| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 375221000 | Loopback mode | 48 |
| 20080205498 | METHOD FOR EDGE FORMATION OF SIGNALS AND TRANSMITTER/RECEIVER COMPONENT FOR A BUS SYSTEM - A method is provided for edge formation of signals and transmitter/receiver component for a bus system. A transmitter/receiver component for a bus system comprises a driver transistor, which is to be looped between a bus line of the bus system and a reference potential and is used to output signals on the bus line, a control unit for the driver transistor, a high-frequency interference detector, which is configured in such a way that it detects a high-frequency interference level on the bus line of the bus system, whereby the control unit is configured in such a way that it controls the driver transistor, depending on the detected high-frequency interference level, in such a way that an edge steepness of the output signals increases when the high-frequency interference level on the bus line increases, and an edge steepness of the output signals decreases when the high-frequency interference level on the bus line decreases. | 08-28-2008 |
| 20080219334 | Managing Bit Error Rates on Point-To-Point Wireless Links in a Network - In one embodiment, a method includes receiving, from a decoder connected to a wireless receiver for communication with a remote apparatus, first error data that indicates a current error rate that corresponds to a first inbound data packet received from the remote apparatus. Based in part on the first error data, it is determined whether the remote apparatus should increase a current signal to noise ratio. If so, then a first outbound data packet is sent to an encoder connected to a wireless transmitter. The first outbound data packet includes first link conditioning request data that indicates a current signal to noise ratio for one or more data packets received from the remote apparatus based at least in part on the first error data. The remote apparatus increases signal to noise ratio of transmissions in response to receiving the outbound data packet. | 09-11-2008 |
| 20080240212 | Transmitter/receiver device and method of testing transmitter/receiver device - A transmitter/receiver device includes: a transmitter unit including a parallel/serial converting circuit, a waveform deteriorating circuit, and a transmitter circuit; and a receiver unit including a receiver circuit, a serial/parallel converting circuit, and an error detecting circuit. The parallel/serial converting circuit converts a transmitter-side parallel signal to a transmitter-side serial signal. The waveform deteriorating circuit deteriorates a signal waveform of the transmitter-side serial signal. The transmitter circuit transmits to the receiver unit the signal whose waveform is deteriorated. The receiver circuit receives, as a receiver-side serial signal, the signal transmitted from the transmitter circuit. The serial/parallel converting circuit converts the receiver-side serial signal to a receiver-side parallel signal. The error detecting circuit detects a bit error rate of the receiver-side parallel signal. | 10-02-2008 |
| 20090010317 | Nullification of transmitter noise at receive signal frequency - According to one exemplary embodiment, a transceiver for nullification of a noise component in a transmitter comprises a noise nullification module loading a selected node in the transmitter. The noise nullification module comprises a mixer that receives inputs from the selected node and a local oscillator, where the mixer is also coupled to a filter such that the noise nullification module presents a low impedance at an approximate frequency of a noise component so as to nullify the noise component. In one embodiment, the noise nullification module results in band-pass filtering of an approximate receive signal frequency so as to nullify a noise component at the receive frequency. In another embodiment, the noise nullification module results in notch filtering of an approximate transmit signal frequency so as to nullify a noise component at a receive signal frequency. | 01-08-2009 |
| 20090041101 | TEST APPARATUS - A test apparatus includes a transmitting-side jitter measuring unit which measures a jitter of a transmission signal output from a transmitting circuit, a jitter applying unit which applies a jitter to the transmission signal and inputs the signal to a receiving circuit, a jitter range measuring unit which determines whether the logical value of the transmission signal detected by the receiving circuit is equal to a preset expectation value for each amplitude of the jitter applied to the transmission signal by the jitter applying unit, and measures the range of jitter amplitudes within which the logical value of the transmission signal is equal to the expectation value, and a jitter tolerance measuring unit which calculates jitter tolerance of the receiving circuit based on the jitter of the transmission signal measured by the transmitting-side jitter measuring unit and the range of jitter amplitudes measured by the jitter range measuring unit. | 02-12-2009 |
| 20090041102 | JITTER INJECTION CIRCUIT, ELECTRONICS DEVICE, AND TEST APPARATUS - Provided is a jitter injection circuit that injects jitter having a predetermined amplitude to a transmission signal outputted from a transmission circuit, and inputs the resulting transmission signal to a reception circuit, the jitter injection circuit including: a retiming section that receives the transmission signal from the transmission circuit, and performs retiming on an edge timing of the received transmission signal in accordance with a given clock signal; and a jitter injection section that injects the jitter having the predetermined amplitude to the transmission signal outputted from the retiming section, and inputs the resulting transmission signal to the reception circuit. | 02-12-2009 |
| 20090161740 | TRANSCEIVER WITH SWITCH CIRCUIT FOR ROUTING DATA FROM RECEIVER TO TRANSMITTER - A transceiver includes a receiver unit including a clock and data recovery unit. The transceiver includes a transmitter unit and a digital core coupled to the receiver unit and the transmitter unit. A switch circuit is positioned after the clock and data recovery unit, and is configured to route data from the receiver unit to the transmitter unit in a test mode of the transceiver. | 06-25-2009 |
| 20090168856 | System and Method for Adaptive Equalization of In-Package Signals - A system and method for adaptive equalization of in-package signals. A method for operating a wireless communications device having a transmitter and a receiver includes receiving a transmitted signal at the receiver, wherein the receiving of the transmitted signal occurs by mutual inductance, converting the received transmitted signal into a baseband signal, equalizing the baseband signal, computing a correction signal from the equalized baseband signal, and providing the correction signal to the transmitter. The equalizing of the baseband signal helps to eliminate or reduce multipath arising from mutual inductance between the transmitter and the receiver. The elimination of the multipath helps to improve the quality of the correction signal, thereby helping to increase the performance of the wireless communications device. | 07-02-2009 |
| 20090207896 | CONFIGURABLE LOAD IMPEDANCE FOR POWER AMPLIFIER PREDISTORTION CALIBRATION - An integrated circuit radio transceiver and method therefor includes an integrated circuit radio transceiver operable to provide specified gain levels and transmit path filter responses to correspond with a selected power spectral density mask. Changes in gain may be provided solely digital gain changes or may include analog gain module gain changes. A transmitter selects from one of at least three masks to reduce or eliminate spectral regrowth out of band to satisfy EVM requirements. Circuitry is provided to allow a transceiver to determine in advance what pre-distortion compensation settings are required for the various gain settings. | 08-20-2009 |
| 20090290623 | Signal amplitude distortion within an integrated circuit - An integrated circuit | 11-26-2009 |
| 20090290624 | Programmable jitter generation circuit - 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. | 11-26-2009 |
| 20090304054 | SERDES WITH JITTER-BASED BUILT-IN SELF TEST (BIST) FOR ADAPTING FIR FILTER COEFFICIENTS - 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). | 12-10-2009 |
| 20100008409 | METHOD FOR CLOCK JITTER STRESS MARGINING OF HIGH SPEED INTERFACES - 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. | 01-14-2010 |
| 20100008410 | Continuous Open Loop Control to Closed Loop Control Transition - This disclosure relates to a continuous open loop control to closed loop control transition. | 01-14-2010 |
| 20100103994 | Interface With Variable Data Rate - 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. | 04-29-2010 |
| 20100166049 | RECEIVER I-Q BALANCE CALIBRATION - 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. Optionally, the filter is trained based on training signals generated by inputting equal in-phase and quadrature phase training signals to the I-Q baseband mixer, and multiplying the result by the trained decoupling matrix. | 07-01-2010 |
| 20100172398 | Transceiver Amplifier And Delay Deviation Compensation Method - 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. | 07-08-2010 |
| 20100329316 | Techniques for transmission of channel quality data in wireless systems - 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. | 12-30-2010 |
| 20110075715 | Calibration of quadrature imbalance via loopback phase shifts - Apparatuses, systems, and methods for calibration of quadrature imbalance in direct conversion transceivers are contemplated. A transceiver controller may perform a self-calibration to address quadrature imbalance. The controller may isolate the transmitter and receiver from any antennas, couple the radio frequency (RF) section of the transmitter to the RF section of the receiver via a loopback path, and inject a calibration signal into the transmitter. In the loopback path, the controller may phase-shift the signal that propagates through the transmitter using two different phase angles to produce two different signals that propagate into the receiver. By measuring the two different signals that exit the receiver, the controller may be able to calculate correction coefficients, or parameters, which may be used to adjust elements that address or correct the quadrature imbalance for both the transmitter and receiver. | 03-31-2011 |
| 20110206100 | WIDE BAND TRANSCEIVER AND DATA RECEIVING METHOD USING A TUNABLE NOTCH FILTER AND PRE-ESTIMATED OPTIMAL NOTCH FILTER PARAMETERS - Data is received with a transceiver circuit with a receiver branch ( | 08-25-2011 |
| 20110243205 | METHOD OF COMPENSATING FOR ERROR AND TRANSCEIVER SYSTEM USING THE METHOD - A method of compensating for an error and a transceiver system using the method. The method includes determining whether a distortion occurs in data received by a receiving unit; if it is determined that the distortion occurs in the received data, changing at least one of a plurality of transmission parameters of the received data by one step; transmitting the received data using the changed at least one transmission parameter in a transmitting unit; and repeatedly performing the determining, the changing, and the transmitting until it is determined that the distortion does not occur in the received data. | 10-06-2011 |
| 20110292978 | Calibration of quadrature imbalances using wideband signals - Calibration of quadrature imbalance in direct conversion transceivers is contemplated. A transceiver controller may perform a self-calibration to address quadrature imbalance. The controller may couple the radio frequency (RF) section of the transmitter to the RF section of the receiver via a loopback path and transfer a wideband signal into the transmitter. In the loopback path, the controller may phase-shift the wideband signal that propagates through the transmitter using two different phase angles to produce two different signals that propagate into the receiver. By measuring the transmitter and receiver signals, and performing a Fast Fourier Transform calculation, the controller may be able to calculate correction coefficients, or parameters, which may be used to adjust elements that address or correct the quadrature imbalance for both the transmitter and receiver. | 12-01-2011 |
| 20120020392 | COMMUNICATION SYSTEM, NETWORK ELEMENT AND METHOD FOR ANTENNA ARRAY CALIBRATION - A network element for a wireless communication system is locatable to couple at least one base station to an antenna array comprising a plurality of antenna elements. The network element comprises a plurality of independent transceiver circuits coupled to at least one of a plurality of respective antenna elements of the antenna array; and logic arranged to apply at least one complex digital signal to at least one transceiver signal path of a transceiver circuit of the plurality of independent transceiver circuits. A feedback path is arranged to provide feedback of the at least one complex digital signal such that it is capable of facilitating determination of latency mismatch error response between at least two transceiver signal paths. Adjustment means comprises delay logic arranged to receive a complex digital signal and provide a modified representation of the received complex digital signal in response to the latency mismatch error response of the at least two transceiver signal path. | 01-26-2012 |
| 20120063496 | Wireless Transmitters - Transmitter circuits for generating baseband signals having low receiver-band noise are disclosed. In one embodiment, the transmitter circuit comprises an active filtering-and-amplifying component comprising a first input configured to receive a first input signal, and a first output configured to output a first output signal. The transmitter circuit further comprises a passive filtering component comprising a second input connected to the first output and configured to receive the first output signal, a passive pole arrangement comprising a number of switchable resistance elements and a capacitance element connected across the plurality of switchable resistance elements, and a second output configured to output a second output signal having reduced noise as compared to the first output signal. The transmitter still further comprises a number of feedback loops connecting the passive filtering component to the first input. | 03-15-2012 |
| 20120120992 | LO GENERATION AND DISTRIBUTION IN A MULTI-BAND TRANSCEIVER - 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. | 05-17-2012 |
| 20120236912 | METHOD AND SYSTEM FOR COMPENSATING FOR ESTIMATED DISTORTION IN A TRANSMITTER BY UTILIZING A DIGITAL PREDISTORTION SCHEME WITH A QUADRATURE FEEDBACK MIXER CONFIGURATION - Aspects of a method and system for compensating for estimated distortion in a transmitter by utilizing a digital predistortion scheme with a quadrature feedback mixer configuration are presented. Aspects of the system may include an RF transmitter that enables generation of an RF output signal in response to one or more generated input signals. One or more feedback signals may be generated by performing frequency downconversion on the RF output signal within a corresponding one or more feedback mixer circuits. The generated one or more feedback signals may be inserted at a corresponding one or more insertion points in an RF receiver. Each insertion point may be between a receiver mixer circuit and corresponding circuits that generate a baseband signal based on the corresponding one of the feedback signals. | 09-20-2012 |
| 20120257656 | TRANSCEIVERS HAVING LOOPBACK SWITCHES AND METHODS OF CALIBRATING CARRIER LEAKAGE THEREOF - 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. | 10-11-2012 |
| 20120263215 | TRANSCEIVER CAPABLE OF IQ MISMATCH COMPENSATION ON THE FLY AND METHOD THEREOF - A transceiver capable of IQ mismatch compensation on the fly and a method thereof. The transceiver comprises a transmitter circuit and a loop-back circuit. The transmitter circuit is configured to up-convert a modulation signal on the fly to generate a first RF signal. The loop-back circuit is configured to down-convert the first RF signal and then digitize the down-converted first RF signal to determine a first IQ mismatch parameter based on a first statistical measure of the digitized down-converted RF signal. The transmitter circuit is further configured to compensate for first IQ mismatch in the transmitter circuit according to the first IQ mismatch parameter to generate an IQ compensated modulation signal. | 10-18-2012 |
| 20120327985 | COMMUNICATIONS SYSTEM INCLUDING JAMMER USING CONTINUOUS PHASE MODULATION (CPM) AND ASSOCIATED METHODS - A communications system includes a target receiver having a passband and configured to receive an intended signal within the passband. The communications system also includes a jammer configured to jam the target receiver from receiving the intended signal. The jammer has at least one antenna, a jammer receiver coupled to the at least one antenna, a jammer transmitter coupled to the at least one antenna, and a controller configured to cooperate with the jammer receiver. The controller is configured to detect the intended signal and to generate an interfering signal comprising a continuous phase modulation (CPM) waveform having a constant envelope so that the interfering signal at least partially overlaps the passband of the target receiver. | 12-27-2012 |
| 20130121388 | LOW COMPLEXITY FREQUENCY SELECTIVE IQ MISMATCH DIGITAL RX BALANCER AND TX INVERSE BALANCER FOR NON-IDEAL RF FRONT-END - A system for reducing a mismatch between an in-phase (I) signal and a quadrature phase (Q) signal is disclosed. The system includes a phase compensation block comprising an infinite impulse response (IIR) filter configured to reduce a first portion of a mismatch between an I signal and a Q signal, wherein the first portion includes frequency selective phase mismatch. The system further includes a gain compensation block comprising a finite impulse response (FIR) filter configured to reduce a second portion of the mismatch, wherein the second portion includes frequency selective gain mismatch. The phase compensation block and the gain compensation block are calibrated at least in part based on a loopback signal, wherein the loopback signal is routed from a transmitting portion of a radio frequency (RF) circuitry back to a receiving portion of the RF circuitry. | 05-16-2013 |
| 20130121389 | Estimation Of Intentional Phase Shift In a Calibration Apparatus - Embodiments of the present invention provide an apparatus comprising a transceiver having a receiver and a transmitter connected through a segment of a calibration loop back path. The apparatus also comprises a control system configured to communicate with the transceiver. The calibration loop back path has an intentional phase shift that can be toggled between an off state and an on state by the control system. The control system is configured to calculate the intentional phase shift by examining the difference of a first and second phase angle. The first phase angle is obtained from the transmission of a first pair of signals with the intentional phase shift in the off state. The second phase angle is obtained from the transmission of a second pair of signals with the intentional phase shift in the on state. | 05-16-2013 |
| 20130156078 | COST-EFFECTIVE LINEARIZATION FOR WIRELESS COMMUNICATION - 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. | 06-20-2013 |
| 20130156079 | AMPLIFIERS AND TRANSCEIVER DEVICES USING THE SAME - 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. | 06-20-2013 |
| 20130223489 | Transceiver IQ Calibration System and Associated Method - 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. | 08-29-2013 |
| 20130287076 | CALIBRATION OF COMMUNICATION PROCESSING PATH - 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. | 10-31-2013 |
| 20130301691 | On-Chip Interferers for Standards Compliant Jitter Tolerance Testing - Systems and methods that facilitate on-chip testing are provided. An integrated circuit can include a transmitter configured to transmit a communications signal via a communications channel. The integrated circuit can also include a receiver configured to receive the communications signal via the communications channel. A jitter creation module also can form part of the integrated circuit and can introduce jitter into the system thereby allowing for on-chip jitter testing. The jitter creation module can form either part of the transmitter or receiver and can introduce the jitter by phase interpolation. | 11-14-2013 |
| 20140029653 | LO GENERATION AND DISTRIBUTION IN A MULTI-BAND TRANSCEIVER - 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. | 01-30-2014 |
| 20140036973 | CALIBRATION FOR POWER AMPLIFIER PREDISTORTION - 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. | 02-06-2014 |
| 20140133532 | Serial data transmission system and method - 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. | 05-15-2014 |
| 20140269863 | TRANSMITTER LO LEAKAGE CALIBRATION SCHEME USING LOOPBACK CIRCUITRY - A method and apparatus for estimating and compensating TX LO leakage using circuitry on a loopback path connecting the transmitter and receiver are provided. The TX LO leakage may be estimated by measuring the DC signal on the receiver, measuring the phase difference between the received LO signal and the receiver LO signal, and filtering LO harmonics that may arise from the use of non-linear mixers. The DC signal on the receiver may be measured by opening and closing the loopback path, or changing the gain of the loopback path, or flipping the phase of looped back TX signal. The method may be used in an initialization or tracking calibration scheme. | 09-18-2014 |
| 20140269864 | TRANSMIT LEAKAGE CANCELLATION - 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. | 09-18-2014 |
| 20140321516 | TRANSCEIVER IQ CALIBRATION SYSTEM AND ASSOCIATED METHOD - Local oscillator (LO) in-phase/quadrature (IQ) imbalance correction data are generated for one or both of the transmitter and receiver of a radio-frequency (RF) communication device. An RF transmitter output signal is generated by the transmitter from a known test signal and transmitted to the receiver, where a baseband receiver signal is produced. A signal characteristic of the receiver baseband signal is measured in the presence of phase shifts introduced in the transmitter output signal. Joint LO IQ imbalance figures of merit are computed from the signal characteristic measurements, each characterizing signal processing artifacts in the receiver baseband signal caused by joint signal processing in the transmitter and the receiver under influence of transmitter LO IQ imbalance and receiver LO IQ imbalance. The LO IQ imbalance correction data are determined from the computed JFMs so that the transmitter LO IQ imbalance is distinctly characterized from the receiver LO IQ imbalance from measurements obtained through no greater than two (2) phase shifts. | 10-30-2014 |
| 20150016493 | SERIALIZER/DESERIALIZER APPARATUS WITH LOOPBACK CONFIGURATION AND METHODS THEREOF - The present invention is directed to integrated circuits. In a specific embodiment, high frequency signals from an equalizer are directly connected to a first pair of inputs of a sense amplifier. The sense amplifier also has a second pair of inputs, which can be selectively coupled to output signals from a DAC or high frequency loopback signals. There are other embodiments as well. | 01-15-2015 |
| 20150030058 | CQI FEEDBACK FOR MIMO DEPLOYMENTS - The present disclosure provides a receiver, a transmitter and methods of operating a receiver and a transmitter. In one embodiment, the receiver includes a receive portion employing transmission signals from a transmitter, having multiple transmit antennas, that is capable of transmitting at least one spatial codeword and adapting a transmission rank. The receiver also includes a feedback generator portion configured to provide a channel quality indicator that is feedback to the transmitter, wherein the channel quality indicator corresponds to at least one transmission rank. | 01-29-2015 |
| 20150036727 | CALIBRATION OF QUADRATURE IMBALANCE VIA LOOPBACK PHASE SHIFTS - Apparatuses, systems, and methods for calibration of quadrature imbalance in direct conversion transceivers are contemplated. A transceiver controller may perform a self-calibration to address quadrature imbalance. The controller may isolate the transmitter and receiver from any antennas, couple the radio frequency (RF) section of the transmitter to the RF section of the receiver via a loopback path, and inject a calibration signal into the transmitter. In the loopback path, the controller may phase-shift the signal that propagates through the transmitter using two different phase angles to produce two different signals that propagate into the receiver. By measuring the two different signals that exit the receiver, the controller may be able to calculate correction coefficients, or parameters, which may be used to adjust elements that address or correct the quadrature imbalance for both the transmitter and receiver. | 02-05-2015 |
| 20150326236 | FRACTIONAL-N SYNTHESIZER WITH PRE-MULTIPLICATION - A fractional-N frequency synthesizer that suppresses integer boundary spurs. A frequency synthesizer includes a fractional-N phase locked loop (PLL) and a reference frequency scaler. The reference frequency scaler is coupled to a reference clock input of the PLL, the reference frequency scaler includes a programmable frequency divider, and a programmable frequency multiplier connected in series with the programmable frequency divider. Each of the divider and multiplier is configured to scale a reference frequency provided to the PLL by a programmable integer value. | 11-12-2015 |
| 20150349838 | METHOD AND APPARATUS FOR ADAPTIVE TRANSMIT POWER CONTROL - Systems and methods for dynamically adjusting transmit gain in a transceiver. The gain is adjusted in order to provide the maximum gain. The amount of distortion is measured. The gain is increased until the distortion reaches a predetermined limit. The gain of several components can be adjusted independently. | 12-03-2015 |
| 20160149652 | SCHEME FOR PERFORMING BEAMFORMING CALIBRATION BY MEASURING JOINT SIGNAL Path MISMATCH - A method operative on a wireless transceiver device for performing beamforming calibration includes: measuring at least one joint signal response of at least one circuit loopback between a transmitter of the wireless transceiver device and a receiver of the wireless transceiver device to determine the measurement result; and calibrating joint signal path mismatch according to the measurement result for s multiple antenna beamforming system operating on the wireless transceiver device. | 05-26-2016 |
