Patents Issued in April 24, 2003
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Publication number: 20030076858Abstract: A data transmission scheduler sends different layers of data transmissions over a network at different times, according to available bandwidth. Data in the lowest layer is always sent immediately, without any delay, to form a basic image. Data in a higher layer or layers, which enhances the basic image, is sent during time periods of bandwidth otherwise unused. The scheduler operates to maintain an overall datarate equal to an average target bitrate. In other embodiments the scheduler can also maintain a maximum bursting datarate below a preset maximum.Type: ApplicationFiled: October 19, 2001Publication date: April 24, 2003Applicant: Sharp Laboratories of America, Inc.Inventor: Sachin G. Deshpande
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Publication number: 20030076859Abstract: This invention improves channel synchronization during a channel reset in a ciphering-deciphering wireless communication system. In the prior art at least in four situations, there is no well-defined or effective rules to ensure the channel synchronization after a channel reset between connected stations. This invention provide a method and a system to fulfill the gaps by clearly defining which and when a new cipher key for ciphering/deciphering shall be applied at either the receiving side or the transmitting side of the connected stations. This invention provides clear defined rules to eliminate these uncertainties so as to establish a more stable and effective communication system.Type: ApplicationFiled: September 19, 2002Publication date: April 24, 2003Inventor: Sam Shiaw-Shiang Jiang
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Publication number: 20030076860Abstract: A telecommunications node architecture is disclosed that comprises multiple add/drop multiplexors that are interconnected in a novel topology to enhance the reliability of the telecommunications network. Furthermore, the architecture of the illustrative embodiment ameliorates the well-known “add-before-drop” problem.Type: ApplicationFiled: October 10, 2001Publication date: April 24, 2003Inventor: Walter Michael Pitio
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Publication number: 20030076861Abstract: A system and apparatus for packaging a laser diode is provided according to the present invention. It includes a solid structure having a first cavity, wherein the first cavity receives a fiber pipe with optical fiber, which is aligned to the laser diode. The solid structure also includes a recess that receives the fiber pipe; and a step for receiving a sealing ring. The solid structure is multi-layered and may be manufactured from ceramic material, beryllium oxide or aluminum nitride. The solid structure includes a second cavity that accommodates a fiber alignment mechanism; a sub-mount on which the laser diode is placed; and/or heat sink used for conducting heat from the laser diode.Type: ApplicationFiled: October 19, 2001Publication date: April 24, 2003Inventors: Kirit S. Dharia, Robert Franks, Ivair Gontijo, Junpeng Guo, Yet-Zen Liu, M.P. Ramachandra Panicker, Ruai Yu
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Publication number: 20030076862Abstract: A semiconductor laser device comprises a semiconductor laser chip, a first member which has one surface substantially perpendicular to a direction of an emission laser beam and has a concave having a bottom face substantially parallel to the one surface, and a second member inserted into the concave and joined to the first member. The semiconductor laser chip is disposed to the bottom face of the concave of the first member. The second member is inserted and joined into the concave of the first member so as to cover the semiconductor laser chip. Consequently, it is avoided to impair smoothness of the one surface of the first member, so that it is possible to precisely join the first and second members after being joined together to a desired apparatus at the one surface.Type: ApplicationFiled: October 18, 2002Publication date: April 24, 2003Inventor: Takashi Itoh
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Publication number: 20030076863Abstract: A method for prolonging the service life and increasing manufacturing output, respectively, of solid-state lasers provided and predetermined, respectively, for continuous operation, which includes forming the lasers into a laser bar with a group of active laser strips arranged next to one another at a mutually spaced distance, activating the active laser strips during the continuous operation by having current applied jointly thereto, and providing the laser bar with at least one group of further laser strips, respectively, arranged in interspaces between respective adjacent active laser strips of the group thereof. While the current is applied to the active laser strips, the method further includes applying no current to the further laser strips so that the further laser strips are inactive, and checking the functionality of the active laser strips during the continuous operation, and activating at least one of the inactive laser strips if a failure of at least one of the active laser strips should occur.Type: ApplicationFiled: March 19, 2001Publication date: April 24, 2003Inventor: Thomas Zelenka
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Publication number: 20030076864Abstract: A lower multilayer reflection film (2), a light emitting layer forming portion (6) and an upper multilayer reflection film (8) are sequentially formed on a substrate (1) to form a semiconductor laminated portion (9), and a current injection region A is formed at a part of the semiconductor laminated portion so as to emit light from the surface in the center thereof. And, according to the present invention, the current injection region A is formed so as to be deflected from a center of the substrate. As a result, there is provided a surface light emitting type semiconductor laser capable of monitoring a light emitting power correctly and controlling it automatically in order to achieve the constant light emitting power in a case where the surface light emitting type laser chip is used as a light source for a pickup or the like.Type: ApplicationFiled: October 22, 2002Publication date: April 24, 2003Inventors: Hironobu Sai, Jun Ichihara
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Publication number: 20030076865Abstract: A variable semiconductor all-optical buffer and method of fabrication is provided where buffering is achieved by slowing down the optical signal using a control light source to vary the dispersion characteristic of the medium based on electromagnetically induced transparency (EIT). Photonic bandgap engineering in conjunction with strained quantum wells (QWs) and quantum dots (QDs) achieves room temperature operation of EIT. Photonic crystals are used to sharpen the spectral linewidths in a quantum well structure due to its density of states and in a quantum-dot structure caused by the inhomogeneity of the dot size, typically observed in state-of-the-art QD materials. The configuration facilitates monolithic integration of an optical buffer with an amplifier and control laser to provide advantages over other material systems as candidates for optical buffers.Type: ApplicationFiled: September 20, 2002Publication date: April 24, 2003Applicant: THE REGENTS OF THE UNIVERSITY OF CALIFORNIAInventors: Connie J. Chang-Hasnain, Pei-Cheng Ku
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Publication number: 20030076866Abstract: A multiple reflectivity band reflector (MRBR) includes a stack of dielectric layers, arranged so that the reflector has a reflectivity profile comprising a plurality of reflectivity bands, e.g. at least first and second wavelength bands with reflectivity above a lasing threshold reflectivity, separated by a third wavelength band between the first and second wavelength bands having reflectivity below the lasing threshold reflectivity. A laser having at least a first mirror and an MRBR as the second mirror has a laser cavity, at least a portion of which is defined by the first mirror and the MRBR. An active region located within the laser cavity contains a material that is capable of stimulated emission at one or more wavelengths in the first and second wavelength bands. The gain spectrum of the laser is adjusted to select one of the first and second wavelength bands, thereby providing for lasing at a wavelength within the selected wavelength band. The laser may be, e.g.Type: ApplicationFiled: July 18, 2002Publication date: April 24, 2003Applicant: APPLIED OPTOELECTRONICS, INC.Inventors: James N. Baillargeon, Wen-Yen Hwang, Klaus Alexander Anselm, Chih-Hsiang Lin
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Publication number: 20030076867Abstract: A method of detecting fire ignition sources includes using an electronic temperature sensor to probe potential ignition sites. The fire hazards for the sites are determined based on at least one of measurements of temperatures at or near the site, measurements of rate of temperature rise at or near the site, and measurements of temperature gradients at or near the site. Apparatus for performing the method is also described.Type: ApplicationFiled: October 23, 2001Publication date: April 24, 2003Inventors: Randall S. Mundt, James C. Mundt
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Publication number: 20030076868Abstract: An apparatus to combine temperature indicator sticks used in the welding, metal fabrication, and heat treatment industries and capable of identifying a given temperature of an object is disclosed. The apparatus includes a first temperature indicator stick comprised of a compound which melts at a first temperature, and a second temperature indicator stick formed of another compound which melts at a second temperature. The Apparatus further includes a connector physically connecting the first and second indicator sticks in a single assembly. A method to provide a dual temperature indicator stick is also disclosed.Type: ApplicationFiled: October 23, 2001Publication date: April 24, 2003Inventors: Pramathesh Desai, Victor I. Deonarine
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Publication number: 20030076869Abstract: An apparatus to combine temperature indicator sticks used in the welding, metal fabrication, and heat treatment industries and capable of identifying at least two given temperatures is disclosed. The apparatus includes a first temperature indicator stick aligned along a first axis and comprised of a compound which melts at a first temperature, and a second temperature indicator stick aligned along a second axis and formed of another compound which melts at a second temperature. The apparatus also includes a connector physically connecting and aligning the first and second indicator sticks.Type: ApplicationFiled: December 18, 2001Publication date: April 24, 2003Inventor: Victor I. Deonarine
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Publication number: 20030076870Abstract: A method for retransmitting coded bits by a transmitter in response to a retransmission request from a receiver in a mobile communication system which separates coded bits output from an encoder into coded bits with higher priority and coded bits with lower priority, and transmits from the transmitter to the receiver a stream of symbols obtained by symbol mapping the coded bits by a specific modulation technique. The method comprises determining orthogonal codes available for retransmission; separating the coded bits with higher priority and the coded bits with lower priority into a plurality of sub-packets with a given size, and selecting a part of the sub-packets or sub-packets to be repeatedly transmitted, depending on the determined number of available orthogonal codes; and transmitting a stream of symbols obtained by symbol-mapping coded bits of the selected sub-packets by the specific modulation technique, with the determined available orthogonal codes.Type: ApplicationFiled: October 18, 2002Publication date: April 24, 2003Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Yong-Suk Moon, Hun-Kee Kim, Jae-Seung Yoon
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Publication number: 20030076871Abstract: An efficient system for determining if a paging channel should be received and processed adapted for use a wireless communications device in a wireless communications system employing a quick paging channel. The system includes a first mechanism for receiving an electromagnetic signal having both pilot signal and quick paging signal components. A second mechanism provides one or more initial quality parameters (Epilot1/Îo1,Epilot1) indicative of a quality of a signal environment in which the electromagnetic signal is propagating. The one or more initial quality parameters are based on the pilot signal and are associated with a first symbol of the quick paging signal. A third mechanism ascertains whether a second symbol of the quick paging channel signal or the subsequent paging channel should be processed based on the one or more initial quality parameters and provides a first indication in response thereto.Type: ApplicationFiled: January 18, 2001Publication date: April 24, 2003Inventors: Farrokh Abrishamkar, Shimman Patel
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Publication number: 20030076872Abstract: We have devised both a high data transmitter and a high data receiver that uses both Walsh codes and quasi orthogonal functions in spreading and despreading transmitted and received signals.Type: ApplicationFiled: August 21, 2002Publication date: April 24, 2003Inventors: Louay M. A. Jalloul, Abhijit G. Shanbhag
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Publication number: 20030076873Abstract: The invention provides a data transmitting device for transmitting data on a channel. The device is operable in a communication system that can simultaneously convey data of a plurality of data transmitting devices on one channel. The device comprises an interleaver for interleaving a source data stream, thereby generating an interleaved data stream. Further, means for transmitting said interleaved data stream on said channel is provided. The interleaver characteristics differ from interleaver characteristics of at least one other data transmitting device that simultaneously transmits data on the channel. The invention further provides a corresponding data receiving device. By decorrelating the interleavers and deinterleavers for synchronised data transmission, the invention reduces inter-stream interference.Type: ApplicationFiled: September 30, 2002Publication date: April 24, 2003Inventors: Christian Wengerter, Alexander Golitschek Edler Von Elbwart, Eiko Seidel
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Publication number: 20030076874Abstract: A reverse synchronization method, which is used in a wireless system utilizing orthogonal spreading codes with Interference Free Window characteristic, wherein the transmission time of the signal from a remote unit is adjusted with respect to a predetermined Interference Free Window [−n, +n], such that the arrival time in a base station of the signal from the said remote unit falls within the said predetermined Interference Free Window. This eliminates inter-symbol interferences and multiple access interferences when multipath signals from a same remote unit and signals from different remote units arrive within an Interference Free Window.Type: ApplicationFiled: December 3, 2002Publication date: April 24, 2003Applicant: Linkair Communications, Inc.Inventors: Daoben Li, Weidong Chen, Haiyang Gao, Shiu Ming Joseph Ho, Yongsheng Zhang, Yuanhua Deng
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Publication number: 20030076875Abstract: The invention provides methods and apparatus for multiple user detection (MUD) processing that have application, for example, in improving the capacity CDMA and other wireless base stations. One aspect of the invention provides a multiprocessor, multiuser detection system for detecting user transmitted symbols in CDMA short-code spectrum waveforms. A first processing element generates a matrix (hereinafter, “gamma matrix”) that represents a correlation between a short-code associated with one user and those associated with one or more other users. A set of second processing elements generates, e.g., from the gamma matrix, a matrix (hereinafter, “R-matrix”) that represents cross-correlations among user waveforms based on their amplitudes and time lags. A third procesing element produces estimates of the user transmitted symbols as a function of the R-matrix.Type: ApplicationFiled: March 14, 2002Publication date: April 24, 2003Inventor: John H. Oates
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Publication number: 20030076876Abstract: The invention relates to a method of performing code acquisition on a signal to be received and to a receiver implementing the method. In the method the receiver receives a signal from a transmitter by at least two antenna beams, and to perform code acquisition, the antenna beams formed are searched at different delays of the spreading code. The number M of antenna beams can also be changed adaptively by determining a signal-to-noise ratio and by forming a number of antenna beams which is proportional to the signal-to-noise ratio. The receiver performs code acquisition by receiving a signal from the transmitter and by searching the antenna beams formed at the different delays of the spreading code.Type: ApplicationFiled: August 9, 2002Publication date: April 24, 2003Inventors: Marcos Katz, Savo Glisic, Jari Iinatti
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Publication number: 20030076877Abstract: In a code division multiple access signal receiving apparatus for demodulating transmit data by subjecting a receive signal to despread processing using a code sequence identical with a spreading-code sequence on a transmitting side, a cross-correlation detector calculates a cross-correlation value, on a per-symbol basis, between a spreading-code sequence for spread-spectrum modulating local-station-addressed transmit data and a spreading-code sequence for spread-spectrum modulating other-station-addressed transmit data; a discriminator discriminates whether the calculated cross-correlation value has exceeded a threshold value; and a switch halts input, to a decoder, of a portion of the receive signal that corresponds to the full interval or partial interval of a symbol where the cross-correlation value exceeds the threshold value.Type: ApplicationFiled: December 4, 2002Publication date: April 24, 2003Inventor: Takaharu Nakamura
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Publication number: 20030076878Abstract: A system, method, and signal are disclosed for line probing. The invention provides an improved signal for line probing having desirable characteristics. In various embodiments the signal comprises a periodic sequence having good autocorrelation characteristics. The periodic sequence of the invention provides a faster and more accurate evaluation of the channel. Another embodiment of the invention comprises processing of the received sequence to determine a desired or maximum data rate for the line or channel. The invention also provides an evaluation and calculation of the noise on the line or channel.Type: ApplicationFiled: January 16, 2001Publication date: April 24, 2003Inventors: William W. Jones, Ragnar H. Jonsson, Sverrir Olafsson
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Publication number: 20030076879Abstract: A method for calibrating an impulse radio distance measuring system comprising an impulse radio transceiver by conducting a pulse through a transmit receive switch to an antenna, receiving return energy which has been discharged across the transmit receive switch, determining a time of arrival of the return energy. The return energy is comprised of two distinct pulses, one of which represents discharge of the transmit switch as the original pulse travels to the antenna, the second represents energy reflected from the antenna and again discharged across the transmit receive switch while the switch is in the transmit position. The timing of the un-reflected energy is determined then the timing of the reflected energy relative to the un-reflected energy is determined through auto-correlation of the time domain scan of the received composite waveforms.Type: ApplicationFiled: September 17, 2002Publication date: April 24, 2003Inventors: David W. Langford, Dennis L. Troutman
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Publication number: 20030076880Abstract: A method and a circuit for controlling a switching frequency signal used in a direct current to direct current (DC to DC) converter are proposed. The DC to DC converter generates an output voltage to drive a system. The switching frequency signal is generated by inputting a modulation frequency to a pulse width modulation (PWM) circuit. The method includes steps of: 1. generating a control signal from the system to stop the pulse width modulation (PWM) circuit to generate the switching frequency signal when a signal is received by the system; and 2. restarting the pulse width modulation (PWM) circuit to generate the switching frequency signal in order to increase the output voltage to drive the system when the output voltage from the DC to DC converter is under a predetermined voltage.Type: ApplicationFiled: October 15, 2002Publication date: April 24, 2003Inventors: Pei Pei Yang, Darcherng Su, Ko-Chin Wang
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Publication number: 20030076881Abstract: An apparatus and method for coding and decoding image data in which image data are input, and the input data are separated into key frames and intermediate frames (which are frames other than the key frames). A pixel by pixel matching is then performed between the key frames to allow generation of both virtual key frames and intermediate frames between the key frames by interpolating the matching results. Actual frames, which may be key frames or intermediate frames, are then coded by determining a difference between virtual frames and actual frames, so that the actual frames can be coded based on the small amount of difference data.Type: ApplicationFiled: April 24, 2002Publication date: April 24, 2003Inventors: Kozo Akiyoshi, Nobuo Akiyoshi, Yoshihisa Shinagawa
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Publication number: 20030076882Abstract: The present invention relates to a filter circuit for a set of original data (X0-X7) able to implement in series the steps of discrete transformation (DCT2), correction (ZER) of odd transformed data and inverse discrete transformation (IDCT2). The filter circuit takes advantage of the fact that the paths corresponding to the even and odd transformed data are completely separate with the exception of a first processing stage (ST1) of the discrete transformation and a last processing stage (ST8) of the inverse discrete transformation in order to connect a first half of the data issuing from the first stage to the last processing stage. The implementation of the filter circuit is thus simplified, both making said circuit less expensive and giving it a lower power consumption. For optimized implementation, the filter circuit functions in differential mode.Type: ApplicationFiled: September 20, 2002Publication date: April 24, 2003Inventor: Jean Gobert
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Publication number: 20030076883Abstract: The invention relates to a method of coding motion information associated to an image sequence, comprising the steps of subdividing each image into blocks and applying to each block a block-matching algorithm for defining a shifted block as the prediction of the current block, the motion vector between said shifted and current blocks being the predicted vector associated to said current block and all the motion vectors similarly predicted for a whole current image constituting a motion vector field associated to said current image. For each current image, the motion information constituted by said associated motion vector field is finally coded. According to the invention, the motion vector C to be coded is approximated by a spatio-temporal predictor P defined by a relation of the type: P=&agr;·S+&bgr;·T, where S and T are spatial and temporal predictors respectively, and (&agr;, &bgr;) are weighting coefficients respectively associated to said spatial and temporal predictors.Type: ApplicationFiled: September 25, 2002Publication date: April 24, 2003Inventors: Vincent Bottreau, Beatrice Pesquet-Popescu
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Publication number: 20030076884Abstract: The invention concerns a method (200, 300) and system (100) for performing a trick mode on a video signal containing a plurality of original pictures. The method includes the steps of receiving a trick mode command (212, 312) and selectively inserting (214, 324) at least one dummy bidirectional predictive picture in the video signal using field-based prediction to form a trick mode video signal. In one arrangement, each dummy bidirectional predictive picture can be a one-directional predicted picture, and the method can further include the step of predicting each dummy bidirectional predictive picture from a reference picture. In another arrangement, the predicting step can further include predicting each dummy bidirectional predictive picture from a single field associated with the reference picture.Type: ApplicationFiled: June 7, 2002Publication date: April 24, 2003Inventors: Shu Lin, Donald Henry Willis
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Publication number: 20030076885Abstract: A system and method that reduces computational complexity of a decoder by identifying a skippable region in an overlaid area. The invention provides a system for processing encoded video data, comprising: an analysis system that determines if a current video frame having an overlaid area acts as a reference for future video frames; and a system for identifying a skippable region in the overlaid area. The invention may also include a system for identifying a portion of the overlaid area as the skippable based on analysis of motion vectors or motion vector ranges.Type: ApplicationFiled: October 19, 2001Publication date: April 24, 2003Applicant: Koninklijke Philips Electronics N.V.Inventors: Yingwei Chen, Shaomin Peng, Tse-Hua Lan, Zhun Zhong
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Publication number: 20030076886Abstract: In a moving picture decoding display apparatus and moving picture decoding display method according to the present invention, moving picture decoder 101 decodes a moving picture signal, RGB matrix manipulation section 103 converts the decoded video signal in YCbCr format into a video signal in RGB format, contrast/brightness adjusting section 104 adjusts the contrast and brightness of the video signal in RGB format, and liquid crystal display module section 110 displays the adjusted video signal on liquid crystal panel 109. At this point, operation control section 105 switches on and off the operation of RGB matrix manipulation section 103 and contrast/brightness adjusting section 104 corresponding to the actual frame rate in moving picture decoder 101, and only when the operation is “on”, the section 105 controls so that the video signal from contrast/brightness adjusting section 104 is stored in video RAM 107 in liquid crystal display module section 110.Type: ApplicationFiled: November 7, 2002Publication date: April 24, 2003Inventors: Hideki Nagata, Tadashi Kayada
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Publication number: 20030076887Abstract: Digital TV system with a PVR function and method for making a stream jump therein, wherein, upon reception of a stream jump order from a user, searching the storage medium for a target GOP the user, or a system designated, changing a reproducing position to a TP next to a TP having a picture header among TPs in a prior picture positioned right forward of the searched target GOP, and starting reproduction from the changed reproducing position, thereby preventing occurrence of a decoding error while maintaining continuity of CC values in decoding TPs of a target GOP, to permit no broking of picture even in the stream jump.Type: ApplicationFiled: September 26, 2002Publication date: April 24, 2003Inventors: Tae Hyoung Kim, Eunsam Kim
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Publication number: 20030076888Abstract: A method, apparatus, and computer program product for combining a subband decomposition and a linear signal processing filter (LSPF). Operations performed include merging the LSPF, via superposition, with each synthesis filter of the first level of the subband decomposition into a set of composite filters; generating an equivalent structure for the low-pass composite filter and its adjacent upsampler to allow combining the equivalent structure with the synthesis filter on the next level of the subband decomposition; repeatedly operating the merging on the next level of the subband decomposition; creating an equivalent structure for the intermediate structure generated by the merging step and its adjacent upsampler in order to allow for combination of the equivalent structure with the at least one synthesis filter on the next level; repeating the operations for each remaining level to generate a composite subband synthesis linear operator, which operates directly on data of the subband decomposition.Type: ApplicationFiled: May 7, 2002Publication date: April 24, 2003Inventor: Cindy Daniell
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Publication number: 20030076889Abstract: Constellations (22) arranged in a concentric circle pattern provide simplified control of modulated communication. A plurality of concentric circles (26, 28, 30) with defined points (24) include convolutionally coded and uncoded bits. Constellation patterns having three or four concentric circles (26, 28, 30) are provided. A magnitude error for each of the points (24) allows for deviations during communication. The constellations (22) provide efficient communication using non-linear channels.Type: ApplicationFiled: October 23, 2001Publication date: April 24, 2003Inventors: Christopher W. Walker, Holly C. Osborne
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Publication number: 20030076890Abstract: Techniques for transmitting and receiving signals using a linear propagation channel, and the detection and decoding of the signals, are described. The symbols are decoded by computing the likelihood of each bit in a block of data in light of all blocks of received complex data and the constraints imposed by the channel code. Extrinsic information and a priori information are exchanged in an iterative fashion until desired performance is achieved. Extrinsic probability values are computed by searching through hypotheses in the constellation of available symbols to maximize the extrinsic probability values, with decoding employing a stored list of candidate points for discovered within a search radius, the list comprising the solution points found within the smallest radii.Type: ApplicationFiled: July 26, 2002Publication date: April 24, 2003Applicant: Lucent Technologies, Inc.Inventors: Bertrand Martyn Hochwald, Stephan Ten Brink
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Publication number: 20030076891Abstract: A method and apparatus for transmitting/receiving signals in a multiple-input multiple-output communication system provided with a plurality of antenna elements is disclosed. Accordingly, the present invention provides a plurality of antenna groups at one distance having the antenna elements arranged at the other distance, a method and a means for identifying the groups and adding an identifier for the groups. It further provides a method and an apparatus for allocating power for the groups.Type: ApplicationFiled: October 21, 2002Publication date: April 24, 2003Applicant: LG Electronics Inc.Inventor: Seung Hwan Won
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Publication number: 20030076892Abstract: Techniques for an electronic shelf label (ESL) system which uses a digital modulation technique for a modulated backscatter uplink from an ESL to a communication base station (CBS) which utilizes pseudo-random sequences instead of a single continuous wave frequency. The CBS transmits a message to an ESL using a Manchester coded amplitude modulated carrier. After receiving the message, the ESL responds by reflectively modulating a continuous wave (CW) signal with a pseudo-random code sequence. Multiple pseudo-random code sequences may be chosen, with each code sequence corresponding to a particular response. The code sequence is modulated onto a kHz carrier which is used to reflectively modulate the CW signal received from the CBS. The CBS then receives the reflectively modulated signal and correlates the received signal to determine message transmitted.Type: ApplicationFiled: October 23, 2001Publication date: April 24, 2003Applicant: NCR CorporationInventor: Albertus Maria Gerardus Claessen
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Publication number: 20030076893Abstract: A transmitter is disclosed for transmitting a digital information signal via a transmission medium. The digital information signal can be divided into one or more sub-signals. Each sub-signal is transmitted as a non-encoded or as an encoded signal. In which way the sub-signal is transmitted depends on the compression that can be achieved by the encoder. If the compression is low the sub-signal is transmitted in non-encoded form. For the receiver an identification is added to the composite signal to be transmitted. A first component of the identification signal indicates if one or more sub-signals are transmitted in encoded form. A second component of the identification signal indicates for each sub-signal whether it appears in encoded or non-encoded form in the composite signal. The invention provides a composite signal with a minimal number of bits.Type: ApplicationFiled: November 18, 2002Publication date: April 24, 2003Applicant: Koninklijke Philips Electronics N.V.Inventors: Alphons A.M.L. Bruekers, Johannes M.M. Verbakel, Marcel S.E. Van Nieuwenhoven
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ADAPTIVE DIGITAL PRE-DISTORTION CIRCUIT USING ADJACENT CHANNEL POWER PROFILE AND METHOD OF OPERATION
Publication number: 20030076894Abstract: There is disclosed a pre-distortion adjustment circuit for use in an RF transmitter that adjusts the actual adjacent channel power (ACP) noise profile of an RF power amplifier to fully use the ACP profile allowed under the applicable RF communication standard. The pre-distortion adjustment circuit pre-distorts selected components of the input signal to the RF power amplifier so that the actual output ACP profile appears similar to, if not the same as, the ACP profile under the standard. The distortion required is determined based on information extracted from the input signal, the output signal, and the standard ACP profile. The pre-distortion adjustment circuit allows significant overdrive of the RF power amplifier while maintaining the ACP noise in the RF output below the levels allowed under the standard.Type: ApplicationFiled: August 5, 1999Publication date: April 24, 2003Inventors: HANG JIN, JOSEPH R. CLEVELAND -
Publication number: 20030076895Abstract: The invention relates to a method and an apparatus for preventing interference, particularly in telecommunications systems operating in burst mode, where the interference arises particularly when the signal has a signal level below a threshold level value and/or the signal has a constant amplitude over time. An artificial interference signal having at least one interference signal frequency is added in the processing path in the system so that the signal level exceeds the threshold level value or at least one amplitude that is constant over time is prevented.Type: ApplicationFiled: November 18, 2002Publication date: April 24, 2003Inventor: Christian Kranz
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Publication number: 20030076896Abstract: The invention relates to a method for the linearization of a high-frequency high-capacity amplifier by means of adaptive digital predistortion of the input signals of the amplifier (5) by determining correctional values that are approximated from DESIRED sender signals detected at the amplifier input and ACTUAL sender signals detected at the amplifier output. To this end, I/Q data continuously derived from the DESIRED sender signals at the digital base band modulator (1) and I/Q data derived by a measuring unit (4) at the amplifier output from the ACTUAL sender signals are fed to a neuronal network for evaluation and for the calculation of correctional values.Type: ApplicationFiled: October 30, 2002Publication date: April 24, 2003Inventors: Carsten Ball, Gerrit Buhe
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Publication number: 20030076897Abstract: The invention relates to AC coding. The phase angle or the duration of pulses are marked by half-periods or periods and are then provided as stages. The aim of the present invention is to flexibly adjust the bandwidths and bit rates. The number of filler elements that are allocated to the active code elements is increased or reduced. Bit rate flexibility is obtained by increasing or reducing the positions or stages or by configuring the code elements of virtual code words in a serial manner in relation to code words for transmitting information, whereby said code elements are arranged in parallel.Type: ApplicationFiled: July 16, 2002Publication date: April 24, 2003Inventor: Josef Dirr
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Publication number: 20030076898Abstract: A digital (de)modulation system uses a larger code set of M codes for N length codes, where M>N, to provide an increased data rate while maintaining the coding gain. For example, the system can use 16 different codes each having a length of 11 chips in a code set while the conventional M-ary keying systems use a code set size of 8 for 11-chip codes or 8-chip codes. By extending the code set size, the system increases the data rate of the system. With 16 codes and the ability to change the sign of the code to be transmitted, the system can encode 5 data bits on both I and Q, so a total of 10 data bits can be encoded per code symbol. In this embodiment, a code symbol contains an 11 chip code on a I modulation branch and an 11 chip code on a Q modulation branch. As such, using 11 chip codes and a chip rate of 11 Mhz, the system provides a data rate of 10 Mbps while conventional M-ary keying systems can only achieve 8 Mbps using the same code length and chip rate.Type: ApplicationFiled: July 29, 2002Publication date: April 24, 2003Inventor: Richard D.J. van Nee
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Publication number: 20030076899Abstract: A polyphase channelizer converts an intermediate frequency wideband signal into a complex signal that is sampled by parallel analog-to-digital converters having a bank of samplers respectively clocked by staggered clocking signals for respective converters for feeding I and Q quadrature samples to a polyphase filter bank of finite impulse response filters driving a fast Fourier transform processor for providing channelized digital signal outputs. The parallel analog-to-digital converters can operate at lower speeds but are parallel connected for effectively operating at required higher speeds. The channelizer channelizes the wideband signal using a polyphase clock for enabling high speed sampling and converting through low speed parallel analog to digital converters.Type: ApplicationFiled: October 18, 2001Publication date: April 24, 2003Applicant: The Aerospace CorporationInventors: Rajendra Kumar, Tien M. Nguyen
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Publication number: 20030076900Abstract: A system and method facilitate estimating noise in a received signal. The received signal includes a plurality of data tones. Noise is estimated for a selected subset of data tones for each data burst, such that noise estimates for all data tones can be computed over a plurality of data bursts. As a result of spreading the noise estimates over more than one burst, the overall computations associated with obtaining the noise estimates can be reduced based on the size of the respective subsets. The updated data tone noise estimates further can be employed in subsequent processing, such as in beamforming calculations.Type: ApplicationFiled: October 24, 2001Publication date: April 24, 2003Inventors: David Patrick Magee, Srinath Hosur
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Publication number: 20030076901Abstract: A system for calculating DC offset and achieving frame detection is described. In one embodiment, the present invention includes an electronic device with an integrated receiver module. The receiver module can take advantage of a known synchronization pattern such as the Bluetooth access code to determine an initial DC offset and to provide frame detection.Type: ApplicationFiled: October 22, 2001Publication date: April 24, 2003Inventors: Rebecca W. Yuan, Jyothis Indirabhai, Kevin Yen
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Publication number: 20030076902Abstract: A system and method for compensating for DC offset and/or clock drift on a wireless-enabled device is described. One embodiment includes a radio module, an A/D converter connected to the radio module, a DC tracking loop connected to the A/D converter, and a multi-hypothesis bit synchronizer.Type: ApplicationFiled: October 22, 2001Publication date: April 24, 2003Inventor: Rebecca Yuan
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Publication number: 20030076903Abstract: An improved zero phase restart circuit (308). A lookup table technique is employed to avoid an extensive series of calculations.Type: ApplicationFiled: November 12, 2002Publication date: April 24, 2003Applicant: Infineon Technologies North America Corp., a Delaware CorporationInventors: Jonathan Ashley, Matthias Driller
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Publication number: 20030076904Abstract: Systems and methods are provided for performing signal processing on communication data utilizing scale reduced Fast Fourier Transform computations. The present invention provides scaling in a Fast Fourier Transform computation at stages where it is determined that bit growth is present and omits scaling at stages where it is determined that bit growth is absent. The determination is based on the characteristics of the input signal. The determination can be made off-line by modeling and/or simulation or in real-time by analyzing the input signal to determine stages at which bit growth is present and/or absent and setting the stage scaling accordingly.Type: ApplicationFiled: October 19, 2001Publication date: April 24, 2003Inventor: David Patrick Magee
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Publication number: 20030076905Abstract: The present invention relates to a method and a device for data extraction from a data stream containing at least one data packet. First, comparing a bit stream derived from a received digital data stream with an expected bit sequence is performed by packet detector (17) to determine a correlation value (CorrVal) for detecting a data packet. Then, a data extraction unit (19, 20, 21, 22) is started for data extraction when the correlation value (CorrVal) exceeds a threshold value (CorrThres) indicating that a data packet has been detected. Thereafter, comparing the received bit stream with the expected bit sequence to determine a new correlation value (CorrVal) is continued by the packet detector (17). Finally, restarting data extraction is initiated by a sync-control module (23) when the new correlation value (CorrVal) exceeds the former correlation value (MaxCorrVal).Type: ApplicationFiled: October 19, 2001Publication date: April 24, 2003Inventors: Markus Schetelig, Harald Kafemann
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Publication number: 20030076906Abstract: The present invention provides automatic gain control (AGC) for a wide variety of conditions encountered in DSL scenarios. In particular, the proposed AGC approach addresses the problem of analog front end saturation in which a plurality of gain stages (i.e., programmable gain amplifiers) and filter stages are interleaved with inaccessible intermediate points. The gain settings of each of the PGAs is increased (614) until the received signal exceeds a given threshold (620) or until the maximum setting for that PGA has been reached (624). If the current PGA setting has been maximized, the next PGA is considered (628) and the process is repeated until no additional gain is needed or until the available PGAs are exhausted. This process is iterated (630) with different maximum PGA settings for each iteration to enable a more uniform gain distribution.Type: ApplicationFiled: September 28, 2001Publication date: April 24, 2003Inventor: Fernando A. Mujica
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Publication number: 20030076907Abstract: A filter and processing sequence is described that efficiently combines and performs two or more tasks required to demodulate a composite 3G (third generation) wireless signal formed by a combination of wideband 3.84 MHz (UMTS or UTRA) carriers and narrowband 1.2288 MHz CDMA-2000 carriers. The three tasks, applied to each spectral component of the 3G wireless signal and described in the order of a traditional filtering structure are: Spectral translation, Bandwidth Reduction, and Sample Rate Selection. These tasks are traditionally implemented in three distinct pieces of hardware or software modules.Type: ApplicationFiled: May 9, 2001Publication date: April 24, 2003Inventor: Frederic Joel Harris