Large-signal dynamics of an ultrafast semiconductor laser at digital modulation rates approaching 10 Gbit/s

High-fidelity pseudorandom digital modulation at 8.2 Gbit/s of an ultrahigh speed semiconductor laser is demonstrated. Studies using simple but representative pulse patterns at 10 Gbit/s give insights into the maximum digital modulation rate attainable from a given laser, as well as relations between large-signal digital performance and small-signal analog response

SIMULASI SISTEM MODULASI DIGITAL DENGAN DSK TMS320C6713

The continued development of communication systems, particularly in the field of digital modulation requires the practitioners (students) who explore the field of telecommunications to understand more clearly the digital modulation. This final project created a prototype on-board (hardware simulation) digital modulation system using TMS320C6713 DSK board. Making the program using C language software Code Composer Studio (CCS) version 3 is used specifically for programming the TMS320C6713 DSK. Modulation technique that is used for simulation is a digital modulation technique using Binary Phase Shift Keying (BPSK). This final project through several stages that is, put the theories relating to digital modulation systems, created progam simulations than implemente to TMS320C6713 DSK board, and finally analyzed the results of the simulation. Keyword - DSK TMS320C6713, Digital Modulations, BPS

Acquisition of pseudonoise signals by sequential estimation

Rapid Acquisition by Sequential Estimation /RASE/ system is used in the receivers of tracking and communications systems to bring identical locally generated pseudonoise digital modulation signal into time synchronization with the incoming pseudonoise signal. This acquisition system is particularly suited for medium input signal-to-noise ratios

Digital Modulation in Telecommunications

Import 04/07/2011Tématem této práce jsou digitální modulace v telekomunikacích. Řekneme si, co je modulace, dělení na analogové a digitální modulace, kde se zaměříme na typy digitálních modulaci. Popíši amplitudové, frekvenční i fázové klíčování. V další části najdete popis DSL technologií, historický vývoj přes symetrické DSL až po asymetrické. Podrobněji si popíšeme především ADSL. Následně vysvětlím digitální modulace v ADSL. Jsou to CAP modulace, používána do roku 1996 a DMT modulace, která nastoupila na místo CAP a využívá se stále. Praktickou částí je návod na vytvoření vybrané digitální modulace na výukovém stroji TIMS, ve formě laboratorního měření pro studenty, včetně ukázkového protokolu. Praktická část je mnou vytvořena laboratorní práce pro studenty, na výukovém stroji TIMS.The topic in this work is digital modulation in Telecommunications. We will talk about, what is modulation, division on analog and digital modulation, where we focus on digital modulation. I will describe amplitude, frequency and phase shift keying. In second part you will find the describtion of DSL technology, historical evolution from symmetric DSL to asymmetric. I will look in detail on ADSL. Afterwards I will explain digital modulation in ADSL. These are CAP modulation, used till year 1996 and DMT modulation, which takes place instead of CAP, until today. Practical part is guideline on how to create choosen digital modulation on the learning system TIMS in form of laboratory measurement for students, including exemplary protocol.460 - Katedra informatikydobř

Pembuatan Modul Praktikum Teknik Modulasi Digital 8-QAM, 16-QAM, dan 64-QAM dengan Menggunakan Software

Making module digital modulation techniques have been created in such a way as to be used as an experimental module, particularly for digital modulation technique 8-QAM, 16-QAM, and 64-QAM which will be used by students as a means to perform digital modulation technique that practicum of students are expected digital modulation system can be understood more clearly. This final project made by practice module available for description about processing technique in digital modulation clearerly and directional so that of practitioners earning correctness clearly comprehend image of process from delivery and acceptance of technique in digital modulation 8-QAM,16-QAM, and 64-QAM. At this making of visualisation apply MATLAB progamming to can present delivery process result graph and acceptance of technique in 8-QAM,16-QAM, and 64-QAM. keyword : Digital Modulation, 8-QAM,16-QAM, and 64-QAM, MATLA

Advanced digital modulation: Communication techniques and monolithic GaAs technology

Communications theory and practice are merged with state-of-the-art technology in IC fabrication, especially monolithic GaAs technology, to examine the general feasibility of a number of advanced technology digital transmission systems. Satellite-channel models with (1) superior throughput, perhaps 2 Gbps; (2) attractive weight and cost; and (3) high RF power and spectrum efficiency are discussed. Transmission techniques possessing reasonably simple architectures capable of monolithic fabrication at high speeds were surveyed. This included a review of amplitude/phase shift keying (APSK) techniques and the continuous-phase-modulation (CPM) methods, of which MSK represents the simplest case

Flexible digital modulation and coding synthesis for satellite communications

An architecture and a hardware prototype of a flexible trellis modem/codec (FTMC) transmitter are presented. The theory of operation is built upon a pragmatic approach to trellis-coded modulation that emphasizes power and spectral efficiency. The system incorporates programmable modulation formats, variations of trellis-coding, digital baseband pulse-shaping, and digital channel precompensation. The modulation formats examined include (uncoded and coded) binary phase shift keying (BPSK), quatenary phase shift keying (QPSK), octal phase shift keying (8PSK), 16-ary quadrature amplitude modulation (16-QAM), and quadrature quadrature phase shift keying (Q squared PSK) at programmable rates up to 20 megabits per second (Mbps). The FTMC is part of the developing test bed to quantify modulation and coding concepts

Digital modulation of the nickel valence state in a cuprate-nickelate heterostructure

Layer-by-layer oxide molecular beam epitaxy has been used to synthesize cuprate-nickelate multilayer structures of composition (La$_2$CuO$_4$)$_m$/LaO/(LaNiO$_3$)$_n$. In a combined experimental and theoretical study, we show that these structures allow a clean separation of dopant and doped layers. Specifically, the LaO layer separating cuprate and nickelate blocks provides an additional charge that, according to density functional theory calculations, is predominantly accommodated in the interfacial nickelate layers. This is reflected in an elongation of bond distances and changes in valence state, as observed by scanning transmission electron microscopy and x-ray absorption spectroscopy. Moreover, the predicted charge disproportionation in the nickelate interface layers leads to a thickness-dependent metal-to-insulator transition for $n=2$, as observed in electrical transport measurements. The results exemplify the perspectives of charge transfer in metal-oxide multilayers to induce doping without introducing chemical and structural disorder