FPGA implementation of Reed Solomon codec for 40Gbps Forward Error Correction in optical networks

Reed-Solomon error correcting codes (RS codes) are widely used in communication and data storage systems to recover data from possible errors that occur during data transfer. A growing application of RS codes is Forward Error Correction (FEC) in the Optical Network (OTN G.709), which uses RS(255,239) to support the OTU-3 (43.018 Gbps) standard. There have been considerable efforts in the area of RS architecture for ASIC implementation. However, there appears to be little reported work on efficient RS codec (encoder and decoder) for Field Programmable Gate Arrays (FPGAs), which has increasing interests in industry. This thesis investigates the implementation and design methodology of the RS(255,239) codec on FPGAs. A portable VHDL code is developed and synthesized for Xilinx\u27s Virtex4 and Altera\u27s StratixII. The FPGA architectures are analyzed and the required design methodologies are adopted to efficiently utilize the available resources. Unfortunately, due to the fixed size of FPGA devices, the RS decoder is not only constrained by the required timing of the system, but also by the size of the targeted device. This research will facilitate the decision-making process for selecting a reconfigurable device for a RS decoder, implementing the Berlekamp-Massey Algorithm

Conception au niveau système de l'application de protocole sans fil WIMAX

RÉSUMÉ Communiquer est le principe même de l'homme. Au l des siècles les modes de communication ont beacoup évolué passant d'un simple échange vocal entre deux personnes à un échange via des appareils (téléphones, ordinateurs,..) d'où la naissance des systèmes de télécommunication. La technologie sous-jacente tient à l'implantation de réseaux de communication qui sont les noyaux de la communication. C'est ainsi que de nos jours on a des réseaux internet, de téléphonie, de télévision, etc. Avec l'évolution des civilisations et l'expansion démographique, on cherche désormais à minimiser la surface occupée par ces réseaux tout en maintenant la même qualité de service. On assiste ainsi à l'émergeance de nouveaux réseaux de communication sans aucune interconnexion laire. Le Wimax est l'une de ces technologies émergeantes. Grâce à ses techniques de modulation telles que l'OFDM, elle permet une meilleure qualité de service que les réseaux existants. Elle est ainsi utilisée pour de nombreuses applications telles que la communication par vidéo conférence (VoIP), un accès étendu à internet, aux hotspot wi et aux réseaux cellulaires . Le problème qui se pose est de savoir comment implanter de nouveaux réseaux de façon rapide et ecace tout en respectant les contraintes de coûts et de temps de conception liées au marché.----------ABSTRACT Now a days, Wireless systems are everywhere. They had a tremendous growth in recent years. From personnal area networks like bluethooth to local networks like Wi, most of the communications systems contains wireless systems which have dierents networks and users. A major problem of these systems is the interoperability and deployment of wireless networks. This is why a lot of research are made to nd solutions and Wimax is one of them. Wimax (wireless interoperability for microwave access) is a metropolitan area network which use dierent transmission mode for pmp or mesh links to portable access due to OFDM modulation. With the improvement of Wireless technology and because of the tight costs and time-to-market constraints, the main challenge is to get fast and ecient design method. To meet these requirements, a method of conception, ESL is mainly used. In this report, a design process of the physical layer of the IEEE 802.16 standard with the OFDM modulation using an ESL Eclipse-based platform of software/hardware platform is presented. This ESL environment, with his integrated tools, build embedded applications and architectures by rening the transaction-level communications to some pin and cycle-accurate protocols as well as the generation of synthesizable hardware from the system-level specications. Those tools automate creation and modication of modules in an ESL design ow and make abstraction of all the implementation details to built an ESL architecture. The main contribution of this work is the multilevel design on baseband of the PHY-OFDM layer of the IEEE 802.16 standard using an ESL (electronic system Level) environnement of software/hardware partitionning and the use of a multisystem cosimulation technique between the ESL model built with the SpaceStudio platform and a model built on Simulink for validation through cosimulation interfaces of heterogeous systems