Crosstalk

This paper presents a novel physics-based analytical
TSV model that allows fast and accurate design
space exploration of signal propagation and
attenuation properties in 3D ICs, and represents a
useful tool for circuit designers and process
engineers. A through silicon via(TSV), is a vertical
interconnection method between chips and also is the
critical enabling technology for three-dimensional
integrated circuits (3D ICs). The model equations are
based on simple process data including physical
dimensions, passivation thickness, substrate doping,
and TSV type without requiring full access to process
parameters of a particular TSV technology. Working
the other way around, by setting the parasitic
threshold voltage and minimum MOS capacitance of
a specific TSV, the model can provide a list of
process specifications. The model has been validated
against measured results published in literature. Our
experiments show that TSV parasitic MOS capacitor
threshold voltage and minimum capacitance values
computed using the aforementioned model are within
25% and 5 % of measured data. The resulting
complex RLC model, taking into account the
coupling effects between neighboring TSVs as well,
has been experimentally validated under DC and
high-frequency AC conditions. Moreover, timing
libraries compatible with conventional EDA tools
have been generated to run realistic timing analysis
for 3D stacked integrated circuits, such as 3D I/Os.

Crosstalk noise is a crucial factor affecting chip performance in deep submicron technologies. Among all possible crosstalk noise sources, clock is the most common aggressor as well as victim. Crosstalk on clock nets can increase clock jitter, which may degrade significantly the system performance. It is therefore imperative to design clock buffers to reduce the coupling effects. In this paper, we address the crosstalk effect on clock networks. We propose an algorithm to size clock buffers for given buffered clock trees such that the induced clock jitter is minimized. Our experimental results show a significant reduction of clock jitter by sizing the clock buffers without increasing the total area of buffer.

Increasingly more users around the globe use the web browser on a daily basis, in mobile and desktop devices. Recent advances in web technologies allow playback and real-time streaming of audiovisual content within the browser and, in parallel, they allow advanced sound manipulation with the Web Audio API. The work presented here explores the possibilities of sound spatialization, exclusively, with the processing power of the browser.

Immersive audio systems can be used to render virtual sound sources in three-dimensional (3-D) space around a listener. This is achieved by simulating the head-related transfer function (HRTF) amplitude and phase characteristics using digital filters. In this paper, we examine certain key signal processing considerations in spatial sound rendering over headphones and loudspeakers. We address the problem of crosstalk inherent in loudspeaker rendering and examine two methods for implementing crosstalk cancellation and loudspeaker frequency response inversion in real time. We demonstrate that it is possible to achieve crosstalk cancellation of 30 dB using both methods, but one of the two (the Fast RLS Transversal Filter Method) offers a significant advantage in terms of computational efficiency. Our analysis is easily extendable to nonsymmetric listening positions and moving listeners

Bandwidth (BW) is one of the most crucial resources in the communication industry. Fiber optic communication is band limited and typically occurs over the C-band. As modulation rates for optical signals increase each channel occupies more BW in the optical band, meaning less channels will be available at higher modulation rates. In order to squeeze more channels together over a band, pulse shaping can be done. Pulse shaping is a process by which an optical signal is shaped such that its BW is reduced in the frequency domain. Various techniques for pulse shaping are used, with the objective of limiting the bandwidth of each channel while eliminating Intersymbol Interference (ISI) and crosstalk.

A filter-bank modulation technique called filtered multitone (FMT) and its application to data transmission for very high-speed digital subscriber line technology are described. The proposed scheme leads to significantly lower spectral overlapping between adjacent subchannels than for known multicarrier techniques such as discrete multitone (DMT) or discrete wavelet multitone. FMT modulation mitigates interference due to echo and near-end crosstalk signals, and increases the system throughput and reach. Signal equalization in an FMT receiver is accomplished in the form of per-subchannel symbol-spaced or fractionally spaced linear or decision-feedback equalization. The problem of channel coding for this type of modulation is also addressed, and an approach that allows combined removal of intersymbol-interference via precoding and trellis coding is described. Furthermore, practical design aspects regarding filter-bank realization, initial transceiver training, adaptive equalization, and timing recovery are discussed. Finally, simulation results of the performance achieved by FMT modulation for very high-speed digital subscriber line systems, where upstream and downstream signals are separated by frequency-division duplexing, are presented and compared with DMT modulation

This paper describes an impulse noise measurement system for digital subscriber line channels composed by open hardware/software elements developed using the universal software radio peripheral and GNU is not Unix Radio. The proposed system proved to be capable of digitizing real occurrences of impulse noise. The goal is to use such system in large scale measurement campaigns, and then derive stochastic models for behavioral description of impulse noise. These models will provide better methods to reduce impulse noise effects, ever improving the quality of service in digital subscriber line transmissions.

The condition number of the matrix of electro-acoustic head-related transfer functions (HRTF) in a two-channel sound reproduction system has been used as a measure of robustness of the Atal-Schroeder (1962) crosstalk canceler. A comparative study has been made using results produced by computer simulations and HRTFs measured in an anechoic chamber by means of a dummy head. It has been found that acoustic scattering by the head has a very important and beneficial influence on robustness, specially for large loudspeaker separations. For narrow loudspeaker separations of less than about 40 degrees it is found that crosstalk cancellation exhibits a large variation of alternating very low and very high robustness. Also, simulations and measurements have been made of the natural channel separation under the same conditions. Scattering by the head is seen to provide a good level of natural channel separation at high frequencies and large loudspeaker angles. At low frequencies or small loudspeaker angles natural channel separation is poor