Abstract: A method for data communication includes providing an order for assigning bits of an input data stream to tones in a multi-tone modulation scheme, and allocating respective bit-loading values to the tones, such that some of the tones are allocated a first bit-loading value and other tones are allocated at least one second bit-loading value. The order is modified so as to form pairs of the tones that are allocated the first bit-loading value, with one or more of the other tones intervening between at least some of the pairs. The input data stream is modulated by assigning the bits to the tones in accordance with the modified order and the respective bit-loading values, and encoding the bits that are assigned to each of the pairs of the tones as a constellation point.

Abstract: Digital data is transmitted in a block-based hyperframe that consists of N frames. Each frame carries multiplexed data from one or more user data channels and a control channel. Control channel information is unequally allocated among the N frames, the amount of information carried in each frame varying according to the frame's position in the hyperframe. All of the user data channels except one carry a predetermined number of transmission units in each frame. The excepted user data channel carries a calculated amount needed to round out the particular frame. Following multiplexing, a block encoder defines the frames and adds error detection or error correction information. The number of frames per hyperframe and the total number of transmission units for the control channel are available to a receiver, which can then demultiplex the hyperframe.

Abstract: Methods and systems provide an efficient power save mode for multi carrier modems, such as DMT based ADSL and VDSL modems. Fast transitions from power save mode to full operational mode occur, without the overhead of transmitting large quantities of configuration information between the transmitter and receiver. Signal constellation size changes occurring while operating in power save mode to continue to apply once full operational mode is resumed. Multiple power save modes are enabled, each having a different level of power dissipation and crosstalk, both far end crosstalk and near end crosstalk. Power dissipation and crosstalk can thus be graduated on a line, according to a user-requested bit rate.

Abstract: A method for digital communication includes generating time-domain symbols having a predetermined symbol duration in accordance with a discrete multi-tone (DMT) modulation scheme. A cyclic extension is added to each of the time-domain symbols so as to form data blocks having a block length that is not an integer multiple of the symbol duration. A training pattern is generated on one or more tones of the DMT modulation scheme, wherein the training pattern is periodic over a sequence of the data blocks with a period equal to the symbol duration. The sequence of the data blocks is transmitted over a communication channel to a receiver, which processes the training pattern so as to determine a response of the channel to the one or more tones.

Abstract: The optical pointing device, i.e. a computer mouse, includes an optical assembly, having a lens and light guide, that is formed integrally with a base or footplate. The optical assembly and the footplate are designed as a single, homogenous unit and are molded in a single operation. This device does not require assembly of separate components.

Abstract: An image sensor includes a power supply ripple rejection circuit having an input connected to a supply voltage reference, and an output connected to an output voltage reference. The power supply ripple rejection circuit reduces the affect of variance in the supply voltage reference on the output voltage reference.

Abstract: A geometric processing stage for a pipelined engine for processing video signals and generating processed video signal in space coordinates (S) adapted for display on a screen. The geometric processing stage includes: a model view module for generating projection coordinates of primitives of the video signals in a view space, said primitives including visible and non-visible primitives, a back face culling module arranged downstream of the model view module for at least partially eliminating the non visible primitives, a projection transform module for transforming the coordinates of the video signals from view space coordinates into normalized projection coordinates (P), and a perspective divide module for transforming the coordinates of the video signals from normalized projection (P) coordinates into screen space coordinates (S). The back face culling module is arranged downstream the projection transform module and operates on normalized projection (P) coordinates of said primitives.

Abstract: The implementation of transactions on an integrated circuit comprising a plurality of functional modules connected to a packet router is described. Each functional module generates request packets for implementing memory access operations, each request packet having an operation field comprising eight bits of which a packet type bit denotes the type of the packet, four operation family bit denote the function to be implemented by the packet and three operation qualifier bits act to qualify the function.

Abstract: A method for forming a sensor is provided, together with a sensor formed according to the method. Photoresist material is deposited on a surface of the sensor, and is then patterned and etched to form an array of microlens structures. The structures are spaced close together in a predetermined pattern so that when a reflow process is performed, the structures melt and coalesce to form a barrier. The barrier defines a region for constraining or channeling the flow of reagent and analyte samples used in bio-optical sensors.

Abstract: A bio-optical sensor has a surface provided with an array of sensing pixels and calibration pixels. The sensing and calibration pixels are arranged in an interleaved fashion. The sensing and calibration pixels may be interleaved 1:1, or they may be arranged in interleaved blocks. The image plane receives an analyte and a reagent that reacts with the analyte to produce light. The sensing pixels generate signals as a function of the light produced.

Abstract: An optical pointing device includes a variable frame rate controller to reduce power consumption. Frame rate can be varied through analog devices by varying the reference current, or through digital devices by varying the length of time between successive frames. The variable frame rate controller can accept input from various measurements such as velocity of the device, or a spatial frequency of the surface on which the device is situated.

Abstract: An image sensor array of active pixel elements is arranged in rows and columns. Each column has an output circuit for reading out pixel image signals. The output circuit includes a pair of sample capacitors, a switching circuit operable based upon pixel switches for applying pixel voltages to the pair of sample capacitors. At least one optically masked pixel is provided so that output image signals obtained therefrom represent substantially only the column fixed pattern noise (FPN). An image processing circuit records the column FPN for each column from the optically masked pixels, records the image signal from the sensor array of active pixels, and subtracts the column FPN column-wise from the image signal.

Abstract: An image sensor includes an array of digital pixels, a first frame store for storing reference data, and a second frame store for storing image data. The reference and image data are combine to cancel an off-set of the pixels in the array. A re-set and a calibration phase are performed while a shutter is closed to obtain reference data during a calibration phase. A comparator measures an off-set time to gather information on the off-set of the pixels. During or after an exposure phase a conversion time is measured representative of the illumination on the pixel. During the calibration phase the off-set is measured. This digital technique requires a much smaller voltage swing on the pixel, and known techniques and can be performed in a shorter time. This increases the overall frame rate of the image sensor since the time taken for the reset and calibration phases is less than the time taken for the exposure phase.

Abstract: A solid state image sensor includes an array of pixels and a corresponding array of microlenses. The positions of the microlenses relative to their corresponding pixels may vary according to the distances of the pixels from a central optical axis of the image sensor to substantially eliminate vignetting of light collected by the microlenses.

Abstract: A method for transmission of high-speed digital signals includes transmitting a data signal over a communication line responsive to input data, the data signal having a data frequency spectrum. During an idle interval in the input data, two idle signals are transmitted in alternation: a first idle signal, having a first frequency spectrum that is substantially stationary relative to the data frequency spectrum, and a second idle signal, having a second frequency spectrum that is substantially non-stationary relative to the data frequency spectrum.

Abstract: An active pixel image sensor is formed on a P-type epitaxial layer on a P-type substrate. An active pixel array is in the P-type epitaxial layer. Each pixel includes an N-well functioning as a collection node, and a P-well adjacent the N-well. The P-well includes only NMOS transistors functioning as active elements. The in-pixel transistors cooperate with off-pixel PMOS transistors to form A-D converters.

Abstract: The optical biometric sensor apparatus and methods for analyzing images of biometric features such as fingerprints are adapted to distinguish between live body members and inanimate objects, and to detect spoofing devices applied to live body members. Live body members are detected by transmitting IR light from a first IR light source through an object to an image sensor. The IR transmission characteristics of a live body member vary with the human heartbeat, and multiple images are analyzed to verify whether the object is a genuine live body member. A visible light source illuminates the object for obtaining a detailed image from the sensor for conventional biometric analysis. Transmitted IR images and reflected visible light images are also processed to detect the presence of spoofing devices applied to live body members. Multiple IR and visible light sources of different wavelengths may be used for this purpose.

Abstract: An integrated circuit comprising a plurality of functional modules and interconnected via a packet router for conveying request and response packets is described. Transactions involve the dispatch of request packets and receipt of corresponding response packets. Each packet conveys a number of transaction attributes which can control how the packet is managed by control circuitry which controls the flow of packets on the packet router. For example the transaction attributes can include a transaction number, a grouping indicator, a priority indicator and a post indicator.

Abstract: A method for attaching a sensor and a housing to opposite sides of a mounting substrate is provided. The sensor has a sensing face that includes a sensing area and at least one signal output contact thereon. The mounting substrate has a circuitry face and at least one signal input contact thereon. The mounting substrate also has an opening therethrough. The method includes positioning the sensing area over the opening so that the at least one signal output contact of the sensor makes contact with the at least one signal input contact of the mounting substrate. The mounting substrate receives the housing so that the housing and the sensor are in alignment.

Abstract: An image sensor includes an array of pixels, with each pixel including a photodiode, and a first output circuit for deriving a linear output signal by applying a reset signal to the photodiode and reading a voltage on the photodiode after an integration time. A second output circuit derives a logarithmic output signal by reading a near instantaneous illumination-dependent voltage on the photodiode that is a logarithmic function of the illumination. In the logarithmic mode, the pixels are calibrated to remove fixed pattern noise. The pixels may be operated in linear and log modes sequentially, with the linear output being selected for low light signals and the log output being selected for high light signals.