Abstract: An embodiment of the present invention provides an apparatus, including a transceiver adapted for use in a wireless network using a fast feedback channel design that incorporates a 2-two level adaptive fast feedback channel framework separating uplink (UL) fast feedback channels into primary and secondary UL fast feedback channels.

Abstract: A programmable logic device integrated circuit (“PLD”) includes high-speed serial interface (“HSSI”) circuitry in addition to programmable logic circuitry. The HSSI circuitry includes multiple channels of nominal data-handling circuitry (typically including clock and data recovery (“CDR”) circuitry), and at least one channel of nominal clock management unit (“CMU”) circuitry (typically including phase-locked loop (“PLL”) circuitry or the like). To increase the flexibility with which the channels can be used, the nominal data-handling channels are equipped to alternatively perform CMU-type functions, and the nominal CMU channel is equipped to alternatively perform data-handling functions.

Abstract: The disclosure can provide methods and systems for autocalibrating a transceiver. The method can include upconverting a bandpass input signal by mixing the bandpass input signal with a first local oscillator signal to form an initial transmitter signal. The initial transmitter signal can be looped back to a receiver and downconverted with a second local oscillator signal having a frequency that is different from the first local oscillator to form an intermediate frequency signal. At least one of a gain and a phase of the transmitter can be adjusted based on a transmitter image sideband of the intermediate frequency signal to generate a calibrated transmitter signal having minimized transmitter image sideband.

Abstract: Loading and ordering techniques are provided for one-sided and two-sided vectored line groups, as well as loading methodologies that also can be used on a single line, in communication systems such as Digital Subscriber Line (DSL) binders. In particular, a method for loading bits into a plurality of lines in a vectored DSL system using Discrete MultiTone (DMT) modulation is disclosed. The method iteratively determines two or more of the following sequentially: line ordering for each tone; power spectral density for the transmitted signal of each line; and bit allocation for the signal of each line. In some embodiments, line ordering may include order-swapping which may assign a first line to a first initial position, assign a second line to a second initial position, move the first line to the second initial position, and move the second line to the first initial position.

Abstract: A system and method are provided for multi-modulus division. The method accepts an input first signal having a first frequency and divides the first frequency by an integral number. A second signal is generated with a plurality of phase outputs, each having a second frequency. Using a daisy-chain register controller, phase outputs are selected and supplied as a third signal with a frequency. Selecting phase outputs using the daisy-chain register controller includes supplying the third signal as a clock signal to registers having outputs connected in a daisy-chain. Then, a sequence of register output pulses is generated in response to the clock signals, and register output pulses are chosen from the sequence to select second signal phase outputs. By using 8-second signal phase outputs, a third signal is obtained with a frequency equal to the second frequency multiplied by one of the following numbers: 0.75, 0.875, 1, 1.125, or 1.25.

Abstract: A communication circuit includes a near end transmitter, a hybrid having an input in communication with an output of the near end transmitter, and a near end adjustable load replication transmitter having an adjustable load. The communication circuit further includes a subtractor configured to subtract an output from the near end adjustable load replication transmitter from the output from the near end transmitter and the hybrid. The communication circuit further includes a near end receiver responsive to an output of the subtractor and a calibration circuit configured to adjust the adjustable load against a reference load.

Abstract: Disclosed is a semiconductor IC device using a low-price oscillator, which is capable of bidirectional communication with a host and features a low price. In bidirectional communication between a host and a device, the device comprises a synchronization establishment unit, a frequency difference detector, a frequency generator, and an oscillator providing a reference signal. The synchronization establishment unit to which an output signal from the host is inputted outputs a received signal, a synchronization establishment signal and a reception data. The frequency difference detector detects a frequency difference between a received signal and a transmitting signal, and outputs a frequency coordination signal to the frequency generator. The number of frequency division of the frequency generator is controlled by the frequency coordination signal, and the frequency generator is capable of matching the frequency of the transmitting signal which is an output signal with the frequency of the received signal.

Abstract: Disclosed is a method and an apparatus for self-calibrating direct current (DC) offset and imbalance between orthogonal signals, which may occur in a mobile transceiver. In the apparatus, a transmitter of a mobile terminal functions as a signal generator, and a receiver of the mobile terminal functions as a response characteristic detector. Further, a baseband processor applies test signals to the transmitter, receives the test signals returning from the receiver, and compensates the imbalance and DC offset for the transmitter side and the receiver side by using the test signals.

Abstract: An apparatus (1) comprising a receiver (20) for receiving signals via channels defined by a channel transfer matrix H and a transmitter (10) is provided with a channel estimator (30) for generating first and second channel estimation information and a correlator estimator (31) for correlating the first and second channel estimation information with each other and for, in response to a correlation, generating a correlation factor and a transmitting feedback unit (32) for, in dependence of the correlation factor, estimating eigenparameters of a covariance matrix HHH and for, in response to an estimation, generating feedback information and a receiving feedback unit (33) for receiving the feedback information for adjusting the transmitter (10), to avoid complex matrix processes and to get the feedback information in a simple way. A power estimator (34) estimates a first and second power value for the first and second channel estimation information for normalizing the correlation factor.

Abstract: An upstream signal power in a communication system is optimized. At least one system parameter is determined and a bits and gains table is modified. For example, a maximum received power parameter for the transmitting device is used by the receiving device to calculate a power backoff parameter. The power backoff parameter is used to calculate the bits and gains table which is then used by the transmitting device. The new SNR may be estimated. This estimation may distinguish between noise sources that vary with the signal level received and those that do not.

Abstract: A wireless communication system using a media access control (MAC) layer comprising a subscriber unit system and a base station system. The base station system is configured to receive a request for a communication service, dynamically select between a first portion of the MAC layer corresponding to a first wireless transmission link using a licensed radio frequency and a second portion of the MAC layer corresponding to a second wireless transmission link using an unlicensed radio frequency, and exchange communications for the communication service over the selected one of the first portion and the second portion of the MAC layer. The subscriber unit system is configured to transmit the request for the communication service to the base station system and exchange the communications for the communication service over the selected one of the first portion and the second portion of the MAC layer.

Abstract: A system and method for the provision for the auto detection and data exchange within different data transmission environments, such as those involving serial devices, Bluetooth-based devices, ZigBee-based devices, WiFi-based devices and/or WiMax-based devices is provided for in the present invention.

Abstract: The present invention provides a transceiver for receiving and transmitting data over a network, and a method for testing the same. In particular, the present invention provides a physical layer transceiver having a built-in-self-test (BIST) device that allows for, among other things, pulse density/width variation and jitter control.

Abstract: A feedback section acquires an analog signal that has passed through a band-pass filter, and converts the analog signal to a digital signal. A digital signal processing section compares the digital signal obtained from the feedback section and an input digital signal with each other to measure modulation accuracy, and performs delay correction on a subsequently input digital signal so as to improve the modulation accuracy.

Abstract: In an I-Q receiver, I-Q baseband mixer receives a real signal, and outputs an in-phase baseband information signal and a quadrature baseband information signal, a decoupling compensator multiplies in-phase baseband information signal and the quadrature baseband information signal by a trained decoupling matrix that, based on adaptive training in response to purely in-phase and purely quadrature phase training signals, decouples the in-phase baseband information signal from a quadrature component of the I-Q signal, and decouples quadrature-phase baseband information signal from an in-phase component of the I-Q signal. Optionally, a trained I-arm-Q-arm imbalance compensator performs a filter compensation on one or both of the decoupled in-phase baseband signal and the quadrature-phase baseband signal output by the trained decoupling matrix.

Abstract: A localization process in a network of source devices and sink devices on a 1394 bus, is performed by a source device while it is communicating to a sink device, which determines local network links from nonlocal ones. An actual round trip time calculation is performed only by the source device and the sink device can be relatively passive. The duties of the sink device are performed in hardware and involve (trivially) modifying the received message while moving the message from the input isochronous channel buffer to the output isochronous channel buffer.

Abstract: A method for beamforming in a wireless communication begins by receiving a baseband signal. The method continues by receiving a feedback signal that includes a subset of angles, wherein a set of angles provide polar coordinates for a unitary matrix and wherein the subset of angles is a subset of the set of angles. The method continues by determining at least one remaining angle of the set of angles based on the subset of angles. The method continues by determining the polar coordinates for the unitary matrix. The method continues by digitally beamforming the baseband signal using the unitary matrix.

Abstract: A wireless communications system is provided with reduced sideband noise and carrier leakage. In the system, at least one transmitter modulates at least one input signal with a first carrier to generate a modulated output signal, and at least one receiver receives the modulated output signal and demodulates the same with a second carrier to generate at least one demodulated output signal. The first and second carriers are at different frequencies, such that the sideband noise and carrier leakage generated by different sources can be distinguished.

Abstract: In a method for performing equalization of a communication system, a predetermined signal can be transmitted from a transmitter unit to a receiver unit in a downchannel direction on a transmission line, for example as a pair of differential signals which simultaneously transition in opposite directions on respective signal conductors of the transmission line. At the receiver unit, an eye opening of the signal received from the transmission line can be analyzed to determine equalization information. Equalization information can be transmitted from the receiver unit to the transmitter unit in an upchannel direction on the transmission line and be received at the transmitter unit. Using received equalization information, a transmission characteristic of the transmitter unit can be adjusted.

Abstract: An apparatus and method of aiding synchronization between a master transceiver and a slave transceiver is disclosed. The method includes the master transceiver transmitting data signals that are received by the slave transceiver. The slave transceiver locks a slave clock to the data signals with a slave phase-locked loop. The slave transceiver transmits slave clock information to the master transceiver.

Abstract: A communication circuit comprises a near end transmitter, and adjustable near end replication transmitter and a near end receiver. The near end transmitter is configured to generate a transmission signal and comprises a first plurality of current sources. Outputs of the first plurality of current sources are summed to generate the transmission signal. The adjustable near end replication transmitter comprises a second plurality of current sources. Outputs of the second plurality of current sources are summed to generate a replication signal in accordance with the transmission signal. The replication signal from the adjustable near end replication transmitter is subtracted from the transmission signal from the near end transmitter and a received signal from a communication channel to generate a subtraction signal. The near end receiver is configured to receive the subtraction signal.

Abstract: A method for communication over a communication link, which includes a transmitter and a receiver, includes transmitting and receiving data, which is encoded using a specified forward error correction (FEC) code, modulated using a specified modulation scheme and transmitted at a given power level. One or more parameters of the communication link are monitored. A condition, which is based on values of one or more of the parameters monitored at a plurality of historical time instants, is evaluated. At least one feature of the transmitted data, selected from a group of features consisting of the FEC code, the modulation scheme and the power level, is modified based on the condition.

Abstract: The present invention relates to a system and method for extending the coverage area and communication capacity of a spread-spectrum based wireless network through the use of intelligent repeaters. The system comprises a wireless communication network augmented with low cost channel selective repeaters that is capable of repeating only desired signals, thereby suppressing undesirable interference and increasing network capacity. The repeaters can be integrated into an existing wireless network with minimal impact to the existing network layer topology or control structure.

Abstract: A modem uses information from prior calls in a current call if the current communication line is similar to the communication line of a prior call. During modem training, the current communication line is compared to a communication line used during at least one prior call. If the characteristics are substantially similar, stored data mode information from the prior call(s) is used to design a signal constellation for use during the current call's data mode. If the number of prior calls exceeds a value, then the signal constellation may be designed using previously stored data mode information without using information from the current call's training mode. If the number of prior calls does not exceed the value, then the signal constellation may be designed using the previously stored data mode information and information from the current call's training mode.

Abstract: A device includes a transmitter coupled to a node, where the node is to couple to a wired link. The transmitter has a plurality of modes of operation including a calibration mode in which a range of communication data rates over the wired link is determined in accordance with a voltage margin corresponding to the wired link at a predetermined errorrate. The range of communication data rates includes a maximum data rate, which can be a non-integer multiple of an initial data rate.

Abstract: A method, system and apparatus are provided for detecting a loop-back in a physical layer on an Ethernet link. In the physical layer, a device sends a base page on the Ethernet link. The base page has at least one next page capability bit set. Subsequently, the device receives a received base page. Thereafter, for detecting the loop-back, the next page capability bit is set in the received base page is determined.

Abstract: Aspects of the present disclosure are directed to providing flexible and efficient communication by dynamically adjusting a transmit data rate in response to data status feedback. Such feedback may include information regarding data errors and/or latency. A first communication node communicates with a second communication node and sends data at an initial data rate. The transmit data rate is then selectively adjusted based on data status feedback received from the second communication node or other destination.

Abstract: A device for adjusting a transmit power spectrum of a first transmit/receive device of a communication network, comprising a means for receiving a measure for an attenuation which a signal experiences on a line from the first transmit/receive means to a first subscriber device of the communication network connected to the first transmit/receive means, from the first subscriber device, and a means for determining the transmit power spectrum of the first transmit/receive means for a communication of the first transmit/receive means with the first subscriber device based on the received attenuation measure.

Abstract: A method for Digital Subscriber Line (DSL) handshaking begins when a remote DSL transceiver transmits first signals containing even numbered carriers for a predetermined period of time to initiate the DSL handshaking to produce R-ETONES-REQ. The processing continues when the central office DSL transceiver determines alignment of a hyperframe in accordance with a TCM-ISDN TTR. The processing continues when the central office DSL transceiver transmits first response signals containing odd numbered carriers in accordance with the alignment of the hyperframe to produce C-TONES-TTR. The processing continues when the remote DSL transceiver acquires TTR synchronization in accordance with the C-TONES-TTR. The processing continues when, after acquiring TTR synchronization, the remote DSL transceiver transmits second signals containing even numbered carriers to produce R-TONE-TTR.

Abstract: A multi-transmitter base station for wireless digital communication, having beam forming and digital pre-distortion capabilities, including a shared feedback unit for providing feedback of outgoing Radio Frequency (RF) signals for calibrating a plurality of antennas and for adapting the digital pre-distortion. Related apparatus and methods are also described.

Abstract: High-speed serial interface (“HSSI”) transceiver circuitry (e.g., on a programmable logic device (“PLD”) integrated circuit) includes input buffer circuitry with adaptive equalization capability. The transceiver circuitry also includes an output driver, which may include pre-emphasis capability (preferably controllably settable). Selectively usable loop-back circuitry is provided for allowing the output signal of the input buffer to be applied substantially directly to the output driver. The loop-back circuitry may include a loop-back driver, which may be turned on substantially only when needed for loop-back operations.

Abstract: A wireless communication system is disclosed that transmits a feedback signal containing a channel estimate value between a first wireless communication device and a second wireless communication device. The first wireless communication device that transmits the feedback signals includes: a channel estimation unit that receives signals containing pilot signals, and determines the channel estimate value of a wireless link; a multiplier that multiplies a pilot signal by the channel estimate value; and a multiplexer that multiplexes an output signal from the multiplier with another pilot signal, to generate the feedback signal. The second wireless communication device that receives the feedback signal includes: a separator that separates the signals that are multiplexed in the feedback signal; and channel estimation units that determine the channel estimate value of the wireless link, based on the separated signals.

Abstract: A semiconductor device that includes a module under test that is integrated with the semiconductor device, that receives an input signal from a test module, and that provides an output signal to at least one output terminal based on the input signal. An error detecting module is integrated with the semiconductor device, samples values of the output signal, and outputs the sampled values to the test module.

Abstract: Apparatus and methods for selecting a transmit power level and subcarrier modulation assignments based on measured channel conditions to achieve a performance level for communications over a symbol-modulated subcarrier communication channel are provided. In some embodiments, the transmit power level may be changed depending on whether a desired packet error rate and/or a desired link data rate can be achieved based on selected subcarrier modulation assignments and a selected transmit power level.

Abstract: A method of and system for determining the time required for a digital bit or bit stream to traverse a round-trip path from a source transceiver to at least one destination transceiver and back is disclosed. The relative timing of the transmitted bit or bit stream is compared to the return bit or bit stream using a high speed comparison configuration so as to provide in substantially real-time various measurements related to or derived from the time required to traverse the round trip path, including distance measurement in indoor positioning, real-time locating, adaptive cruise control, intelligent transportation systems, robotics, collision avoidance, personnel accountability, emergency location, search/rescue. In addition, a method of and system for determining the distance between transceivers, and a method of and system for determining the angular position of a transceiver with respect to at least two other transceivers are disclosed.

Abstract: A method is provided for self-calibrating the mismatch and the direct current (DC) offset occurring in a mobile transceiver. The transmitter of the mobile terminal is used as a signal generator and the receiver thereof is used as a response characteristic measurer. The baseband processor calibrates the mismatch and the DC offset for the receiving and transmitting sides using a test signal received from the transmitter. When multiple input subcarriers are used in a mixer present on a reception stage, self-calibration is performed using multiple received test signals obtained from one transmission test signal.

Abstract: An active step attenuator can attenuate the RF signal from a cable modem or other RF source. The active step attenuator converts the RF energy into a DC control signal that controls the attenuation applied to the RF signal. The voltage of the control signal is proportional to the RF energy, so that the active step attenuator attenuates a stronger RF signal more than a weaker RF signal. The active step attenuator may be in the form of a diplex circuit, one branch of which passes signals in one frequency band without attenuation and the other branch of which actively attenuates signals in another frequency band.

Abstract: In a radio communication system, transmitter and receiver stations share information on a maximum number of bits communicated per symbol. The transmitter station encodes a signal with sufficient error correcting capabilities to create a codeword. The transmitter station allocates the bits from the codeword to each symbol, modulates the symbols using a modulation type which processes symbols each having a number of bits equal to or smaller than the maximum number of bits per symbol, and transmits the modulated symbols. The receiver station demodulates the symbols using a modulation type which processes a larger number of bits per symbol as the transmission path quality is higher from among modulation types which process symbols having a number of bits equal to or smaller than the maximum number of bits per symbol.

Abstract: A method for transmitting a sequence of data blocks of equal length includes obtaining part of a matrix for the impulse response function of a communication channel between a transmitter and a receiver. The part relating to channel-induced interference between sampling intervals of adjacent ones of the data blocks. The method includes designing a set of one or more linearly independent waveforms based on the obtained part of the matrix for the impulse response function and transmitting a sequence of the data blocks over the channel from the transmitter to the receiver. Each data block of the sequence is a weighted linear superposition of the one or more waveforms of the designed set.

Abstract: A method for clock jitter stress margining of high speed interfaces including generating a jittered clock signal via a clock signal generator of a high speed interface controller card, inputting the jittered clock signal to a control input of a looped-back port of the high speed interface controller card, inputting a test pattern signal to the looped-back port generated from a logic circuitry of the high speed interface controller card, receiving the test pattern signal to the logic circuitry from the looped-back port via the transmitter to the receiver, monitoring a bit error rate of the looped-back port by comparing the received test pattern signal to the inputted test pattern signal, and outputting a fail indication signal if the bit error rate is within a fail threshold.

Abstract: This disclosure relates to a continuous open loop control to closed loop control transition.

Abstract: Various embodiments are disclosed relating to a wireless transceiver. In an example embodiment, a wireless transceiver may include a transmitter adapted to output a signal at an image frequency (e.g., a simulated image) for a channel during a first mode (e.g., calibration mode) of operation. The wireless transceiver also includes a receiver adapted to receive, via loopback from the transmitter, the (e.g., simulated) image frequency signal and to determine digitally a receiver in-phase/quadrature-phase (I/Q) signal calibration adjustment based on the (simulated) image frequency signal to improve a match in amplitude and a predetermined phase shift between I and Q signals of the receiver during the first (e.g., calibration) mode of operation. The I/Q calibration adjustment may be applied to received signals during a second mode (e.g., operation mode) of operation to improve image rejection.

Abstract: A serial data link (10) includes a transmitter (12) using a differential transmitter cell (20) to transmit data using differential signals and a receiver (14) using a differential receiver cell (22) to receive differential signals. When the transmitter (12) is in a power-down state, the differential signals from the differential transmitter cell (20) are set to an illegal state that is detected by the receiver cell (22). Upon detecting the illegal state, unnecessary circuitry in the receiver (14) is shut off or placed in a low power state to conserve energy. When data transmission resumes, the receiver cell (22) automatically restores power to its circuitry and resumes receiving data.

Abstract: A first device transmits data over a first branch of a communications link toward a second device. That second device loops the received data pattern back over a second branch of the communications link. A bit error rate of the looped back data pattern is determined and a pre-emphasis applied to the transmitted data pattern is adjusted in response thereto. The first device further perturbs the data pattern communications signal so as to increase the bit error rate. The pre-emphasis is adjusted so as to reduce the determined bit error rate in the looped back data pattern in the presence of the perturbation. The steps for perturbing the signal and adjusting the pre-emphasis are iteratively performed, with the perturbation of the signal increasing with each iteration and adjustment of the pre-emphasis being refined with each iteration. The signal is perturbing by injecting modulation jitter into the signal (increasing each iteration) and adjusting amplitude of the signal (decreasing each iteration).

Abstract: The present invention provides an integrated circuit comprising a serial transmitter, a serial receiver and a serial connection providing communication between the serial transmitter and the serial receiver. The serial transmitter comprises a clock generator and a serializer for serializing data to be transmitted to the serial receiver. A clock control unit coupled to the clock generator alters the clock phase of the clock signal to stress test the serial receiver.

Abstract: An integrated circuit 2 includes a serial data transmitter 12 and a serial data receiver 14. A signal amplitude distorting circuit 30 is provided to introduce distortion in the amplitude of a serial data signal generated by the serial data transmitter 12 and looped back to the serial data receiver 14 so as to stress test the serial data receiver 14.

Abstract: In transmitting channel quality information (CQI) by a mobile station (MS) in a communication system, the mobile station receives from a base station (BS) information of an allocation of a CQI channel and information as to a modulation to be performed on the CQI. CQI channel signal is generated based on the CQI and the modulation information, where the CQI corresponds to a measured channel state. The CQI channel signal is transmitted to the BS over the allocated CQI channel.

Abstract: The present invention provides a way of hysteretic switching for efficiently reducing the heavy switching between two adjacent coarse intervals. The present invention disposes a number of fine intervals to cover a range which is larger than the length of one coarse interval. Each coarse interval comprises some extra fine intervals which are exceeded the boundary of the coarse intervals in one side. The heavy switching will be postponed until the extra fine intervals are used up. In the meantime, the fine calibration unit records the number of extra fine interval which be used. An extra-boundary value will be recorded in the fine calibration unit for determining an initial fine interval in another coarse interval if the heavy switching occurs. It should be noted that the extra-boundary value could be a positive or minus value corresponding to which a forward coarse interval or a backward coarse interval the reference signal drifts into.

Abstract: A serial interface for a programmable logic device can be used as a conventional high-speed quad interface, but also allows an individual channel, if not otherwise being used, to be programmably configured as a loop circuit (e.g., a phase-locked loop). This is accomplished by disabling the data loop of clock-data recovery circuitry in the channel, and reconfiguring the reference loop to operate as a loop circuit. In addition, instead of providing a high-speed quad interface having four channels and one or more clock management units (CMUs), a more flexible interface having five or more channels can be provided, and when it is desired to use the interface as a high-speed quad interface, one or more channels can be configured as loop circuits to function as CMUs.

Abstract: In a mobile device having a primary baseband circuit and a secondary baseband circuit and an interface between the primary baseband circuit and a secondary baseband circuit, a method for testing the interface and primary and secondary baseband circuits comprising the steps of: setting the secondary baseband circuit into a loopback mode; sending a test signal from the primary baseband circuit to the secondary baseband circuit; receiving at the primary baseband circuit a second signal, the second signal being the first signal looped back from the secondary baseband circuit; and comparing the second signal with an expected result.