Abstract

To achieve the massive device connectivity and high data rate demanded by 5G, wireless transmission with wider signal bandwidths and higher-order multiple-input multiple-output (MIMO) is inevitable. This work demonstrates a possible function split option for the next generation fronthaul interface (NGFI). The proof-of-concept downlink architecture consists of real-time sigma-delta modulated signal over fiber (SDoF) links in combination with distributed multi-user (MU) MIMO transmission. The setup is fully implemented using off-the-shelf and in-house developed components. A single SDoF link achieves an error vector magnitude (EVM) of 3.14% for a 163.84 MHz-bandwidth 256-QAM OFDM signal (958.64 Mbps) with a carrier frequency around 3.5 GHz transmitted over 100 m OM4 multi-mode fiber at 850 nm using a commercial QSFP module. The centralized architecture of the proposed setup introduces no frequency asynchronism among remote radio units. For most cases, the 2 × 2 MU-MIMO transmission has little performance degradation compared to SISO, 0.8 dB EVM degradation for 40.96 MHz-bandwidth signals and 1.4 dB for 163.84 MHz-bandwidth on average, implying that the wireless spectral efficiency almost doubles by exploiting spatial multiplexing. A 1.4 Gbps data rate (720 Mbps per user, 163.84 MHz-bandwidth, 64-QAM) is reached with an average EVM of 6.66%. The performance shows that this approach is feasible for the high-capacity hot-spot scenario.

Parallel implement of real-time delta-sigma modulation for digital mobile fronthaul

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Opt. Express 31(26) 44401-44409 (2023)

Digital Mobile Fronthaul Based on Delta–Sigma Modulation for 32 LTE Carrier Aggregation and FBMC Signals

Jing Wang, Zhenhua Yu, Kai Ying, Junwen Zhang, Feng Lu, Mu Xu, Lin Cheng, Xiaoli Ma, and Gee-Kung Chang
J. Opt. Commun. Netw. 9(2) A233-A244 (2017)

Improvement of the transmission performance in multi-IF-over-fiber mobile fronthaul by using tone-reservation technique

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Opt. Express 23(23) 29615-29624 (2015)

Multiple beam-steering for 5G multi-user MIMO mobile fronthaul based on IFoF and RoF transmission

Kosuke Nishimura, Hsuan-Yun Kao, Shota Ishimura, Kazuki Tanaka, and Ryo Inohara
Opt. Continuum 1(5) 1165-1175 (2022)

Experimental investigation of inter-core crosstalk tolerance of MIMO-OFDM/OQAM radio over multicore fiber system

Jiale He, Borui Li, Lei Deng, Ming Tang, Lin Gan, Songnian Fu, Perry Ping Shum, and Deming Liu
Opt. Express 24(12) 13418-13428 (2016)