Tommaso Foggi

Università di Parma | UNIPR · Department of Engineering and Architecture

We investigate the performance of free-space optical communication systems in the presence of atmospheric turbulence to assess the advantages that a coherent communication system can bring with respect to a conventional intensity modulation and direct detection (IM/DD) system. The perspective is an information-theoretic one, hence we evaluate the m...

Non-terrestrial networks will play a crucial role in future wireless 6G systems to ensure ubiquitous connectivity and to complement terrestrial networks. With reference to a LEO constellation, this letter performs a comparison in terms of pragmatic capacity between the OFDM and the OTFS modulation in a scenario where multi-satellite diversity is em...

The paper summarizes the recent investigation on feasibility of adapting state-of-the-art coherent fiber-optics (FO) systems for Free Space Optical (FSO) scenarios. This investigation is critically dependent on the intertwined aspects of architecture, as well as device and propagation impairments (including the channel) appearing in the aforementio...

We consider time-frequency-packed systems in an additive white Gaussian noise scenario. With respect to systems employing time packing, thus introducing intentional intersymbol interference only, a further improvement of the spectral efficiency is obtained by packing the adjacent carriers closer in frequency. The adoption of a multiuser detector ca...

In the frame of ongoing efforts between space agencies to define an on-off-keying-based optical low-Earth-orbit (LEO) direct-to-Earth (DTE) waveform, this paper offers an in-depth analysis of the Variable Data Rate (VDR) technique. VDR, in contrast to the currently adopted Constant Data Rate (CDR) approach, enables the optimization of the average t...

Fast and reliable synchronization in free-space optical (FSO) communications is a crucial task that has received little attention so far. Since in these applications the data rate is much higher than in traditional radio-frequency (RF) systems, novel technological constraints may arise in the design of the synchronization algorithms, as for example...

In the frame of ongoing efforts between space agencies to define an on-off-keying-based optical low-Earth-orbit (LEO) direct-to-Earth (DTE) waveform, this paper offers an in-depth analysis of the Variable Data Rate (VDR) technique. VDR, in contrast to the currently adopted Constant Data Rate (CDR) approach, enables the optimization of the average t...

In the frame of ongoing efforts between space agencies to define an on-off-keying-based optical low-Earth-orbit (LEO) direct-to-Earth (DTE) waveform, this paper offers an in-depth analysis of the Variable Data Rate (VDR) technique. VDR, in contrast to the currently adopted Constant Data Rate (CDR) approach, enables the optimization of the average t...

The 5G ecosystem is radically shifting Information and Communication Technologies (ICT) towards a system directly tailored and optimised to support vertical markets and services. In order to design and implement the ambitious 5G network, Satellite Communications (SatCom) have been recognised as a promising solution to extend and complement terrestr...

The 5G ecosystem is radically shifting Information and Communication Technologies (ICT) towards a system directly tailored and optimised to support vertical markets and services. In order to design and implement the ambitious 5G network, Satellite Communications (SatCom) have been recognised as a promising solution to extend and complement terrestr...

We compare the main multicarrier modulation formats when employed over channels with nonlinear amplification. Using a general and unified discrete‐time model that encompasses orthogonal frequency division multiplexing (OFDM) and its most popular alternatives, we perform a comparison using the achievable spectral efficiency, computed in the presence...

In this paper, the detection of LoRa signals from a low-earth orbit (LEO) satellite is considered. The use of a LEO satellite to collect messages from the terminals, as an alternative to terrestrial base stations in rural areas, represents a major challenge due to the specific impairments of this scenario, e.g., Doppler effects and interfering sign...

The demand for transmitting optical signals with high spectral efficiency (SE) by exploiting cost-effective systems and techniques is raising an increasing interest in the area of wide or metro area networks (WAN/MAN). Recently, many different solutions, e.g., amplitude modulation formats, direct-detection schemes, line codes, and simple signal pro...

The integration of satellite and terrestrial networks is a promising solution for extending broadband coverage to areas not connected to a terrestrial infrastructure, as also demonstrated by recent commercial and standardisation endeavours. However, the large delays and Doppler shifts over the satellite channel pose severe technical challenges to t...

Satellite Communication systems are a promising solution to extend and complement terrestrial networks in unserved or under-served areas. This aspect is reflected by recent commercial and standardisation endeavours. In particular, 3GPP recently initiated a Study Item for New Radio-based, i.e., 5G, Non-Terrestrial Networks aimed at deploying satelli...

Satellite Communication systems are a promising solution to extend and complement terrestrial networks in unserved or under-served areas. This aspect is reflected by recent commercial and standardisation endeavours. In particular, 3GPP recently initiated a Study Item for New Radio-based, i.e., 5G, Non-Terrestrial Networks aimed at deploying satelli...

In optical dedicated path protection ( 1 + 1 ), the same optical signal is transmitted along both working and backup paths. Thus, in 1 + 1 , the transmission parameters need to be configured according to the most impaired path, e.g., the backup one. This implies that the working signal is typically served with higher than necessary quality of trans...

This paper presents results on the achievable spectral efficiency and on the energy efficiency for a wireless multiple-input-multiple-output (MIMO) link operating at millimeter wave frequencies (mmWave) in a typical 5G scenario. Two different single-carrier modem schemes are considered, i.e., a traditional modulation scheme with linear equalization...

3GPP is finalising the first release of the 5G New Radio physical layer. To cope with the demanding 5G requirements on global connectivity and large throughput, Satellite Communications might be a valuable resource to extend and complement terrestrial networks. In this context, we introduce an integrated architecture for 5G-based LEO mega-constella...

Potential of directly-modulated VCSELs, widely employed for low-cost and energy-efficient intra-data center transmissions, is here studied for transmissions up to access/metro scenarios. In particular, the manuscript refers to long-wavelength VCSELs for intensity modulation/direct detection (IM/DD) on-off keying transmission over standard single-mo...

LTE-based satellite systems in LEO constellations are a promising solution for extending broadband coverage to areas not connected to a terrestrial infrastructure. However, the large delays and Doppler shifts over the satellite channel pose severe technical challenges to a traditional LTE system. In this paper, two architectures are proposed for a...

We experimentally demonstrate for the first time hitless spectrum defragmentation exploiting signals overlap in a field trial. Spectrum resources are shared without signals loss. The defragmentation procedure was successfully verified through 32Gbaud PM-QPSK-TFP signals over 1320km installed fiber.

In Elastic Optical Networks, advanced transmission techniques based on coherent detection strategies have been proposed and exploited to provide high flexibility in resource allocation. So far, these techniques have assumed the constraint of each optical signal being transmitted along a dedicated frequency slot, by carefully avoiding frequency over...

Future wireless networks will extensively rely upon bandwidths centered on carrier frequencies larger than 10GHz. Indeed, recent research has shown that, despite the large path-loss, millimeter wave (mmWave) frequencies can be successfully exploited to transmit very large data-rates over short distances to slowly moving users. Due to hardware compl...

Sub-Nyquist time frequency packing technique was demonstrated for the first time in a super-channel field trial transmission over long-haul distances. The technique allows a limited spectral occupancy even with low order modulation formats. The transmission was successfully performed on a deployed Australian link between Sydney and Melbourne which...

The path computation element (PCE) architecture was originally proposed with a stateless condition, i.e., considering only network reserved resources during constraint-based path computations. More recently, a stateful architecture was introduced to additionally maintain the state of computed and established label switch paths (LSPs). Furthermore,...

Flexible grid optical networks allow a better exploitation of fiber capacity, by enabling a denser frequency allocation. A tighter channel spacing, however, requires narrower filters, which increase linear intersymbol interference (ISI), and may dramatically reduce system reach. Commercial coherent receivers are based on symbol by symbol detectors,...

Time-frequency packing (TFP) transmission provides the highest achievable spectral efficiency with a constrained modulation format and detector complexity. In this work, the application of the TFP technique to fiber-optic systems is investigated and experimentally demonstrated. The main theoretical aspects, design guidelines, and implementation iss...

An innovative receiver architecture for the satellite-based automatic identification system has been recently proposed. In this paper, we describe a few modifications that can be introduced on the algorithms for synchronization and detection, which provide an impressive performance improvement. The receiver architecture has been designed for an on-...

An innovative receiver architecture for the satellite-based Automatic Identification System (AIS) has been recently proposed. In this paper, we describe a few modifications that can be introduced on the algorithms for synchronization and detection, that provide an impressive performance improvement with respect to the previous system. The receiver...

We consider realistic long-haul optical links, with linear and nonlinear impairments, and investigate the application of time-frequency packing with low-order constellations as a possible solution to increase the spectral efficiency. A detailed comparison with available techniques from the literature will be also performed. We will see that this te...

Relevant benefits of the active stateful PCE architecture are experimentally demonstrated on a flexgrid network testbed. Two experiments are reported, including a first demo on PCE-controlled code-adaptation applied to a 1Tb/s super-channel.

The complete overlap of two source-independent optical signals, configured with the same central frequency, is successfully demonstrated for the first time. Specifically designed control plane extensions are also proposed and successfully implemented.

We consider realistic long-haul optical links, where nonlinear effects represent the main impairment, and investigate the application of time-frequency packing with low-order constellations as a the most viable solution to increase the spectral efficiency. We will see that this technique allows to overcome the relevant theoretical and technological...

We propose an accurate and low-complexity blind adaptive algorithm for chromatic dispersion (CD) compensation and estimation in coherent optical systems. The method is based on a Frequency Domain Equalizer (FDE), a low complexity Time Domain Equalizer arranged in a butterfly structure (B-TDE) and an Optical Performance Monitoring (OPM) block in a l...

We investigate the time-frequency packing technique on long-haul optical links in order to increase the spectral efficiency. This solution is compared to high-order formats at equal bit or baud rate, demonstrating that higher spectral efficiency can be more effectively reached.

We demonstrate the feasibility of a novel time-frequency packing technique to implement DP-QPSK communication with a record spectral efficiency ranging from 5.14 to 4.3 bit/s/Hz over a distance ranging from 3000 km to 5200 km of uncompensated standard fiber, respectively.

An accurate and low complexity blind adaptive chromatic dispersion compensation and estimation algorithm for coherent optical systems is proposed and experimentally validated. The method is based on a Frequency Domain Equalizer, a low complexity Butterfly Time Domain Equalizer and an Optical Performance Monitoring in a loop configuration.

An accurate and low complexity blind adaptive chromatic dispersion compensation and estimation algorithm for coherent optical systems is proposed and experimentally validated. The method is based on a Frequency Domain Equalizer, a low complexity Butterfly Time Domain Equalizer and an Optical Performance Monitoring in a loop configuration.

We investigate the application of time and frequency packing techniques, an extension of the classical faster-than-Nyquist signaling, to long-haul optical links. These techniques provide a significant spectral efficiency increase and represent a viable alternative to overcome the theoretical and technological issues related to the use of high-order...

Cited By (since 1996): 1, Export Date: 25 July 2012, Source: Scopus, Art. No.: 5979171, CODEN: JLTED, doi: 10.1109/JLT.2011.2164237, Language of Original Document: English, Correspondence Address: Colavolpe, G.; University of Parma, Dipartimento di Ingegneria dell'Informazione, I-43100 Parma, Italy, References: Colavolpe, G., Foggi, T., Forestieri,...

The popular single-carrier QPSK modulation format is compared with 8PSK BICM and TCM schemes in 100 Gbps optical links in linear and nonlinear regime, with or without inline dispersion compensation.

Coherent detection has recently allowed the adoption of high-order modulation formats in single-carrier optical systems where a simple feed-forward equalizer, in proper configuration, is able to perfectly compensate for fiber linear impairments, such as group velocity dispersion and polarization-mode dispersion. In this letter, the blind update of...

In coherent optical systems, the phase noise due to transmit and receive lasers has a significant impact on the receiver performance - the sensitivity to phase noise and the capability of electronic processing to compensate for its effects are reduced for increasing lasers'' linewidths. However, a detailed analysis of the effects of phase noise on...

A novel technique to cancel laser phase noise in coherent receivers is proposed. The equivalent laser linewidth is reduced by a factor of 10, and coherent detection of DQPSK signals affected by strong phase noise is experimentally demonstrated.

We analyze the orthogonal frequency division multiplexing (OFDM) technique in long-haul next generation optical communication links and compare it with the well-established single-carrier (SC) data transmission using high-level modulation formats and coherent detection. The analysis of the two alternative solutions is carried out in the 100 Gbps sc...

Orthogonal frequency division multiplexing (OFDM) and single-carrier (SC) data transmission are compared as potential candidates for the next generation coherent long-haul 100 Gbps optical communication systems. The comparison takes into account impairments either general or mainly related to coherent detection, e.g., group velocity dispersion (GVD...

OFDM is compared to the well-established single-carrier data transmission using high-level modulation formats and coherent detection. The analysis of the two alternative solutions is carried out in the 100 Gb/s scenario.

This paper investigates optical coherent systems based on polarization multiplexing and high-order modulations such as phase-shift keying (PSK) signals and quadrature ampli-tude modulations (QAM). It is shown that a simple linear receiver processing is sufficient to perfectly demultiplex the two transmitted streams and to perfectly compensate for g...

The optimal receiver processing based on maximum-likelihood sequence detection (MLSD) is employed with high-order phase and amplitude modulations in optical transmission systems affected by typical channel impairments such as group velocity dispersion (GVD), polarization mode dispersion (PMD), and phase uncertainties due to phase noise. A couple of...

This paper analyzes optical transmission systems based on high-order modulations such as phase-shift keying signals and quadrature amplitude modulations. When the channel is affected by group velocity dispersion (GVD), polarization mode dispersion (PMD), and phase uncertainties due to the laser phase noise, the optimal receiver processing based on...

Conference code: 72898, Export Date: 25 July 2012, Source: Scopus, Art. No.: 4528212, doi: 10.1109/OFC.2008.4528212, Language of Original Document: English, Correspondence Address: Colavolpe, G.; University of Parma, Dept. of Information Engineering, viale G. P. Usberti 181/A, Parma, Italy, References: T. Foggi et al., Maximum-likelihood sequence d...

Maximum likelihood sequence detection represents the most efficient technique in the electrical domain to combat fiber impairments such as polarization-mode dispersion and group-velocity dispersion. In order to successfully apply this technique, it is mandatory to estimate some key channel parameters needed by the Viterbi processor. We propose a si...

This paper thoroughly investigates the maximum-likelihood sequence detection (MLSD) receiver for the optical ON-OFF keying (OOK) channel in the presence of both polarization mode dispersion and group velocity dispersion (GVD). A reliable method is provided for computing the relevant performance for any possible value of the system parameters, with...

In high-speed optical transmission systems, one of the most challenging impairments is represented by the signal distortions produced by polarization-mode dispersion (PMD). In this paper, we analyze the limits of electronic compensation schemes, in the form of maximum-likelihood sequence detection receivers. With a constraint on the front-end proce...

I sistemi di comunicazione in fibra ottica risentono di diversi tipi di disturbi, quali ad esempio la dispersione cromatica e la dispersione dei modi di polarizzazione. La compensazione ottica di tali disturbi è possibile ma complessa e costosa, mentre le tecniche di elaborazione elettronica del segnale presentano diversi vantaggi, semplicità, cost...