About: Jitter is a(n) research topic. Over the lifetime, 22644 publication(s) have been published within this topic receiving 245586 citation(s). The topic is also known as: signal jitter & timing jitter.
01 Nov 1996-
Abstract: Delay-locked loop (DLL) and phase-locked loop (PLL) designs based upon self-biased techniques are presented. The DLL and PLL designs achieve process technology independence, fixed damping factor, fixed bandwidth to operating frequency ratio, broad frequency range, input phase offset cancellation, and, most importantly, low input tracking jitter. Both the damping factor and the bandwidth to operating frequency ratio are determined completely by a ratio of capacitances. Self-biasing avoids the necessity for external biasing, which can require special bandgap bias circuits, by generating all of the internal bias voltages and currents from each other so that the bias levels are completely determined by the operating conditions. Fabricated in a 0.5-/spl mu/m N-well CMOS gate array process, the PLL achieves an operating frequency range of 0.0025 MHz to 550 MHz and input tracking jitter of 384 ps at 250 MHz with 500 mV of low frequency square wave supply noise.
01 Jun 1999-IEEE Journal of Solid-state Circuits
Abstract: A companion analysis of clock jitter and phase noise of single-ended and differential ring oscillators is presented. The impulse sensitivity functions are used to derive expressions for the jitter and phase noise of ring oscillators. The effect of the number of stages, power dissipation, frequency of oscillation, and short-channel effects on the jitter and phase noise of ring oscillators is analyzed. Jitter and phase noise due to substrate and supply noise is discussed, and the effect of symmetry on the upconversion of 1/f noise is demonstrated. Several new design insights are given for low jitter/phase-noise design. Good agreement between theory and measurements is observed.
01 Jun 2007-Nature Photonics
TL;DR: The keys generated in the first quantum key distribution experiment to enable the creation of secure keys over 42 dB channel loss and 200 km of optical fibre are secure against both general collective attacks on individual photons and a specific collective attack on multiphotons.
Abstract: We report the first quantum key distribution (QKD) experiment to enable the creation of secure keys over 42 dB channel loss and 200 km of optical fibre. We used the differential phase shift QKD (DPS-QKD) protocol, implemented with a 10-GHz clock frequency and superconducting single-photon detectors (SSPD) based on NbN nanowires. The SSPD offers a very low dark count rate (a few Hz) and small timing jitter (60 ps, full width at half maximum, FWHM). These characteristics allowed us to achieve a 12.1 bit s–1 secure key rate over 200 km of fibre, which is the longest terrestrial QKD over a fibre link yet demonstrated. Moreover, this is the first 10-GHz clock QKD system to enable secure key generation. The keys generated in our experiment are secure against both general collective attacks on individual photons and a specific collective attack on multiphotons, known as a sequential unambiguous state discrimination (USD) attack.
01 May 1976-IEEE Transactions on Communications
TL;DR: A new class of fast-converging timing recovery methods for synchronous digital data receivers is investigated, and a general method is outlined to obtain near-minimum-variance estimates of the timing offset with respect to a given steady-state sampling criterion.
Abstract: A new class of fast-converging timing recovery methods for synchronous digital data receivers is investigated. Starting with a worst-case timing offset, convergence with random binary data will typically occur within 10-20 symbols. The input signal is sampled at the baud rate; these samples are then processed to derive a suitable control signal to adjust the timing phase. A general method is outlined to obtain near-minimum-variance estimates of the timing offset with respect to a given steady-state sampling criterion. Although we make certain independence assumptions between successive samples and postulate ideal decisions to obtain convenient analytical results, our simulations with a decision-directed reference and baud-to-baud adjustments yield very similar results. Convergence is exponential, and for small loop gains the residual jitter is proportional and convergence time is inversely proportional to the loop gain. The proposed algorithms are simple and economic to implement. They apply to binary or multilevel PAM signals as well as to partial response signals.
19 Aug 2002-
TL;DR: An end-to-end methodology, called Self-Loading Periodic Streams (SLoPS), for measuring avail-bw, and the relation between avail- bw and TCP throughput is examined.
Abstract: The available bandwidth (avail-bw) in a network path is of major importance in congestion control, streaming applications, QoS verification, server selection, and overlay networks. We describe an end-to-end methodology, called Self-Loading Periodic Streams (SLoPS), for measuring avail-bw. The basic idea in SLoPS is that the one-way delays of a periodic packet stream show an increasing trend when the stream's rate is higher than the avail-bw. We implemented SLoPS in a tool called pathload. The accuracy of the tool has been evaluated with both simulations and experiments over real-world Internet paths. Pathload is non-intrusive, meaning that it does not cause significant increases in the network utilization, delays, or losses. We used pathload to evaluate the variability ('dynamics') of the avail-bw in some paths that cross USA and Europe. The avail-bw becomes significantly more variable in heavily utilized paths, as well as in paths with limited capacity (probably due to a lower degree of statistical multiplexing). We finally examine the relation between avail-bw and TCP throughput. A persistent TCP connection can be used to roughly measure the avail-bw in a path, but TCP saturates the path, and increases significantly the path delays and jitter.