Eye Jitter Research Articles

A 2.1-Gb/s 12-Channel Transmitter With Phase Emphasis Embedded Serializer for 55-in UHD Intra-Panel Interface

Phase and amplitude emphasis are combined in a 2.1-Gb/s 12-channel transmitter for ultra-high definition (UHD) intra-panel interface. The transmitter performs phase emphasis within the final 2:1 stage of its 20:1 serializer. This reduces data-dependent jitter (DDJ) without increasing IO capacitance by making the timing of bit transitions depend on the previous data. We have also proved the compensation effect of this emphasis by a mathematical analysis. The low-voltage differential signaling (LVDS) driver in the transmitter can accommodate a 300-mV variation in common-mode voltage and swings of 300 mV–1.2 V in the output signal, so as to match the variations between channel characteristics which occur in large displays. A prototype was fabricated in 28-nm CMOS, and occupies 1.35 mm2; it was tested on a 55-in $3840 \times 2160$ thin-film transistor liquid-crystal display (TFT-LCD) intra-panel interface, where it compensated for channel losses exceeding 10 dB, while reducing eye jitter by 38%: phase emphasis is responsible for about half of this reduction.

A Robust Noninvasive Eye Control Approach For Disabled People Based on Kinect 2.0 Sensor

A noninvasive eye control approach based on Kinect 2.0 was proposed to improve life quality for people with upper limb disabilities. First, Kinect 2.0 was used to track the critical points of the canthus and eyelid. Second, the greyscale differential algorithm was used to position the iris. Finally, a novel eye control model based on the canthus coordinates, central coordinates of pupils, and eyelid distance was established for cursor control. To reduce the calibration difficulty and the interference from eye jitter on the control, incremental indirect control was performed to ensure smooth and gradual cursor motion to the fixation point. To solve the Midas touch problem, an eye switch was proposed to reduce excessive unconscious cursor movement. Benefitting from the Kinect 2.0 advantages of high resolution, high efficiency, and good stability, the control speed reached 19.9fps in MATLAB, which meets the requirement for real-time control. The method also offers good adaptability to various noise sources, such as rotation, occlusion, and scaling. The experimental results suggest the availability and robustness of the new approach.

Optical interferometric synthesis of PAM4 signals based on dual-drive Mach–Zehnder modulation

In this work, optical interferometric synthesis and demodulation of four-level pulse amplitude modulation (PAM4) signals by using commercial dual-drive Mach–Zehnder Modulator (DD-MZM) is proposed and studied. Simulations are carried out and signal quality is evaluated in terms of eye jitter, linearity and so on for the PAM4 signals generated by the proposed DD-MZM with improved performance unfolded. Experimental generation of the optically synthesized PAM4 signals up to 50 Gbaud (100 Gbps) is achieved. The transmission of the PAM4 signals over 5-Km standard single mode fiber (SSMF) is carried out with error-free below the FEC limit (3.8E-3) without digital equalization at 90 Gbps. The linear-amplifier-free configuration by DD-MZM leads to simplified implementation and improved performance for high speed PAM4 signal generation, which would be of great significance for short reach optical interconnection.

Signal Integrity Performance Analysis of Mutual Coupling Reduction Techniques Using DGS in High Speed Printed Circuit Boards

In this article, the Signal Integrity performance analysis of mutual coupling reduction with defective ground structures (DGS) in high speed PCBs has been investigated. The performances of these structures are analyzed, in terms of Time domain, Error Vector Magnitude (EVM), eye pattern and timing jitter. A NRZ test signal with Quadrature Phase Shift keying modulation, with a carrier frequency of 3.5 GHz is used for the EVM measurements. From the EVM measurements, it is observed that the PCB with Circular DGS has the lowest EVM of 1.195 % rms compared to other techniques. Further, the eye pattern and jitter analysis show that the circular DGS has the lowest jitter value of 8 ps at 1Gbps data rate. Finally, the electromagnetic compatibility of proposed method is checked with the surface current distribution and radiated emission analysis. These investigations show that the adoption of the circular DGS in the high speed PCB design, reduces the spacing between two traces without degrading the signal quality.

Study on directional eye movements in non‐frontal face images for eye‐controlled interaction

AbstractDirectional eye movements based eye‐controlled interaction focuses on interpreting the horizontal, vertical, and diagonal eye movements or their combinations as inputs to design user interfaces for people who suffer with severe mobility disabilities. In this paper, we take into consideration the inherent eye jitter and evaluate the accuracy of dynamic tracking of horizontal, vertical, diagonal, and rectangular eye movements prior to using them. We observe that the rectangular eye gesture composed of short horizontal and vertical eye movements has the best tracking accuracy in the presence of jitter. Finally, we present methods for identifying horizontal and vertical eye movements based on the trajectory of eye pupil centers from non‐frontal face images. We find that the methods are robust and effective within ±20°deflective azimuths of non‐frontal faces. This effectiveness is demonstrated by using the rectangular eye gesture as an interface to perform a painting task.

LVDS Transmission Analysis Based on Eye Pattern and Jitter

LVDS Transmission Analysis Based on Eye Pattern and Jitter

Analytical Eye-Diagram Determination for the Efficient and Accurate Signal Integrity Verification of Single Interconnect Lines

In this paper, a new efficient and accurate analytical eye-diagram determination technique for interconnect lines is presented. The simplest input test signal model for the intersymbol interference analysis of high-speed data links is mathematically formulated. Since input test patterns for eye boundaries are determined analytically, it is considered very convenient and efficient. The proposed technique shows excellent agreement with the SPICE-based simulation in both eye height and jitter, i.e., within 5% error for nondiscontinuous data paths and 10% error for discontinuous data paths. The method is much more computation-time-efficient than the pseudorandom bit sequence-based SPICE simulation in the order of magnitude.

Improvements of Time-Domain Transmission Waveform and Eye Diagram of Serpentine Delay Line Using Open-Stub Type Guard Traces in Embedded Microstrip Line

The utilization of guard traces with two grounded vias at both ends to improve the time-domain transmission (TDT) waveform and eye diagram for a serpentine delay line has been investigated. However, it is not easy to accomplish because the position of the pad of a grounded via is surrounded by a serpentine trace. This is especially true for normal manufacturing technology, where the size of via pad is larger. Therefore, this paper proposes the use of open-stub type guard traces (OSGTs), to reduce crosstalk noise in the TDT waveform and eye diagram of a serpentine delay line, in an embedded microstrip structure. The OSGT, i.e., the guard trace, at one end is a grounded via and at the other is open-ended. The crosstalk reduced efficiency for using OSGTs is almost the same as when using two-grounded-via type guard traces on the serpentine delay line in the time-domain. This is because, the open-end of the OSGTs leads to the noise cancellation mechanism. A graphic method was used to illustrate the noise cancellation mechanism and ringing crosstalk noise generation on the TDT waveform. Two useful design graphs were used to evaluate the maximum flat voltage level of a laddering wave. Based on HSPICE simulation, it was demonstrated that the utilization of OSGTs can significantly reduce the original TDT crosstalk level, thereby greatly improving eye opening and jitter. Finally, this paper also performs time-domain measurement and 3-D full-wave simulation to validate the proposed analyzes.

Pluggable Optical Board Interconnection System With Flexible Polymeric Waveguides

Pluggable optical board interconnection system using flexible optical waveguide for direct-coupling to reduce the transmission loss is proposed and demonstrated. For the direct coupling between waveguides of boards, we use optical plug and adaptor with flexible polymeric waveguide and guide pins. Flexible polymeric optical waveguide is fabricated using hot embossing technique. Eye pattern and jitter characteristics of the backplane system is presented at 10 Gb/s.

AN ALGORITHM TO COUNTERACT EYE JITTER IN GAZE-CONTROLLED INTERFACES

One of the major concerns in developing efficient gaze-controlled user interfaces is inherent eye jitter, which presents a key limitation on the pointing accuracy achievable with an eye tracker. To counteract eye jitter, we developed a grab-and-hold algorithm. The efficiency of the algorithm was tested experimentally in a target acquisition task. Results suggest that the grab-and-hold algorithm affords a dramatic 57% reduction in error rates overall. The reduction is as much as 68% for targets subtending 0.35 degrees of visual angle. However, there is a cost which surfaces as a slight increase in movement time (10%). These findings indicate that measures like the algorithm presented here have the potential of making eye gaze a more suitable input modality. 1. Indroduction