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A tandem dual electrode Mach Zehnder modulator (DE-MZM) generated W-band optical code division multiple access (OCDMA) radio-over-fiber (ROF) system is proposed and the simulation results are presented. We have investigated a method to upconvert a baseband laser signal to the millimeter wave band (W-band in this case) by utilizing two cascaded DE-MZMs driven by lower frequency sine-wave generators...
We report on technical challenges associated with the use of directly modulated lasers in the mobile fronthaul networks based on radio-over-fiber (RoF) technology. In particular, the effects of dispersion-induced RF power fading and multi-path interference are investigated through theoretical and experimental analyses for the RoF-based transmission system implemented by using directly modulated lasers.
In this paper we present a multi-flow transmitter developed within the EU project PANTHER and we evaluate its first proof-of-concept demonstration of up to two single- or dual-polarization optical flows with selectable wavelength, m-QAM modulation format, number of carriers and destination. Multiflow operation is realized by two polymer boards allowing optical carrier management and optional polarization...
Semiconductor optical amplifiers (SOAs) have been receiving intense interest for use as external modulators in a variety of fundamental and advanced applications. However the employment of these modules for the target purpose is hindered by their limited modulation bandwidth. Motivated by this fact, in this invited paper we review the main outcome of our recent research on enabling the direct modulation...
A three dimensional modulation, which can improve the channel capacity of visible optical wireless transmission, is proposed, where it is implemented by the use of the simultaneous modulation of amplitude, phase, and frequency without the request of additional physical bandwidth compared with two dimensional modulation such as quadrature amplitude modulation (QAM). Using the proposed technique, a...
In this paper, we perform a case study focusing on both regeneration assignment (RA) and regeneration placement (RP) in a translucent elastic optical network. We consider six different heuristics to solve RA and RP problems and we perform a jointly analysis of the impact of these algorithms in network performance in terms of path request blocking probability. These analyses are performed using network...
Next-generation access networks (NGANs) mainly include wavelength division multiplexing (WDM) based 60GHz Radio over Fibre systems (60G-RoF) and WDM Passive Optical Networks (WDM-PONs). Semiconductor optical amplifier may be the key device of colorless unit in these WDM based systems. The device can be effectively utilized as external modulator because it can perform simultaneously amplification and...
The development of InP-based 4- and 8-channel IQ Mach-Zehnder modulator PICs as basic active building blocks in advanced hybrid terabit super-channel OFDM/Nyquist WDM transmitter components is reported for the first time.
Sliceable Bandwidth-variable Transponders (SBVTs) enhance the configurability and flexibility of Flexgrid optical networks. A single SBVT can be used to transmit and receive several optical signals each modulated with a specific format. A SBVT can be seen as a set of sub-transponders that can be specifically configured to end a specific lightpath, by defining, among other parameters, the modulation...
This paper presents a novel highly spectral efficient 5G offset-QAM Orthogonal Frequency Division Multiplexing (OQAM-OFDM) Radio over Fibre (RoF) systems for small cell RANs at 28 GHz. The wide bandwidth photodiode at the remote radio head (RRH) is used for remote heterodyning centralized optical local oscillator (LO) and the downstream optical single sideband (OSSB) signal to generate the millimeter...
In this paper, average bit error rate (BER) and outage probability are analysed in the free-space optical (FSO) system employing subcarrier intensity modulation (SIM) with differential phase shift keying (DPSK). The FSO channel is described by the lognormal atmospheric turbulence and the pointing error effects. Closed-form analytical expressions for the average BER and outage probability are proposed...
The performance of a hybrid M-ary quadrature amplitude modulation multi-pulse pulse-position modulation (hybrid QAM-MPPM) technique is investigated in free space optical channels. The bit-error rates (BERs) of intensity-modulation direct detection (IM-DD) systems adopting the hybrid technique is obtained. Our results reveal that, under the conditions of comparable data rates, same bandwidth, and same...
In 5G wireless systems, centralized RAN (C-RAN) is an architectural choice where the signal waveforms received by Remote Radio Heads (RRH) are transparently forwarded to base band units (BBU), in many cases using an optical fronthaul. Although C-RAN highly simplifies the RRH, which is positive from the operational cost standpoint, much of the system complexity and cost is shifted towards the optical...
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