Abstract: A laser system and method. The inventive laser includes an annular gain medium; a source of pump energy; and an arrangement for concentrating energy from the source on the gain medium. In a more specific implementation, a mechanism is included for rotating the gain medium to effect extraction of pump energy and cooling. In the illustrative embodiment, the pump source is a diode array. Energy from the array is coupled to the medium via an array of optical fibers. The outputs of the fibers are input to a concentrator that directs the pump energy onto a pump region of the medium. In the best mode, plural disks of gain media are arranged in an offset manner to provide a single resonator architecture. First and second mirrors are added to complete the resonator. In accordance with the inventive teachings, a method for pumping and cooling a laser is taught.

Abstract: According to the invention, a diode side pumped laser is provided. The laser has an optical cavity formed between a first and a second reflective surface. A Nd:YLF lasing medium is located within the cavity along its optical axis. The Nd:YLF lasing medium can desirably be a single Nd:YLF lasing rod which has a length of 90 mm or more. A plurality of diode bars are provided in optical communication with the Nd:YLF lasing medium preferably a lasing rod. The diode bars extend along substantially the pumpable length of the lasing rod and radially around the periphery of the lasing rod. The diode bars have radiation outlets in optical communication with the lasing rod for supplying electromagnetic radiation on pumping paths to the rod. The lasing rod receives an average linear power density from the diode bars of less than 50 watts/cm. The pumping paths traverse substantially the entire pumpable length of the lasing rod substantially perpendicular to the direction of propagation of energy in the laser cavity.

Abstract: A high power narrow band, high repetition rate laser light source optical improvement apparatus and methods are disclosed with a fast angularly positionable mirror having a mirror mounting frame, a reflective optic with a coefficient different from that of the mounting frame, at least one flexure mount fromed in the mounting frame that is flexible having flexure arm attached the flexture to the mounting frame. The apparatus may include a flexure force mechanism having an elongated rod. The force mechanism may pre-stress the flexure. The mirror maybe a grating which includes a substrate with metallic layer formed on the substrate, and a protective coating made of silica formed on the reflective metallic layer. The grating maybe actively tuned using an electro- or magneto-sensitive element. Oxides of the metal in the reflective layer may be removed by a hydrogen purge system exposed to deep ultraviolet radiation.

Abstract: A system and method is provided for transmitting data signals and additional information signals having partially overlapping frequency bands simultaneously within a wire based communication system over the same wired medium using a spread spectrum technique for modulating the additional information signals.

Abstract: A programmable spread spectrum clock generator (SSCG) reduces electromagnetic interference by spreading the frequency bandwidth of an output signal. The rate at which the frequency of the output signal changes, as well as other aspects of the output signal, are software programmable. The programmable SSCG receives a periodic signal whose cycles have substantially identical periods and outputs the output signal whose cycles have periods that vary smoothly over a plurality of cycles of the periodic signal. The programmable SSCG generates a control signal using the periodic signal. The programmable SSCG includes a variable delay element that generates the output signal by delaying the periods of the periodic signal based on the magnitude of the control signal. The output signal is generated without using a phase locked loop. Moreover, successive cycles of the output signal rarely have identical periods.

Abstract: Disclosed is a receiver capable of simplifying hardware required for finger and combiner in accordance with the channel characteristics in a 3rd generation mobile communication system using physical channels recommended by the 3GPP (3rd generation partnership project). The rake receiver for the mobile communication system complying with the 3GPP standard includes fingers for performing in parallel a radio signaling of downlink physical channels recommended in the 3GPP standard and inputted through multiple paths in a first-in first-out (FIFO) manner, combiners for summing a certain channel of different time offsets outputted from the fingers with an identical timing, and a selector for controlling the different physical channels outputted from the fingers to be summed by the different combiners, respectively.

Abstract: A method for setting spreading code delays in RAKE receiver branches include, for instance: determining solutions for the code delays that include a code delay candidate for the branch to be processed and for in the order of delay preceding branches. The solutions maximize the sum of the signal strengths in the branch to be processed and in the preceding branches. The method also includes that the delays of the branches are selected in accordance with the last determined solution.

Abstract: A timing and carrier error detector module (127) of a communication receiver (111). The timing and carrier error detector module uses phase information of a correlated signal (e.g. a Barker de-spread signal) to generate a timing signal and carrier error signal. In one example, the phase information includes a phase error signal of the correlated signal. In one example, the timing and carrier error detector module calculates an indication of the variance of the phase error signal for a plurality of sample positions over a plurality of Barker symbol intervals. The timing signal is based upon the sample position having a minimum indication of a variance.

Abstract: A network fabric physical layer includes a driver coupled to a receiver via a bus, which implements a multiphase encoded protocol. A multiphase sequencer sequences (data or command/control) words for the driver. The driver outputs the sequenced words onto the bus as a differential multiphase encoded waveform. The receiver receives the differential multiphase encoded waveform and performs statistical analysis to determine data integrity checking. The bus is a concurrent differential bi-directional bus and each transmitting driver includes impedance compensation circuitry on both ends of a transmission line so that each drives its signal value with the impedance characteristics of the transmission line. The receiver also includes jitter immunity.

Abstract: Estimation of gain and phase imbalance of an upconverting transmitter. A transmitter transmits symbols containing vector components of pre-specific relationship in an analog signal. A receiver (also contained in a transceiver along with the transmitter) examines the symbols to determine the phase and gain imbalances in the transmitter based on the analog signal. An aspect of the present invention enables the balance estimation circuit to be integrated along with the transmitter and the receiver into a single monolithic integrated circuit.

Abstract: A spectrum measurement system, comprising a preamplifier for receiving and pre-amplifying input signals from a wireless communication device; a down converter coupled to the preamplifier for decreasing frequencies of the input signals amplified and generating corresponding intermediate frequency (IF) signals; an IF filter coupled to the down converter for filtering the IF signals based on a predetermined frequency resolution and predetermined center frequency; a power meter coupled to the IF filter for measuring powers of the IF signals; and a personal computer coupled to the power meter via a first control interface operation to generate frequencies corresponding to the powers, the PC being operative to read frequencies, convert the frequencies into real frequencies based on a calibration table, and plot a frequency analysis graph.

Abstract: A channel adapted for at least one of providing and receiving signals comprises a channel clock domain, whereby said channel clock domain is under clock control of a channel clock. The channel clock domain comprises at least one of: a drive path adapted for providing signals and a receive path adapted for receiving signals. The channel further comprises a service clock domain adapted for at least one of providing data to and receiving data from said channel clock domain, whereby said service clock domain is under clock control of a service clock.

Abstract: A plurality of signals are received in a shared spectrum. Samples of the received user signals are produced as a received vector. The received vector is segmented into a plurality of segments. For each segment, successively determining symbols for each user or group of signals (the group of signals having similar received power) by determining symbols for one user/group and removing a contribution of that one user/group from the received vector. The determined symbols corresponding to each segment are assembled into a data vector.

Abstract: Disclosed is an adaptive receiving MIMO (multi input and multi output) system and method which decides a symbol detecting order so as to estimate the symbol having the minimum summation of weights of least square errors at the time of estimating the symbol for respective equalizers provided in parallel by the number of transmit antennas, and updates filter tap coefficients based on the RLS algorithm according to the detecting orders. Therefore, the filter tap coefficients are directly updated without tracking channels in the time-varying channel environment, and accordingly, detection performance very similar to those of the channel tracking and conventional V-BLAST scheme is provided with reduced complexity.

Abstract: A decision feedback equalizer (DFE) architecture uses feedback samples that are over-sampled with respect to the symbol rate. On-baud feedback samples are quantized with a slicer, while off-baud samples are linear, IIR samples. Both forward and feedback filters are fractionally-spaced, but adapted only at the baud instances.

Abstract: An encoding manager performs a first-pass encoding of a video sequence, collecting modeling data concerning the sequence in the process. The encoding manager utilizes collected data to construct a model concerning the sequence, the model including bit overhead for each frame and data concerning transitions that occur during the sequence. The encoding manager uses the data model to generate a rate profile for the video sequence, avoiding buffer underflow by allocating bits from hard to easy segments as needed. The encoding manager utilizes the rate profile to perform a second-pass encoding of the video sequence, adjusting quantization and bit rate for frames as necessary to avoid underflow and conform to the bit budget for the video sequence.

Abstract: A VSB communication system or transmitter for processing supplemental data packets with MPEG-II data packets includes a VSB supplemental data processor and a VSB transmission system. The VSB supplemental data processor includes a Reed-Solomon coder for coding the supplemental data to be transmitted, a null sequence inserter for inserting a null sequence to an interleaved supplemental data for generating a predefined sequence, a header inserter for inserting an MPEG header to the supplemental data having the null sequence inserted therein, a multiplexer for multiplexing an MPEG data coded with the supplemental data having the MPEG header added thereto in a preset multiplexing ratio and units. The output of the multiplexer is provided to an 8T-VSB transmission system for modulating a data field from the multiplexer and transmitting the modulated data field to a VSB reception system.

Abstract: An encoded-data converting apparatus and method are provided. First encoded data generated by using first encoding to encode image data is input. Header information included in the first encoded data is extracted. Header information based on second encoding is generated from the header information included in the first encoded data. Variable-length-code conversion is set up based on a predetermined parameter for use in the second encoding and an encoding parameter used in the first encoding. Encoded data in one frame is extracted from the first encoded data. A variable length code in the encoded data in the frame is converted in accordance with the variable-length-code conversion. DC components in the encoded data in the frame are decoded into quantized values and the quantized values are used to perform predictive encoding based on the second encoding. The obtained outputs are shaped and output as data encoded by the second encoding.

Abstract: Methods and apparatus, including computer program products, implementing and using techniques for computing motion vectors in a digital video sequence are disclosed. A recursive hierarchical method is used to determine a motion vector by using multiple resolution levels of the image frames. A best motion vector is first determined for the lowest resolution level. The best motion vector is propagated to a higher resolution level, where some adjustments are made and a new best motion vector is determined. The new best motion vector is propagated to yet another higher resolution level, where more adjustments are made and another new best motion vector is determined. This process is repeated until the highest, original, resolution level has been reached and a best motion vector has been identified. The identified best motion vector at the original resolution level is used for performing motion compensation.

Abstract: A multi-part fixed codebook includes both individual fixed codebooks for each channel and a shared fixed codebook. Although the shared fixed codebook is common to all channels, the channels are associated with individual lags. Furthermore, the individual fixed codebooks are associated with individual gains, and the individual lags are also associated with individual gains. The excitation from each individual fixed codebook is added to the corresponding excitation (a shared codebook vector, but individual lags and gains for each channel) from the shared fixed codebook.

Abstract: A method for processing a video bitstream is disclosed. The method generally includes the steps of (A) determining co-located motion information for a plurality of co-located sub-blocks in a co-located macroblock of the video bitstream, (B) storing the co-located motion information for (i) at least a first three of the co-located sub-blocks along a left side of the co-located macroblock, (ii) at least a second three of the co-located sub-blocks along a right side of the co-located macroblock and (iii) less than all of the co-located sub-blocks and (C) inferring current motion information for a current macroblock co-located in a different picture from the co-located macroblock using the co-located motion information that was stored.

Abstract: The frame-memory control-section partitions a frame memory into a plurality of sectors and stores decoded video data of frames not used as predictive video in the frame memory. The frame-memory control-section writes a top-field data and a bottom-field data of the decoded video data into separate free sectors of the frame memory. In reading and displaying the decoded video data from the frame memory, the frame-memory control-section simultaneously releases the sector that stores the top-field data and the sector that stores the bottom-field data during the last display field period of the display video.

Abstract: A system and method are provided for stopping a quantized signal from a noise-shaper with a significantly reduced inband transient, compared to a traditional random stop of a noise-shaped signal. The noise-shaped signal is stopped at a favorable time controlled by a detector that monitors the noise-shaped signal. The detector indicates the occurrence of a good time to stop the noise-shaper such that the transient due to the stop is minimized in a fashion that substantially reduces the inband disturbance.

Abstract: A receiver for orthogonal frequency division multiplexing signals, including art A/D converter for converting receiver analog signals to a digital signal data stream, wherein the digital signal data stream includes symbols separated by guard segments. The receiver also includes an I/Q demodulator for producing a first set of complex I and Q components from the digital signal data stream and a guard segment length detector using the first set of I and Q components. It further includes an extractor for identifying and removing the guard segments of the detected length from the digital signal data stream and an FFT demodulator for demodulating the symbols of the digital signal data stream to produce second sets of complex I and Q components.

Abstract: A matrix {circumflex over (V)} of eigenvectors is derived using an iterative procedure. For the procedure, an eigenmode matrix Vi is first initialized, e.g., to an identity matrix. The eigenmode matrix Vi is then updated based on a channel response matrix ? for a MIMO channel to obtain an updated eigenmode matrix Vi+1. The eigenmode matrix may be updated for a fixed or variable number of iterations. The columns of the updated eigenmode matrix may be orthogonalized periodically to improve performance and ensure stability of the iterative procedure. In one embodiment, after completion of all iterations, the updated eigenmode matrix for the last iteration is provided as the matrix {circumflex over (V)}.

Abstract: The present invention comprises systems, methods, and devices for detecting the presence of a specified signal type by autocorrelating the signal with a time-delayed copy of itself, by simultaneously crosscorrelating the signal with an expected signal type, and by then comparing the results of the autocorrelation and crosscorrelation to determine whether or not the signal is present and to ascertain its type.

Abstract: A turbo decoder is disclosed that receives a demodulated input signal before a hard decision, including blocks each of multiple data units, and outputs a decoded signal block by block. The turbo decoder includes a decoding part outputting a decoded output signal and extrinsic likelihood information based on the input signal and preliminary likelihood information, the extrinsic likelihood information being used as the preliminary likelihood information in creating the next output signal; a specification part specifying a data unit of the block with respect to which no error is detected in error checking performed on each data unit of the hard decision output signal; and a replacement part inputting a signal sequence, created by replacing signal data before the hard decision with those after the hard decision with respect to the data unit specified by the specification part, to the decoding part as the input signal.

Abstract: A method and apparatus for encoding data bits in a DMT modulation system is provided utilizing a 64-state Trellis encoder to achieve further improvement in the achievable coding gain by employing coset partitioning, bit conversion, and constellation encoding that fit the DMT modulation. The coding gain of the new coder is around 5.63 dB, which is about 0.96 dB higher than the current Trellis coder in the DMT standard.

Abstract: The present invention relates in general to a method, apparatus, and article of manufacture for providing high-speed digital communications through a communications channel. In one aspect, the present invention employs adaptive or adjustable equalization circuitry and techniques in the transmitter and/or receiver to enhance the system performance of, for example, a system using the PAM-4 coding.

Abstract: An identification tag is provided in which radio frequency (RF) circuitry and ultrawide bandwidth (UWB) circuitry are both provided on the same tag, along with some UWB-RF interface circuitry. The RF circuitry is used to detect when the identification tag must be accessed, and is used to connect the UWB circuitry with a power supply. The UWB circuitry then performs the necessary communication functions with a distant device and the power supply is again disconnected. In this way the power supply is only accessed when the UWB circuitry is needed and it's usable lifetime can be maximized.

Abstract: A wireless communication system (10). The system comprises a user station (12). The user station comprises despreading circuitry (22) for receiving and despreading a plurality of slots received from at least a first transmit antenna (A121) and a second transmit antenna (A122) at a transmitting station (14). Each of the plurality of slots comprises a first channel (DPCH) comprising a first set of pilot symbols and a second channel (PCCPCH) comprising a second set of pilot symbols. The user station further comprises circuitry (50) for measuring a first channel measurement (?1,n) for each given slot in the plurality of slots from the first transmit antenna and in response to the first set of pilot symbols in the given slot. The user station further comprises circuitry (50) for measuring a second channel measurement (?2,n) for each given slot in the plurality of slots from the second transmit antenna and in response to the first set of pilot symbols in the given slot.

Abstract: Techniques for direct modulation of a switching-mode power amplifier with adaptive digital predistortion are disclosed. A baseband digital modulated signal is decomposed into an amplitude signal and a phase signal in polar coordinates. The amplitude signal is used to modulate supply voltages of the power amplifier. The phase signal is used to modulate a voltage-controlled oscillator (VCO) of a phase-locked loop (PLL), which generates a phase-modulated radio-frequency (RF) carrier coupled to the input of the power amplifier. The digital predistortion is implemented by using a feedback demodulator, which regenerates the baseband amplitude and phase information from the output of the power amplifier. The VCO drift and other non-linear effects of the power amplifier are compensated. High power efficiency and high linearity for different modulation standards are achieved.

Abstract: A quadrature modulator includes a local oscillator oscillating at an oscillation frequency equal to 4/(2N+1) times a carrier frequency where N is a natural number, a frequency conversion block for multiplying the oscillation frequency by a factor of (2N+1)/2, a divider for dividing the multiplied oscillation frequency to output a pair of orthogonal carrier waves, first and second multipliers for modulating the carrier waves with a digital baseband signal, and an adder for adding the modulated carrier waves to output a carrier signal having the carrier frequency. The frequency conversion block includes a divider for dividing the oscillation frequency, N frequency mixers cascaded from one another and a band-pass-filter, which are cascaded in this order.

Abstract: A method for reference signal generating in an ultra wideband (UWB) communication system which sends out and receives data by using at least two reference signals of predetermined frequencies. A first signal group, which comprises a local oscillation (LO) signal and a signal at a predetermined phase difference with respect to the LO signal, is generated. One among at least two intermediate frequency (IF) signals is selected for the adjustment of the frequency of the LO signals, and a second signal group, which comprises the selected IF signal and a signal at a predetermined phase difference with respect to the selected IF signal, is generated. Two mixed signals are generated from the first and the second signal groups, the mixed signals being mixed without overlap, and a reference signal is generated by adding the two generated signals.

Abstract: A baseband shaping device includes a plurality of coefficient memories, each memory having an input address bus, a multiplexor input and a coefficient value output. The device further includes a plurality shift registers, each having an input coupled to a respective one of the coefficient value outputs, a digital to analog clock input and an output. The device further includes a plurality of negative value circuits, each circuit having an input coupled to a respective one of the first shift register outputs and an output, a plurality of multiplexors, each having a first input coupled to a respective one of the first shift register outputs and a second input coupled to a respective one of the output of the plurality of negative value circuits. The device further includes a plurality of second shift registers, and an adder having a plurality of inputs coupled to the plurality of second shift registers.

Abstract: Methods and apparatus are described for estimating a gain offset between two channels in a communication system. The gain offset arises from the system's transmission of signals on the two channels at different powers. The estimated gain offset is used for determining a set of complex channel estimates.

Abstract: In a secure method of deciding on a communication channel in a data decompression device, the compressor detects channels that vary from one frame to another, which are referred to as “active” channels. It transmits active and passive channels in a data block which also contains a state code locating the active data in the starting frame in order to be able to reconstitute it in the decompressor. A reference pattern is transmitted incorporating the passive channels and a majority vote statistical analysis is applied to the states of the passive channels to decide on the state (0 or 1) of each bit constituting the pattern repeated by each passive channel. One particular application of the method is to a satellite telecommunication system.

Abstract: A receiving method for dual-mode receiver. When a received communication signal is a wideband signal, the dual-mode receiver is configured as a direct-conversion receiver, and when a received communication signal is a narrowband signal, the dual-mode receiver is configured as a low-IF receiver.

Abstract: A method for payload-based channel estimation of a wireless channel begins by receiving a frame via the wireless communication channel. The frame includes a training sequence, a frame information section, and a plurality of time sequential data payload sections. As the frame is being received, the method continues by determining a channel estimation based on the training sequence. The method continues as the frame is being received by determining a channel estimation of a data payload section of the plurality of time sequential data payload sections to produce a payload channel estimation. The method continues as the frame is being received by updating the channel estimation based on the payload channel estimation to produce an updated channel estimation.

Abstract: A desired signal and at least one interfering signal are joint demodulated with a Viterbi equalizer having an adaptive total number of states. The total number of states is based on channel impulse response (CIR) coefficients associated with the desired signal and the at least one interfering signal.

Abstract: A synchronization unit for performing fine synchronization in the Time Domain, the synchronization unit includes a storage configured to store reference signals. A multiplier capable of calculating sum of zero product shift, sum of minus one product shift, and sum of plus one product shift, based on the reference signals. A signal analyzer capable of computing left, center, and right cross-correlation points based on the sum of minus one product shift, the sum of plus one product shift, and the sum of zero product shift. A timing error estimation unit capable of estimating timing error of the received signal based on the left cross-correlation point and the right cross-correlation point. A phase estimation unit capable of estimating common phase error of the received signal based on the sum of zero product shift.

Abstract: The present invention relates to a method for transmitting signaling information between an access point and a terminal of a multi-carrier radio communication network, said signaling information comprising information related to the different sub-carriers (and being transmitted on one predefined sub-carrier) according to the present invention, the method comprises the steps of performing a de-correlation transformation on said signaling information by exploiting the correlation between at least two sub carriers and applying an entropy compression on said de-correlated signaling information.

Abstract: Systems and methods for providing frequency compensation over a wide range of frequency drift are shown. The preferred embodiment utilizes a sweep mode function to provide frequency compensation over a range of frequency drift broader than the frequency drift accommodated by a phase lock loop, without increasing the noise characteristics of the phase lock loop. Accordingly, the preferred embodiment operates in a phase lock loop mode while frequency drift can be compensated for by the lock range of the phase lock loop circuitry. The preferred embodiment operates in sweep mode to step through a range of offset frequencies to position the phase lock loop mode where frequency drift can be compensated for by the lock range of phase lock loop circuitry. Additionally, a preferred embodiment of the present invention includes a drift mode in order to monitor frequency offset information, such as may be used in performing sweep mode functions and/or other control or management functions.

Abstract: Various apparatuses and methods are described to reduce interference in signals subject to intermodulation products and high power narrow band interfering signals on lower power wideband signals. Apparatuses and methods described herein also provide the capability for supporting multi-standards, multi-modes and multi-bands in wireless and wired applications with a single receiver or a receiver with minor variations. The receiver described herein samples the entire band in which there can be signals of interest or signals that can generate interference. All of these signals are sampled in one bit stream and the bit stream is processed to isolate signals of interest and interfering signals. The isolated interfering signals are then cancelled out of the signals of interest.

Abstract: Improved performance, particularly gain in SNR, in high-bandwidth OFDM receivers, software and systems is achieved by compensating channel estimates not only for carrier frequency offset and phase noise, but also for interference caused by sample phase jitter. At high bandwidths, e.g. using 256 QAM symbol constellation, significant SNR improvement is gained by determining and applying a corresponding compensation to each data sub-carrier channel, the compensation preferably including a term that increases linearly with the sub-carrier index.

Abstract: A receiver system and method are disclosed for processing multipath propagated signals and multiband signals. The receiver includes a zero-intermediate frequency converter for demodulating one of the plurality of multipath propagated signals to produce a demodulated signal; and a sampling module for sampling the demodulated signal.

Abstract: A non-uniform filter bank is created by joining sections of oversampled uniform filter bands that are based on complex exponential modulation (as opposed to cosine modulation). Each filter bank handles a given, non-overlapping frequency band. The bands are not of uniform bandwidth, and the filters of different banks have different bandwidths. The frequency bands of the different filter banks cover the frequency of interest with gaps in the neighborhoods of the filter band edges. A set of transition filters fills those gaps.

Abstract: A method of operating a message receiver for a message, that is present as a burst, which includes at least a training sequence and useful data is performed by stepwise synchronizing the receiver with the burst as the burst is received.

Abstract: A circuit and method for generating a local clock signal and a telecommunications system incorporating the circuit or the method. In one embodiment, the circuit includes: (1) a phase detector for receiving an input data signal, (2) (at least) first and second continuously controllable delay lines, coupled to the phase detector, for producing respective first and second candidate local clock signals and (3) delay line selector, coupled to the first and second delay lines, for selecting one of the first and second candidate local clock signals to be the local clock signal based on phase excursions in the input data signal.

Abstract: A photocatalytic substance having the properties of an n-type semiconductor is deposited on a surface of a metal base made of a stainless steel or Inconel. When necessary, the hydrogen concentration of the reactor water is increased. A current produced by the photocatalytic substance when the same is irradiated with light or radioactive rays in a nuclear reactor flows through the metal base to reduce corrosion current. When necessary, the photocatalytic substance is provided on its surface with at least one of Pt, Rh, Ru and Pd.