High Capacity Converged Passive Optical Network and RoF-Based 5G+ Fronthaul Using 4-PAM and NOMA-CAP Signals

Abstract

Network architectural changes to satisfy all the 5G+ mobile network specifications and requirements are necessary due to the popularization of streaming and cloud applications on omnipresent portable devices. The combination of massive installation of micro-cell antenna sites with the cloud access radio network (C-RAN) architecture has recently been nominated as a promising technology for high-capacity mobile fronthaul links, albeit at a high cost. An alternative approach for next-generation fronthaul networks is to utilize the already deployed passive optical networks (PONs) where wireless and wired services may coexist in a converged manner. Non-orthogonal multiple access (NOMA) modulation with multi-band carrierless amplitude and phase modulation (NOMA-CAP) has recently been investigated as a promising 5G+ modulation format candidate to increase the capacity and flexibility of future mobile networks. Here, we experimentally demonstrate the convergence of a NOMA-CAP wireless waveform with a single-carrier wired signal in a PON scenario using radio-over-fiber (RoF) technology. Specifically, fifteen NOMA-CAP bands, with two NOMA power levels to double the capacity, transmit 15 Gb/s multiplexed with a digital 10 Gb/s four-level pulse amplitude modulation (PAM-4) signal for downlink application. Two converged system implementations have been considered, first using electrical frequency division multiplexing (EFDM) and secondly using the hybrid EFDMwavelength division multiplexing (EFDM-WDM). Successful transmission through a 25 km span of standard single-mode fiber is achieved with negligible transmission penalty for both proposed converged solutions.

Results and Achievements of the ALLIANCE Project: New Network Solutions for 5G and Beyond

“…NOMA-CAP modulation has recently been investigated as a promising B5G modulation format candidate to increase the capacity and flexibility of future mobile networks. In the framework of the ALLIANCE project, we have experimentally demonstrated the convergence of a NOMA-CAP wireless waveform with a single-carrier wired signal in a PON scenario using RoF technology [69]. Figure 5 shows the reference scenario for this work where the Pulse Amplitude Modulation 4-level (PAM4) has been used for legacy systems and NOMA-CAP for the future B5G fronthaul.…”

“…Figure 5 shows the reference scenario for this work where the Pulse Amplitude Modulation 4-level (PAM4) has been used for legacy systems and NOMA-CAP for the future B5G fronthaul. Two NOMA levels (strong and weak) have been considered per each CAP band [69]. We have also first experimentally demonstrated NOMA-CAP as a modulation format for split-enabled optical interconnects with a capacity of up to 630 Gb/s using 7-core MCF and requiring an electrical bandwidth of 25 GHz.…”

A Single-Photodiode Framework for the Co-Detection of Hybrid Digital and Analog Radio-Over-Fiber Signals

“…By extracting the ARoF signal from the combined signal through subtraction, exploiting the distinct characteristics of DRoF and ARoF signals, improved spectral efficiency can be achieved [10]. Similar studies has also been carried out for hybrid fixed-mobile networks, where the wireless signals are modulated at the null point of the baseband signal for passive optical network (PON) [11]- [13]. Nevertheless, it is worth noting that the focus of the aforementioned research studies primarily revolves around the generation of optical tones to facilitate signal transmission in hybrid optical access technologies.…”

Effect of Phase Noise on the Optical Millimeter-Wave Signal in the DWDM-RoF System

“…Several techniques have been reported to improve the capacity of RoF communication systems [9][10][11]. The performance of multiple modulation formats, such as dual-polarization quadrature phase-shift keying (DP-QPSK), dual-polarization 16-ary quadrature amplitude modulation (DP-16QAM), DP-64QAM, and DP-256QAM, was studied in C-band systems with different transmission distances.…”