Narrow filtered DPSK implements order-1 CAPS optical line coding

A novel family of optical line codes has been presented elsewhere, here referred to as combined amplitude-phase shift (CAPS) codes. We show here that narrow filtering of a differential phase shift keying signal with bandwidth equal to about 2/3 of the bit rate turns out to closely implement the order-1 CAPS line coding. Performance of the two systems is compared for various types of optical filters

Optical Time-Frequency Packing: Principles, Design, Implementation, and Experimental Demonstration

Time-frequency packing (TFP) transmission provides the highest achievable spectral efficiency with a constrained symbol alphabet 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 issues are discussed, focusing on those aspects which are peculiar to TFP systems. In particular, adaptive compensation of propagation impairments, matched filtering, and maximum a posteriori probability detection are obtained by a combination of a butterfly equalizer and four 8-state parallel Bahl-Cocke-Jelinek-Raviv (BCJR) detectors. A novel algorithm that ensures adaptive equalization, channel estimation, and a proper distribution of tasks between the equalizer and BCJR detectors is proposed. A set of irregular low-density parity-check codes with different rates is designed to operate at low error rates and approach the spectral efficiency limit achievable by TFP at different signal-to-noise ratios. An experimental demonstration of the designed system is finally provided with five dual-polarization QPSK-modulated optical carriers, densely packed in a 100 GHz bandwidth, employing a recirculating loop to test the performance of the system at different transmission distances.Comment: This paper has been accepted for publication in the IEEE/OSA Journal of Lightwave Technolog

UX Evaluation of a Tractor Cabin Digital Twin Using Mixed Reality

Understanding user experience (UX) is essential to design engaging and attractive products, so nowadays has emerged an increasingly interest in user- centred design approach; in this perspective, digital technologies such as Virtual Reality (VR) and Mixed Reality (MR) could help designers and engineers to create a digital prototype through which the user feedback can be considered during the product design stage. This research aims at creating an interactive Digital Twin (DT) using MR to enable a tractor driving simulation and involve real users to carry out an early UX evaluation, with the scope to validate the design of the control dashboard through a transdisciplinary approach. MR combines virtual simulation with real physical hardware devices which the user can interact with and have control through both visual and tactile feedback. The result is a MR simulator that combines virtual contents and physical controls, capable of reproducing a plowing activity close to reality. The principles of UX design was applied to this research for a continuous and dynamic UX evaluation during the project development