• Phonetics and Speech Sciences
• /
• v.10 no.4
• /
• pp.121-125
• /
• 2018

This paper describes procedures of changing and measuring voice quality in terms of jitter. Jitter synthesis method was applied to the TD-PSOLA analysis system of the Praat software. The jitter component is synthesized based on a Gaussian random noise model. The TD-PSOLA re-synthesize process is used to synthesize the modified voice with artificial jitter. Various vocal jitter parameters are used to measure the change in quality caused by artificial systematic jitter change. Synthetic vowels, natural vowels and short sentences are used to check the change in voice quality through the synthesizer model. The results shows that the suggested method is useful for voice quality control in a limited way and can be used to alter the jitter component of voice.

• Journal of Broadcast Engineering
• /
• v.16 no.5
• /
• pp.722-737
• /
• 2011

In this paper, we propose an estimation of network jitter that occurs when transmitting TCP packets containing MPEG-2 TS in progressive streaming service over wired or wireless Internet networks. Based on the estimated network jitter size, we can calculate required de-jitter buffering time to absorb the network jitter at the receiver side. For this purpose, by exploiting the PCR timestamp existing in the TS packet header, we create a new timestamp information that is marked in the optional field of TCP packet header to estimate the network jitter. By using the proposed de-jitter buffering scheme, it is possible to employ the conventional T-STD buffer model without any modification in the progressive streaming service over IP networks. The proposed method can be applicable to the recently developed international standard, MPEG DASH (dynamic adaptive streaming over HTTP) technology.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.5 no.7
• /
• pp.1295-1300
• /
• 2001

This paper presents the system that decreases the Jitter value having an important effect for signal quality in optical disc memory. Level controller of input signal was made and applied to line between format generator and laser beam recorder of DVD. This try means to decrease jitter value without adjustment for many kinds of mastering process. Experimental results show that the jitter value is about 6.9%.

• Journal of Communications and Networks
• /
• v.6 no.2
• /
• pp.182-191
• /
• 2004

In this paper, performances of different ultra-wideband (UWB) modulation schemes in the presence of timing jitter are evaluated and compared. Static and Rayleigh fading channels are considered. For fading channels, Oat and dispersive channels are assumed. First, bit error rate (BER) performances for each case are derived for a fixed value of timing jitter. Later, a uniform distribution of jitter is assumed to evaluate the performance of the system, and the theoretical results are verified by computer simulations. Finger estimation error is treated as timing jitter and an appropriate model is generated. Furthermore, a worst case distribution that provides an upper bound on the system performance is presented and compared with other distributions. Effects of timing jitter on systems employing different pulse shapes are analyzed to show the dependency of UWB performance on pulse shape. Although our analysis assumes uniform timing jitter, our framework can be used to evaluate the BER performance for any given probability distribution function of the jitter.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.2
• /
• pp.298-302
• /
• 2006

Models for the phase noise and jitter of the ring oscillator with the power supply noise are suggested and verified by simulations. The power supply noise is converted into the phase-noise by the narrow band phase modulation. The phase-noise appears as sideband frequencies apart from the center frequency of the ring oscillator as much as the frequency of the power supply noise. A jitter model describing the linear relation of jitter with the amplitude of the power supply noise is suggested and verified by simulation.

• The KIPS Transactions:PartC
• /
• v.10C no.4
• /
• pp.455-462
• /
• 2003

Techniques for the reduction of SRTS jitter and pointer adjustment jitter are studied. To reduce the stuffing jitter several methods have been proposed, such as bit leaking, stuff threshold modulation and sigma delta modulation. The characteristics of jitter generated in SRTS and pointer adjustment systen implementing these reduction techniques is analyzed with computer simulation. The results show that ms jitter value decreases to less than 50% as compared to a conventional pointer adjustment system. The amplitude of SRTS jitter using new techniques decreases or Increases dependent on system parameter.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.8
• /
• pp.1713-1718
• /
• 2004

It has been known that 1/f noise of MOSFET is generated by the superposition of single random telelgraph signals (RTS). In this study, jitters caused by 1/f noise of MOSFET are analysed with RTS supplied to all of the nodes of the CMOS ring oscillator under investigation. Through the analysis of the variations of jitters and jitter ratios with varying values of the amplitude of RTS, it is found that the jitters and the jitter ratios are proportional to the amplitude of RTS. And the analysis of FFT of the outputs of the ring oscillator reveals that the jitters are closely related to the phase noise of the high order harmonics of the ring oscillator outputs.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2004.05b
• /
• pp.682-684
• /
• 2004

The effect of 1/f noise by the random telegraph signal(RTS) on the phase noise and the jitter of CMOS ring Oscillator is investigated. 10 parallel piece-wise-linear current sources connected to each node model the RTS signals. The In, the power spectral density and the jitter of output of the ring oscillator are simulated as functions of the amplitude and time constant of RTS current source. It is confirmed that the increase of amplitude of RTS is directly related to the increase of the width of phase noise md the value of jitter. The shorter the time constant is, the wider width of FET peak and the larger value of cycle to cycle jitter are.

• Journal of IKEEE
• /
• v.25 no.2
• /
• pp.234-242
• /
• 2021

In case implementation of microwave photonic (MWP) systems for phased array radars (PARs), noise and time delay error should be minimized to obtain accurate beam direction. Time delay error in MWP systems is generated from signal noise and timing jitter. In this paper, noise and timing jitter in MWP systems for PAR is researched, also according to the amplification of an erbium-doped fiber amplifier, noise and timing jitter variation is verified by an experiment. Timing jitter is decreased and SNR is increased if we amplify the signal by using an erbium-doped fiber amplifier, up to the amplification rate of signal and noise is similar.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.23 no.5
• /
• pp.867-871
• /
• 2013

In this paper, a major factor in determining voice quality that corresponds to the jitter and jitter buffer algorithm for removing jitter will be described. We analyze various jitter buffer algorithms and suggest ways to improve performance of jitter buffer algorithm.