Abstract: A front-end module includes: a first front-end circuit that transmits signals in a first band in a CA mode; and a second front-end circuit that transmits signals in a second band in the CA mode. The second front-end circuit includes a second quadplexer for the first and second bands. The first front-end circuit includes: a first quadplexer for the first and second bands; and an impedance variable circuit that is connected to a transmission terminal that is included in the first quadplexer and corresponds to the second band. In the CA mode, the impedance variable circuit serves as a reflection circuit that causes reflection of transmission waves in the second band. In a non-CA mode, the impedance variable circuit serves as a matching circuit that transmits or absorbs transmission waves in the second band.

Abstract: A front-end circuit includes: a filter that converts an unbalanced radio frequency signal inputted to an input terminal into two balanced radio frequency signals, and outputs one of the two balanced radio frequency signals from an output terminal and the other of the two balanced radio frequency signals from another output terminal; a low-noise amplifier connected to the output terminal; and a low-noise amplifier connected to the other output terminal.

Abstract: Disclosed are a mobile terminal capable of starting data sharing through an infrared signal and a control method therefor. To this end, the mobile terminal may comprise: a wireless communication unit for performing wireless communications; and infrared transceiver for transmitting and receiving an infrared signal; a user input unit for receiving a user input; and a control unit for controlling a first infrared signal to be output through the infrared transceiver when a first user input is received through the user input unit, and controlling shared data to be transmitted to an external terminal through the wireless communication unit when a second infrared signal is received from the external terminal which has received the first infrared signal.

Abstract: A lighting apparatus that is used in a positioning system and is locatable in plural number in a limited area is provided. The lighting apparatus for use in the positioning includes a power supplier that supplies power, a lighting unit that is lit by the power supplied by the power supplier, and a beacon transmitter. The beacon transmitter operates by the power supplied by the power supplier, and transmits a beacon that is a signal for positioning. The beacon includes a long-distance beacon transmitted with first transmission power and a short-distance beacon transmitted with a second transmission power less than the first transmission power. The beacon transmitter transmits at least the long-distance beacon intermittently.

Abstract: A microwave backhaul system having quadruple capacity. In one embodiment, an outdoor communication unit in a microwave backhaul system is provided, which includes a first and second dual channel processing modules that are each configured to process two transmission/reception channels. The outdoor communication unit also includes two transmitter modules that are each configured to upconvert two channels for transmission at vertical polarization and a horizontal polarization.

Abstract: A system is provided for transmitting a low code rate spatially multiplexed channel on multiple antennas. The system includes a transmitter and a processor. The processor is configured such that the processor encodes a block of information bits to form channel coded bits, wherein the ratio of the number of channel coded bits to the number of information bits is greater than one; and the processor maps the channel coded bits to modulation symbols, and each channel coded bit is mapped once to a modulation symbol. The transmitter is configured to transmit a first portion of the modulation symbols using a spreading sequence on a first antenna of the multiple antennas and to transmit a second portion of the modulation symbols using the spreading sequence on a second antenna of the multiple antennas.

Abstract: Techniques for supporting data transmission and reception on multiple bands for carrier aggregation are disclosed. In an exemplary design, an apparatus (e.g., a wireless device) includes first and second antenna interface circuits coupled to first and second antennas, respectively. The first antenna interface circuit includes a first quadplexer for first and second bands. The second antenna interface circuit includes a second quadplexer for the first and second bands. The first quadplexer may be a duplicate of the second quadplexer, which may simplify implementation. Each antenna interface circuit may further include a diplexer, a duplexer, a triplexer, another quadplexer, switches, etc. The first and second quadplexers may support data transmission and reception on two bands in a first band group. Other circuits in the first and second antenna interface circuits may support data transmission and/or reception on additional bands, possibly in one or more other band groups.

Abstract: A transceiver includes a transmitter circuit, a receiver circuit, and the loopback switch. The transmitter circuit performs a digital-to-analog conversion (DAC) operation on a calibration code without a transmission digital signal in a calibration mode to generate a calibration signal. The transmitter circuit up-converts the calibration signal and generates a transmission signal. The receiver circuit down-converts the transmission signal in the calibration mode and generates a receiving digital signal. The loopback switch electrically connects an output terminal of the transmitter circuit and an input terminal of the receiver circuit in the calibration mode. Thus, the transceiver may stably reduce a carrier leakage irrespective of processes, voltages, and temperatures.

Abstract: A fractional rate converting filter in a wireless transceiver comprising a delay line, multiplier circuit, adder circuit, and selector. The delay line receives a digital input signal at a first sample rate and has delay blocks each providing an output and receiving samples gated at a plurality of clock cycles of an integer sub-multiple frequency of a clock. The outputs are multiplied by corresponding filter tap coefficients. Each filter tap coefficient is spaced by a first integer Y. The adder circuit receives and sums the tap outputs to provide an output signal. The selector iteratively shifts the coefficients by a second integer Z. The output of each delay block is multiplied by corresponding shifted filter tap coefficients. The delay blocks are inhibited from receiving another input sample during the plurality of clock cycles. The output signal has a second sample rate at the integer sub-multiple frequency of the clock.

Abstract: Techniques for supporting data transmission and reception on multiple bands for carrier aggregation are disclosed. In an exemplary design, an apparatus (e.g., a wireless device) includes first and second antenna interface circuits coupled to first and second antennas, respectively. The first antenna interface circuit includes a first transmit (TX) filter for a first band, which may be part of a first triplexer or duplexer. The first TX filter filters a first radio frequency (RF) signal prior to transmission via the first antenna. The second antenna interface circuit includes a second TX filter for a second band, which may be part of a second triplexer or duplexer. The second TX filter filters a second RF signal prior to transmission via the second antenna. The first and second RF signals may be transmitted simultaneously on the first and second bands for carrier aggregation.

Abstract: A method of operation in a receive circuit is disclosed. The method comprises entering an initialization mode followed by receiving training data from a lossy signaling path. The training data originates from a transmit circuit. The received training data is sampled and minimax transmit equalizer coefficients are generated based on the sampled data. The minimax transmit equalizer coefficients are then transmitted back to the transmit circuit. The initialization mode is exited and an operating mode initiated, where transmit data precoded by the minimax transmit equalizer coefficients is received.

Abstract: A digital subscriber line arrangement includes a downstream modem, an upstream modem and a copper pair connection between the modems. Each modem includes electrical length estimation function code means which causes the respective modem to measure the attenuation of signals transmitted by the other modem at a plurality of different frequencies, and to combine these measurements, or functions thereof, together to form a combined attenuation measure and to use this combined measure to form an electrical length estimation, KL0bis. The downstream modem is operable to transmit its electrical length estimation to the upstream modem, and the upstream modem is operable to generate a definitive electrical length estimation in dependence upon both the received estimation from the downstream modem and the estimation made by the upstream modem. Having generated a definitive electrical length estimation, the upstream modem is operable to transmit this to the downstream modem.

Abstract: Systems and methods for controlling transmission of signals are described. A camera-side modem is configured to receive two signals from a video camera and to extract a received passband signal from a transmission line. A detector in the camera-side modem generates an enable signal when the received passband signal is identified. The enable signal is used to control transmission of at least one of the baseband video signal and the passband video signal. The passband signal may be identified by an estimate of mean square error in a quadrature amplitude demodulator, a measurement of reliability provided by a constellation detector, a measurement of reliability based on a sequence of frame synchronizations and/or an estimate of mean square error in an equalizer. The detector may monitor a gain factor in an automatic gain control module of the camera-side modem and/or a magnitude of the received passband signal.

Abstract: Disclosed is an apparatus that includes a plurality of parallel digital signal transmitters that each receive one of a plurality of digital sub-signals wherein each of the plurality of digital signal transmitters is configured to transmit one of the plurality of digital sub-signals that each have about the same bandwidth. The apparatus also includes a combiner coupled to the transmitters and configured to shift some of the plurality of digital sub-signals and to combine the plurality of shifted digital sub-signals into a combined digital signal that has a total bandwidth of that is approximately equal to the sum of the bandwidths of the plurality of digital sub-signals. The total bandwidth comprises a plurality of shifted bandwidths of the plurality of digital sub-signals at about the same offset with respect to each other. The combined digital signal is transmitted over a digital subscriber loop.

Abstract: Methods and apparatus are provided for pseudo asynchronous testing of receive paths in serializer/deserializer (SerDes) devices. A SerDes device is tested by applying a source of serial data to a receive path of the SerDes device during a test mode. The receive path substantially aligns to incoming data using a bit clock. A phase is adjusted during the test mode of the bit clock relative to the source of serial data to evaluate the SerDes device. The source of serial data may be, for example, a reference clock used by a phase locked loop to generate the bit clock. The phase of the bit clock can be directly controlled during the test mode, for example, by a test phase control signal, such as a plurality of interpolation codes that are applied to an interpolator that alters a phase of the bit clock.

Abstract: An integrated circuit chip implements a high-speed switch that includes: a switch fabric; control logic that controls the transmission of digital signals through the switch fabric; a transceiver block comprising one or more transceivers, each transmitting digital signals between the control logic and a corresponding external device; a data converter physical interface comprising one or more data converters, each performing a conversion between analog and digital signals, wherein digital signals associated with the one or more data converters are routed through the switch fabric; and a signal processing engine coupled to the control logic, wherein the signal processing engine performs on-chip processing of digital signals received from the transceiver block and the data converter physical interface.

Abstract: A high-speed switch that includes a switch fabric, and both high-speed serial ports and data converter physical ports. A first set of data converter physical ports may perform analog-to-digital conversions, such that an external analog signal may be converted to a digital input signal on the switch. The converted digital input signal may then be routed through the switch fabric in accordance with a serial data protocol. A second set of data converter physical ports may perform digital-to-analog conversions, such that an internal digital signal received from the switch fabric may be converted to an analog output signal on the switch. The converted analog output signal may then be transmitted to an external destination in accordance with a serial data protocol.

Abstract: A system is provided for transmitting information through a speech codec (in-band) such as found in a wireless communication network. A modulator transforms the data into a spectrally noise-like signal based on the mapping of a shaped pulse to predetermined positions within a modulation frame, and the signal is efficiently encoded by a speech codec. A synchronization sequence provides modulation frame timing at the receiver and is detected based on analysis of a correlation peak pattern. A request/response protocol provides reliable transfer of data using message redundancy, retransmission, and/or robust modulation modes dependent on the communication channel conditions.

Abstract: A wireless repeater with an antenna array determines the antenna weights to modify the spatial selectivity of the antenna array to reduce interference and improve the quality of signal reception. The antenna weights are determined using an error minimizing algorithm to minimize the error between a desired receive signal and a reference signal or an adaptive metric optimization algorithm to calculate adaptively antenna weights to minimize the signal-to-noise ratio of a desired receive signal.

Abstract: In order to enable simultaneous communication using a plurality of frequencies, provided is a mobile communication terminal including: a first combining circuit 210 that receives transmission signals of two frequency bands, and outputs a combined signal; a triplexer 220 including: a transmitting filter 221 that filters the signal inputted by the first combining circuit 210 and outputs the resultant signal; and a receiving filter A 222 and a receiving filter B 223 that each filter an inputted given signal and output the resultant signal; a combined signal filter 230 including: a filter P 231 having the same pass characteristic as that of the transmitting filter 221; and a filter Q 232 having the same pass characteristic as that of the receiving filter B 223, the combined signal filter 230 filtering the signal outputted by the first combining circuit 210 and outputting the resultant signal; a phase adjuster 240 that adjusts a phase of the signal outputted by the combined signal filter 230 to a phase opposite to

Abstract: The present invention relates to an antenna and radio arrangement comprising at least a first antenna and a second antenna, each having a first antenna port and a second antenna port, the arrangement further comprising at least four first transmitting means, where the first antenna's first antenna port is connected to a first transmitting means, the first antenna's second antenna port is connected to a second transmitting means, the second antenna's first antenna port is connected to a third transmitting means, and the second antenna's second antenna port is connected to a fourth transmitting means. At least two transmitting means transmit signals to the corresponding antenna ports, said signals being modulated by the same stream of digital signals and having the same radio carrier frequency, thus accomplishing a spatial combining of the output signals. The present invention also relates to a corresponding method.

Abstract: A method and system for fractionally converting sample rates. Fractional rate conversion for a transmit path of a transceiver is achieved by upsampling an input signal having a first sample rate by a first integer factor, removing aliasing resulting from the upconversion process, and then downsampling the intermediate signal by a second integer factor to provide a final signal having a second sample rate. The first factor and the second factor are selected to obtain a desired output sample rate that is a fraction of the sample rate of the input signal.

Abstract: Techniques are described for permitting uplink feedback for downlink transmission over downlink-only RF carriers to occur using uplink control channels belonging to another fully-configured RF carrier herein known as a primary carrier. Uplink feedback channels can be allocated for the downlink-only RF carriers in the uplink control regions of a fully-configured RF carrier immediately following the uplink control channels for the primary carrier are allocated. The uplink feedback channels for downlink-only RF carriers can be allocated based on global or local index number of each downlink-only RF carrier in sequential order based on ascending or descending sorting of the index numbers.

Abstract: Provided is a transmitter and a receiver for a high-throughput wireless communication system. The transmitter includes a baseband transmitter, a DIF transmitter, and a RF transmitter. The baseband transmitter performs a MAC protocol process on transmission signals and reception signals and processes the transmission signals by dividing an entire transmission band into n bands in a physical layer process of the transmission data, where n is a natural number. The DIF transmitter combines transmission signals of each band from the baseband transmitter and outputs m channel signals corresponding to a number of transmission antennas, where m is a natural number. The RF transmitter modulates each of the channel signals transferred from the DIF transmitter and transmits the modulated signals through m antennas.

Abstract: A subscriber station is capable of encoding a bandwidth request message. The subscriber station includes a controller and a transmitter coupled to the controller. The transmitter includes a linear channel encoder and a Quadrature Phase Shift Keying (QPSK) modulation block. The channel encoder uses a generator matrix comprising alphabets from Galois field (GF) (2). Each column of the generator matrix belongs to a twelve dimensional subspace and wherein the code generated using the generator matrix has a minimum hamming distance no greater than thirty.

Abstract: A method and a device for cancelling transmitter interference in a transceiver, and a transceiver are provided. The method includes: coupling a part of radio frequency signals output from a transmitter, performing amplification, frequency conversion, analog-digital conversion, and digital filtration on the coupled signal by an interference receiver, and outputting a digital signal; performing adaptive equalization on the digital signal output from the interference receiver, and delaying predetermined time of the digital signal output from a receiver, and subtracting the equalized digital signal from the delayed digital signal.

Abstract: A system includes at least one adaptive filter coupled to a first communication channel and at least one other communications channel. The at least one adaptive filter includes at least one set of adaptive filter coefficients. A memory stores at least one predetermined set of filter coefficient thresholds. The filter coefficient thresholds may be indicative of channel faults, channel to channel faults or a length of the channel. A controller is configured to compare the set of filter coefficients to the predetermined set of filter coefficient thresholds. The controller is configured to determine the information about the channels based on compare results.

Abstract: A system is provided for transmitting a low code rate spatially multiplexed channel on multiple antennas. The system includes a transmitter and a processor. The processor is configured such that the processor encodes a block of information bits to form channel coded bits, wherein the ratio of the number of channel coded bits to the number of information bits is greater than one; and the processor maps the channel coded bits to modulation symbols, and each channel coded bit is mapped once to a modulation symbol. The transmitter is configured to transmit a first portion of the modulation symbols using a spreading sequence on a first antenna of the multiple antennas and to transmit a second portion of the modulation symbols using the spreading sequence on a second antenna of the multiple antennas.

Abstract: An adaptive differential pulse-code modulation-demodulation system and method thereof is provided. The method includes steps of modulating an analog audio input signal into a data packet, including a plurality of digital data through adaptive differential pulse-code modulation, an initial value and a scale factor associated with the digital data, to be sent to the communication network, and demodulating the data packet according to the digital data, the initial value and the scale factor, thereby reconstructing the data packet to an analog audio output signal.

Abstract: A radio transmitter select its operating frequency based on the frequency characteristics of a collocated receiver and clock harmonics. The radio transmitter can dynamically change its operating frequency in a wide enough range so as to avoid frequencies where its spurs fall on the receive frequency of the collocated receiver. The frequency characteristics of the clock harmonic of the radio transmitter and the collocated receiver are obtained, then a range of operating frequencies is calculated to enable the collocated devices to operate without undue interference.

Abstract: Methods and apparatus are provided for pseudo asynchronous testing of receive paths in serializer/deserializer (SerDes) devices. A SerDes device is tested by applying a source of serial data to a receive path of the SerDes device during a test mode. The receive path substantially aligns to incoming data using a bit clock. A phase is adjusted during the test mode of the bit clock relative to the source of serial data to evaluate the SerDes device. The source of serial data may be, for example, a reference clock used by a phase locked loop to generate the bit clock. The phase of the bit clock can be directly controlled during the test mode, for example, by a test phase control signal, such as a plurality of interpolation codes that are applied to an interpolator that alters a phase of the bit clock.

Abstract: Methods and apparatus for adapting a channel estimation scheme in a transceiver in a communication system are disclosed to adapt channel estimation to the transceiver environment, particularly for high Doppler environments. The disclosed methods and apparatus effect determination of an estimate of a power delay profile of a channel or a time correlation of the channel, or both. A channel estimation scheme is then determined based on at least one of the determined power delay profile and time correlation of the channel. By basing determination of a channel estimation scheme on the power delay profile and/or the time correlation of the channel, the channel estimation scheme is adapted to the particular environment of the transceiver by accounting for the delay spread of the channel and/or the speed of the transceiver.

Abstract: The invention relates to methods and a high speed communication device that allow one of a plurality of high speed communication devices connected to a transmission line having a normal impedance to effectively receive data. The high speed communication device can include a transmission line interface connected to the transmission line, a receiver connected to the transmission line interface, and a transmitter selectively coupled to the transmission line interface. The transmitter can have an impedance substantially equal to the normal line impedance. The high speed communication device can present a high impedance to the transmission line with respect to the normal line impedance when the transmitter is not coupled to the transmission line interface, and the high speed communication device can present an impedance to the transmission line that is substantially equal to the normal line impedance when the transmitter is coupled to the transmission line interface.

Abstract: An apparatus comprising an artificial noise (AN) controller coupled to a digital subscriber line (DSL) transmitter and configured to adjust an AN level for a signal transmitted by the DSL transmitter, wherein the AN level is adjusted based on an actual signal to noise ratio (SNR) of the signal from the receiver to achieve a desired SNR for the signal. Also disclosed is a method comprising maintaining a data rate in a line at about a desired level by adjusting an AN level in a transmitted signal based on a SNR of a received signal.

Abstract: According to an embodiment of a communication device, the communication device includes communication circuitry configured to communicate via a plurality of transmission channels. The communication circuitry includes crosstalk reduction circuitry to reduce crosstalk for a part of the plurality of transmission channels by joint processing of data of the part of the transmission channels. This part is selected from the plurality of transmission channels depending on a grouping of the transmission channels into at least two groups. Each of the at least two groups is assigned a target bit rate. The target bit rate differs for different groups.

Abstract: Apparatus, systems, and methods are provided for transmitting messages over a serial interface. A method comprises receiving a first signal at a first time and receiving a second signal at a second time, the second time being after the first time. If a difference between the second time and the first time is less than a threshold time period, the method comprises generating a first message that is representative of the first signal and the second signal and transmitting the first message over the serial interface. In accordance with one embodiment, the threshold time period is equal to one half of an interface acquisition delay time period associated with the serial interface.

Abstract: A communication circuit for providing a bi-directional data transmission over a signal line, thereby receiving a first digital data stream and transmitting a corresponding first signal into a near end of a signal line to a remote device, the remote device being connected to a far end of the signal line, receiving a second signal at the near end of the signal line from the remote device and deriving a second digital data stream therefrom, having a replica generator for providing, in response to the first digital data stream or a signal derived therefrom, a replica signal, and an extraction circuit for extracting the second digital data stream from the second signal in response to the replica signal and a comparator signal deduced from the near end of the signal line and an automatic test equipment having a plurality of communication circuits each providing a bi-directional data transmission.

Abstract: A method of analyzing the performance of a modem connection. The method includes connecting a line interface to a communication link carrying signals of a modem connection, between a pair of end modems, collecting signals passing on the communication link, between the end modems, through the line interface, determining quality or transmission characteristics regarding the modem connection, responsive to signals collected through the line interface, and displaying information on the determined characteristics.

Abstract: Systems and methods for resolving signal-to-noise ratio margin difference n dual latency discrete multi-tone (DMT)-based xDSL systems under colored noise conditions. Rather than assuming a constant power spectral density (PSD) for noise over fast and interleaved data paths of a dual latency system, band edges vulnerable to colored noise are determined and data on the fast data path is allocated away from these band edges. Also, receive windowing may be used to further enhance performance.

Abstract: A data sharing methodology and structure for communication between users of digital Internet-accessible devices, such as set-top boxes, is described. Users of Internet-accessible devices can establish connections between trusted users of other Internet-accessible devices and transfer personal information using either the Internet or the public switched telephone network (PSTN). Some examples of the type of information that may be transferred include IP addresses, e-mail, multimedia objects, and voice data. Once personal identification information has been exchanged, future communications may be easily re-established and maintained.

Abstract: Digital signals from a group of three or more circuits (104, 105, 106) are used to create an encoded or combined signal on a common transmission line (108). The encoded signal is then decoded at each different circuit to produce or recreate the digital signal asserted by each different circuit in the group. The encoded signal comprises a signal included in a set of unique signal values, with each signal in the set corresponding to a different combination of digital signals asserted by the group of circuits. Decoding the encoded signal at each circuit (104, 105, 106) in the group involves comparing the encoded signal to a particular reference voltage from a set of reference voltages. A particular reference voltage used in this comparison may be selected using one or more digital signals already decoded from the encoded signal.

Abstract: A character and/or graphics pattern area for recording specific data is provided on a CD-ROM. When an original disk is prepared, a specific pit pattern corresponding to the specific data is recorded at a first predetermined tracking linear velocity controlled by a specific tracking linear velocity control system for each track so that a character and/or graphics pattern cannot be identified. When a copy disk is produced from the original disk, if data is recorded at a second tracking linear velocity controlled by a specific tracking linear velocity control system, the character and/or graphics pattern of visible size appears on the copy disk because of an optical reflection factor difference between areas caused by placement of the specific pit pattern corresponding to the specific data.