200-m Photonics-Aided Terahertz Wireless Transmission of 253-Gbit/s DP-OFDM Signals Utilizing Multidimensional Nonlinear Equalization

We experimentally demonstrate a large-capacity and long-haul photonics-aided dual-polarization (DP) terahertz wireless transmission system at 300 GHz. Orthogonal frequency division multiplexing (OFDM) scheme is employed to resist dispersion effects in the fiber link and multipath effects in the wireless link. To extend wireless transmission distance, we deploy high-gain dielectric plano-convex lenses, conical antennas (CAs), low-noise amplifiers (LNAs) as well as integrated mixer/amplifier/multiplier chain (IMAMC). We propose and utilize a low-complexity multiple-input and multiple-output (MIMO) hybrid time-frequency-polarization domain (TFPD) trigonometric-memory-polynomial (TMP) nonlinear equalizer (NLE), which is utilized to simultaneously eliminate in-phase/quadrature (I/Q) imbalance, inter-symbol interference (ISI), inter-carrier interference (ICI), polarization crosstalk and nonlinear impairments for DP-OFDM signals. Compared to the traditional MIMO Volterra-NLE, the MIMO-TFPD-TMP-NLE reduces the required number of real multiplications by 37.7%. By utilizing advanced THz modules and DSP algorithms, we have successfully achieved a record-breaking air interface user rate (AIUR)-distance product of 50.6 Gbit/s·km (253 Gbit/s × 0.2 km) in the THz band (above 0.3 THz).