Abstract: A transceiver for reducing transmit signal leakage is described. The transceiver includes a downconverter that downconverts a receive signal to produce a feedback signal. The transceiver also includes a weight learning module that correlates the feedback signal with a transmit signal to obtain a weight. The transceiver further includes a transmit leakage estimator that obtains an estimated transmit leakage signal based on the weight and the transmit signal. The transceiver also includes a transmit leakage reducer that reduces the transmit leakage in the receive signal based on the estimated transmit leakage signal.

Abstract: A communication system includes digital signals that carry data and correspond to channels of a composite signal to be transmitted across a communication channel. Active channels are detected and used to configure digital processing. In one embodiment, active channels are detected, where a particular active channel corresponds to the presence of a particular one of the digital signals. Active channel detection may be used to configure pre-distortion of a composite signal to be transmitted to compensate for distortion in a digital-to-analog converter. Likewise, active channel detection may be used to optimize the configuration of an up-converter. In one embodiment, a programmable device is configured based on detected active channels into a plurality of different configurations.

Abstract: A transceiver in-phase and quadrature (IQ) calibration method is provided. When calibrating the transceiver, an adjusting unit is connected to an output terminal of a transmitter to receive a first radio-frequency (RF) signal. The adjusting unit adjusts a phase delay of the first RF signal to generate a second RF signal to be inputted to an input terminal of a receiver. Through adjusting the phase delay of the first RF signal, both the transmitter and the receiver can be calibrated at the same time.

Abstract: A receiver device for receiving a signal that comprises one or more periodic features, the receiver device comprising: a detector configured to listen to the signal during at least a first reception phase, and to be triggered when a feature of the signal is received so as to determine the time of reception of that feature; and a receiver configured to process time-limited segments of the signal so as to derive information from features of the signal received during those segments, the receiver being configured to be dependent on the detector such that after the first reception phase the timings of the time-limited segments processed by the receiver are dependent on the time of reception determined by the detector.

Abstract: In a modular signal mirroring system each point-to-point RF transceiver end has a controller module coupled to one or more I/O modules. The I/O modules have various input and output circuits. A signal received at the near end is reconstructed at the far end after being transmitted in an RF packet. The reconstructed signal may be the same as the input signal, inverted from the input signal or level-shifted from the input signal. It is representative of the input signal following the input signal's state after a time-quantization latency. Transmission between the two ends is via a periodic transmission controlled in a master slave protocol. If a transmission is not received in a timely manner or, in some systems, if intentional interference with transmissions is detected, the reconstructed signal is forced to a safe state determined by local switch settings. The settings include the last known good state.

Abstract: The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.

Abstract: An amplifier is provided. The amplifier includes a pair of first input transistors, a first load, and a first canceling circuit. The pair of first input transistors is coupled between a pair of first differential nodes and a reference voltage source, for receiving a pair of input signals. The first load is coupled to the pair of first differential nodes and a pair of differential output terminals of the amplifier. The first canceling circuit is coupled between the first differential nodes. The canceling circuit is capable of balancing voltages, respectively, at the first differential nodes when the amplifier is turned off.

Abstract: The present invention provides a method and system for channel status information feedback based on a hierarchical codebook, the method comprising steps of: generating a hierarchical codebook; configuring the generated hierarchical codebook to a transmit end and a receive end, respectively; and feeding back channel state information from the receive end to the transmit end based on the hierarchical codebook, wherein the step of generating a hierarchical codebook further comprises the following steps: i) dividing each level of codeword in a to-be-generated codebook into a plurality of segments based on a basic codebook; ii) a module configured to generate each level of codeword in a first stage, wherein the each level of codeword is selected from the basic codebook; and iii) generating each level of codeword in other stages, wherein the each level of codeword is selected a pre-provided training sample matrix.

Abstract: This disclosure relates to radio frequency (RF) functional testing of transceivers of wireless devices.

Abstract: Systems and methods for decreasing the amount of information sent on a feedback channel are disclosed. Spectral binning and/or a Markov state model may be used to reduce the amount of information sent on the feedback channel.

Abstract: The ability of clock and data recovery (“CDR”) circuitry on an integrated circuit (“IC”) to handle jitter in a serial data input signal can be tested by using transmitter circuitry on the IC to produce a serial data output signal whose time base has been subjected to modulation. Loop-back circuitry on the IC may be used to apply the serial data output signal to the CDR circuitry as the serial data input signal of the CDR circuitry. Modulation circuitry on the IC may be used to cause the above modulation of the time base of the serial data output signal.

Abstract: A method and apparatus for evaluating and optimizing a signaling system is described. A pattern of test information is generated in a transmit circuit of the system and is transmitted to a receive circuit. A similar pattern of information is generated in the receive circuit and used as a reference. The receive circuit compares the patterns. Any differences between the patterns are observable. In one embodiment, a linear feedback shift register (LFSR) is implemented to produce patterns. An embodiment of the present disclosure may be practiced with various types of signaling systems, including those with single-ended signals and those with differential signals. An embodiment of the present disclosure may be applied to systems communicating a single bit of information on a single conductor at a given time and to systems communicating multiple bits of information on a single conductor simultaneously.

Abstract: An energy converter based transmitter, a method, a multi-element antenna array are provided for a radio frequency (RF) transmission. For example, the energy converter based transmitter can include a control circuit, a multiple input single output (MISO) operator, and an antenna. The control circuit is configured to receive input information and generate amplitude control signals and phase control signals. The MISO operator is configured to receive the amplitude control signals and the phase control signals and to generate an RF output signal. Further, the antenna is configured to receive and transmit the RF output signal.

Abstract: An analog radio frequency input and an analog feedback from an output of a radio frequency amplifier are digitized and down-converted. Pre-distortion coefficients are calculated based on the down-converted input and down-converted feedback and the down-converted input is filtered using the pre-distortion coefficients. The filter output is then up-converted to a carrier frequency and converted to analog to be provided to the radio frequency amplifier.

Abstract: A communications device, in one aspect as a portable wireless communications device, includes an in-phase modulator and power amplifier that receives a baseband I signal and modulates and amplifies the I signal. A quadrature modulator and power amplifier receives a baseband Q signal and modulates and amplifies the Q signal. A power combiner sums and outputs the I and Q signals. An I demodulator circuit receives a signal fed back from the I power amplifier and demodulates the fed back signal to produce demodulated I signals. A Q demodulator circuit receives a signal fed back from the Q power amplifier and demodulates the fed back signal to produce demodulated Q signals. A processor compares the digital, baseband I and Q signals with a demodulated I and Q signals to compensate for amplitude, frequency and phase modulation errors.

Abstract: A method for improving multiple-input multiple-output MIMO downlink transmissions includes obtaining a channel state information CSI report including preferred matrix index PMI for precoding, channel quality index CQI and rank index RI at a base station from user terminals through a channel feedback; applying selectively a signal-to-interference-plus-noise-ratio SINR offset to a SINR of said CSI report; applying selectively a rate matching responsive to SINR offset or the CSI report; and controlling or adjusting the SINR offset.

Abstract: The present invention relates to a wireless communication system, and discloses a method and apparatus for transmitting/receiving a signal in a wireless communication system that supports multi-user MIMO transmission. According to one embodiment of the present invention, a method in which a mobile station receives a signal in a wireless communication system that supports multi-user MIMO transmission, comprises: a step of receiving information on the entirety of the transmission rank of the multi-user MIMO transmission; a step of receiving a reference signal and data for demodulation for the mobile station on the basis of the information on the entirety of the transmission rank; a step of acquiring channel information on the mobile station from the reference signal for demodulation; and a step of demodulating said data on the basis of the acquired channel information.

Abstract: In a wireless communication system performing wireless communication via a wireless transmission path, a first wireless communication apparatus includes a receiver that receives a wireless signal via a wireless transmission path, a disconnection detector that detects disconnection of a wireless line connected to a second communication apparatus, a modulation controller that selects a modulation scheme, enabling communication under poor conditions in a transmission path, rather than a modulation scheme which has been used in wireless communication, and a transmitter that notifies the modulation scheme selected by the modulation scheme controller to the second wireless communication apparatus. The second wireless communication apparatus includes a receiver that receives the selected modulation scheme from the first wireless communication apparatus, and a transmitter that transmits signals to the first wireless communication apparatus based on the selected modulation scheme which is received by the receiver.

Abstract: Embodiments for at least one method and apparatus of transmitting a transmission signal through a plurality of antennas are disclosed. One method includes generating at least one dynamically adjustable phase shifted signal from the transmission signal. The transmission signal and the at least one dynamically adjustable phase shifted signal are separately amplified. The amplified transmission signal and the amplified at least one dynamically adjustable phase shifted signal are combined within a multiport network. An output signal for each of the plurality of antennas is generated by the multiport network.

Abstract: Embodiments of the present disclosure describe devices, methods, computer-readable media and systems configurations for communication of channel state information among network entities. In various embodiments, may calculate first-, second- and third-stage channel state information for nodes of a coordinated multipoint measurement set. Other embodiments may be described and/or claimed.

Abstract: A serial data transmission system includes a sending terminal for sending data, a receiving terminal for receiving the data sent by the sending terminal, a first connecting capacitor connected between the sending terminal and the receiving terminal, and a second connected capacitor connected between the sending terminal and the receiving terminal. The sending terminal includes a sending terminal driving unit, and an amplitude detecting unit connected to the sending terminal driving unit. The sending terminal driving unit outputs a pair of differential signals according to signals of the received data. The amplitude detecting unit detects changes in amplitudes of the differential signals outputted by the sending terminal driving unit, and outputs an indicating signal for indicating whether the sending terminal is properly connected to the receiving terminal. A serial data transmission method is further provided.

Abstract: Transceiver calibration is a critical issue for proper transceiver operation. The transceiver comprises at least one RF transmit chain and one RF receive chain. A closed loop path is formed from the digital block, the RF transmit chain, the substrate coupling, the RF receive chain back to the digital block and is used to estimate and calibrate the transceiver parameters over the operating range of frequencies. The substrate coupling eliminates the need for the additional circuitry saving area, power, and performance. In place of the additional circuitry, the digital block which performs baseband operations can be reconfigured into a software or/and hardware mode to calibrate the transceiver. The digital block comprises a processor and memory and is coupled to the front end of the RF transmit chain and the tail end of the RF receive chain.

Abstract: Systems and methods are for generating a codebook by: generating a multi-resolution codebook by selecting a common precoder index from a low resolution codebook for a group of adjacent resource blocks (RB)s and for each RB within the group, selecting a high-resolution codebook to fine-tune each RB precoder; and generating feedback for the multi-resolution codebook by quantizing channel state variations.

Abstract: Aspects of the present disclosure describe an efficient channel estimation algorithm for high-speed processing of dedicated reference signals. The channel estimation algorithm may utilize one or more compressed interpolation matrices. The compressed interpolation matrices may be selected based on the Doppler value and signal to noise ratio (SNR) of the channel.

Abstract: Devices and methods related to devices capable to perform digital output power measurement besides attenuation control are provided. A device includes a digital signal processing unit, a transmitter and a feedback receiver. The digital signal processing unit is configured to control attenuation along a transmission path and a feedback path based on a comparison of a power of a digital input signal with a raw power of a corresponding digital feedback signal, and to calculate an output power value of an analog RF signal to be broadcasted, using the raw power of the digital feedback signal and one or more feedback gain factors related to gain in the feedback receiver.

Abstract: An evaluation device is configured to provide a transceiver system with performance information thereof. The transceiver system models a channel between a transmitter and a receiver thereof using Nakagami distribution with a fading parameter. The evaluation device includes a setting module operable to set an average signal-to-noise rate (SNR) for the channel between the transmitter and the receiver, a computing module operable to estimate a symbol error rate related to a signal received by the receiver from the transmitter based upon the fading parameter and the average SNR, and an output module operable to provide the average SNR and the symbol error rate as the performance information of the transceiver system.

Abstract: Devices and methods for serial loopback testing in an integrated circuit (IC) are provided. To implement loopback testing, an equalizer stage of a receiver of the IC is powered down. In addition, the common-mode voltage of the equalizer stage is reduced and/or a bulk node of the equalizer stage is connected to ground. Doing so may reduce the impact of capacitive coupling from the input pins of buffer, thereby improving the quality of the loopback output signal.

Abstract: A VCO of a PLL outputs a first differential signal of frequency FVCO. A first divide-by-two circuit local to the VCO divides the first differential signal and outputs a first quadrature signal of frequency FVCO/2. Two of the component signals of the first quadrature signal are routed to a second divide-by-two circuit local to a first mixer of a first device. The second divide-by-two circuit outputs a second quadrature signal of frequency FVCO/4 to the first mixer. All four signals of the first quadrature signal of frequency FVCO/2 are routed through phase mismatch correction circuitry to a second mixer of a second device. In one example, FVCO is a tunable frequency of about ten gigahertz, the first device is an IEEE802.11b/g transmitter or receiver that transmits or receives in a first band, and the second device is an IEEE802.11a transmitter or receiver that transmits or receives in a second band.

Abstract: There is provided a MIMO wireless communication system, which comprises at least one base station having plural transmitting antennas and at least one user equipment having at least one receiving antennas, the base station being capable of accommodating plural user equipments by precoding based on a codebook, wherein, each of the plural user equipments comprises: a channel estimation unit for conducting a channel estimation based on a pilot signal transmitted from the base station, to obtain a channel information; a codeword determination unit for determining a first codeword that results in the maximum signal-noise-ratio, and at least one second codeword that results in the minimum signal-noise-ratio, based on the channel information; and a transmission unit for feedbacking the first codeword and the second codeword(s) to the base station, the base station is configured to schedule the user equipments based on the first codeword and the second codeword so that a predetermined system performance metric is opt

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: Communication processing paths include distortions, such as DC offset in the baseband analog path, local oscillator feed-through distortion, and nonlinearity of gm's and power amplifiers which are calibrated for, separately or in combination. The cascaded DC offset and nonlinear distortions are modeled separately or in combination using even-and-odd order polynomials. A loopback path from the output of one or more distortion causing devices passes through a measurement and calculation module. The calculation module calculates predistortion polynomial's coefficients which will be stored in a look-up table to be used by a baseband predistorter to calibrate the path. The look-up table is stored locally or remotely.

Abstract: A method for user equipment operation in a wireless communication system, the wireless communication system having an base station, the method comprising measuring a channel between the UE and the base station, determining a quantized estimate using a codebook to approximate the measured channel, computing an error measure for the quantized estimate and transmitting the error measure and the quantized estimate to the base station for use by the base station in reconstructing an actual channel vector.

Abstract: A wireless transmission apparatus includes a service processing unit, a duplexer, a radio frequency receiving unit, a frequency synthesizer, and a controller. The controller controls, according to a reduced TR interval, the frequency synthesizer to adjust a frequency of a local oscillation signal which is output by the frequency synthesizer to the radio frequency receiving unit. The service processing unit continues to send a service signal as a self-checking signal, and a part of the self-checking signal leaks into the radio frequency receiving unit through the duplexer. After the radio frequency receiving unit mixes a received signal with the local oscillation signal, a frequency of the self-checking signal included in an output signal falls within a pass-band range of an intermediate frequency receiving unit, which ensures that the self-checking signal can be looped back to the service processing unit, thereby determines whether a fault occurs in its own transmission channel.

Abstract: An embodiment of the invention provides an electronic device. The electronic device includes a digital-to-analog converter (DAC), a transmitter front-end (TX FE), an amplifier, an analog-to-digital converter (ADC), and a swap circuitry. The TX FE has a first and a second input end coupled to a first and a second output end of the DAC, respectively. The ADC has a first and a second input end coupled to a first and a second output end of the amplifier, respectively. The swap circuitry is configured to couple the first and second output ends of the DAC to a first and a second input end of the amplifier in a normal state, respectively, and couple the first and second output ends of the DAC to the second and first input ends of the amplifier in a swapped state, respectively.

Abstract: A power line communication modem includes a receiver that receives a noise signal over a power line channel. The signal is OFDM-modulated on a set of sub-carriers, the sub-carriers being separated by a frequency separation. The power line communication modem also includes a processor that identifies a presence of a radio service within one or more fine frequency bands with a first resolution bandwidth by analyzing a plurality of fine frequency bands. The first resolution bandwidth is smaller than the frequency separation. The power line communication modem additionally includes a transmitter that excludes a signal in at least one of the plurality of fine frequency bands, in which the presence of the radio service has been identified, before transmitting the excluded signal.

Abstract: The invention concerns a test method for a transmitter-receiver circuit. This transmitter-receiver circuit includes an antenna, connected to a processing unit, arranged for receiving signals and converting their frequency. The transmitter-receiver circuit also includes a power amplifier connected to said antenna and arranged for sending transmission signals.

Abstract: In one embodiment, a method comprising during a first calibration instance, converting at a first transconductance stage a first output voltage from a power amplifier of a transceiver to a first set of current signals; and during a second calibration instance not overlapping the first calibration instance, converting at a second transconductance stage a second output voltage from the power amplifier to a second set of current signals.

Abstract: Systems and methodologies are described herein that facilitate improved modulation and coding techniques for a multiple-in multiple-out (MIMO) communication system. As described herein, data to be transmitted over a set of physical layers (e.g., corresponding to antennas, beams, etc.) can be processed such that encoding is performed on a per-codeword basis and modulation is performed on a per-layer basis, thereby mitigating performance degradation experienced by traditional systems due to layer imbalance. As further described herein, per-codeword code rate parameters and per-layer modulation parameters can be signaled to a device in various manners, such as through modulation and coding scheme (MCS) signaling, explicit code rate and/or modulation scheme signaling, relative code rate and/or modulation scheme signaling, or the like.

Abstract: A transmitter module for unidirectional communication with a receiver module and a method using the aforementioned. The transmitter module includes a carrier detection portion, a source processing portion coupled to the carrier detection portion and a source transmission portion coupled to the source processing portion. The source processing portion can receive and process an information signal to produce a processed information signal in a manner such that an appropriate carrier signal is modulated with the information signal. The appropriate carrier signal can be based on the detection signals communicated from the carrier detection portion. The source processing portion can further process the information signal in a manner such that the processed information signal is associable with at least one of a unique code and an indication signal. The indication signal is associable with absence of communication of the at least one communication signal in a communication medium.

Abstract: A method for beamforming in a multiple input, multiple output (MIMO) communication system includes receiving a non-sounding data unit, where the non-sounding data unit does not include an indication that the data unit is for estimating a MIMO communication channel, developing an estimate of a reverse channel in which the non-sounding data unit travels based on the non-sounding data unit, developing an estimate of a forward channel based on the estimate of the reverse channel, and developing a steering matrix to perform beamforming in the forward channel based on the estimate of the forward channel.

Abstract: A VCO of a PLL outputs a first differential signal of frequency FVCO. A first divide-by-two circuit local to the VCO divides the first differential signal and outputs a first quadrature signal of frequency FVCO/2. Two of the component signals of the first quadrature signal are routed to a second divide-by-two circuit local to a first mixer of a first device. The second divide-by-two circuit outputs a second quadrature signal of frequency FVCO/4 to the first mixer. All four signals of the first quadrature signal of frequency FVCO/2 are routed through phase mismatch correction circuitry to a second mixer of a second device. In one example, FVCO is a tunable frequency of about ten gigahertz, the first device is an IEEE802.11b/g transmitter or receiver that transmits or receives in a first band, and the second device is an IEEE 802.11a transmitter or receiver that transmits or receives in a second band.

Abstract: One embodiment of the present invention provides a transceiver for wireless communication. The transceiver includes a transmitting circuit, a receiving circuit, a power amplifier coupled to the transmitting circuit, and a looping mechanism configured to establish a closed loop that couples an output of the power amplifier to an input of the receiving circuit in response to a linearity compensation need, thereby facilitating cost-effective linearity compensation.

Abstract: Techniques to enhance the performance in a wireless communication system using segments called subbands and using precoding are shown. According to one aspect, the bandwidth for transmission to an access terminal is constrained to a preferred bandwidth which is less than the bandwidth available for transmission to an access terminal and precoding information related to the subcarriers within the constrained bandwidth is provided to a transmitter. The precoding information related to the subcarriers within a constrained bandwidth provides feedback about the forward link channel properties relative to different subbands and may be fed back on a channel associated with the bandwidth.

Abstract: System and method for testing a high speed data path without generating a high speed bit clock, includes selecting a first high speed data path from a plurality of data paths for testing. Coherent clock data patterns are driven on one or more of remaining data paths of the plurality of data paths, wherein the coherent clock data patterns are in coherence with a low speed base clock. The first high speed data path is sampled by the coherent clock data patterns to generate a sampled first high speed data path, which is then tested at a speed of the low speed base clock.

Abstract: A method and device for reducing interference between a first signal of the carrier current type (Se) transmitted between modems (MCPL) in an electrical network (Re) and a second signal (S) transmitted between modems (M) in another network (R), the signals (Se, S) being coded by distribution of the data over allocated carrier frequencies in the same reserved frequency band (BF). The method includes: a step of measurement, by each modem (MCPL) in the electrical network, of transmission characteristics of each carrier frequency (F) that may be used for coding the first signal (Se), a step of detection, by analysis of the measured transmission characteristics, of at least one second, carrier frequency (F2,n), which is allocated or may be allocated for coding the second signal (S) and is common with at least one first carrier frequency (F1,m), which is allocated for coding the first signal (Se), and a steps of optimisation of the distribution of the data of the first signal (Se) over carrier frequencies.

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: The invention provides a solution for secure and non-manipulatable processing of a data stream in a receiver, possibly in conjunction with a smartcard. A packet identity and a content type identifier associated with the packet identifier are received in encrypted form and securely processed within the receiver to allow an encrypted payload of the data stream to be processed without the possibility to manipulate the content type identifier in an attempt to intercept the payload after decryption.

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: Apparatus may be provided including a spectrum analyzer and decision circuitry. The spectrum analyzer may be configured to ascertain wireless signal signature data from a wide range of frequency bands. The decision circuitry may be configured to modify operation of one or both of a receiver and a transmitter based on the signal signature data.

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.