LTE transmission exploiting pulse width modulation in fibre optic links

Recently it has been demonstrated that pulse width modulation (PWM) can represent a viable solution for the analog optical fronthaul alternative to standard radio over fibre, which still avoids the bandwidth expansion of the digital fronthaul. The PWM encodes the analog samples at the transmitter onto the duration of the on/off keyed optical signal, splitting the sampling and quantization of the radio signal between remote radio units (RRUs) and baseband units (BBUs). In particular in this contribution we demonstrate the capabilities of optical PWM for the transport of LTE signals to support the centralized access network (C-RAN) fronthaul in fibre optic link up to 10-km of standard single mode fibre. The generation and analysis of the radio signals is provided by software modules compliant with the LTE standard which allowed to analyse performance results for the different LTE carriers, channels and services. The PWM optical signal connecting RRUs to BBUs is generated by either directly modulating a DFB laser or an externally seeded reflective semiconductor optical amplifier (RSOA). Both devices could be exploited inside a wavelength division multiplexed passive optical network (WDM PON) architecture where the various RRU-to-BBU links are pooled through virtual point-to-point connections at different wavelengths

Modulation and Equalization Techniques for mmWave ARoF

Fifth generation (5G) is the emerging mobile communications platform that aims to meet the market requirements in terms of enhanced broadband connectivity based on harnessing small cell and mmWave technology. These two in synergy will provide high capacity gain not only through the hyperdense deployment of small cell but also through accessing large swathes of untapped spectrum at mmWave frequencies. The envisaged architecture entails an integrated optical wireless network architecture, where optical technology will complement radio in order to handle the new demands on capacity over the backhaul and fronthaul network, leading to the notion of analog radio over fiber (ARoF). The goal of this chapter is to provide novel approaches to optimize the performances of mmWave ARoF systems that includes developing enabling technology from a digital to signal processing (DSP) and device perspective

Analysis of a framework implementation of the transceiver performances for integrating optical technologies and wireless LAN based on OFDM-RoF

The greatest advantages of optical fibers are the possibility of extending data rate transmission and propagation distances. Being a multi-carrier technique, the orthogonal frequency division multiplexing (OFDM) can be applicable in hybrid optical-wireless systems design owing to its best spectral efficiency for the interferences of radio frequency (RF) and minor multi-path distortion. An optical OFDM-RoF-based wireless local area network (W-LAN) system has been studied and evaluated in this work. The outline for integrating an optical technology and wireless in a single system was provided with the existence of OFDM-RoF technology and the microstrip patch antenna; these were applied in the Optisystem communication tool. The design of the proposed OFDM-RoF system is aimed at supporting mm-wave services and multi-standard operations. The proposed system can operate on different RF bands using different modulation schemes like 4,16 and 64QAM, that may be associated to OFDM and multidata rates up to 5 Gbps. The results demonstrate the robustness of the integrated optical wireless link in propagating OFDM-RoF-based WLAN signals across optical fibers

High Dimensional Modulation and MIMO Techniques for Access Networks

Exploration of advanced modulation formats and multiplexing techniques for next generation optical access networks are of interest as promising solutions for delivering multiple services to end-users. This thesis addresses this from two different angles: high dimensionality carrierless amplitudephase (CAP) and multiple-input multiple-output (MIMO) radio-over-fiber (RoF) systems. High dimensionality CAP modulation has been investigated in optical fiber systems. In this project we conducted the first experimental demonstration of 3 and 4 dimensional CAP with bit rates up to 10 Gb/s. These results indicate the potentiality of supporting multiple users with converged services. At the same time, orthogonal division multiple access (ODMA) systems for multiple possible dimensions of CAP modulation has been demonstrated for user and service allocation in wavelength division multiplexing (WDM) optical access network. 2 x 2 MIMO RoF employing orthogonal frequency division multiplexing (OFDM) with 5.6 GHz RoF signaling over all-vertical cavity surface emitting lasers (VCSEL) WDM passive optical networks (PONs). We have employed polarization division multiplexing (PDM) to further increase the capacity per wavelength of the femto-cell network. Bit rate up to 1.59 Gbps with fiber-wireless transmission over 1 m air distance is demonstrated. The results presented in this thesis demonstrate the feasibility of high dimensionality CAP in increasing the number of dimensions and their potentially to be utilized for multiple service allocation to different users. MIMO multiplexing techniques with OFDM provides the scalability in increasing spectral effciency and bit rates for RoF systems. High dimensional CAP and MIMO multiplexing techniques are two promising solutions for supporting wired and hybrid wired-wireless access networks

High Data Rate Coherent Optical OFDM System for Long-Haul Transmission

The growth in internet traffic has driven the increase in demand for bandwidth and high data rates. Optical Orthogonal Frequency Division Multiplexing is considered as a promising technology to satisfy the increased demand for bandwidth in broadband services. Optical OFDM received a great attention after proposing it as a modulation technique for the long-haul transmission in both direct and coherent detection. However, Coherent Optical OFDM (CO-OFDM) is the next generation technology for the optical communications, since it integrates the advantages of both coherent systems and OFDM systems. It has the ability to overcome many optical fiber restrictions such as chromatic dispersion (CD) and polarization mode dispersion (PMD). Moreover, Integrating the Coherent Optical OFDM with Wavelength Division Multiplexing (WDM) systems will provide the transmission system with a high bandwidth, a significant data rates, and a high spectral efficiency without increasing the cost or the complexity of the system. WDM systems help to enhance the capacity and the data rate of the system by sending multiple wavelengths over a single fiber. This research focuses on the implementation and performance analysis of high data rate coherent optical OFDM for long-haul transmission. The study starts with a single user and extends to the implanting of the WDM system. OptiSystem-12 simulation tool is fully used to design and implement the system. The system utilizes to carry range of data rates start from 10 Gbps to 1 Tbps, 4-QAM (2 bits-per-symbol) is used a modulation type for the OFDM signal, Optical I/Q modulation is employed at the transmitter and coherent detection is employed at the receiver. The performance of the system is studied and analyzed system in terms of Bit-Error-Rate (BER), the effect of the transmission distance on the Optical-Signal-to-Noise-Ratio (OSNR), and the relation of BER and OSNR with regard to the transmission distance

Photonic Modulation and Demodulation techniques for Multi-Gb/s Millimetre wave Wireless Links

Los sistemas de radio sobre fibra(Radio Over fibre ROF) ofrecen el ancho de banda y flexibilidad necesario para la generación y distribución de del señales inalámbricas del futuro en una arquitectura de red óptica, que reduce el coste de las redes centralizando el procesado y simplificando la ubicación de la antena (estación de base EB). El uso de sistemas de comunicaciones ópticas como una media de transporte de señales inalámbricas en enlaces RoF reduce el cuello de botella entre los estándares de acceso inalámbrico y cableado en un dominio convergente óptico. Las redes de acceso ópticas están evolucionando con capacidades de hasta 10 Gb/s con el estándard 10GEPON, dejando un cuello de botella entre tecnologías de acceso inalámbrico y óptico. . Eso ha motivado gran esfuerzo de investigación en la generación y distribución de señales inalámbricas de alta capacidad (> 10 Gb/s) basada en RoF. En esta tesis se ha investigado el uso de técnicas fotónicas para la generación , distribución y demodulación de señales inalámbricas moduladas vectorialmente. Esta tesis está principalmente dedicada a la generación de señales inalámbricas espectralmente eficientes como la modulación de fase en cuadratura (QPSK) o modulación de amplitud cuadratura de multinivel (M-QAM). El trabajo presentado en esta tesis está clasificado en dos partes: la primera de ellas trata de las técnicas fotónicas que utilizan señales eléctricas coherente para la generación y demodulación de señales inalámbricas, mientras la segunda parte trata de usar señales ópticas incoherentes. En la primera parte de la tesis, están presentadas diferentes arquitecturas de sistemas y están analizadas numéricamente, y demostradas experimentalmente. Un nuevo concepto denominado "modulación vectorial fotónica" (PVM) es propuesto para la generación de señales inalámbricas con una modulación M-QAM. Basado en esta técnica se presenta la generación de señales de capacidad 10Gb/s con una modulación de QPSK y 16-QAM.Sambaraju -, R. (2010). Photonic Modulation and Demodulation techniques for Multi-Gb/s Millimetre wave Wireless Links [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8857Palanci