Signal processing with frequency and phase shift keying modulation in telecommunications

Abstract

In this paper represents research improving effectiveness of signal processing in telecommunication devices especially for its part, which relates to providing its noise resistance in conditions of noise and interference. This objective has been achieved through development of methods and means for optimization of filtering devices and semigraphical interpretation of clock synchronization systems in telecommunications with frequency shift keying on the base of stochastic models what determines relevance of the subject. Separately, in an article considered the urgent task is using of modified synchronization methods based on the interference influence of adjacent symbols on the phase criterion tract, in particular the use of the modified synchronization scheme, in order to get a formalized outlook representation of the synchronization schemas based on the polyphase structures with using a bank of filters, that allows to improve the characteristics of digital telecommunication channels. This work is devoted to the examination and modeling of these ways. The proposed ideas and results for the construction of synchronization systems can be used in modern means of telecommunication.

Methodology for Assessing Synchronization Conditions in Telecommunication Devices

“…In article [1], [7], a stochastic model of a synchronization system was proposed. Model of synchronization system is described by stochastic equations in accordance to the scheme Fig.…”

“…The purpose of characters synchronization is to create N samples at the output of the matched filter for each character interval so that one of the samples is aligned with the maximum opening of the eye-diagram [7]. A sample rate of the received signal u(t) is received at a fixed rate 1/T, which is asynchronous with the rate of symbols transmission.…”

“…The timing error detector requires at least two samples per symbol, one of which is the point where a decision can be made. The Gardner timing error detector is based on the detection of zero crossing on eye diagrams and is designed to work with BPSK and QPSK [7].…”

“…The effectiveness of data transmission lowers consequently because of losses in transmission of data required for not only synchronization but also for the signal search time and transition onto monitoring mode for all synchronization systems of the receiver. This raises the question of improving synchronization system especially in ASTESJ ISSN: 2415-6698 case of using in communication systems frequency, phase and quadrature methods of digital modulation [7]- [9]. Papers [4,5] represent linear and nonlinear analysis of clock synchronization devices.…”

Evaluation of the Influence Interpolation and Decimation Conditions on the Energy Gain in Means Telecommunications With Phase Shift Keying

“…Для детекторів з узгодженим фільтром тактовий сигнал використовується для визначення моментів, коли вихідний сигнал узгодженого фільтра повинен бути дискретизований. Нехай прийнятий сигнал визначається виразом [6,7] Діаграма сузір'я перед синхронізатором символів показує вплив змінної часової помилки [10]. Оскільки помилка синхронізації змінюється з часом, сузір'я коливається між пошкодженим і вірним станами.…”