A method for modulating data for transmission within a communication system. The method includes establishing a time-frequency shifting matrix of dimension N×N, wherein N is greater than one. The method further includes combining the time-frequency shifting matrix with a data frame to provide an intermediate data frame. A transformed data matrix is provided by permuting elements of the intermediate data frame. A modulated signal is generated in accordance with elements of the transformed data matrix.

Modulation and equalization in an orthonormal time-frequency shifting communications system

Fiber, cable, and wireless data channels are typically impaired by reflectors and other imperfections, producing a channel state with echoes and frequency shifts in data waveforms. Here, methods of using OTFS pilot symbol waveform bursts to automatically produce a detailed 2D model of the channel state are presented. This 2D channel state can then be used to optimize data transmission. For wireless data channels, an even more detailed 2D model of channel state can be produced by using polarization and multiple antennas in the process. Once 2D channel states are known, the system turns imperfect data channels from a liability to an advantage by using channel imperfections to boost data transmission rates. The methods can be used to improve legacy data transmission modes in multiple types of media, and are particularly useful for producing new types of robust and high capacity wireless communications using non-legacy OTFS data transmission methods.

Otfs methods of data channel characterization and uses thereof

As 5G enters a stable phase in terms of system architecture, 3GPP Release 17 starts to investigate advanced features that would shape the evolution toward 6G. This paper provides an insightful analysis for mobile networks Beyond 5G (B5G) considering the advancements and implications introduced by the evolution of softwarization, agile control and deterministic services. It elaborates the 5G landscape, also investigating new business prospects and the emerging use cases, which will open new horizons for accelerating the market penetration of vertical services. It then overviews the key technologies that constitute the pillars for the evolution beyond 5G considering new radio paradigms, micro-service oriented core network, native IP based user plane, network analytics and the support of the low latency- high reliability transport layer. The open challenges considering both technical and business aspects are then overviewed, elaborating the footprint of softwarization, security and trust as well as distributed architectures and services toward 6G.

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The Road beyond 5G: A Vision and Insight of the Key Technologies

Continuous improvements in communication technologies over copper pair access networks have enabled hybrid fiber/copper access networks that provide ever increasing broadband data rates. Most recently, field trials have demonstrated that crosstalk cancellation, also referred to as vectoring, and bonding two pairs to push data rates of very high speed DSL above 100 Mb/s on a single copper pair and above 200 Mb/s on two copper pairs. Looking ahead, the G.fast project group of the ITU-T is currently defining a new copper access technology to provide aggregate (upstream and downstream) data rates of up to 1 Gb/s over distances up to 250 m. This article provides an overview of some key challenges that need to be addressed for G.fast.

G.fast: evolving the copper access network

A healthy photovoltaic (PV) array has a specific impedance between node pairs, and any ground fault changes the impedance values. Reflectometry is a well-known technique in electromagnetics, and it could be exploited to detect fault and aging-related impedance variations in a PV system. A fault detection algorithm using the spread spectrum time-domain reflectometry (SSTDR) method has been introduced in this paper. SSTDR has been successfully used for detecting and locating aircraft wiring faults. However, the wide variation in impedance throughout the entire PV system, which is caused by the use of different materials and interconnections makes PV fault detection more challenging while using reflectometry. Unlike other conventional ground-fault detection techniques specifically developed for PV arrays, SSTDR does not depend on fault-current magnitudes. Therefore, SSTDR can be used even in the absence of the solar irradiation, which makes it a very powerful fault-detection tool. The proposed PV ground-fault detection technique has been tested in a real-world PV system, and it can confidently detect PV ground faults for different configurations of PV arrays (single and double strings) and fault resistances (0.5, 5, and 10- $\Omega$ ). Moreover, it has been experimentally verified that our proposed algorithm works at low irradiance and can detect specific ground faults that may remain undetected using the conventional ground-fault detection and interrupter (GFDI) fuses.

An Irradiance-Independent, Robust Ground-Fault Detection Scheme for PV Arrays Based on Spread Spectrum Time-Domain Reflectometry (SSTDR)

The present invention relates to a precoder for a communication system arranged to provide transmission blocks for transmission over a transmission channel based on inputted symbol blocks. The precoder is arranged to pre-distort each symbol block based on an estimate of the characteristics of the transmission channel so that the corresponding transmission block appears to be undistorted after transmission over the transmission channel. In accordance therewith, the precoder is arranged to apply Tomlinson-Harashima precoding on a sum of a first measure corresponding to predistortion so as to remove intrasymbol interference and a second measure corresponding to predistortion so as to remove intersymbol interference. The present invention further relates to a method for providing transmission blocks for transmission over a transmission channel in a communication system.

Precoder for a communication system and methods used in said communication system

The fragmentation dynamics of the SF6 molecule following the excitations of S 2p electrons into unoccupied molecular orbitals has been studied using the energy-resolved electron–ion coincidence technique. Fragmentation patterns were found to depend on the particular excitation and on the electronic state of the molecular ion. The spectator resonant Auger decay at the 2p → 6a1g resonance induces changes in the ion distributions as compared to direct photoionization. Furthermore, coincidence spectra related to the same Auger structure display different ion abundances at the 2t2g and 4eg shape resonances. Differences were also found in the Auger decay spectra. These findings give further support for the previously suggested many-electron character of the 4eg shape resonance.

An energy resolved electron-ion coincidence study near the S 2p thresholds of the SF6 molecule

Digital subscriber lines (DSLs) technology is vastly used for high-speed data transmission. Crosstalk is one of the main problems in DSL. The research community has done extensive work on how to optimize spectrum allocation across DSL frequencies and mitigate crosstalk, a subject that has been called dynamic spectrum management (DSM). This text presents a novel DSM solution, referred to as semiblind spectrum balancing (2SB). 2SB performs an optimization process with a virtual line, a fictitious line that represents to each user the damage it causes for all other users. With the aid of message exchanges between modems and a central agent, the method will adjust the virtual line's parameters so that it represents the real crosstalk scenario in the binder. In this paper, we provide the conditions for how such a situation can be achieved and show that it can do so with semicentralization, low complexity and limited crosstalk channel information-only the ratios between crosstalk channels are necessary. Performance is very close to optimal.

Semiblind Spectrum Balancing for DSL

A qualification and monitoring function (604, 606) monitors the line conditions of a last mile access network that is connected with a multi-access broadband network. The qualification and monitoring function (604, 606) sends data to a Resource Manager (602) of the access network upon request. The monitoring function collects, stores, and analyzes performance data, media conditions and stability data using interpretation filters to derive performance indicators. The conditions of the network are also automatically provided to the resource manager (602) for immediate attention if the access network conditions exceed predetermined thresholds.

Distributed resource management for multi-service, multi-access broadband networks

The mechanisms of neutral dissociation of oxygen molecules in the excitation energy range 15-25 eV have been studied in a dispersed fluorescence experiment. By detecting the fluorescence from excit ...

Jaume Rius i Riu

Papers

Precoder for a communication system and methods used in said communication system

An energy resolved electron-ion coincidence study near the S 2p thresholds of the SF6 molecule

Semiblind Spectrum Balancing for DSL

Distributed resource management for multi-service, multi-access broadband networks

Neutral fragmentation of superexcited oxygen molecules