Abstract: A method for filtering noise. The method may include obtaining an output signal from a phase locked loop (PLL) device. The method may include determining, using a digital phase detector and the output signal, an amount of PLL error produced by the PLL device. The method may include filtering, using a delay element and a digital filter, a portion of the amount of PLL error from the output signal to produce a filtered signal in response to determining the amount of PLL error produced by the PLL device.

Abstract: A method for compensating for a sampling clock-offset includes calculating a positive threshold and a negative threshold of pulse-shaped data symbols to be received, calculating a positive sum ratio and a negative sum ratio from received samples, and compensating for a sampling clock-offset in response to the positive sum ratio being less than or equal to the positive threshold and the negative sum ratio being less than or equal to the negative threshold.

Abstract: The present invention provides a method of transmitting broadcast signals. The method includes, formatting, by an input formatting block, input streams into plural PLPs (Physical Layer Pipes); encoding, by an encoder, data in the plural PLPs; processing, by a framing and interleaving block, the encoded data in the plural PLPs to output at least one signal frame; and waveform modulating, by a waveform generation block, data in the at least one signal frame and transmitting, by the waveform generation block, broadcast signals having the waveform modulated data.

Abstract: Provided herein are apparatus and methods for transconductance amplifiers, such as split cascode low-noise transconductance amplifiers (LNTAs). In an embodiment, an LNTA includes split current paths each coupled to a different mixer by way of a different alternating current (AC) coupling capacitor. The split current paths of the LNTA can be enabled during different modes of operation, such as when the input to the LNTA is within different frequency bands.

Abstract: A user equipment device has a control information decoder configured to receive and decode an uplink scheduling grant. A transmit module is configured to receive a rank indicator (RI) extracted by the decoder and adapt a transmission rank in response to the RI. At least two transmit antennas are configured to transmit according to the RI.

Abstract: A radio receiver processing path has a mixer with active interference/blocker cancellation to reduce the intensity of leaked and undesired signals by using a replica of the transmitted signal, emulating the phase and attenuation through the leakage path and subtracting the emulated signal within the mixer. Intermodulation distortions are predicted through the use of nonlinear modeling in the digital baseband between the baseband transmitter and baseband receiver and subsequently subtracted from the received signal. The nonlinear basis functions are combined to model the composite nonlinearity in the signal path based on digital baseband transmitted data. The modeled nonlinearity is subtracted from the received signal, and the result is observed and used to guide the nonlinear modeling parameters using self-contained control loops.

Abstract: The peak level of a high frequency analog signal in an RF receiver is detected by a system which samples the signal and compares it against a static threshold, generating an above/below status. The system is implemented with a sampler of sufficient aperture bandwidth to capture the signal in question, operated at a clock frequency, dynamically chosen as a function of fLO (local oscillator frequency) and the desired fIF (intermediate frequency), to minimize in-band intermodulation products. The sampler produces kickback intermodulation products that are positioned out-of-band, or are of low enough power in-band so as to be inconsequential. Samples are taken for a statistically significant period of time, and the status is used to adapt the threshold to systematically determine the peak amplitude of the signal being observed.

Abstract: Embodiments of the present disclosure provide an estimation apparatus and compensation apparatus for clipping distortion of multicarrier signals and a receiver. The estimation apparatus includes: a first calculating unit configured to multiply an error signal of each subcarrier in all or part of subcarriers in received multicarrier signals by a conjugation of an error signal of a subcarrier neighboring or spaced apart from each subcarrier; a second calculating unit configured to calculate an average value of all results of multiplication; a third calculating unit configured to calculate parameters of the clipping distortion of the multicarrier signals according to the average value; and an estimating unit configured to estimate the clipping distortion of the multicarrier signals according to the calculated parameters of the clipping distortion.

Abstract: Provided is a data transmitter including a signal interval determination unit configured to receive a data input signal corresponding to data to be transmitted, determine time intervals between a synchronization signal and a plurality of data signals according to the data input signal, and output interval signals corresponding to the intervals; a trigger generation unit configured to trigger according to an output signal from the signal interval determination unit; and a signal generation unit configured to receive the trigger to generate the synchronization signal and the data signals.

Abstract: A transmission apparatus includes: a first plug-in unit including: a clock generator to generate a first clock, a first frame-pulse generator to generate a first frame-pulse-signal based on the first clock; a detector to detect a phase-difference between a first phase of the first frame-pulse-signal and a second phase of a second frame-pulse-signal transmitted from other plug-in unit, and generate phase-difference information based on the phase-difference, and a first transmitter to transmit a control-signal including the phase-difference information to the other plug-in unit; and a second plug-in unit being the other plug-in unit, including: a receiver to receive the control-signal, a controller to control a phase of a second clock of the second plug-in unit, based on the phase-difference information, a second frame-pulse generator to generate the second frame-pulse-signal based on the second clock, and a second transmitter to transmit the second frame-pulse-signal to the first plug-in unit.

Abstract: Transients caused by load modulation can fee compensated far by adjusting pulse shapes. A radio frequency (RP) carrier signal can be modulated using load modulation. For the modulated RF carrier signal a particular pattern can be detected for a symbol period that precedes a second symbol that does not use load modulation. In response to the detecting, a pulse shape of the first symbol can be adjusted to mitigate the transients.

Abstract: Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal over the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a baseband signal after a first mapping and a baseband signal after a second mapping by a precoding weight and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.

Abstract: Systems (100) and methods for co-channel separation of communication signals. The methods involve: simultaneously receiving a plurality of communication signals transmitted at disparate relative Doppler frequencies from different locations within a multi-access system; performing matched filtering operations to pre-process each of the plurality of communication signals so as to generate pre-processed digitized samples using a priori information contained in pre-ambles (302, 304) of messages present within the plurality of communication signals; using estimated signal parameters to detect the plurality of communication signals from the pre-processed digitized samples; and demodulating the plurality of communication signals without using a Viterbi decoder.

Abstract: A reference signal transmission scheme is presented. A first user equipment (UE) receives first information identifying which uplink subframe of a plurality of subframes is enabled to transmit an uplink reference signal, and receives second information identifying a sequence used for the uplink reference signal from a base station. The first information is used to identify a different uplink subframe to a first UE group including the first UE and a second UE group other than the first UE group. The second information is determined to assign different orthogonal sequences to each of UEs of the first UE group. The first UE transmits the uplink reference signal to the base station at the uplink subframe identified by the first information using the sequence identified by the second information.

Abstract: A continuous phase modulation method comprises the following steps: receiving a sequence of digital data symbols a(n) to be emitted; transforming the sequence of symbols a(n) to be emitted into a transformed sequence of symbols b(n), each symbol b(n) of which is equal to the sum of a symbol a(n) to be emitted and of a corrective factor equal to a transformation Tf applied to a plurality of differences (a(n)-a(n?1)) between two consecutive symbols to be emitted, the transformation Tf applied being a combination c of at least two differences between two consecutive symbols of the sequence to be emitted, transformed by the application of a non-linear function f; filtering the sequence of transformed symbols b(n) with a shaping filter and modulating the filtered sequence with a phase modulator; said transformation Tf being defined so as to minimize interference between modulated symbols filtered by a receiving filter.

Abstract: A method of selecting filter patterns is provided. The method may include measuring an average sign value of aggregate inter-symbol interference (ISI) for a data sequence using multiple filter pattern combinations of multiple filter patterns; estimating a first analog level of aggregate ISI for a first filter pattern based on a first average sign value, and a second analog level of aggregate ISI for a second filter pattern based on a second average sign value; estimating an analog level of individual ISI of the first filter pattern pair based on the first analog level and the second analog level; estimating, for each possible filter pattern combination, an analog level of aggregate ISI for the first filter pattern pair; and selecting a filter pattern combination for the first filter pattern pair that reduces the analog level of aggregate ISI.

Abstract: A half-rate clock data recovery circuit includes: a voltage-controlled oscillator (VCO) for generating a data sampling clock and an edge sampling clock according to a control voltage; an adjusting circuit for dynamically controlling the VCO to adjust the phase difference between the data sampling clock and the edge sampling clock to be different from 90 degrees in multiple test periods; and a control circuit for instructing the adjusting circuit to respectively utilize different control value combinations to control the VCO in the multiple test periods, and for recording multiple recovered-signal quality indicators respectively corresponding to the multiple test periods. Afterwards, the control circuit instructs the adjusting circuit to utilize a control value combination corresponding to the best quality indicator among the multiple recovered-signal quality indicators to control the VCO.

Abstract: A wireless communication sniffer including: a packet identification module; a channel modeler; single-channel and multi-channel equalization matrix calculators; and an equalizer. The packet identification module identifies a packet as single-user (SU) or multi-user (MU). The channel modeler models the communication channel for the packet as either a set of single-channel or multi-channel parameters responsive to the SU and MU packet identification. The single-channel equalization matrix calculator calculates a single-channel equalization matrix using the set of single-channel parameters, responsive to an SU identification. The multi-channel equalization matrix calculator calculates a multi-channel equalization matrix using the set of multi-channel parameters, responsive to an MU identification. The equalizer equalizes the received communication packet utilizing the single-channel or multi-channel equalization matrix responsive to the SU or MU packet identification respectively.

Abstract: A method and system of compensating for distortion in a baseband in-phase (I) and a corresponding baseband quadrature (Q) signal. The circuit includes an in-phase I attenuator configured to attenuate the baseband in-phase I signal and an in-phase Q attenuator configured to attenuate the baseband Q signal. There are one or more circuits that are configured to receive the attenuated in-phase I signal and the attenuated baseband Q signal. Each circuit performs a different calculation based on predetermined equations configured to determine the IM2, HD2@0°, HD2@90°, IM3@0°, IM3@90°, HD3@0°, and HD3@90°. The distortion compensation circuit is configured to use the result of at least one of the calculation circuits to generate I and Q distortion compensation signals.

Abstract: The present application relates to the field of digital pre-distortion processing. Disclosed in an embodiment of the present application are a pre-distortion parameter obtaining method and pre-distortion system for simplifying calculating complexity of a model while achieving good signal processing effect. The method comprises: after the beginning of periodic filtering processing, obtaining a pre-distorted signal after pre-distortion processing and a first feedback signal after power amplification (S101); obtaining a second feedback signal by eliminating the rated linear gain of the first feedback signal (S102); determining a pre-distortion parameter according to a matrix formed by the second feedback signal and a matrix formed by the pre-distorted signal (S103); updating the pre-distortion parameter index table according to the determined pre-distortion parameter (104).