Radio over Fiber Transceiver's Architectures for Wireless and Satellite Communications
Notice bibliographique
Résumé
The development of the fifth-generation (5G), and beyond, of wireless communications motivates researchers to design innovative architectures in order to guarantee the delivery of data rate as high as 10 Gbps. The existing 4G wireless access architectures broadcast radio frequency (RF) signals below 6 GHz. This congestion in the available spectrum limits the data speed to a few hundred Mbps. Researchers investigated the option of using millimeter wave (mm-wave) between 30-300 GHz as wireless carriers to broadcast and transmit signals with data speed up to 10 Gbps and higher. The need for an efficient wire or wireless broadband link between base stations is vital to allow a variety of applications and services (like interactive HD TV, internet video, augmented reality, vehicle telematics, high-speed train, the wireless cloud office, etc.) to be delivered simultaneously and seamlessly. Using lasers in generating mm-wave carriers is still an active area of research since the 1990s, due to its overall design simplicity and efficiency. By modulating laser light, using a radio-frequency signal, it becomes possible to transmit the latter over standard optical fiber cables, for which the loss in the telecommunication band is as low as 0.2 dB/km. Radio-over- fiber (RoF) technology combines the advantages of radio and photonic devices. RoF technology, therefore, allows extending the distance between central stations and wireless end-users, thus maximizing the coverage of micro-cell and macro-cell based networks. In addition, photonics and RoF can be seen as enabling technologies to generate radio signals at mm-wave frequencies in a cost-effective manner. Hence, RoF technology will lead to reduced Capital Expenditure (CAPEX), and Operational Expenditure (OPEX), compared to traditional all-electronic networks. The electrical-optical-electrical conversion process in RoF links inevitably comes with impairments that degrade the signal quality. Simpler setups, using cheaper off-the-shelf components, can still lead to an acceptable performance by boosting the input RF signal power before optical modulation. Amplification of the RF signal carried by optical fiber is commonly adopted to minimize the impact of photo-detection noise on the dynamic range at the receiver. Unfortunately, this amplification causes the RoF system to behave non-linearly, leading to distortions during the electrical-optical-electrical conversion process that degrades the overall signal quality. To overcome this problem and linearize the RoF link, in this thesis, we propose a novel full-duplex RoF transceiver (TRx) architecture, augmented with an effective digital predistortion (DPD) technique to mitigate the non-linearities of the RoF TRx using a memory polynomial (MP) model. This thesis deals with the implementation of RoF TRx and provides solutions to some of the observed impairments in the electro-optical systems. In the first phase of the research project, the design of a single RoF fronthaul downlink transmitter is built and supported by experimental validation. The second phase of the project is conducted to enhance and upgrade the capability of RF signal generation and bandwidth of the RoF TRx. The third phase is focused on the establishment of a bidirectional link between central baseband unit (BBU) to remote radio head (RRH) and to integrate it with a free-space optics. The fourth phase is accomplished by building dynamic DPD models, which provide on-line feedback information from the RRHs through an established pre-calibrated observation path.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».