Bidirectional OFDM Based MMW/THzW Over Fiber System for Next Generation Communication

Abstract

The modern world and modern technology want 5G communication to satiate their urgent need of multi-gigabits data transmission in small cells. For this aspiration, a bidirectional orthogonal frequency division multiplexing (OFDM) based millimeter wave over and terahertz wave over fiber system is proposed and demonstrated for 5G access fronthaul. A comparative study between millimeter-wave (MMW) and terahertz wave (THzW) regarding 5G communication is also analyzed. With the assistance of L and C band quantum dash laser diode, MMW and THzW are generated. For downstream (DS), 10 Gbps/12.5Gbps (for MMW/THzW) OFDM data in L band is transmitted over 50-km/25-km single mode fiber (SMF) and 100-m free space optics (FSO) distance, on the other side for upstream (US) transmission, 6.5 Gbps/10 Gbps OFDM data in C band is communicated over 50-km/25-km SMF plus 100-m FSO link. The selection of L and C band for DS and US transmission provide the advantages to reduce the Rayleigh back scattering effect in our bidirectional system not only that it also helps to mitigate the intensity-noise as compared to the conventional amplified spontaneous emission source. This research work gives an overview for the reliability of MMW and THzW system regarding 5G communication. The capability of our system becomes build up by obtaining low bit error rate (under FEC limit), proper error vector magnitude (<10.2%), and clear constellation diagram.

Keywords

• Orthogonal frequency division multiplexing
• millimeter wave over fiber
• terahertz wave over fiber
• Injection locking scheme
• Quantum-dash laser diode