Abstract: A monolithic multi-wavelength laser device according to the present invention comprises a substrate, a first-wavelength lasing part having a ridge portion and a second-wavelength lasing part having a ridge portion, while each of the first-wavelength lasing part and the second-wavelength lasing part includes current blocking layers consisting of semiconductor thin films covering the side surfaces of the ridge portion and extending toward at least partial regions of a plane linked with the bottom surface of the ridge portion and an insulation layer, covering the current blocking layers, consisting of an insulating dielectric thin film made of a material having a lower refractive index than the current blocking layers.

Abstract: CO2 slab laser having a gas-filled tubular housing, sealed off at both ends by end pieces, which accommodates two overlapping electrodes extending into the tubular housing and mirrors arranged in the region of the electrodes, where each of the two end pieces holds an electrode, the mirrors are arranged stationary relative to the electrodes and the electrodes, jointly with the mirrors, are adjustable relative to one another.

Abstract: Conventionally, a laser beam is amplified by making a single pass through an amplifier but the laser beam emitted from the oscillator generally has low energy, so the energy stored in the amplifier cannot be fully extracted and only low laser output power and overall efficiency result. According to the method of the invention for amplifying a solid-state laser, the laser beam is passed through the amplifier multiple times and with spatial uniformity so as to achieve efficient extraction of the energy stored in the amplifier and the thermally induced distortion of the laser beam can be compensated by the single amplifier.

Abstract: In one embodiment of the present invention an oxygen iodine laser includes a gas mixing section. Ground state oxygen and a carrier gas are introduced into the first gas mixing section, sometimes separately. The laser includes a discharge region to generate at least said excited oxygen from the flow of the first gas mixing section. A sensitizer gas having a lower ionization threshold than ground state oxygen is also introduced into the first gas mixing section, such that electrons are more easily produced in the electrical generator. The laser system includes introducing a source of iodine into the excited singlet delta oxygen flow to generate a laser-active gas. In another embodiment a conditioner is placed into the gas mixing section to help mix the flow and/or introduce one or more of the aforementioned gases.

Abstract: A frequency hopping spread spectrum telecommunication system is provided, which selects carrier frequencies based on the number of active slots. The duration that carriers have been employed is then based on the number of active slots (401, 402), rather than the number of frames (22). Thus, non-interfered with carriers can be used more often than interfered with carriers, thereby improving voice quality.

Abstract: In a communication system, a method and an accompanying apparatus determine a number of available fingers (110A-N) in a receiver (100). A controller (121) adjusts a threshold based on the determined number of the available fingers (110). The adjusted threshold may be one of, or any combination of, a pilot signal search threshold, a lock/unlock threshold, and a combine/un-combine threshold. The number of available fingers (110) may change after the threshold is adjusted.

Abstract: A Doppler frequency is detected with a high degree of accuracy, deterioration of a transmission diversity effect is prevented, and a good reception property is secured. A reception demodulating unit of a portable communication apparatus according to the present invention has a path search and path selection unit for searching and selecting an optimum path, finger processing units for obtaining a phase variation component as a channel estimated value for each path and coherent-detecting by using its channel estimated value and a phase difference measuring unit for measuring a phase difference, a path timing difference measuring unit for measuring a periodical path timing difference, a frequency error detecting unit for detecting a frequency error of a signal by using a path timing difference and a phase difference, and a Doppler frequency detecting unit for detecting a Doppler frequency on the basis of a frequency error.

Abstract: A method and apparatus to estimate the channel fade (both the amplitude gain/loss and the phase rotation) to assist the receiver to detect and recover the transmitted signal employs a continuous pilot signal such as the pilot code channel or pilot symbols. The channel estimator uses the same scrambling pattern of pilot channel and coherently integrates the continuous pilot signal to yield a channel estimate. The present invention employs adaptive integration duration to yield a channel estimate. The integration duration of the pilot signal for channel estimation is adaptive and proportional to the Doppler period. The Doppler period is proportional to the inverse of Doppler frequency and is an indicator of how fast the channel changes.

Abstract: A structure of a spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc., and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.

Abstract: A radio transmitter/receiver having a QoS control unit for outputting the transmission data in order taking the quality of service (QoS) into consideration. In the case where the information transmission rate for a radio section is not lower than a threshold value, the QoS control operation of the transmission data is omitted, and the transmission data are output in the order of input. In the case where the information transmission rate for the radio section is lower than the threshold value, on the other hand, the QoS control mode is switched in accordance with the information transmission rate for the radio section.

Abstract: A communications device apparatus and method is detailed that allows for improved system statistics gathering of network communication links, dataports, and system status. The improved communications device apparatus and method utilizes a relative time reference or clock for the determination of the starting and ending of system statistics gathering time periods. Thus allowing for the contiguous gathering of system statistics without errors or gaps caused by time changes made to an absolute time reference.

Abstract: A communication device (e.g., a modem) is disclosed as including logic that processes a transmit signal before providing a signal to an echo canceler. The processing may include low pass filtering and decimation of the transmit signal. The low pass filter's cut-off frequency preferably is less than the sampling rate associated with the transmit signal.

Abstract: A xDSL modem having an adaptive compensating filter of null generated by BT (Bridged Tap) minimizes transmission errors. The VDSL having a null compensating filter comprises a null compensator for finding a null frequency generated on a transfer function of a receiving signal before the DFE by predicting and tracing the null frequency to enlarge a signal component of the null frequency. The damage of a signal component resulting from the null generated by BT on a subscriber line is previously compensated before the equalizer. As a result, degradation of transmission speed of xDSL service is prevented and the number of taps in the equalizer is reduced, thereby reducing cost in embodiment of hardware.

Abstract: The present invention provides an iterative method of allocating bandwidth in a twisted pair modem communication network in order to maximize communications speed while reducing NEXT interference. The method determines frequency bandwidths that cause NEXT interference and eliminates these harmful frequencies. In further embodiments, the invention adjusts other parameters of transmission such as decreasing bitloading rates and power within problematic frequency bandwidths, while increasing power and bitloading in the remaining frequencies. The methods provide an iterative process that ensures an appropriate signal to noise ratio and maximum data transfer.

Abstract: A method is provided to provide data to automatically estimate channel performance in a communication system if a different order constellation is used comprising the steps of: receiving an input signal from the channel; passing the input signal to a slicer having an output signal; determining signal noise by taking the difference between the input signal and output signal; identifying a beginning of a noise event when the signal noise is greater than a predefined first threshold; identifying an end of a noise event when the signal noise is less than a predefined second threshold; and providing for output the beginning of the noise event and the end of the noise event. Other systems and methods are disclosed.

Abstract: A dual path equalization structure is used to equalize DMT systems operating over channels in which different impairments dominate the performance of different parts of the channel. Two TEQ/DFT structures are used to process the received signal, each optimized for a different part of the channel. The outputs of the two paths are combined with appropriate frequency-domain equalization to achieve an overall equalization architecture which is better optimized for the whole channel.

Abstract: A signal equalizer that employs micro-electromechanical machine devices for the tap weight controllers. The equalizer includes a substrate on which is formed a forward transmission line rail and a return transmission line rail. A cantilever stanchion is also formed on the substrate that runs parallel with the transmission line rails. A series of spaced apart cantilevers are pivotally mounted to the cantilever stanchion, and extend over the transmission line rails to define a gap therebetween. A weight tap line is coupled to each cantilever, and is responsive to a DC weight signal that controls the position of the cantilever to set the gap between the cantilever and the transmission line rails. A distorted signal is coupled from the forward transmission line rail to the return transmission line rail through the cantilevers.

Abstract: In a telecommunications system, an arithmetic logic unit (ALU) that receives an input signal. The input signal includes a digital signal representative of an analog signal. The ALU selectively performs compression and decompression on the digital signal. The ALU comprises the following elements. A standard ALU component performs standard ALU operations on the input signal. An encoding unit selectively performs compression on the digital signal. A decoding unit selectively performs decompression on the digital signal. An instruction decoder receives and decodes an ALU instruction. An output selector selects a result from one of the standard ALU component, the encoding unit, and the decoding unit in accordance with the decoded instruction and provides the result as an output.

Abstract: The present invention provides methods and apparatus for improving video quality in statistical multiplexing. For each encoding channel in a statistical multiplexer, a respective bit rate need parameter is calculated for encoding of a current frame in that encoding channel. A video buffering verifier level (VBV_Fullness) available to each encoding channel is also calculated. It is then determined whether the VBV_Fullness available to each encoding channel is sufficient for encoding the current frame of that encoding channel based on an initial complexity estimate for that current frame. In the event that the VBV_Fullness is determined to be sufficient, the current frame is encoded using the need parameter. In the event that the VBV_Fullness is determined to be insufficient, the need parameter is scaled by an adaptive panic multiplier and the current frame is encoded using the scaled need parameter.

Abstract: A transmission systems suitable for video.

Abstract: Systems and methods to generate an attention model for computational analysis of video data are described. In one aspect, feature components from a video data sequence are extracted. Attention data is generated by applying multiple attention models to the extracted feature components. The generated attention data is integrated into a comprehensive user attention model for the computational analysis of the video data sequence.

Abstract: A method and system are disclosed for controlling the generation of a systems layer stream, such as a transport stream, that carries a program made up of at least one elementary stream, such as an encoded audio signal or an encoded video signal. The systems layer stream is made up of serial segments, such as packets, which contain information specific to the systems layer, such as headers, and segments of elementary stream data. The bit rate of one or more of the elementary streams is adapted in accordance with a dynamically changing relation that relates the bit rate of such elementary streams to the bit rate of the portion of the systems layer stream that carries them.

Abstract: Methods for bit allocation and power tuning for optimizing a setup time in a multi-channel communication system. In one aspect, a bit allocation method includes measuring a signal-to-noise ratio (SNR) of each subchannel of a channel, determining a greatest allocable bit number of each subchannel using the measured SNR of the subchannels, determining a sum of the greatest allocable bit numbers of the subchannels, and determining a difference between the sum of the greatest allocable bit numbers of the subchannels and a target bit number. The currently allocated bit numbers of one or more subchannels is adjusted until a sum of the currently allocated bit numbers is equal to the target bit number.

Abstract: A reception device receives and demodulates, for each subchannel, data transmitted independently via three subchannels, which are a subchannel of interest and the two upper and lower adjacent subchannels which interfere with the subchannel of interest. A reception portion provided for each subchannel computes, as a soft decision value, the probability that data received from the subchannel of interest is “0” and the probability that the data is “1”, taking into account the degree of coupling between channels, and moreover uses the soft decision values input from the two upper and lower adjacent reception devices to adjust and output the soft decision value for the subchannel of interest, and based on the adjusted soft decision value, decides whether the received data is “0” or “1”.

Abstract: A channel equalizer for a single-carrier receiver interacting with a Trellis decoder and a channel equalization method therefor. The channel equalizer includes a first equalizer having a first feed forward (FF) unit for eliminating a pre-ghost of an input signal and a first feedback (FB) unit for eliminating a post-ghost of the input signal, a Trellis decoder for Trellis-decoding an output signal of the first equalizer, and a second equalizer having a second FF unit for eliminating the pre-ghost of the input signal and a second FB unit for eliminating the post-ghost of the input signal based on a signal decoded by the Trellis decoder. The first and second equalizers, interacting with the Trellis decoder, enable the equalization performance and speed of the channel equalizer to be enhanced.

Abstract: A system for mitigating noise associated with information communication includes means for determining when a first set of information is transmitted by a transmitter. The system includes a receiver for receiving a second set of information in response to the first set of information. The system also includes control means for temporarily suspending at least one process when the determining means determines that the first set of information is being transmitted and for continuing the at least one process after the second set of information has been received by the receiver. The at least one process produces noise that interferes with an integrity of the second set of information received by the receiver.

Abstract: A method is provided for defining a pulse function shape for acting on a data stream for transmission in a telecommunication system which compensates for distortion by a component of the transmitter. The method comprises defining desired cost parameters (e.g., error functions for amplitude, BER, bandwidth, energy, AFC) and defining the shape of the pulse function in dependence of the desired cost parameters and the distortion to be compensated for. A pulse generator, modulator and communications device providing such a pulse function are also provided. Application in dual mode TDMA/CDMA system.

Abstract: A transmitter for a mobile terminal including a polar modulator that compensates for amplitude to frequency distortion (AM to FM distortion) of a power amplifier in the transmit chain is provided. In general, the modulator includes a polar converter that converts an input signal into an amplitude signal and a phase signal. A phase to frequency converter converts the phase signal into a frequency signal. Based on the amplitude signal, compensation circuitry generates a frequency compensation signal that essentially cancels that AM to FM distortion of the power amplifier. A combiner combines the frequency signal and the frequency compensation signal, and the pre-distorted signal is converted into an analog frequency signal and amplified by the power amplifier. Accordingly, when the pre-distorted signal is amplified by the power amplifier, the frequency compensation signal essentially cancels the AM to FM distortion of the power amplifier.

Abstract: 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. The correctional values produced are returned to the digital base band modulator (1) and the data flow flowing from the digital base band modulator (1) to the amplifier input is predistorted with the correctional values produced in the neuronal network.

Abstract: The present invention includes methods and devices to compensate for gain and phase imbalance for OFDM and other multi-carrier symbol transmission systems. More particularly, methods and devices for determining compensation parameters are provided. This invention may be applied to a variety of standards utilizing OFDM technology, including IEEE 802.11a, Hiperlan/2 and MMAC. Further description of the invention and its embodiments are found in the figures, specification and claims that follow.

Abstract: According to one aspect of the present invention, there is provided a signal transmission apparatus for a mobile communication system. In the signal transmission apparatus, a frame segmentation section segments an input frame into Bk bit group, where k=1, . . . , K. A first group of encoders encodes Bk bit group and outputs encoded symbols. A second group of encoders encodes other Bk? bit group and output other encoded symbols. Each encoded symbol is encoded again to the transmit antennas using different functions. A transmission section includes a plurality of antennas in groups of a predetermined number of antennas, and the total number N of antennas is larger than the sum of the number of antenna groups. The transmission antennas transmit symbols encoded by one of the encoders.

Abstract: An arrangement where a transmitter has a plurality of transmitting antennas that concurrently transmit the same symbol, and where the signal delivered to each transmitting antenna is weighted by a factor that is related to the channel transmission coefficients found between the transmitting antenna and receiving antennas. In the case of a plurality of transmit antennas and one receive antenna, where the channel coefficient between the receive antenna and a transmit antenna i is hi, the weighting factor is hi* divided by a normalizing factor, ?, which is ( ? k = 1 K ? ? h k ? 2 ) 1 / 2 , where K is the number of transmitting antennas. When more than one receiving antenna is employed, the weighting factor is 1 a ? ( gH ) H , where g=[g1 . . . gL], H is a matrix of channel coefficients, and ? is a normalizing factor ( ? p = 1 L ? ? q = 1 L ? ? ? k = 1 K ? h pk ? h qk * ? ) 1 / 2 .

Abstract: A transmitter in which modulator output signal values are generated by a multi-level modulation method. The transmitter comprises a look-up table for storing a pre-defined number of values corresponding to data symbols and representing a signal or a pulse format, registers for selecting values representing the signal or the pulse format to be used to defined in-phase and quadrature component values, and adders for defining the modulator output signal values by summing the in-phase and quadrature component values while the number of the in-phase and quadrature component values to be summed is determined by a number of inter-dependent symbols.

Abstract: A radio transmitter and receiver arrangement includes a transmitter and a receiver. The transmitter generates an electromagnetic carrier that varies in frequency throughout a channel interval, and modulates the carrier with an information signal during the channel interval, whereby the carrier is modulated both in frequency and in accordance with the information signal during the channel interval. The receiver receives the carrier that is modulated both in frequency and in accordance with the information signal, generates a detection signal that varies in frequency throughout the channel interval, and mixes the carrier and the detection signal to recover the information signal.

Abstract: Receiver for Receiving Data Frames. According to one aspect, a receiver for receiving data frames which contain information data includes a signal input. Further, the receiver includes a data frame separator circuit for separating the signaling data from the information data. A switching device connects the data present at current input to a data output. A channel decoding circuit decodes the data which is present and generates signals which indicate whether the decoding has been carried out correctly. When correct decoding has taken place, a control circuit buffers all data and outputs a signal to the switching device to connect the buffered information data to the channel decoding circuit. When the signal indicates the correct decoding is received, the control circuit outputs the decoded information data.

Abstract: A receiver for digital data connects to a preceding signal path and the digital data has a lower to upper data frequency range. The receiver includes a received signal input terminal connected to a higher frequency gain circuit that shows highest transfer amplitude at the upper data frequency within the lower to upper data frequency range where the signal has been attenuated in its higher frequency components in the preceding signal path and providing an amplified signal at an amplified signal output terminal. The receiver further includes a latching circuit with two threshold levels, the latching circuit is connected with an input terminal to the amplified signal output terminal and an output terminal providing a digital output signal.

Abstract: An OFDM receiver has an autocorrelation circuit configured for generating autocorrelated power values from samples of received short preamble symbols in a received data packet, and a median filter configured for generating a median autocorrelation value from at least a prescribed minimum number of the autocorrelated signal values. A comparator is configured for detecting a symbol boundary, identifying an end of the short preamble symbols, based on the autocorrelated signal values falling below a threshold that is based on the median autocorrelation value. Hence, the threshold used to identify the symbol boundary is dynamically calculated on a per-packet basis, eliminating errors due to varying energy levels or propagation characteristics from different packet sources; moreover, the median autocorrelation value minimizes effects due to noise components, minimizing false detection errors.

Abstract: An OFDM receiver has an autocorrelation circuit configured for generating an autocorrelation result from samples of received short preamble symbols in a received data packet, where the autocorrelation circuit generates each autocorrelation result based on accumulation of the samples having been received for the short preamble symbols. Hence, by using all received samples of the short preamble symbols, the autocorrelation based on accumulated samples minimizes the effect of noise and provides a more accurate coarse frequency estimation result.

Abstract: An apparatus and method for improving the signal reception of a digital wireless receiver comprises a processing circuit for processing the preamble information of incoming signals, wherein a first predetermined portion of the preamble information is applied to a first antenna and a second predetermined portion of the preamble information is applied to a second antenna to produce a plurality of processed signals, such that the plurality of processed signals is compared to a predefined preamble sequence to obtain a mean-square error (MSE) for the respective antenna. Then, one of the first and second antennas with a lower MSE is selected to receive and process the incoming signals.

Abstract: Techniques are provided for the implementation of a signal processing circuit which expands the dynamic range of the signal processing circuit without interrupting the output of the circuit. The techniques can receive an input signal, process the signal through one of a plurality of signal processing circuits, and switch to processing the signal through another of the plurality of signal processing circuits without disturbing the output of the system.

Abstract: A transceiver for operating in a network wherein the transceiver is arranged to synchronize to a time reference common to the network having distinguishable instances, the transceiver containing a controller for effecting the reading or writing of a real time clock at an identified instance of the common time reference; a transmitter for transmitting an identification of the real time clock value of a first instance and an identification of the first instance, and a receiver for receiving a transmitted identification of a real time clock value and an identification of a first instance.

Abstract: A calculation circuit for calculating a sampling phase error is provided. According to one aspect, a calculation circuit includes a first delay element chain having serially connected delay elements, for delaying a digital estimate of a decision device; a second delay element chain having serially connected delay elements, for delaying an equalized signal; a multiplier array which multiplies the undelayed digital estimate and the delayed estimates of all the delay elements of the first delay element chain by the equalized signal and the delayed output signals of all the delay elements of the second delay element chain to generate product signals; a weighting circuit multiplies the product signals generated by the multiplier array by adjustable weighting factors; and having an adder which adds the product signals weighted by the weighting circuit to the sampling phase error signal.

Abstract: The invention relates to an apparatus and a method for ascertaining and correcting the optimum sampling time for an oversampled input bit stream. This involves feeding the data bit blanked with the current sampling phase into the comparative sequence and using the data bit to ascertain a new, corrected sampling phase. This decision-based approach enables the sampling phase to be continuously corrected.

Abstract: In one embodiment, the present invention provides a phase-locked loop comprising a charge-pump loop filter and a phase detector system. The charge-pump loop filter is configured to provide a control voltage having a voltage level based on a state of a first control signal and on a state of a second control signal. The phase detector system is configured to receive a first clock, a second clock, and a control signal defining a plurality of states including a first state and a second state. The phase detector system is further configured to provide the first control signal and the second control signal each having a state based on a phase difference between the first and second clocks when the control signal has the first state, and to provide the first control signal and second control signal each having a state asynchronously controlled by the control signal when the control signal has the second state.

Abstract: A device for signal transmission in computer tomographs comprising a rotating part supported to be rotatable with respect to a stationary part. A transmission controller is provided on the rotating part for compiling, from video data of a video source and from control information of a control unit, serial data for transmission to the stationary part by means of a rotary joint. A receiving controller is provided in the stationary part for receiving the serial data transmitted by the rotary joint and for evaluating these data and communicating the control information contained therein to a control unit, and the video data to a data sink. The serial data generated by the transmission controller comprise data frames, and video data and control information each being transmitted in a data frame.

Abstract: This invention relates to a medical X-ray device arrangement for producing three-dimensional information of an object in a medical X-ray imaging, the medical X-ray device arrangement comprising an X-ray source for X-radiating the object from at least two different directions and a detector for detecting the X-radiation to form projection data of the object.

Abstract: In one example, a radiation scanning system and method rotates a cargo conveyance after removal from a ship for proper orientation with respect to a scanning source and detector, for scanning. A movable carriage may be provided on a crane system, to rotate the cargo conveyance. A rotating flywheel on the carriage rotates in a direction opposite the direction of rotation of the cargo conveyance, to counterbalance angular momentum generated by the rotating conveyance, to avoid or minimize twisting of the carriage. Feedback is provided to control the rotation of the flywheel. Once the cargo conveyance is in the predetermined position, the conveyance is moved between the radiation source and detector for scanning by a vertically extending radiation beam.

Abstract: An x-ray diffraction-based scanning method and system are described. The method includes screening for a particular substance in a container at a transportation center using a flat panel detector having a photoconductor x-ray conversion layer to detect x-rays diffracted by a particular substance in the container. The diffracted x-rays may be characterized in different ways, for examples, by wavelength dispersive diffraction and energy dispersive diffraction.

Abstract: A method and apparatus for the transportation, remote and unattended mounting, and visual alignment and monitoring of protein crystals for synchrotron generated x-ray diffraction analysis. The protein samples are maintained at liquid nitrogen temperatures at all times: during shipment, before mounting, mounting, alignment, data acquisition and following removal. The samples must additionally be stably aligned to within a few microns at a point in space. The ability to accurately perform these tasks remotely and automatically leads to a significant increase in sample throughput and reliability for high-volume protein characterization efforts. Since the protein samples are placed in a shipping-compatible layered stack of sample cassettes each holding many samples, a large number of samples can be shipped in a single cryogenic shipping container.

Abstract: An X-ray examination apparatus arranged with control means to control a dose of an X-ray source in accordance with a grey-level distribution of an acquired image. The X-ray examination apparatus (1) comprises the X-ray unit (2) arranged to communicate data to the control and processing means (10). The X-ray unit (2) is arranged to generate a beam of X-rays (1f) propagating from an X-ray source (1c). The X-ray source (1c) together with the X-ray detector (1b)can be rotated about an acquisition volume V about a rotation axis (1e). The control and processing means (10) comprises an image processing means (3), which is arranged to compress the first image into the second image. Upon a compression of the first image with the grey-level compression function the resulting second image is forwarded to the control means (6), which is arranged to compute an average pixel value of the second image and to compare it with a pre-stored reference value.