Synchronization Systems in Communication and Control

Phase-locked loops : design, simulation, and applications ; [including CD with PLL design and simulation software]

Stability and oscillation of dynamical systems : theory and applications

It is a receiver for communication with visible light is provided which may be a communication link from a transmitter to a receiver enlarge, whereby a high transfer speed is realized, the assembly is performed by a simple processing circuit. The receiver for communication with visible light includes a receiving unit that is configured to receive a signal of visible light excited by a blue light white LED, which is driven by a driving current signal in accordance with by adding a rising pulse and a falling pulse rising to a edge and a falling edge of transmission data generated is, the transmission data is encoded according to a DC-free RLL code with a minimum run of 1, and NRZI-modulated are before the rising pulse and the falling pulse are added, a photoelectric converter, which is designed , the signal of visible light that is received by the receiving unit, into an electrical signal, an equalizer adapted to equalize the electric signal generated by the photoelectric converter into a doppelbinares signal, a Diskriminiator formed, the from to distinguish outputted to the equalizer doppelbinare signal to produce a 3-value-ring signal, a maximum likelihood decoder, which is formed, the signal generated by the discriminator 3-value signal ML to-decode to output a decoded signal, and a decoder, the formed is RLL decoding the output from the maximum likelihood decoder decoded signal.

Receiver for communication with visible light communication system using visible light and method for communicating with visible light

Yuldashev, Marat Mathematical Models and Simulation of Costas Loops Jyvaskyla: University of Jyvaskyla, 2013, 72 p.(+included articles) (Jyvaskyla Studies in Computing ISSN 1456-5390; 174) ISBN 978-951-39-5488-8 (nid.) ISBN 978-951-39-5491-8 (PDF) Finnish summary Diss. This work is devoted to the development of nonlinear mathematical models of Costas loops. A Costas loop was invented in 1956 by John P. Costas of General Electric. Nowadays, a Costas loop is widely used in many applications including telecommunication devices, global positioning systems (GPS), medical implants, mobile phones, and other gadgets. Costas loop is a phase-locked loop (PLL) based circuit designed to simultaneously perform two tasks — carrier recovery and data demodulation. To performs both of these tasks it has three non-linear elements. So, Costas loop is more complicated circuit than analog PLLs with only one nonlinear element and therefore requires special techniques for its analysis. All this makes the development of non-linear models of Costas loops a difficult task. For high-frequency signals, used in the modern devices, the transient time is thousands of times greater than the signal’s periods. This property of Costas loop further complicates the application of analytical methods and numerical simulation. Also the signal waveforms involved greatly affect the behaviour of Costas circuits. In this work, nonlinear mathematical models of the BPSK Costas loop and the Quadrature Phase Shift Keying (QPSK) Costas loop have been developed. These models allow to facilitate the application of analytical methods and reduce the numerical simulation time, which is a practically relevant significant problem. All theoretical results are rigorously proved. An effective numerical procedure for the simulation of Costas loops based on the phase-detector characteristics is proposed.

Mathematical models and simulation of Costas loops

Yuldashev, Renat Synthesis of Phase-Locked Loop: analytical methods and simulation Jyväskylä: University of Jyväskylä, 2013, 50 p.(+included articles) (Jyväskylä Studies in Computing ISSN 1456-5390; 175) ISBN 978-951-39-5487-1 (nid.) ISBN 978-951-39-5490-1 (PDF) Finnish summary Diss. One of the main approaches for PLL analysis is the numerical simulation of the models on the level of electronic realization. It is a challenging task, because the frequency of oscillators in modern computers and communication systems can reach up to several gigahertz. However, the frequency of the loop bandwidth may be only multiple of kilohertz. This 3 to 6 order of magnitude difference in frequencies makes simulation of PLL very difficult. To overcome these difficulties, a special mathematical model of phase-locked loop, in which only slow time scale of signals phases and frequencies is considered. That, in turn, requires to construct mathematical model of all components of the PLL. One of the main components of the PLL is a phase detector, whose operation depends on the waveforms of considered signals. In this work a general approach for analytical calculation of phase detector characteristic for classical phase-locked loop for various signal waveforms is proposed. Obtained PLL and PLL with a squarer models allow to use phase-frequency model for PLL, thereby significantly reducing time required for numerical simulation.

Renat Yuldashev

Papers

Synthesis of phase-locked loop : analytical methods and simulation