT-S SEFDM) significantly boosts capacity. This advanced method achieves higher data rates for future 6G wireless networks.
Area of Science:
- Optical communications and wireless networking
- Terahertz (THz) technology
- Signal processing for high-speed data transmission
Background:
- Photonics-aided THz transmission is crucial for 6G, integrating THz bands with optical networks.
- Spectrally efficient frequency division multiplexing (SEFDM) enhances capacity, especially with limited THz bandwidth.
- Cost constraints on THz devices necessitate efficient multiplexing techniques.
Purpose of the Study:
- To experimentally compare conventional SEFDM with a novel non-orthogonal DFT-spread SEFDM (NO-DFT-S SEFDM).
- To evaluate the performance of different signal detection algorithms for mitigating inter-carrier interference (ICI).
- To assess the capacity and data rate improvements offered by NO-DFT-S SEFDM in a photonics-aided THz system.
Main Methods:
- Experimental investigation of NO-DFT-S SEFDM and conventional SEFDM in a photonics-aided THz system.
- Implementation and comparison of Volterra nonlinear equalization (VNLE), I/Q separation iterative detection (ID), and MAP-Viterbi algorithms for ICI mitigation.
- Utilizing high-gain THz modules like THz lenses and low-noise amplifiers (LNAs).
Main Results:
- NO-DFT-S SEFDM achieved a 31.3% capacity increase over orthogonal frequency division multiplexing (OFDM) and 23.5% over conventional SEFDM (BER threshold 2.4e-2 @20% SD-FEC).
- A maximum line rate of 168 Gbit/s and a net rate of 129.2 Gbit/s were achieved over a 100-m wireless THz link at 300 GHz.
- NO-DFT-S SEFDM demonstrated reduced peak-to-average power ratio (PAPR) compared to conventional SEFDM.
Conclusions:
- NO-DFT-S SEFDM is a promising technique for enhancing the capacity of photonics-aided THz transmission systems.
- The investigated signal detection algorithms effectively mitigate ICI in bandwidth-compressed systems.
- The experimental results validate the potential of NO-DFT-S SEFDM for achieving high data rates in future 6G communication.
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