Multi-cell coordination for 60 GHz RoF fronthaul enabled by a non-orthogonal multiple access scheme without successive interference cancellation

• Published in: Optics letters Vol. 43; no. 17; p. 4236
• Main Authors: Tian, Yu, Lim, Christina, Nirmalathas, Ampalavanapillai, Lee, Ka-Lun
• Format: Journal Article
• Language: English
• Published: United States 01.09.2018
• ISSN: 1539-4794
• DOI: 10.1364/OL.43.004236

We propose and experimentally demonstrate a non-orthogonal multiple access (NOMA) enabled 60 GHz radio-over-fiber (RoF) fronthaul system with coordinated base stations, improving the data rate and coverage of 60 GHz RoF systems. First, coordinated multipoint transmission using space-time block coding (STBC) is adopted in fronthaul, achieving 1.3 dB improvement in receiver sensitivity compared to two fronthaul links' transmission without STBC. Second, multi-cell coordination in RoF fronthaul is presented, where a multi-level code (MLC)-based NOMA scheme is employed. A sum rate of 6 Gbps for three users is achieved along 10 km fronthaul transmission and 1.24 m wireless transmission. The experimental results show that the valid power allocation ratio range improves from 3.5≤R≤4.2 in conventional superposition code-based NOMA fronthaul to 3≤R≤5 in our proposed coordinated MLC-NOMA fronthaul link.