Experimental comparison of DSB and CS-DSB mmW formats over a hybrid fiber and FSO fronthaul network for 5G

The telecommunication world is experiencing the 5th generation (5G) networks deployment including the use of millimeter wave (mmW) frequency bands to satisfy capacity demands. This leads to the extensive use of optical communications, especially the optical fiber connectivity at the last mile access and the edge networks. In this paper we outline fiber and free space optics (FSO) technologies for use as part of the 5G optical fronthaul network. We investigate two different mmW transmission schemes based on (i) the conventional analog radio over fiber transmission using one Mach-Zehnder modulator (MZM) with double sideband (DSB) optical modulation, and (ii) an optical-based frequency doubling with one MZM biased at the null point to introduce carrier suppression DSB (CS DSB) transmission and second MZM used for data modulation. Both systems are assessed in terms of the error vector magnitude, signal-to-noise ratio, dynamic range and phase noise. We consider a configuration for the fronthaul network in the frequency range 2 (FR2) at 27 and 39 GHz with the scale of bandwidth up to 400 MHz with M-quadrature amplitude modulation and quadrature phase shift keying. Results are also shown for FR1 at 3.5 GHz. Moreover, we investigate for the first time the 5G new radio signal transmission under strong turbulence conditions and show the turbulence-induced FSO link impairment. We finally demonstrate the CS DSB scheme performs well under chromatic dispersion-induced fading for the frequency up to 40 GHz and single mode fiber length of 30 km, whereas the DSB format seems more appropriate for an antenna seamless transmission

Improving Energy Efficiency for IoT Communications in 5G Networks

Increase in number of Internet of Things (IoT) devices is quickly changing how mobile networks are being used by shifting more usage to uplink transmissions rather than downlink transmissions. Currently, mobile network uplinks utilize Single Carrier Frequency Division Multiple Access (SC-FDMA) schemes due to the low Peak to Average Power Ratio (PAPR) when compared to Orthogonal Frequency Division Multiple Access (OFDMA). In an IoT perspective, power ratios are highly important in effective battery usage since devices are typically resource-constrained. Fifth Generation (5G) mobile networks are believed to be the future standard network that will handle the influx of IoT device uplinks while preserving the quality of service (QoS) that current Long Term Evolution Advanced (LTE-A) networks provide. In this paper, the Enhanced OEA algorithm was proposed and simulations showed a reduction in the device energy consumption and an increase in the power efficiency of uplink transmissions while preserving the QoS rate provided with SC-FDMA in 5G networks. Furthermore, the computational complexity was reduced through insertion of a sorting step prior to resource allocation

Modeling Interference Between OFDM/OQAM and CP-OFDM: Limitations of the PSD-Based Model

To answer the challenges put out by the next generation of wireless networks (5G), important research efforts have been undertaken during the last few years to find new waveforms that are better spectrally localized and less sensitive to asynchronism effects than the widely deployed Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM). One of the most studied schemes is OFDM-Offset Quadrature Amplitude Modulation (OFDM/OQAM) based on the PHYDYAS filter pulse. In the recent literature, spectrum coexistence between OFDM/OQAM and CP-OFDM is commonly studied based on the Power Spectral Density (PSD) model. In this paper, we show that this approach is flawed and we show that the actual interference injected by OFDM/OQAM systems onto CP-OFDM is much higher than what is classically expected with the PSD based model in the literature. We show that though using OFDM/OQAM in secondary systems is still advantageous, it brings limited gain in the context of coexistence with incumbent CP-OFDM systems.Comment: 7 pages, 9 figures, ICT 201

Performance Analysis of a 5G Transceiver Implementation for Remote Areas Scenarios

The fifth generation of mobile communication networks will support a large set of new services and applications. One important use case is the remote area coverage for broadband Internet access. This use case ha significant social and economic impact, since a considerable percentage of the global population living in low populated area does not have Internet access and the communication infrastructure in rural areas can be used to improve agribusiness productivity. The aim of this paper is to analyze the performance of a 5G for Remote Areas transceiver, implemented on field programmable gate array based hardware for real-time processing. This transceiver employs the latest digital communication techniques, such as generalized frequency division multiplexing waveform combined with 2 by 2 multiple-input multiple-output diversity scheme and polar channel coding. The performance of the prototype is evaluated regarding its out-of-band emissions and bit error rate under AWGN channel.Comment: Presented in 2018 European Conference on Networks and Communications (EuCNC),18-21 June, 2018, Ljubljana, Sloveni