Abstract: The present invention provides for a propagated signal using multiple pulse per group keying and a method of using the same. In one embodiment the propagated signal includes: (1) an element of data contained within a time period of the propagated signal, the time period divided into a group of time slots; and (2) multiple pulses distributed in a predetermined manner among the time slots by pulse group keying to encode the data.

Abstract: A communication system including a queue length extracting function unit extracting from information stored for each connection, a parameter setting function unit for setting the contracted parameters of a sustainable cell rate and peak cell rate and contracted parameters of fluctuation values allowed in these bandwidths for each connection, a parameter managing memory (43) for storing the queue length information and the contracted parameter information, a bandwidth calculating function unit for re-storing in the memory results of periodic calculation of the bandwidths allocated to connection so that the contracted parameters are observed, and a transfer polling information generating function unit (45) for determining timings of transfer of information in accordance with the calculated allocated bandwidth and outputting it as the polling information.

Abstract: In a communication system in which a plurality of communication terminals sequentially transfer data to a server during the respective transmission permissible periods assigned to the respective communication terminals, the communication terminal transfers a preamble for synchronization to the server at a time of starting the transmission permissible period, converts a data frame for every 8 bits into every 10 bit-code, and transmits to the server, the signal string with a code indicating the head added there, during the transmission permissible period, and turns a communication to the server into a zero signal state, during a period other than the transmission permissible period, while the server establishes a synchronization by reading the preamble for synchronization inserted into the signal string received from each of the communication terminals, converts a portion of the zero signal state of the signal string into a predetermined special code string, and inversely transforms the received signal string i

Abstract: In an information transmission method, a radio communications system, a base station and a mobile station, a TBS size, a modulation scheme and the number of codes in a multicode are converted into identification data having a relatively smaller data size before being transmitted to a destination of communication. The TBS size is identified by using, in combination, an identification code identifying a channelization code set, an identification code identifying a modulation scheme, and an identification code obtained by converting a combination of the number of codes in a multicode and a modulation pattern identification (TFRC) into a corresponding code. Accordingly, the data size for TBS size identification is reduced.

Abstract: A method for transmitting and receiving leased line data, an apparatus for transmitting leased line data, and an apparatus for receiving leased line data are provided. The method includes storing received leased line data in a FIFO; packing the leased line date stored in the FIFO into the payload of a DSL frame; and transmitting the packed DSL frame. According to the method, leased line data can be transparently transmitted by adding minimum function blocks to the DSL modem, and with the simple circuit structure, the blocks can be integrated into one chip such that no additional external circuits are needed and a low-priced DSL modem chip that can transmit leased line data can be implemented.

Abstract: The present invention relates to a method for ensuring access to a transmission medium at a predetermined point in time, for transmission of a data packet. This is achieved by making one or more communication pons on which the packet is to be transmitted unavailable for conflicting traffic for a period of time that is set to expire at the desired point in time, and preparing the data packet to be transmitted as soon as said communication port again is made available. Also described is a time server for distributing time information packets utilizing the method.

Abstract: An n-level look-ahead network converts input values to intermediate values that are provided to a plurality of multiplexers arranged to form a pipelined multiplexer loop. The first stage of the multiplexer loop consists of a single multiplexer. The second stage consists of at least two multiplexers. Communication links couple the output ports of the second stage multiplexers to the input ports of the first stage multiplexer. A first feedback loop electrically couples the output port of the first stage multiplexer to the control port of the first stage multiplexer. This first feedback loop has a first delay device having a first delay time. A second feedback loop couples the output port of the first stage multiplexer to the control ports of the second stage multiplexers. This second feedback loop includes the first delay device and a second delay device having a second delay time.

Abstract: Digital circuits and methods for designing digital circuits are presented. In an embodiment, a number of bits (B) of a bit-stream to be processed in parallel by a digital circuit is selected. A clocking rate (C) is selected for the digital circuit such that a product (P), P being equal to B times C, is equal to at least 1 gigabit per second. An initial circuit capable of serially processing the bits of the bit-stream at a data processing rate less than P is formed. This initial circuit includes a feedback loop having N+1 delays. N is a whole number greater than zero. The initial circuit is unfolded by a factor of B to form B parallel processing pipelines for the bits of the bit-stream. An N-step look-ahead network is formed to provide inputs to the B parallel processing pipelines. The unfolded circuit is retimed to achieve the selected clocking rate (C).

Abstract: It is so arranged that a voice code can be converted even between voice encoding schemes having different subframe lengths. A voice code conversion apparatus demultiplexes a plurality of code components (Lsp1, Lag1, Gain1, Cb1), which are necessary to reconstruct a voice signal, from voice code in a first voice encoding scheme, dequantizes the codes of each of the components and converts the dequantized values of code components other than an algebraic code component to code components (Lsp2, Lag2, Gp2) of a voice code in a second voice encoding scheme. Further, the voice code conversion apparatus reproduces voice from the dequantized values, dequantizes codes that have been converted to codes in the second voice encoding scheme, generates a target signal using the dequantized values and reproduced voice, inputs the target signal to an algebraic code converter and obtains an algebraic code (Cb2) in the second voice encoding scheme.

Abstract: A laser system including a controller for monitoring and controlling various functions of a laser assembly. The laser controller may include a wavelength tuning circuit for adjusting and locking the wavelength of the external cavity. To perform various monitoring and control functions, the controller may include circuitry for monitoring various parameters associated with operation of the laser, such as temperature indicating signals and/or signals from light detectors such as photodiodes.

Abstract: A laser system including a controller for monitoring and controlling various functions of a laser assembly. The laser controller may include a wavelength tuning circuit for adjusting and locking the wavelength of the external cavity. To perform various monitoring and control functions, the controller may include circuitry for monitoring various parameters associated with operation of the laser, such as temperature indicating signals and/or signals from light detectors such as photodiodes.

Abstract: A laser system including a controller for monitoring and controlling various functions of a laser assembly. The laser controller may include a wavelength tuning circuit for adjusting and locking the wavelength of the external cavity. To perform various monitoring and control functions, the controller may include circuitry for monitoring various parameters associated with operation of the laser, such as temperature indicating signals and/or signals from light detectors such as photodiodes.

Abstract: A third harmonic laser system includes a fundamental wave resonator for generating fundamental laser beam, a second harmonic laser generator for converting fundamental laser beam to a second harmonic laser beam, and a third harmonic laser generator for mixing the second harmonic laser beam with the fundamental laser beam so as to produce a third harmonic laser beam. Multi-pass tripling is used for producing the third harmonic laser beam by means of reflecting and polarizing mirrors, and that the outputted third harmonic laser beam has a high efficiency of about 51% and a high power up to 8.6W.

Abstract: An elongated structure includes a core, at least one and preferably a plurality of gain medium layers disposed about said core for providing a plurality of characteristic emission wavelengths, and a growth matrix or functionalized support suitable for the synthesis therein or thereon of a chemical compound. Other embodiments can be spherical, or planar with a plurality of optical gain medium dots, each providing a different emission wavelengths. Also disclosed is a technique for selectively locating micro-laser beads of interest, and then aiming a laser source at the bead(s) of interest in order to interrogate the optically encoded identification information. Also disclosed is a bead of a type that includes a functionalized support, and that further includes a gain medium coupled to a structure that supports the creation of at least one mode for electromagnetic radiation, and/or which has a dimension or length in one or more directions for producing and supporting amplified spontaneous emission (ASE).

Abstract: A system for producing a green or UV output beam for illuminating a large area with relatively high beam fluence. A Nd:glass laser produces a near-infrared output by means of an oscillator that generates a high quality but low power output and then multi-pass through and amplification in a zig-zag slab amplifier and wavefront correction in a phase conjugator at the midway point of the multi-pass amplification. The green or UV output is generated by means of conversion crystals that follow final propagation through the zig-zag slab amplifier.

Abstract: The invention relates to a laser with a decoupling means for emitting a laser output depending on at least one influenceable parameter and a mode-coupling means for coupling a plurality of the laserable modes of the resonator. According to the invention, a detection means is provided for detecting a value related to the emitted laser output and a parameter varying means for varying the at least one parameter in response to the detected value.

Abstract: An optical margin testing system is provided for automatic power control loops. An optical circuit includes a laser diode and a monitor diode coupled to the automatic power control loop. A bias generator circuit generates a control signal. The control signal is applied to the automatic power control loop. The control signal enables an operation point of the laser diode to both increase and decrease by a set percentage value for optical margin testing. The bias generator circuit includes a tri-state receiver. An input signal is applied to the tri-state receiver for selecting one of a normal operational mode, an increased set percentage value operational mode, and a decreased set percentage value operational mode. A current mirror is coupled to the tri-state receiver provides the control signal that is applied to the automatic power control loop.

Abstract: A wavelength variable light source emits a light whose wavelengths continuously change from a preset start wavelength up to a stop wavelength to a measuring object. A timing information output section generates timing information showing emission timings of lights emitted from the wavelength variable light source and having start and stop wavelengths and a plurality of wavelengths obtained by delimiting the wavelengths between the start and stop wavelengths in predetermined steps. A light receiving section receives the light output from the measuring object and outputs a signal showing a measured value of a received light. A plurality of amplifiers receive the signal output from the light receiving section and amplify the signal at each predetermined amplification factor.

Abstract: The present invention relates to the control or stabilisation of the lasing wavelength of a source of laser radiation (8), comprising a semiconductor material laser (2), a substrate (4) to which the laser (2) is mounted, a resonant optical cavity (15) within the semiconductor material (16,18,20), the cavity (15) having an active medium (16) for generating laser radiation (8) and one or more gaps (28) in the semiconductor material (16,18,20) within the cavity (15), wherein the substrate (4) is deformable by the application of a mechanical stress (14) to vary the size of said gap(s) (28) in order to change the optical size of said gap(s) and hence to vary the wavelength of laser radiation (8) generated by the semiconductor laser (2).

Abstract: The invention relates to a pump chamber (2), in which laser active medium is stored. The pump light is introduced into said pump chamber (2), by means of one or several fluid light guides (12), whereby the fluid used as a light guide is used as coolant for the laser active medium (1).

Abstract: A laser bar is soldered to a conventional microchannel copper heat sink whose coefficient of thermal expansion (CTE) is locally modified in the area where the laser bar is soldered to better match the CTE of the laser bar. A strip of ceramic material having a CTE lower than that each of the laser bar and of the copper heat sink is soldered to portions of the metallic heat sink located adjacently to the surface area on which the laser bar is located. The inclusion of the ceramic strips enables a laser bar having a nominal CTE of 6.6×10−6/K, to be soldered directly to a copper heat sink having a nominal CTE of 16.5×10−6/K without incurring thermal distortions at the interface that would limit the useful life of the laser bar.

Abstract: A small-sized light source of laser diode modules includes a plurality of coolerless laser diode modules without built-in Peltier devices arranged in a dense cluster, where each module includes a laser diode chip, optical components, a metal substrate with the laser diode chip and the optical components mounted thereon. It further includes a plurality of laser diode modules with a built-in cooler, where each module includes a laser diode chip, optical components, a metal substrate with the laser diode chip and the optical components mounted thereon, and a Peltier device thermally connected to the metal substrate.

Abstract: An elongated structure includes a core, at least one and preferably a plurality of gain medium layers disposed about said core for providing a plurality of characteristic emission wavelengths, and a growth matrix or functionalized support suitable for the synthesis therein or thereon of a chemical compound. Other embodiments can be spherical, or planar with a plurality of optical gain medium dots, each providing a different emission wavelengths. Also disclosed is a technique for selectively locating micro-laser beads of interest, and then aiming a laser source at the bead(s) of interest in order to interrogate the optically encoded identification information. Also disclosed is a bead of a type that includes a functionalized support, and that further includes a gain medium coupled to a structure that supports the creation of at least one mode for electromagnetic radiation, and/or which has a dimension or length in one or more directions for producing and supporting amplified spontaneous emission (ASE).

Abstract: An injection locking type or MOPA type of gas laser device which requires only a small installation area and allows easy maintenance. For this purpose, the laser device includes a seed laser unit (11) for exciting a laser gas inside a laser chamber (12) and oscillating seed laser light (21) and an amplifier (111) for exciting a laser gas inside an amplifying chamber (112) and amplifying pulse energy of the seed laser light (21), and allows the laser chamber (12) and the amplifying chamber (112) to be evacuated to the same side with respect to an optical axis of the seed laser light (21).

Abstract: There is to provide a laser apparatus that emits a laser beam by exciting gas enclosed in a chamber, including a gas characteristic detecting mechanism for detecting a characteristic of the gas in the chamber, and a calculation mechanism for calculating an oscillation wavelength and/or a wavelength spectral bandwidth of the laser beam based on a detected result by the gas characteristic detecting mechanism.

Abstract: An etalon includes an analyzer, a first &lgr;/4 plate having an optical axis forming a 45 degree angle with respect to an optical axis of the analyzer and receiving a light transmitted via the analyzer, and a second &lgr;/4 plate having an optical axis which is parallel to or 90 degrees to the optical axis of the, first &lgr;/4 plate and receiving a light transmitted via the first &lgr;/4 plate. A reflection may occur between the first and second &lgr;/4 plates.

Abstract: A method of producing a distributed reflector that includes a grating, wherein regions (21) are provided in the grating material transversely to the longitudinal axis of the grating, wherein the refractive index in said regions is lower or higher than the refractive index in surrounding parts of the grating, and wherein the distance between mutually adjacent regions (22) is varied. The invention is characterised by giving the regions (21) mutually the same width, and determining the positions of the various regions along the longitudinal axis (X) of the grating in relation to the wavelengths to be reflected.

Abstract: A light source apparatus equipped with a GaN type semiconductor laser, wherein deformation of the shape of the light spot due to fluctuations in the drive current of the light emitting element is prevented, is provided. A light source apparatus equipped with a GaN type semiconductor laser is provided with a slit panel or other spatial filter for eliminating stray light, which amounts to 20% or less of the total output occurring when the GaN type semiconductor laser is driven at maximum output, from the light emitted from the GaN type semiconductor laser.

Abstract: We disclose a new structure that allows the creation of sharp and asymmetric lineshapes in optical microcavity systems. In this structure, the response function can vary from 0% to 100% in a frequency range that is narrower than the full width of the resonance itself. Therefore, an optical switch, based upon this structure, may require far less frequency shift to operate, compared with conventional microcavity-based structures. This method may also be used to improve the sensitivity of optical sensors based upon microcavity structures.

Abstract: A laser diode collimating system comprises a collimating lens for receiving a laser beam from a laser diode LD. First and second orthogonally arranged cylindrical lenses are provided through which the laser beam passes. The cylindrical lenses are positioned so as to have a substantially common focal plane and operate substantially independently on the divergence and/or convergence of the laser beam in its fast axis and slow axis directions respectively. A convex lens, through which the beam passes, has a focus lying in the said common focal plane.

Abstract: A sensor designed for measurement of conducted heat flux passing through a solid object consists of a thin film thermopile deposited on a planar substrate whose thermal properties match those of the solid object. The thermopile is protected by a thin rectangular plate made of the same material as the substrate. The sensor is imbedded in the solid object and measures the vector of heat flux along the thermopile axis with minimal distortion of the heat flow pattern. Applications include measurement of heat flux in casting molds, boiler tubes, well surveying instruments and laser weapons testing.

Abstract: Temperature of molten silicon 1 in an infrared image furnace 2 including a halogen lamp 8 as a heating source to grow a single crystal of silicon in a floating-zone method is measured with high precision according to light radiated from the molten silicon 1. By disposing an optical path tube extending to the molten silicon 1, light propagating from the molten silicon 1 in a particular direction can be extracted. As a result, light radiated from the molten silicon 1 can be extracted while reducing the influence of disturbance of light from various directions such as light radiated from the halogen lamp 8, reflected light and scattered light thereof, and the like. Luminance of light thus extracted is measured by a CCD camera 7 to obtain the temperature according to the luminance, and hence the temperature can be measured with high precision using a measuring apparatus of a simple configuration.

Abstract: A method and apparatus for measuring the core temperature of an animal or human. Emissions from the eyeball are detected, at one or more wavelengths selected on the basis of various factors, including the ability of that wavelength to reach the interior of the eyeball. An illumination marker shines a spot of light on the eyeball, such that the spot corresponds to the area from which emissions are being detected.

Abstract: A temperature sensor is integrated together with an integrated circuit on a chip, the sensor delivering a temperature-dependent measuring signal or at least emitting a signal when the chip temperature falls below a specific prescribed value. For such an eventuality, the chip includes a special circuit device thereon, by which a current flow is generated through a provided structure of electrical conductors that keeps the temperature of the integrated circuit above a prescribed minimum temperature.

Abstract: A system for generating (PN) spread signals is provided. The system includes a first clock synchronized with a second clock and at least three first pseudo-noise (PN) component code generators coupled to the first clock. A logic combiner is coupled to the PN component code generators and is adapted to generate a composite PN code. Both clocks are coupled to respective N-bit and M-bit counters.

Abstract: A universal rake receiver architecture includes modular independent processing units that can be flexibly programmed to support different modes of operation. The processing units are capable of performing the basic correlation calculations of DS-CDMA and each unit has an internal local memory and controller that controls its mode of operation. Each unit performs the required synchronization and demodulation operations for a multipath of a signal in the digital domain using all-digital frequency and timing correction techniques. Frequency feedback need not be supplied to the analog section of the receiver. Interpolation most preferably is used to find the optimum sampling position of each incoming chip. This independence allows the receiver to be used with one to several antennas without design modifications.

Abstract: In a UMTS (universal mobile telecommunications system) based system, a wireless receiver implements “effective signal-to-noise (Eb/No) based BER estimation.” In particular, the wireless receiver comprises a rake receiver, a processor and memory. The rake receiver processes a received signal and provides signal-to-noise ratio values for each slot of each received frame of the received signal. The processor converts these signal-to-noise ratio values for each received frame into an effective signal-to-noise ratio value for the received signal. The processor then uses the effective signal-to-noise ratio value as a pointer, or index, into a look-up table (stored in the memory) and retrieves a BER estimate therefrom.

Abstract: Novel techniques are disclosed for detecting discontinuous transmission (DTX) over a communication channel. A received data frame is characterized as one of a Good frame, Erasure, or DTX. If a Good frame is not initially detected, a multi-dimensional quality metric is used to characterize the received frame as either an Erasure or DTX. A two dimensional quality metric may be generated using energy per bit to noise power ratio as a first dimension and re-encoded symbol error count as a second dimension. Alternatively, re-encoded symbol energy may be used as the second dimension of the quality metric. The communication channel may be a CDMA wireless communication channel capable of DTX and the device may be a base station, base station controller, or mobile station.

Abstract: Techniques for time tracking diversity pilots are disclosed. In one aspect, an early and a late energy calculation is made on each incoming symbol using a first pilot sequence for despreading. The difference between the two energies is used to drive a tracking loop, which generates a time reference for producing a first pilot estimate and a second pilot estimate, the two estimates used for demodulating data. In another aspect, the early and late energies are made including a plurality of incoming symbols, the number of which corresponds to the number of symbols in a run of positive or negative values in an orthogonalizing sequence. The orthogonalizing sequence is used to generate a second pilot sequence from a first pilot sequence, the resulting second pilot sequence being orthogonal to the first. These aspects have the benefit of simplifying the hardware or processing steps required for transmit diversity time tracking, resulting in cost savings, power savings, simplicity of design, and the like.

Abstract: A power estimator for a Code Division Multiple Access (CDMA) receiver. A noise estimate of a received channel may be made by demodulating a received signal using an empty code or Walsh channel. The noise estimate may also be made by demodulating the Pilot signal in systems where potentially all Walsh codes are assigned to active channels. Where the channels are quadrature phase modulated, the noise estimator may take advantage of the Pilot channel configuration by demodulating only the quadrature element of the Pilot channel. The noise estimator demodulates the Pilot using signal processing stages that statistically correspond to the signal processing performed on traffic channels. The statistics of the processing performed in the noise estimate closely track the statistics of the signal processing performed on the traffic channels.

Abstract: A receiver and method for weight detection use received channel estimations and prior feedback information sent to a transmitter to estimate channel weights. The estimated channel weights may have been used by a base station to transmit diversity mode signals. In one embodiment, a trellis algorithm may be used to determine weights with no significant time-slot delay. The weights may be used to generate channel taps for use by a rake receiver in combining multipath components of received signals. In one embodiment, the receiver and method for weight detection may be suitable for use in closed loop diversity mode communication systems, including a Wideband Code Division Multiple Access (WCDMA) system.

Abstract: A receiver includes a searcher to identify pilot signals within a received signal and a pilot tracking unit to continuously track pilot signals identified by the searcher. The pilot signals tracked by the pilot tracking unit may include pilot signals associated with an affiliated base station as well as pilot signals associated with non-affiliated base stations. In at least one embodiment, the pilot tracking unit continuously tracks most or all of the pilot signals identified by the searcher.

Abstract: A method of estimating the difference in frequency between base station transmissions received over a radio channel and a locally generated carrier frequency in a mobile receiver. The differential phase shifts imparted to different parts of a received synchronization code because of a frequency offset of the local reference oscillator are detected in the receiver. A series of partial correlations of the received synchronization code over a single transmission slot allows detection of the differential phase shifts. Signal to noise ratios may be improved by means of a series of overlapping partial correlations. The period over which the correlations are performed is much less than the coherence time of the radio channel.

Abstract: Techniques for deriving interpolated pilot symbols for a gated pilot in a wireless (e.g., IS-856, cdma2000, or W-CDMA) communication system. In one method, first and second recovered pilot symbols for first and second time instances, respectively, are initially obtained (e.g., derived based on pilot bursts for the gated pilot). A phase change induced in the received signal at a third time instance between the first and second time instances is estimated. First and second phase-rotated symbols are next derived based on the first and second recovered pilot symbols and the estimated induced phase change. Interpolated pilot symbols between the first and third time instances are then derived (e.g., using linear interpolation) based on the first recovered pilot symbol and the first phase-rotated symbol. Similarly, interpolated pilot symbols between the third and second time instances are derived based on the second phase-rotated symbol and the second recovered pilot symbol.

Abstract: A region searcher, a method of driving the same, and a code searcher using the same are disclosed. When a predetermined region is iteratively searched, the energy value corresponding to the same hypothesis location value is stored by using a searcher having divided two buffers, thereby the implementation complexity thereof can be remarkably reduced, without using a simple memory.

Abstract: An apparatus for handling high speed data communication signals in at least one input channel. Each communication signal is encoded in signal excursions in at least one predetermined format. The apparatus includes: (a) at least one input locus coupled with each input channel for receiving the signals; (b) at least one output locus for presenting selected communication signals in a desired format in at least one output channel; and (c) a plurality of treating circuits for treating the signal excursions in a plurality of formats that include the predetermined format and the desired format. Each treating circuit is coupled with at least one respective input locus and at least one respective output locus. The apparatus presents sufficiently low capacitance between input loci and output loci to impart substantially zero time delay to the communication signals.

Abstract: A bit-error-rate (BER) test is a crucial test for wireless devices to pass, since a device with a high BER does not perform at its best. BER tests are both costly and difficult to perform due to a delay incurred by the device under test (DUT) 215 and the testing hardware that is variable in nature. Because the delay is variable, a hardware BER test that can compensate for the delay is difficult to build and a software BER test that can easily compensate for the delay is very slow. The present invention provides a method and apparatus that can compensate for the variable delay. By doing so, a hardware BER test, which is considerably faster than a software BER test, is easily implemented.

Abstract: Equalization for ports of a crosspoint switch at least partially offsets transmission losses such as skin loss. The equalization may be tailored on a port-by-port basis using adaptive equalization or adjustable equalization, but fixed equalization may be used. In some implementations, each input port or output port of a crosspoint switch has a dedicated equalization circuit that has filtering characteristics that are based on the signal characteristics (e.g., jitter) measured at the affected output port. For an adjustable equalization approach, the adjustable equalization circuitry includes various switched connections that are selectively coupled and decoupled to achieve the target level of equalization.

Abstract: A digital filter is provided for simultaneously filtering different components of a time-division-multiplexed signal. The digital filter comprises an odd number of a plurality of taps. A center tap and odd-numbered taps counted from the center tap all have coefficients equal to zero. The remaining taps, i.e., even-numbered taps counted from the center tap have coefficients for defining the filtering characteristic.

Abstract: A decision feedback structure for recovering a bit stream out of received signals is disclosed, wherein the sampling instant may be tuned in dependence of the sequence or pattern of the preceding bits so as to follow the bit sequence dependent instant of the maximum eye opening. The decision-feedback equalizer structure includes decision means for making a bit value decision at a sampling instant, a feedback path to feed back bit values to said decision means and means for adapting the sampling instant for a bit value decision made by said decision means with respect to the sampling phase depending on the bit values of preceding bits, in particular depending on the bit value of the previous bit.