Chaotic receivers for optical communication systems

El objetivo de esta tesis concierne al estudio de sistemas de detección de señales enmascaradas en entornos ruidosos. En concreto para escenarios hibridos de comunicaciones wireless que conectan con redes ópticas. Se propone la implementación de un sistema caótico como alternativa a los métodos de detección deterministas. Este sistema estará basado en un receptor Duffing no lineal de segundo orden. Se pretende implementar y caracterizar un receptor caótico para la detección de señales binarias (ASK, PSK y FSK). Además, se propondrá una modificación del sistema de recepción caótico Duffing con respecto a su implementación convencional. Con objeto de evaluar el rendimiento en términos de Bit Error Ratio (BER) y relación señal a ruido (SNR), se presentarán diferentes métodos para la decisión de símbolos. Estos métodos habrán de estar implementados a continuación de nuestro receptor caótico y junto con este último, compondrán el receptor de nuestro sistema. Una vez implementado el receptor, se llevarán a cabo una serie de simulaciones con objeto de comparar el rendimiento del sistema de recepción caótico Duffing frente a los métodos de demodulación estandar. Finalmente, se realizará un montaje óptico en el laboratorio para escenarios de radio sobre fibra a fin de demostrar experimentalmente los resultados obtenidos en las simulaciones. Este estudio se centrará en analizar aquella simulación que anteriormente hubiese resultado más ventajosa con respecto a los métodos de demodulación estandar

Fiber-wireless links supporting high-capacity W-band channels

Seamless convergence of fiber-optic and the wireless networks is of great interest for enabling transparent delivery of broadband services to users in different locations, including both metropolitan and rural areas. Current demand of bandwidth by end-users, especially using mobile devices, is seeding the need to use bands located at the millimeter-wave region (30-300 GHz), mainly because of its inherent broadband nature. In our lab, we have conducted extensive research on high-speed photonic-wireless links in the V-band (50-75GHz) and the W-band (75-110GHz). In this paper, we will present our latest findings and experimental results on the W-band, specifically on its 81-86GHz sub-band. These include photonic generation of millimeter-wave carriers and transmission performance of broadband signals on different types of fibers and span lengths. Seamless convergence of fiber-optic and the wireless networks is of great interest for enabling transparent delivery of broadband services to users in different locations, including both metropolitan and rural areas. Current demand of bandwidth by end-users, especially using mobile devices, is seeding the need to use bands located at the millimeter-wave region (30-300 GHz), mainly because of its inherent broadband nature. In our lab, we have conducted extensive research on high-speed photonic-wireless links in the V-band (50-75GHz) and the W-band (75-110GHz). In this paper, we will present our latest findings and experimental results on the W-band, specifically on its 81-86GHz sub-band. These include photonic generation of millimeter-wave carriers and transmission performance of broadband signals on different types of fibers and span lengths

Simultaneous optical carrier and radio frequency re-modulation in radio-over-fiber systems employing reflective SOA modulators

We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data remodulation, thus avoiding the use of local radiofrequency oscillator at the station sites

Resource Management in Converged Optical and Millimeter Wave Radio Networks: A Review

Three convergent processes are likely to shape the future of the internet beyond-5G: The convergence of optical and millimeter wave radio networks to boost mobile internet capacity, the convergence of machine learning solutions and communication technologies, and the convergence of virtualized and programmable network management mechanisms towards fully integrated autonomic network resource management. The integration of network virtualization technologies creates the incentive to customize and dynamically manage the resources of a network, making network functions, and storage capabilities at the edge key resources similar to the available bandwidth in network communication channels. Aiming to understand the relationship between resource management, virtualization, and the dense 5G access and fronthaul with an emphasis on converged radio and optical communications, this article presents a review of how resource management solutions have dealt with optimizing millimeter wave radio and optical resources from an autonomic network management perspective. A research agenda is also proposed by identifying current state-of-the-art solutions and the need to shift all the convergent issues towards building an advanced resource management mechanism for beyond-5G

Digital coherent detection of multi-gigabit 16-QAM signals at 40 GHz carrier frequency using photonic downconversion

We experimentally demonstrate detection of multi-gigab it 16-QAM modulated signals, of up to 4 Gb/s at a 40 GHz carrier frequency by combining photonic downconversion and low bandwidth electronics We experimentally demonstrate detection of multi-gigabit 16-QAM modulated signals, of up to 4 Gb/s, at a 40 GHz carrier frequency by combining photonic downconversion and low bandwidth electronics

Implementation of Entropically Secure Encryption: Securing Personal Health Data

Entropically Secure Encryption (ESE) offers unconditional security with shorter keys compared to the One-Time Pad. In this paper, we present the first implementation of ESE for bulk encryption. The main computational bottleneck for bulk ESE is a multiplication in a very large finite field. This involves multiplication of polynomials followed by modular reduction. We have implemented polynomial multiplication based on the gf2x library, with some modifications that avoid inputs of vastly different length, thus improving speed. Additionally, we have implemented a recently proposed efficient reduction algorithm that works for any polynomial degree. We investigate two use cases: X-ray images of patients and human genome data. We conduct entropy estimation using compression methods whose results determine the key lengths required for ESE. We report running times for all steps of the encryption. We discuss the potential of ESE to be used in conjunction with Quantum Key Distribution (QKD), in order to achieve full information-theoretic security of QKD-protected links for these use cases