Abstract: A channel estimation method including: a channel estimation device employs a two-dimensional channel estimation method and utilizes the channel estimate of an original pilot frequency to conduct channel estimation on an encrypted pilot frequency, so as to obtain the channel estimate of the encrypted pilot frequency; the channel estimation device employs a one-dimensional channel estimation method and utilizes the channel estimate of the encrypted pilot frequency to conduct channel estimation on all resources, so as to obtain the channel estimates on all resources.

Abstract: A hybrid analog-digital, dual path, delta-sigma modulator (DSM) based fractional-N phase-lock-loop (PLL) that includes an integral path and a proportional path is provided. The integral path is implemented in the digital domain. The proportional path may be implemented in either the digital or analog domain. A feed-forward error correction signal generator is used to generate a feed-forward signal for attenuating in-band spurs generated by the quantization error of the integral path phase detector.

Abstract: This application discusses, among other things, apparatus and methods for suppressing irrelevant edges of a phase modulated signal. In an example, a method can include receiving phase modulation information at a suppression circuit of a communication device, computing distances between transitions of a phase modulation signal, the phase modulation signal associated with the phase modulation information, comparing the distances to a threshold distance at a comparator of the suppression circuit, and suppressing a first transition of the phase modulation signal associated with the phase modulation information if a first distance is less than the threshold distance.

Abstract: A method for generating a multi-band signal transforms multiple base-band envelope signals into a sequence of symbols representing a signal including a plurality of disjoint frequency bands. Each frequency band corresponds to a single base-band envelope signal. Each symbol corresponds to amplitude of the signal and is a number selected from a finite set of numbers. The method encodes the sequence of symbols as a plurality of pulse width modulation (PWM) signals. Each PWM signal includes a plurality of codes for encoding each symbol, such that a sum of values of the codes of the set of PWM signals encoding a symbol is proportional to a value of the symbol. The method amplifies the PWM signals to produce a plurality of amplified signals and combines the amplified signals to produce the multi-band signal.

Abstract: Components, systems, and methods for reducing location-based interference in distributed antenna systems operating in multiple-input, multiple-output (MIMO) configuration are disclosed. Interference is defined as issues with received MIMO communications signals that can cause a MIMO algorithm to not be able to solve a channel matrix for MIMO communications signals received by MIMO receivers in client devices. These issues may be caused by lack of spatial (i.e., phase) separation in the received MIMO communications signals. Thus, to provide phase separation of received MIMO communication signals, multiple MIMO transmitters are each configured to employ multiple transmitter antennas, which are each configured to transmit in different polarization states. In certain embodiments, one of the MIMO communications signals is phase shifted in one of the polarization states to provide phase separation between received MIMO communication signals.

Abstract: An apparatus includes a first circuit, a second circuit, and a third circuit. The first circuit may be configured to buffer a plurality of antenna carrier sample streams. The second circuit is coupled to the first circuit and may be configured to generate message data through pipelined processing and mapping of the antenna carrier samples. The third circuit is coupled to the second circuit and may be configured to generate a master frame in response to the processed and mapped message data.

Abstract: Dynamic antenna switching based on weighted signal to noise ratio (SNR). A wireless device may include multiple antennas. SNR at each active antenna may be calculated. An antenna-specific weight may be applied to each antenna's SNR. The antenna-specific weights may further be radio specific and/or transmit or receive specific in some cases. Antenna selection (possibly just for a specific radio and/or for transmit or receive operations, depending on the specificity of the antenna weights), including potentially switching which antenna is used, may be based on the resulting weighted SNR values for each antenna. If the antenna-specific weights are radio specific and/or transmit or receive operation specific, the method may be performed multiple times with different antenna-specific weights to select antenna(s) for different radios and/or for other operations.

Abstract: The scalable digital predistortion system and method provides compensation for the nonlinear distortions of power amplifiers and transmitters. The scalable digital predistortion system and its associated update algorithms provide scalability in terms of signal bandwidth and average power, allowing for low complexity updates following changes in the signal's bandwidth and/or power level. The method applies both memory polynomial functions and memoryless predistortion functions for compensating for the nonlinear distortions.

Abstract: Until when a desired signal is received in a reception mode, a level comparator extracts a portion of a frequency-domain signal output from a Fourier transformer, the portion matching with the frequency of the desired signal, and, when the reception level of the extracted portion matching with the frequency of the desired signal is higher than a predetermined threshold value, determines that an interference signal exists. An LO frequency controller sets the frequency of a local signal (LO) based on the determination result in the level comparator such that the frequency of intermodulation distortion caused by the interference signal becomes an intermediate frequency of the frequency band of the desired signal. When it is determined that the interference signal exists, an RX controller changes gain settings of a low-noise amplifier circuit and gain settings of a variable gain amplifier circuit and changes the cutoff frequency of a filter circuit.

Abstract: A receiver estimates a vector of emitted symbols over a MIMO transmission channel which are emitted by a emitting antennas. The receiver receives a vector of received symbols on receiving antennas. Estimation of the vector of emitted symbols is made by calculating a metric associated with a criterion for each vector of a subset of all possible vectors of emitted symbols and selecting an estimation for said vector of emitted symbol as the vector of emitted symbols among said subset which minimizes said metric.

Abstract: An apparatus for mapping data in a wireless communication system. The apparatus includes circuitry for generating a precoding matrix for multi-antenna transmission based on a precoding matrix indicator (PMI) feedback from at least one remote receiver where the PMI indicates a choice of precoding matrix derived from a matrix multiplication of two matrices from a first code book and a second codebook. The apparatus further includes circuitry for precoding one or more layers of a data stream with the precoding matrix and transmitting the precoded layers of data stream to the remove receiver.

Abstract: A method of estimating a frequency offset based on a training symbol in a receiver of an orthogonal frequency division multiplexing (OFDM) system, includes receiving a first training symbol having a periodicity and a predetermined second training symbol, and calculating a correlation value for the first training symbol based on a coherence phase bandwidth (CPB). The method further includes determining a position of a peak value from the correlation value for an integer multiple frequency offset candidate based on a threshold value, and calculating a correlation value for the second training symbol based on the CPB. The method further includes estimating a position corresponding to a maximum value of the correlation value for the second training symbol as the frequency offset based on the position of the peak value.

Abstract: A wireless communication apparatus includes a wireless section configured to receive a plurality of signals via a plurality of antennae from a transmitting device having another plurality of antennae; and a demodulation section configured to apply QR decomposition to a channel matrix generated based on the received signals from the wireless section, to extract a plurality of weight coefficients corresponding to a symbol to be demodulated from a unitary matrix Q, to filter the received signals weighted with the weight coefficients, and to separate the filtered received signals based on a submatrix of an upper triangular matrix R.

Abstract: Systems and techniques relating to IQ mismatch estimation and compensation are described. A described technique includes obtaining samples of a received signal via circuitry having an IQ mismatch; determining an estimated gain imbalance parameter for the IQ mismatch based on an in-phase average value of in-phase training samples and a quadrature average value of quadrature training samples; determining an estimated phase imbalance parameter for the IQ mismatch based on a combined average value, the estimated gain imbalance parameter, and a squared average value, the combined average value being based on a pair-wise multiplication of the in-phase training samples and the quadrature training samples, the squared average value being based on squared versions of the in-phase training samples; updating the in-phase data samples based on the estimated gain imbalance parameter to produce updated in-phase data samples; and updating the quadrature data samples by respectively adding quadrature update values thereto.

Abstract: System, methods and apparatus are described that facilitate transmission of data, particularly between two devices within an electronic apparatus. Information is transmitted in N-phase polarity encoded symbols. A clock recovery circuit may be calibrated based on state transitions in a preamble transmitted on two or more connectors. A calibration method is described. The method includes detecting a plurality of transitions in a preamble of a multiphase signal and calibrating a delay element to provide a delay that matches a clocking period of the multiphase signal. Each transition may be detected by only one of a plurality of detectors. The delay element may be calibrated based on time intervals between detections of successive ones of the plurality of transitions.

Abstract: Systems and methods for multi-phase signaling are described herein. In one embodiment, a method for receiving data comprises receiving a sequence of symbols from a plurality of conductors, and generating a clock signal by detecting transitions in the received sequence of symbols. The method also comprises delaying the received sequence of symbols, and capturing one or more symbols in the delayed sequence of symbols using the clock signal, wherein a previous symbol in the delayed sequence of symbols is captured using a clock pulse in the clock signal generated based on a detected transition to a current symbol in the received sequence of symbols.

Abstract: A method of generating a reference signal includes acquiring a base sequence and acquiring a reference signal sequence with a length N from the base sequence. Good PAPR/CM characteristics of the reference signal can be kept to enhance performance of data demodulation or uplink scheduling.

Abstract: A method including correlating a code having a first offset with a signal to produce a first correlation result; correlating the code having a second offset with the signal to produce a second correlation result; determining a cost function using the first correlation result and the second correlation result; and adjusting the first offset and the second offset in dependence upon the cost function, wherein the cost function uses a first weighting for the first correlation result and a second, different weighting for the second correlation result.

Abstract: A reception circuit has: a phase detector that detects a phase code based on a phase of data in relation to a first clock signal; a calibration signal generator that, in a calibration mode, adjusts a frequency of the first clock signal or the data so that the phase code detected by the phase detector changes; a calibrator that, in the calibration mode, stores a difference between the phase code and an ideal value of the detected phase, and that, in a normal operation mode, outputs the ideal value in correspondence with the phase code detected by the phase detector; and a phase adjustor that, in the normal operation mode, adjusts a phase of the first clock signal based on the phase code detected by the phase detector and the ideal value, and that outputs to the phase detector.

Abstract: Systems and methods are provided for processing a signal using simplified channel statistics. In an example implementation, a channel profile for a multipath channel is estimated by detecting, within a given range, a number of channel taps associated with a channel impulse response, and assigning each of those channel taps a uniform amplitude value corresponding to a constant signal strength. A signal may be received through the multipath channel and filtered based on the estimated channel profile.