Abstract: The present disclosure provides a detailed description of techniques for implementing a low power buffer with dynamic gain control. More specifically, some embodiments of the present disclosure are directed to a buffer having a gain boost configuration and a current shunt circuit to control the gain of a respective gain boosting transistor of the gain boost configuration. The current shunt circuit and resulting gain are dynamically controlled by a gain control signal such that the buffer gain can be adjusted to within an acceptable range of the target gain for the current operating and device mismatch conditions. In one or more embodiments, the gain boost configuration with dynamic gain control can be deployed in a full differential implementation. Both analog and digital dynamic calibration and control techniques can be used to provide the gain control signals to multiple current shunt circuits and multiple buffers.

Abstract: Each of a plurality of modules comprises a respective one of a plurality of antenna elements, and each of a subset of the plurality of modules comprising a respective one of a plurality of transceivers, wherein the plurality of modules are interconnected via one or more communication links. The circuitry may be operable to receive a calibration signal via the plurality of antenna elements, determine, for each one of the antenna elements, a time and/or phase of arrival of the calibration signal, calculate, based on the time and/or phase of arrival of the calibration signal at each of the plurality of antenna elements, electrical distances between the plurality of antenna elements on the one or more communication links, and calculate beamforming coefficients for use with the plurality of antenna elements based on the electrical distances.

Abstract: A first communication device receives sounding feedback packets from a plurality of second communication devices in a group of second communication devices for OFDMA communication. Each sounding feedback packet includes beamforming feedback information to be used by the first communication device for beamforming to the corresponding second communication device, and one or more quality indicators corresponding to one or more sub-channel blocks of an orthogonal frequency division multiplexing (OFDM) communication channel associated with the corresponding second communication device. Respective sub-channel blocks are allocated based on the quality indicators, to respective ones of the second communication devices in the group. The first communication device transmits an OFDMA data unit that includes respective OFDM data units directed to respective ones of the second communication devices in the group.

Abstract: A broadcast signal receiver is disclosed. A broadcast signal receiver according to an embodiment of the present invention comprises a synchronization & demodulation module performing signal detection and OFDM demodulation on a received broadcast signal; a frame parsing & deinterleaving module performing parsing and deinterleaving of a signal frame of the broadcast signal; a demapping & decoding module performing conversion of data of at least one Physical Layer Pipe (PLP) of the broadcast signal into the bit domain and FEC decoding of the converted PLP data; and an output processing module outputting a data stream by receiving the at least one PLP data.

Abstract: Provided are a reception device, a reception method and a transmission reception system capable of reducing the influence of distortion in a received signal and achieving high demodulation performance without performing a computation process having a great amount of calculations. The reception device receives a signal containing a known signal part and a data part, and includes a conversion unit that converts the signal received by a reception unit into a digital signal, a region determination unit that determines a nonuse region which is a periodic region containing distortion in the digital signal, on a basis of a first digital signal in the known signal part contained in the digital signal and a known signal held in advance, and a demodulation unit that performs demodulation on the digital signal by using a second digital signal in a region other than the nonuse region in the digital signal.

Abstract: A signal interference cancellation system includes a signal filter that receives an interference signal and is in communication with a receiver that also receives the interference signal. The signal filter includes (a) a modulation system that modulates the interference signal to generate a modulated signal, (b) a first frequency range within which the modulation system amplifies quadrature components of the modulated signal, (c) a second frequency range within which the modulation system amplifies non-quadrature components of the modulated signal, and (d) a signal adder that combines the amplified quadrature and non-quadrature components of the modulated signal from (b) and (c) to generate an interference cancellation signal. The signal filter communicates the interference cancellation signal to the receiver for cancelling the interference signal.

Abstract: Methods and systems for crest factor reduction may comprise generating an original waveform, generating a distortion signal by reducing a crest factor of the original waveform, generating an error signal by subtracting out the original waveform from the distortion signal, and generating a conditioned waveform by adding the error signal to the original waveform. The crest factor of the original waveform may be reduced based on spectral mask requirements. The crest factor of the original waveform may be reduced using a limiter. The power amplifier may comprise a programmable gain amplifier (PGA). The distortion signal may be generated based on a PGA model and/or a predistortion model. A signal from an output of the PA may be fed back to the PGA model. The PGA model may be dynamically configured. The crest factor of the original waveform may be reduced in an analog domain and/or a digital domain.

Abstract: A receiving device includes a first calculating circuit, an error slicer, a data slicer, a second calculating circuit, and an equalization circuit. The first calculating circuit is configured to generate a calculating signal according to an equalized signal and a feedback signal. The error slicer is configured to generate an error signal according to the calculating signal. The data slicer is configured to generate a data signal according to the calculating signal. The second calculating circuit is configured to generate a first, a second, and a third equalization coefficient according to the data signal and the error signal. The equalization circuit is configured to generate the feedback signal according to the first, the second, and the third equalization coefficient. A gain value of the equalization circuit is associated with the first equalization coefficient. A time constant of the equalization circuit is associated with the second and the third equalization coefficient.

Abstract: An adjustable signal equalization device includes an equalizer circuitry, an analog-to-digital converter (ADC), a calculation circuitry, and a comparator circuitry. The equalizer circuitry has a transfer function, and processes an input signal based on the transfer function to generate an output signal. The ADC generates a digital signal according to the output signal. The calculation circuitry performs an accumulation according to the first digital signal to generate a first accumulated value and a second accumulated value, and generates a first detection signal and a second detection signal according to the first accumulated value and the second accumulated value. The comparator circuitry compares the first detection signal with the second detection signal to output a control signal to the equalizer circuit if the first detection signal is different from the second detection signal, in order to adjust the transfer function.

Abstract: A clock correction method is provided. The clock correction method includes the following steps: receiving a training signal in a communication protocol, wherein the training signal carries a specific signal pattern occurring repeatedly; performing frequency division on the training signal according to a number of toggles of the specific signal pattern so as to generate an equalization training sequence clock; and correcting a frequency of an output clock of an oscillator according to the equalization training sequence clock.

Abstract: A first communication device receives sounding feedback packets from a plurality of second communication devices, wherein each sounding feedback packet includes one or more channel quality indicators (CQIs) corresponding to one or more groups of orthogonal frequency division multiplexing (OFDM) subcarriers associated with the corresponding second communication device. The first communication device selects a group of second communications devices, based on the received one or more CQIs, for orthogonal frequency division multiple access (OFDMA) communication. The first communication device transmits at least one OFDMA data unit that includes respective data directed to two or more second communication devices of the group, where the respective data are transmitted via respective groups of subcarriers that were allocated to the two or more second communication devices of the group by the first communication device using the received CQIs.

Abstract: Quadrature Amplitude Modulation (QAM) methods, apparatus, and systems are disclosed.

Abstract: A system, method, and computer program product is provided to select at least one channel based on one or more channel characteristics and initiate a first transmission to a first multiple-input-multiple-output (MIMO)-capable portable wireless device, and further initiate a second transmission to a second multiple-input-multiple-output (MIMO)-capable portable wireless device, such that at least a portion of the first transmission occurs simultaneously with at least a portion of the second transmission and both occur via a first wireless protocol; and is further configured to initiate a third transmission to a third multiple-input-multiple-output (MIMO)-capable portable wireless device via a second wireless protocol including a 802.11n protocol, where the first wireless protocol includes another 802.11 protocol other than the 802.11n protocol.

Abstract: An antenna subsystem receives an analog desired signal, noise, and interference via a communication channel. The desired signal includes modulated encoded digital information. A local oscillator (LO) modulation subsystem generates a modulated LO. The LO modulation subsystem generates a modulated LO to maximize the symbol signal-to-noise ratio of the decoded digital information based on a plurality of: the desired signal, the interference and the noise expected in the communication channel, the characteristics of the converter, and the ability of the DSP to remove the Modulated LO from the converted signal. A mixer mixes the received signal and the modulated LO. A converter converts the mixed signal from analog to digital. A digital signal processor (DSP) removes the modulated LO and desired signal modulation, and decodes the desired signal encoded digital information.

Abstract: A method and circuitry for switching current to a load. The circuitry for supplying a current to a load comprises a sensor configured to sense the current supplied via a sensor input and to produce an output signal representing a time derivative of the sensed current, and a switch configured to switch the current, a switching frequency of the switch being controlled by said output signal representing a time derivative of the sense current, thereby producing a switched output current to the load.

Abstract: A receiver apparatus models and corrects the frequency-dependent and the frequency-independent mismatches between I and Q paths jointly by polynomial estimations. The receiver apparatus may sample digitized I and Q path signals. The sampled data point may be modeled in equations with real and imaginary components. The sampled discrete time-domain data may be converted to frequency-domain data. Multiple statistics values based on the frequency-domain data may be computed. Coefficients for the polynomial equations may be estimated based on the computed statistic values. The channel mismatches may be estimated from the polynomial equations and used to compensate the mismatch either on the I path or the Q path.

Abstract: A system for data transfer in a rotorcraft includes a power bus extending from a power source in a main fuselage of the rotorcraft to provide electrical power to electrical loads located in a tail boom section of the rotorcraft, a first power line communication node on the power bus in the tail boom section of the rotorcraft, a second power line communication node on the power bus in the main fuselage of the rotorcraft, and a digital sensor bus connected to the first power line communication node. Information from the digital sensor bus is transmitted to the first power line communication node and across the power bus to the second power line communication node.

Abstract: One embodiment of the disclosure relates to supporting distinct single-input single-output (SISO) services in a multiple-input multiple-output (MIMO) baseband circuit, particularly suited for a distributed antenna system (DAS). In this regard, in one aspect, two communication paths in the MIMO baseband circuit are reconfigured to distribute two distinct SISO signals. A quadrature modulator modulates the two distinct SISO signals to two different radio frequency (RF) bands, respectively, based on a modulation frequency. In another aspect, the two or more distinct SISO signals are provided to the quadrature modulator using two intermediate frequencies (IFs) that are determined based on the center frequencies and bandwidths of the two different RF bands. By reconfiguring the MIMO baseband circuit to distribute the two distinct SISO signals, it is possible to retro-support new wireless communication services and/or new RF bands in existing DAS installations without replacing the MIMO baseband circuit.

Abstract: Embodiments described herein include a receiver, a method, and a plurality of high-pass filters for demodulating a radio frequency (RF) signal. An example receiver includes a plurality of high-pass filters. The receiver includes a demodulator configured to demodulate an RF signal received at an input of the demodulator and configured to output a demodulated signal. The receiver also includes a plurality of high-pass filters connected to an output of the demodulator. The plurality of high-pass filters are configured to receive the demodulated signal and configured to high-pass filter the demodulated signal. The plurality of high-pass filters are configured to operate with a first set of filter responses during a first time period of the demodulated signal and configured to operate with a second set of filter responses during a second time period of the demodulated signal.

Abstract: The present disclosure describes systems and methods for determining intermodulation distortion in a system such as, but not limited to, a communication system. In an embodiment, intermodulation distortion is determined by injecting a signal into a frequency band which interacts with a second signal, searching a second frequency band for a product signal formed from the first and second signals, applying a cyclostationarity detection technique to the product signal and identifying the product signal as an intermodulation distortion signal.