Abstract: In a system including a first and a second modem pool, each modem pool including a plurality of modems, where each modem in one of the modem pools is paired with a corresponding modem in the other the modem pools, a method for controlling aggregate throughput including initializing each of the modems at an outbound throughput and an inbound throughput, where the outbound and inbound throughputs of at least one of the modems are determined independently from one another, determining an aggregate outbound throughput each of the modem pools, and for each of the modem pools whose aggregate outbound throughput exceeds an associated optimal aggregate throughput, reducing the outbound throughput of any of the modems until the aggregate outbound throughput equals the optimal aggregate throughput.

Abstract: A method of transmitting a data file over a communication medium (100), comprising determining relative desired reconstruction time frames for different parts of the file, allocating different transmission rates for the different parts of the file responsive to said determining, dividing the file into sections, encoding the sections using a FEC (forward error correction) code having the property that a file section can be reconstructed once a sufficient amount of encoded data relating to that data section is received (104), and transmitting the encoded sections to have effective retransmission rates matching said different retransmission rates (102), such that the parts can be reconstructed in their respective desired time frame.

Abstract: A system and method for management of bandwidth in a fiber optic, ethernet-based, TDMA communications system. A request/grant process is used to control the use of upstream bandwidth. A sense of time must therefore be shared by a headend and remote end-user devices. The invention provides for a gigabit media-independent interface in a media access controller to detect start-of-frame delimiters in incoming data. This allows for synchronization of a headend and end-user devices. The invention also allows for phase locking a transmit bit rate, at a headend, to the headend's clock. Transmitted data can the be used downstream to derive a local clock. Synchronization can also be maintained by the use of synchronization bytes in MPEG frames and/or variable length frames. Efficient bandwidth usage can also be facilitated by the use of maximum data units in allocating bandwidth in unsolicited grants, and by allowing flexible fragmentation and/or prioritization of internet protocol (IP) packets.

Abstract: In the present invention, the overhead data transmission rate in a multicarrier communication system (1) may be changed and/or selected. More specifically, this rate may be selected during an initial negotiation process and/or during a steady state mode of operation.

Abstract: The present invention is directed to a method for setting a user equipment identifier as user equipment identification information used when data received through a dedicated logical channel is transmitted through a common transport channel. The method includes transmitting data and a message type indicator as user equipment identification information from a RRC layer to an RLC layer; setting a user equipment identifier indicator according to the received message type indicator in the RLC layer and transmitting it with the data to a MAC layer; and selecting a user equipment identifier type and a user equipment identifier according to the set user equipment indication identifier, adding it to a header of a MAC SDU in the MAC layer and transmitting it to a corresponding MAC layer in a receiving device.

Abstract: In a data transmission method of the present invention, when transmission data are converted into the characters and the characters are transmitted as transmission signals in accordance with inputted data and a data transmission instruction, the interval between the data groups after the character conversion is broadened and then the characters are transmitted in a case where it is judged that the interval between the data groups after the character conversion is shorter than the interval between the data groups before the character conversion. This ensures communication devices to stably transmit and receive the data group even when the interval between the data groups after the character conversion is different from the interval between the data groups before the character conversion due to timing caused by the character conversion of the data.

Abstract: A method of transmitting a context identifier of header compression on a data packet connection in a telecommunications system, in which the context identifier can be transmitted either as part of a compressed data packet or in the header of a data packet to be transmitted at the convergence protocol layer of the telecommunications system. The transmission method of the context identifier is selected by comparing the space available in the header of the convergence protocol layer data packets with the number of context identifiers defined for the compression method, and attaching the context identifiers to the headers of the convergence protocol layer data packets or to a compressed data packet, depending on whether the space available in the header of the convergence protocol layer data packets is larger or smaller than the number of context identifiers defined for the compression method.

Abstract: The present invention relates to a device for combining at least two data signals having an input data rate into a single data stream having an output data rate being higher than the input data rate for transmission on a shared medium or vice versa, particularly, to a single SDH/SONET framer capable of handling a large range of SDH/SONET frames from STM-i to STM-j with an aggregated total capacity corresponding to an STM-j frame where i and j are integers in the range from 1 to 64 or higher according to the STM-N definition of the SDH/SONET standards. More over, the present invention can also be extended to work with STS-1 as lowest range. STS-1 exists in SONET only not SDH and corresponds to a data rate of 51.5 Mb/s a third of the 156 Mb/s of STM-1.

Abstract: The system provides communication of information between at least two protective relays serving a power system line. The communication comprises a series of successive data messages of four characters, each of which includes eight data bits, on eight data channels. The data bits include output function status bits from the transmitting relay on user selected channels, serialized analog data bits on other user selected channels, and virtual terminal data bits on still other user selected channels. A synchronization channel produces information to synchronize the transmission/receiving of the analog data and the virtual terminal data, on the basis of frames of data, each frame containing 18 messages.

Abstract: A fixed client and a mobile client for receiving multiple description media streams. In one embodiment, the client comprises a multiple description receiving portion which is adapted to receive a plurality of multiple description bitstreams. The client includes memory coupled to the multiple description receiving portion for storing the plurality of multiple description bitstreams in respective portions thereof. The client of the present embodiment also includes a synchronization module coupled to the memory for blending the plurality of multiple description bitstreams. In one embodiment, a decoder is coupled to the synchronization module for decoding the plurality of multiple description bitstreams. A source control module for determining appropriate operation characteristics of the client is also coupled to the synchronization module. Also, a user interface device is coupled to the decoder to present to a user, media previously encoded into the plurality of multiple description bitstreams.

Abstract: A system and method are provided for statistical-multiplexing, comprising a multi-criteria optimization algorithm for video bit stream control, and an alignment of average video bit-stream rates with treatment priorities of cascaded multiplexer's inputs. The first criterion is a grouping of the encoders in accordance with content recipient's wishes. The second criterion involves adjusting the proportions of the average bit rates of the bit streams, wherein these proportions are represented in the form of integer-to-integer fractions, in accordance with the calculated optimal scanning arrays of a plurality of said cascaded multiplexers.

Abstract: A method, apparatus and computer program for multiplexing a number of second channels, in particular logical channels, in accordance with the UMTS protocol architecture for the air interface, onto a first channel, in particular a transport channel, in accordance with the UMTS protocol architecture for the air interface, in a transmission apparatus and/or for demultiplexing in the opposite direction in a receiving apparatus, with the channels that are involved being configured by means of at least one configuration command, in particular with regard to the size of the data units to be transported by them. In the configuration, at least one size of data units is in each case supported by only a single second channel, in order to allow data units of this size to be allocated to the relevant second channel.

Abstract: The invention relates to a transmitter comprising a multilayer multiplexing device for generating an output stream having an output rate, multiplexed from elementary input streams having elementary rates, the multilayer multiplexing device comprising at least a first, master multiplexer and, subsequent thereto, a second, slave multiplexer, the master multiplexer receiving an input stream, referred to as multiplexed input stream at at least one input, multiplexed by the slave multiplexer from at least a first and a second elementary input stream, and a third elementary input stream at at least a second input, the master multiplexer having means for controlling said output rate so as to guarantee a predetermined minimum average output rate.

Abstract: In order to allow geographically separate SONET/SDH networks to be interconnected transparently without changes in clock content, payload and overhead, it has conventionally necessary to use dark fiber. For relatively low bandwidth operators this is prohibitively expensive. The present invention proposes a scheme using a mapping and virtual concatenation scheme to allow SONET/SDH to be carried in a bandwidth efficient manner over a SONET/SDH link whilst maintaining clock integrity.

Abstract: A saturable absorber Q-switch includes a monocrystalline lattice having the formula Mg1-xCoxAlyOz where x is greater than 0 and less than 1, y is greater than 2 and less than about 8, and z is between about 4 and 13. The lattice has tetrahedral and octahedral positions, and most of the magnesium and cobalt occupy tetrahedral positions. In one embodiment, the molar ratio of aluminum to the combined amount of magnesium and cobalt in the monocrystalline lattice can be controlled during growth of the monocrystalline lattice to thereby form a saturable absorber Q-switch that exhibits a 4T1 spectrum for the cobalt ion of at least about 1544 &mgr;m.

Abstract: Described is a system for measuring, tuning and locking wavelengths of lasers. The system comprises a laser diode that emits a front (or source) laser beam for modulating communication signals and a rear laser beam for sensing and locking the central wavelength of the source laser beam. The rear laser beam is split into a first and a second laser beams. A first adjustable wavelength filter receives the first laser beam at a first incident angle to generate a first reference laser beam, and a second wavelength filter receives the second laser beam at a second incident angle to generate a second reference laser beam. A first photo-detector generates a first reference photo-current in response to the first reference laser beam, and a second photo-detector generates a second reference photo-current in response to the second reference laser beam. The current difference between the first and second reference photo-currents is utilized to measure, tune and lock the central wavelength of the source laser beam.

Abstract: An external cavity laser apparatus and method wherein wavelength or channel selection is carried independently from adjustment of external cavity optical path length. The apparatus comprises a wavelength or channel selector tuner and an external cavity tuner, wherein the wavelength tuner is uncoupled from the external cavity tuner. The tuning mechanisms for wavelength selection and cavity optical path length are configured to operate independently or orthogonally with respect to each other. The wavelength tuner may operate according to a first, channel selection signal, while the external cavity tuner operates according to a second, external cavity adjustment signal. The wavelength tuner and external cavity tuner may operate under the control of the same, or of separate controllers.

Abstract: External cavity lasers apparatus and methods that allow fast tuning, high wavelength stability, low cavity losses, and form factors that are comparable to solid state, fixed wavelength lasers. The apparatus comprise a gain medium emitting a light beam, a tunable wavelength selection element positioned in the light beam and configured feed back light of a selected wavelength to the gain medium, and a microelectromechanical systems (MEMS) actuator element operatively coupled to the tunable wavelength selection element. The MEMS actuator element may be configured to actuate the tunable wavelength selection element according to a first degree of freedom to select the wavelength of the feedback to the gain medium, and to actuate the actuate the tunable wavelength selection element according to a second degree of freedom to provide phase control of the feedback.

Abstract: A wavelength-tunable semiconductor laser is constructed by a semiconductor substrate; an optical waveguide provided over the upper surface of the semiconductor substrate; a front light reflection area that is provided at the front side in a laser beam emission direction by a part of the optical waveguide and comprises an SG-DBR mirror achieved by structurally repeating a portion comprising a pair of diffraction grating portion and a non-diffraction grating portion over plural periods on the assumption that the portion is set as one period; a rear light reflection area that is provided at the rear side in the laser beam emission direction by a part of the optical waveguide and comprises an SSG-DBR mirror achieved by structurally repeating, over plural periods, a portion in which the pitch of a diffraction grating pitch regularly varies from one end to the other end, both the ends being spaced at a predetermined distance, on the assumption that the portion is set as one period; an active region comprising an ac

Abstract: A method and apparatus for controlling the extinction ratio and average output power of an optical device is disclosed. The method includes calculating a ratio of a first slope of a first characteristic curve to a second slope of a second characteristic curve. A modulation current is calculated based on the ratio.

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 semiconductor device and method for providing a light source suitable for use as a pumping light source in a Raman amplification system are provided. The device upon which the method is based includes an active layer configured to radiate light, a light reflecting facet positioned on a first side of the active layer, and a light emitting facet positioned on a second side of the active layer thereby forming a resonator between the light reflecting facet and the light emitting facet. A diffraction grating is positioned within the resonator along a portion of the length of the active layer, and a non-current injection area is formed along the diffraction grating so as to suppress injection current in the portion of the length of the active layer. The non-current injection area preferably has a length Li greater than a length Lg of the diffraction grating by an amount necessary to prevent scatter injection current from affecting the diffraction grating.

Abstract: A surface emitting semiconductor laser device including a substrate and a layer structure formed thereon, the layer structure including an active layer, p-type and n-type distributed Bragg reflector (DBR) sandwiching therebetween the active layer, and first and second selectively-oxidized layers disposed within or in vicinities of the p-type and n-type DBRs, respectively, each of the p-type and n-type DBRs including a plurality of layer pairs each including a lower reflection layer and a higher reflection layer, each of the selectively-oxidized layers including a central AlxGa1-xAs area (x≧0.98) and a peripheral oxide area formed by oxidizing an outer periphery of the central AlxGa1-xAs area, the peripheral oxide area of the first selectively-oxidized layers has a width smaller than a width of the peripheral oxide area of the second selectively-oxidized layer.

Abstract: A semiconductor laser having a mesa structure includes active laser layers. The mesa structure is confined by Fe—InP lateral semi-insulating layers. A p blocking layer is interposed between the mesa structure and the lateral semi-insulating layers. Performance at high temperature and linear laser operation are improved. A preferred application is for manufacturing SIBH-DFB lasers for direct modulation in the 10 Gbit/s range.

Abstract: In a semiconductor laser element, an active layer is sandwiched between first-conductivity type and second-conductivity type cladding layers, and a second-conductivity type contact layer is disposed above the second cladding layer with an intermediate bandgap layer interposed between the second cladding layer and the contact layer, the second-conductivity type contact layer having a bandgap different from a bandgap of the second-conductivity type cladding layer, the intermediate bandgap layer having an intermediate bandgap between the bandgaps of the second-conductivity type cladding layer and the second-conductivity type contact layer. The second-conductivity type contact layer has at least a first contact layer, an intermediate second contact layer and a third contact layer stacked in this order and the second contact layer has an impurity density lower than impurity densities of the first and third contact layers.

Abstract: A vertical cavity surface emitting laser (VCSEL) having asymmetrical optical confinement is described. Polarization of VCSELs having symmetrical structures tend to be unpredictable and switchable. The VCSEL of the present invention has vertically etched apertures into the top bragg mirror in order to confine the optical path into an asymmetric structure. This has the effect of locking polarization into a fixed mode.

Abstract: In a semiconductor laser device: a p-type AlzGa1-zAs cladding layer is formed above an active layer, where z≧0.3; a p-type GaAs contact layer is formed on the cladding layer except for at least one near-edge portion of the cladding layer; and an electrode is formed on at least the contact layer. The upper surface of each of the at least one near-edge portion of the cladding layer is insulated, where each of the at least one near-edge portion of the cladding layer is located in a vicinity of one of opposite end facets perpendicular to the direction of laser emission.

Abstract: An optically tuned transistor network is disclosed. High quality epitaxial layers of monocrystalline materials grown over monocrystalline substrates enables the formation of complementary metal oxide semiconductors along with light sources such as vertical cavity surface emitting lasers in one integrated circuit. By coupling the light source to active devices fabricated on the same substrate and coupling them with optical interconnects, light can be illuminated on the active regions of the active devices to tune various performance characteristics of the active device.

Abstract: A semiconductor laser element comprising a first stripe and a second stripe which are formed at a distance, and emits a first laser beams and a second laser beams from end surfaces of the first stripe and the second stripe; a first lens to separate the distance between the first laser beams and the second laser beams emitted from the semiconductor laser element; a half-wave plate which rotates the plane of polarization of the first laser beams by 90 degrees; a polarization beam combiner which multiplexes the first laser beams and the second laser beams which are entered, and emits both the laser beams; and an optical fiber which receives the laser beams emitted from the polarization beam combiner, and sends them to the outside are included.

Abstract: Disclosed is a laser having a laser diode coupled with a passive intra-cavity tapered waveguide.

Abstract: The invention provides a ≧4 kHz repetition rate argon fluoride excimer laser system for producing an UV wavelength 193 nm output. The ≧4 kHz repetition rate argon fluoride excimer laser system includes an argon fluoride excimer laser chamber for producing a 193 nm discharge at a pulse repetition rate ≧4 kHz. The ≧4 kHz repetition rate argon fluoride excimer laser chamber includes magnesium fluoride crystal optic windows for outputting the 193 nm discharge as a ≧4 kHz repetition rate excimer laser 193 nm output with the magnesium fluoride crystal optic windows having a 255 nm induced absorption less than 0.08 Abs/42 mm when exposed to 5 million pulses of 193 nm light a fluence ≧40 mj/cm2/pulse and a 42 mm crystal 120 nm transmission of at least 30%.

Abstract: A method of minimizing contamination of optical components of a laser resonator is disclosed. The resonator components are located in an enclosure, which may contain contaminants including water vapor and organic favor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a desiccant, an organic vapor trapping material, and a particulate matter filter then returns the extracted gas to the enclosure. The purging system is particularly useful for ultrafast lasers and ultraviolet lasers where the power of the laser radiation increases the probability of destabilizing reactions between laser radiation and contaminants.

Abstract: An integrated optically pumped vertical cavity surface emitting laser (VCSEL) is formed by integrating an electrically pumped in-plane semiconductor laser and a vertical cavity surface emitting laser together with a beam steering element formed with the in-plane semiconductor laser. The in-plane semiconductor laser can be a number of different types of in-plane lasers including an edge emitting laser, an in-plane surface emitting laser, or a folded cavity surface emitting laser. The in-plane semiconductor laser optically pumps the VCSEL to cause it to lase. The in-plane semiconductor laser is designed to emit photons of relatively short wavelengths while the VCSEL is designed to emit photons of relatively long wavelengths. The in-plane semiconductor laser and the VCSEL can be coupled together in a number of ways including atomic bonding, wafer bonding, metal bonding, epoxy glue or other well know semiconductor bonding techniques. The beam steering element can be an optical grating or a mirrored surface.

Abstract: An external cavity laser in a hermetically sealed container and methods for hermetically sealing the external cavity laser. The external cavity laser may be tunable by various mechanisms to allow transmission at multiple selectable wavelength channels.

Abstract: A laser apparatus wherein a gain medium and an optical output assembly are mounted on a common, thermally conductive substrate which provides selective thermal control of the gain medium and output components on the substrate while avoiding unnecessary thermal control of other laser components, and methods for selectively cooling a gain medium and output components of a laser apparatus.

Abstract: A fiber-optic laser source capable of emitting one useful wavelength at a given time, electrically step-tunable to the ITU grid wavelengths, is disclosed. The laser preferably comprises a diode-pumped rare-earth doped fiber amplifier as gain medium, a periodic filter to define ITU grid lasing wavelengths, and a tunable filter electrically step tunable to any wavelength defined by the periodic filter. The arrangement is enclosed in a ring single mode optical fiber resonator. The ring resonator may be made, in part or in total, with polarization-maintaining optical fiber. The resonator also comprises in-line optical isolators to ensure unidirectional operation and to eliminate undesired reflections. A polarization controller and polarizer device and a gain-flattening filter may also be included within the resonator depending on the desired output characteristics of the laser. The laser may be designed to operate in single cavity longitudinal mode.

Abstract: A thermogravimetric analyzer comprising a base, a magnet secured to the base, a coil pivotally coupled to the base, a beam coupled to the coil such that the beam can pivot with the coil, a sample support supported by the beam, and a heat chamber substantially surrounding the sample support. The beam preferably comprises a material having at least 25% carbon by volume and a thermal expansion coefficient of less than 1×10-6/K and a thermal conductivity of at least 100 W/mK.

Abstract: The present invention provides a method for testing an electronic component comprising exposing the electronic component to a test fluid comprising a fluoroketone that is essentially non-flammable. Preferably the test fluid is comprised of 90% by weight to 100% by weight of the fluoroketone.

Abstract: The invention provides a dual thermometer system for the measurement and display of temperature data taken at two separate locations within an oven. In one aspect, the invention provides an elongated probe connected with a flexible electronic cable. The probe houses two temperature sensors—one for sensing internal food temperature, one for sensing inside oven air temperature. The sensors are space apart within the probe such that the one sensor can be positioned substantially within a food item and the other sensor can positioned substantially outside of the food item and within the oven. Signals from the sensors are relayed from the probe and through the cable; external electronics may attach to the cable to acquire the signals and display associated temperatures. In another aspect, signals from temperature sensors are relayed from the probe and through the cable to a first wireless termination.

Abstract: A temperature meter for measuring temperature of a measurement target object to which a temperature sensor cannot be fixed directly is formed by a temperature sensor configured to measure an observed temperature in a vicinity of the measurement target object; a timer configured to measure a temperature observation time; and a calculation processor configured to calculate the temperature of the measurement target object according to the observed temperature and the temperature observation time by carrying out a prescribed calculation processing.

Abstract: A method of stabilizing a clinical thermometer and the apparatus thereof are disclosed. The method comprises the steps of pre-heating the surrounding temperature to a pre-set temperature prior to using the clinical thermometer for measuring temperature; and providing compensational temperature by way of heat energy by a control circuit such that the surrounding temperature is maintained and stabilized at the pre-set temperature so as to avoid the change of the surrounding temperature from affecting the measured temperature. The stabilizing devices for a clinical thermometer comprises a clinical thermometer probe head which is a material capable of producing heat energy; and a heating controller connected to the probe head which provides cavity heating for the probe head prior to temperature measuring to the pre-set surrounding temperature, thereby the heating controller causes the surrounding temperature to maintain at a constant and stable temperature such that the precision of measuring is accurate.

Abstract: Disclosed is a method for generating frequency sequences in a wireless system. The method for generating frequency sequences creates sequences having a deterministic form. That is, the frequency sequences are created in vector form, where the vector columns represent sequences and the vector rows represent channels.

Abstract: A CDMA receiver wherein power consumption can be reduced by conducting receiving operation according to the kind of receiving data is provided. The CDMA receiver obtains a CDMA signal by executing RAKE combination to outputs from a plurality of finger sections in a RAKE combining section. A CPU detects a parameter indicating the kind of transmitting data from the signal after the RAKE combination to control the number of finger sections to be activated according to the detected kind of data. Moreover, a searcher section selects finger sections in the number specified by the CPU so that a timing generating section can supply clock signals to only the selected finger sections. Thereby, it becomes possible to activate finger sections in the number according to the kind of data, thus enabling the power consumption to be reduced.

Abstract: In a parallel signal transmission device for converting serial signals into parallel signals at a transmitting unit to be transmitted to a receiving unit, the transmitting unit generates serial code signals from periodically latched parallel signals besides transmitted parallel signals, and adjusts phases of the parallel signals to the serial code signals by delaying the parallel signals by a predetermined delay time; and the receiving unit changes over bits of the parallel signals from the transmitting unit based on recovered clocks, detects bit shift amounts of the parallel signals after bit changeover, and performs skew adjustments of the parallel signals depending on the bit shift amounts.

Abstract: A frequency plan is provided for particular use in a transceiver. Advantageously, a single oscillator may be used to generate desired frequency signals. One or more power splitters receive the signal and equally divide the signal into first and second signals having a frequency substantially equal to the original. Multipliers on each arm of the transceiver receive a signal and increase the frequency of the signal. In one exemplary embodiment, multiple signals having different frequencies may be transmitted over the same cable due in part to the generated frequency separation between the signals. In another exemplary embodiment, multiple signals may be transmitted over multiple cables. Additionally, multiple signals over one or more cables may be transmitted at or below 3 GHz.

Abstract: The invention creates a method for transmitting an analog data stream (101) in which secondary minima are prevented during an equalization of the analog data stream (101) at the receiving end when approximating the channel transfer function of a transmission channel (102), wherein the analog data stream (101) is received via the transmission channel (102), the received analog data stream (101) is converted into a digital data stream (103) in an analog/digital converter (104), the digital data stream (103) is decimated in a decimation device (107) in order to obtain a decimated digital data stream (106), a control signal (128) is derived from either the digital data stream (103) or the decimated digital data stream (106) in accordance with a predeterminable adjustment of a switching device (127), the derived control signal (128) is supplied to a coefficient determining device (125) and wherein equalization coefficients (126) are provided, together with an information item provided by the reference signal (124)

Abstract: An iterative equalization process uses a reduced complexity equalizer as a first stage in the equalization process and a reduced alphabet MLSE equalizer as a later stage. The reduced complexity equalizer is used to identify a reduced alphabet including symbols having a higher probability of representing an actual transmitted symbol. The reduced alphabet is then used as the alphabet for the reduced alphabet MLSE equalizer.

Abstract: A receiver comprises an adaptive filter (22) having an input for a digitized input signal, means (30) for storing a pre-designed filter characteristic, means (26) for analyzing a digital representation of the input signal to determine a desired position of the filter characteristic to match the system requirements, and means (28) for adapting the stored pre-designed filter characteristic in the frequency domain and/or the time domain to match the system requirements and for transforming the adapted filter characteristic to the time domain to update coefficients for the adaptive filter and for loading updated coefficients into adaptive filter. The updating of the coefficients may be done periodically. The adaptation may be one or more of adjusting bandwidth, frequency shift and, in the case of a bandpass characteristic, superimposing characteristics.

Abstract: A channel decoder employs a hybrid frequency-time domain equalizer for effectively combining a frequency domain equalizer with a time domain equalizer to achieve superior static and dynamic multi-path performance compared to conventional decision feedback equalizers. A frequency domain equalizer structure is included within the forward path of a time domain, decision feedback equalizer, with both the frequency domain and time domain portions employing a common error vector. Updates to the taps (frequency bins) may be adapted individually, or fully within the frequency domain without altering the feedback filter. Improved performance, including performance for noisy channels with deep notches, is achieved, and the frequency domain equalizer portion is relieved from equalizing minimum phase zeros of the channel.

Abstract: A method measures an intensity of motion activity in a compressed video. The intensity of the motion activity is used to partition the video into segments of equal cumulative motion activity. Key-frames are then selected from each segments. The selected key-frames are concatenated in temporal order to form a summary of the video.