Abstract: Embodiments of the present disclosure relate to a method and system for estimating State-of-Charge (SoC) of a rechargeable battery, such as for example, a rechargeable battery used to power and electric vehicle (EV). In particular embodiments of the present disclosure are able to estimate SoC of rechargeable batteries that exhibit charge-discharge hysteresis on their open-circuit voltage (OCV), so that it is not necessarily instantly possible to determine state of charge from the OCV. Embodiments of the present disclosure achieve this by maintaining a measure of current supplied by (and in some embodiments voltage across) the rechargeable battery and applying the measured current (and voltage) to a predictive model that comprises a plurality of parallel time-based filters each having a different time constant ranging for example from tenths of a second to a number of seconds, minutes, or hours.

Abstract: Systems and methods for compensating a transmit signal for charge trapping effects of a power amplifier are provided. In certain embodiments, a non-linear filter is trained based on time aligning a first set of observations taken from digital transmit data prior to conversion to a radio frequency transmit signal, and a second set of observations taken from an output of a power amplifier that amplifies the radio frequency transmit signal. In certain implementations, the first set of observations and the second set of observations are obtained without decimation. Rather, decimation is provided after timing alignment. By implementing the DPD system in this manner, signal data is not lost by decimation and more accurate timing alignment between the sets of observations is achieved.

Abstract: There are provided methods and apparatuses for removing a DC offset from an input signal, comprising: receiving the input signal having a first phase and a second phase; applying a high pass filter to the input signal, wherein a transfer function of the high pass filter has a pole coefficient that determines a pole frequency of the high pass filter, comprising: selecting a first pole coefficient of the high pass filter for the first phase, estimating DC offset of the input signal during the first phase, and selecting a second pole coefficient of the high pass filter for the second phase, wherein the first pole coefficient and the second pole coefficient are selected such that the first pole frequency is higher than the second pole frequency; and removing the DC offset from the input signal.

Abstract: There are provided methods and apparatuses for reducing the effect of interference at a receiver of a wireless communications system. They include receiving a transmitted bit stream at the receiver, determining a type of interference present in the transmitted bit stream, the type of interference comprising a first type of interference and a second type of interference, detecting the transmitted bit stream based on the type of interference present in the transmitted bit stream.

Abstract: There is provided methods and apparatuses for tuning a Viterbi detector at a receiver of a wireless communications system. They include: receiving a transmitted bit stream at the receiver; detecting a frequency mismatch between a frequency of a carrier frequency and a frequency of a local oscillator at the receiver to derive a carrier frequency offset error; determining a tuning parameter based on the carrier frequency offset error, the tuning parameter being a value between 0 and 1; and applying the tuning parameter to a Viterbi detuning algorithm in order to reduce the effect of the carrier frequency offset error on performance of the Viterbi detector.

Abstract: Embodiments of the present disclosure relate to a method and system for estimating State-of-Charge (SoC) of a rechargeable battery, such as for example, a rechargeable battery used to power and electric vehicle (EV). In particular embodiments of the present disclosure are able to estimate SoC of rechargeable batteries that exhibit charge-discharge hysteresis on their open-circuit voltage (OCV), so that it is not necessarily instantly possible to determine state of charge from the OCV. Embodiments of the present disclosure achieve this by maintaining a measure of current supplied by (and in some embodiments voltage across) the rechargeable battery and applying the measured current (and voltage) to a predictive model that comprises a plurality of parallel time-based filters each having a different time constant ranging for example from tenths of a second to a number of seconds, minutes, or hours.

Abstract: Systems and methods for compensating a transmit signal for charge trapping effects of a power amplifier are provided. In certain embodiments, a non-linear filter is trained based on time aligning a first set of observations taken from digital transmit data prior to conversion to a radio frequency transmit signal, and a second set of observations taken from an output of a power amplifier that amplifies the radio frequency transmit signal. In certain implementations, the first set of observations and the second set of observations are obtained without decimation. Rather, decimation is provided after timing alignment. By implementing the DPD system in this manner, signal data is not lost by decimation and more accurate timing alignment between the sets of observations is achieved.

Abstract: Apparatus and methods provide predistortion for a phased array. Radio frequency (RF) sample signals from phased array elements are provided along return paths and are combined by a hardware RF combiner. Phase shifters are adjusted such that the RF sample signals are phase-aligned when combined. Adaptive adjustment of predistortion for the amplifiers of the phased array can be based on a signal derived from the combined RF sample signals.

Abstract: Various examples are directed to systems and methods for operating a plurality of power amplifiers. A predistortion circuit may pre-distort an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers. An adaption circuit may receive a first feedback signal from a first power amplifier of the plurality of power amplifiers and generate predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers. The adaption circuit may receive a first feedback signal from a second power amplifier of the plurality of power amplifiers and update the predistortion correlation data to generate updated predistortion correlation data using the first feedback signal from the second power amplifier. The adaption circuit may also generate the predistortion configuration using the updated predistortion correlation data.

Abstract: Apparatus and methods provide predistortion for a phased array. Radio frequency (RF) sample signals from phased array elements are provided along return paths and are combined by a hardware RF combiner. Phase shifters are adjusted such that the RF sample signals are phase-aligned when combined. Adaptive adjustment of predistortion for the amplifiers of the phased array can be based on a signal derived from the combined RF sample signals.

Abstract: Various examples are directed to systems and methods for operating a plurality of power amplifiers. A predistortion circuit may pre-distort an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers. An adaption circuit may receive a first feedback signal from a first power amplifier of the plurality of power amplifiers and generate predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers. The adaption circuit may receive a first feedback signal from a second power amplifier of the plurality of power amplifiers and update the predistortion correlation data to generate updated predistortion correlation data using the first feedback signal from the second power amplifier. The adaption circuit may also generate the predistortion configuration using the updated predistortion correlation data.

Abstract: Apparatus and methods provide predistortion for a phased array. Radio frequency (RF) sample signals from phased array elements are provided along return paths and are combined by a hardware RF combiner. Phase shifters are adjusted such that the RF sample signals are phase-aligned when combined. Adaptive adjustment of predistortion for the amplifiers of the phased array can be based on a signal derived from the combined RF sample signals.

Abstract: An apparatus that implements DPD in a manner that can address OOB instability issues, PE instability issues, or both, is disclosed. The apparatus includes an actuator circuit configured to use a model of a power amplifier (PA) to apply a predistortion to at least a portion of an input signal, and an error correction circuit configured to generate an error signal indicative of a deviation of the output of the actuator circuit from the target output, e.g., in terms of OOB or PE. The apparatus also includes an adaptation circuit configured to update the model based on the error signal. By using such an error in adapting the model used for the DPD, undesirable effects of performing DPD, such as creation or amplification of OOB frequency components, or increasing amplitude of some samples, may be reduced or eliminated.

Abstract: Various examples are directed to systems and methods for operating a plurality of power amplifiers. A predistortion circuit may pre-distort an input signal according to a predistortion configuration to generate a pre-distorted signal for the plurality of power amplifiers. An adaption circuit may receive a first feedback signal from a first power amplifier of the plurality of power amplifiers and generate predistortion correlation data describing a correlation between parameters of a model describing the plurality of power amplifiers. The adaption circuit may receive a first feedback signal from a second power amplifier of the plurality of power amplifiers and update the predistortion correlation data to generate updated predistortion correlation data using the first feedback signal from the second power amplifier. The adaption circuit may also generate the predistortion configuration using the updated predistortion correlation data.

Abstract: An example apparatus includes a power amplifier (PA) and a linearity optimizer. The optimizer includes a PA actuator and a linearity adaptation circuit. The actuator is configured to generate an actuator output based on an actuator input and a vector of complex gains computed by the linearity adaptation circuit based on a feedback signal indicative of PA's output. The adaptation circuit is configured to compute the vector of complex gains in a manner that maximizes the power of the actuator output while ensuring that the deviation of PA's behavior from a linear behavior (e.g., in terms of one or more linearity parameters) is below a threshold. Controlling actuator output in a manner that maximizes its power while taking into consideration one or more linearity parameters to ensure that target linearity is achieved controls drive signals for the PA and, thus, may help in terms of PA linearity and efficiency.

Abstract: Apparatus and methods provide predistortion for a phased array. Radio frequency (RF) sample signals from phased array elements are provided along return paths and are combined by a hardware RF combiner. Phase shifters are adjusted such that the RF sample signals are phase-aligned when combined. Adaptive adjustment of predistortion for the amplifiers of the phased array can be based on a signal derived from the combined RF sample signals.

Abstract: An example apparatus includes a power amplifier (PA) and a linearity optimizer. The optimizer includes a PA actuator and a linearity adaptation circuit. The actuator is configured to generate an actuator output based on an actuator input and a vector of complex gains computed by the linearity adaptation circuit based on a feedback signal indicative of PA's output. The adaptation circuit is configured to compute the vector of complex gains in a manner that maximizes the power of the actuator output while ensuring that the deviation of PA's behavior from a linear behavior (e.g., in terms of one or more linearity parameters) is below a threshold. Controlling actuator output in a manner that maximizes its power while taking into consideration one or more linearity parameters to ensure that target linearity is achieved controls drive signals for the PA and, thus, may help in terms of PA linearity and efficiency.

Abstract: Digital predistortion (DPD) arrangements that use coding to differentiate between contributions from individual power amplifiers (PAs) is disclosed. When used with a phased antenna array having N antenna elements and N corresponding PAs, the arrangements may sequentially apply N codes to input signals provided to N PAs. Each code is a vector having N elements, where each element corresponds to a different PA in that the element is a complex gain applied to an input signal for the PA. Together, the N codes may be arranged as N rows or N columns of a matrix P. The disclosed arrangements may generate N feedback signals by applying the matrix P to a signal generated by a probe antenna element sensing wireless RF signals transmitted by the N antenna elements, and to update DPD coefficients based on the N feedback signals. The N codes may be either orthogonal or non-orthogonal.

Abstract: Apparatus and methods provide predistortion for a phased array. Radio frequency (RF) sample signals from phased array elements are provided along return paths and are combined by a hardware RF combiner. Phase shifters are adjusted such that the RF sample signals are phase-aligned when combined. Adaptive adjustment of predistortion for the amplifiers of the phased array can be based on a signal derived from the combined RF sample signals.

Abstract: An apparatus that implements DPD in a manner that can address OOB instability issues, PE instability issues, or both, is disclosed. The apparatus includes an actuator circuit configured to use a model of a power amplifier (PA) to apply a predistortion to at least a portion of an input signal, and an error correction circuit configured to generate an error signal indicative of a deviation of the output of the actuator circuit from the target output, e.g., in terms of OOB or PE. The apparatus also includes an adaptation circuit configured to update the model based on the error signal. By using such an error in adapting the model used for the DPD, undesirable effects of performing DPD, such as creation or amplification of OOB frequency components, or increasing amplitude of some samples, may be reduced or eliminated.