Abstract: Methods and apparatus for performing automatic gain control (AGC) in bypass and filter modes for radio frequency (RF) front-end circuitry are described. An example method includes operating a receiver in a first mode during a first set of symbols of a first subframe. The method also includes, during a first symbol of the first subframe outside the first set of symbols, determining whether to operate the receiver in the first mode or a second mode in a second subframe, based at least in part on an output of a jamming detection circuit of the receiver in the first symbol. The method also includes controlling the receiver to operate in the first mode or the second mode in the second subframe, in accordance with the determination.

Abstract: Certain aspects of the present disclosure provide object detection based on perturbations in a channel model over time. An example portable apparatus includes a primary antenna, a secondary antenna, a transmit path, a radio frequency (RF) coupler, and a receive path. The transmit path is coupled to the primary antenna and configured to output a transmit signal for transmission via the primary antenna. The RF coupler is coupled to the secondary antenna. The receive path has an input selectively coupled between the transmit path and the RF coupler such that when the receive path is coupled to the RF coupler and configured to operate concurrently with the transmit path, the receive path is configured to receive a reflected portion of the transmit signal from an object located in proximity to the portable apparatus.

Abstract: Certain aspects of the present disclosure provide apparatus and methods for cellular vehicle-to-everything (C-V2X) stationary object detection. One example radio frequency (RF) front-end circuit generally includes a directional coupler having a first port for coupling to an antenna and having a second port; and a delta switch having a first port coupled to the second port of the directional coupler, having a second port, and having a third port for coupling to a receive path for detection of a stationary object. The RF front-end circuit and methods for C-V2X stationary object detection may allow for concurrent (i) stationary object detection and (ii) C-V2X signal reception or transmission.

Abstract: An apparatus is disclosed for waveform-tailored average power tracking. In an example aspect, the apparatus includes an amplifier, a power converter, and an average power tracking module. The amplifier is configured to amplify radio-frequency signals using a supply voltage. The radio-frequency signals have different waveforms. The power converter is coupled to the amplifier and configured to provide the supply voltage. The average power tracking module is coupled to the power converter and configured to adjust the supply voltage according to the different waveforms to cause the supply voltage to vary across at least two waveforms of the different waveforms for related average output powers.

Abstract: Aspects of the present disclosure provide signal amplification. An example method generally includes amplifying a version of a first input signal with a power amplifier in a first state where a bias voltage of the power amplifier is set to a first voltage based on a first tracking mode; obtaining a first output signal of the power amplifier in a second state where the bias voltage is set to a second voltage less than the first voltage; determining a predistortion associated with the power amplifier based at least in part on the obtained first output signal; applying the predistortion to the first input signal; and amplifying a version of the predistorted first input signal with the power amplifier in a third state where the bias voltage is set to a third voltage based on a second tracking mode, wherein the third voltage is less than the first voltage.

Abstract: An antenna detuning method includes: time domain duplexing signal transmission and signal reception by a first antenna of a wireless communication device; providing one or more first indications of time domain duplexing and one or more second indications of signal transmission to a semi-autonomous hardware controller of the wireless communication device; and responding, at the semi-autonomous hardware controller of the wireless communication device, to the one or more first indications of time domain duplexing and the one or more second indications of signal transmission by coupling a second antenna of the wireless communication device to receive circuitry during signal reception by the first antenna and to a termination during signal transmission by the first antenna.

Abstract: An apparatus is disclosed for waveform-tailored average power tracking. In an example aspect, the apparatus includes an amplifier, a power converter, and an average power tracking module. The amplifier is configured to amplify radio-frequency signals using a supply voltage. The radio-frequency signals have different waveforms. The power converter is coupled to the amplifier and configured to provide the supply voltage. The average power tracking module is coupled to the power converter and configured to adjust the supply voltage according to the different waveforms to cause the supply voltage to vary across at least two waveforms of the different waveforms for related average output powers.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless node may receive a configuration indicating a parameter of a signal to be optimized for a portion of a frequency range. The wireless node may transform a feedback signal and a reference signal into a frequency domain. The wireless node may generate an error signal based at least in part on transforming the feedback signal and the reference signal. The wireless node may assign weights to the error signal to generate a weighted error signal. The weights may be assigned to the error signal in the portion of the frequency range and a remaining portion of the frequency range according to the configuration. The wireless node may transmit the signal based at least in part on utilizing the weighted error signal to apply digital pre-distortion to the signal. Numerous other aspects are described.

Abstract: Method and apparatus to signal insertion loss for SRS antenna switching. The apparatus determines an insertion loss for each antenna of a plurality of antennas. The apparatus generates an offset matrix correction based at least on the insertion loss for each antenna of the plurality of antennas. The apparatus transmits the offset matrix correction to a base station. The apparatus may transmit an SRS, at a maximum power, from each antenna of the plurality of antennas to each receive antenna of the base station. The apparatus may collect insertion loss information for each antenna of the plurality of antennas. The insertion loss information indicates at least a power difference for each of the plurality of antennas at the UE.

Abstract: In certain aspects, a system includes a first filter, a second filter, a dummy load, and a switching circuit coupled to the first filter, the second filter, and the dummy load, and coupled to a first antenna and a second antenna. In a first mode, the switching circuit couples the first filter and the second filter to the first antenna, and, in a second mode, the switching circuit couples the first filter and the third filter to the first antenna and couples the second filter to the second antenna. In certain aspects, the dummy load includes a third filter.

Abstract: Certain aspects of the present disclosure provide object detection based on perturbations in a channel model over time. An example portable apparatus includes a primary antenna, a secondary antenna, a transmit path, a radio frequency (RF) coupler, and a receive path. The transmit path is coupled to the primary antenna and configured to output a transmit signal for transmission via the primary antenna. The RF coupler is coupled to the secondary antenna. The receive path has an input selectively coupled between the transmit path and the RF coupler such that when the receive path is coupled to the RF coupler and configured to operate concurrently with the transmit path, the receive path is configured to receive a reflected portion of the transmit signal from an object located in proximity to the portable apparatus.

Abstract: An apparatus is disclosed for waveform-tailored average power tracking. In an example aspect, the apparatus includes an amplifier, a power converter, and an average power tracking module. The amplifier is configured to amplify radio-frequency signals using a supply voltage. The radio-frequency signals have different waveforms. The power converter is coupled to the amplifier and configured to provide the supply voltage. The average power tracking module is coupled to the power converter and configured to adjust the supply voltage according to the different waveforms to cause the supply voltage to vary across at least two waveforms of the different waveforms for related average output powers.

Abstract: Certain aspects of the disclosure related to communications apparatus provides isolation between wireless protocols when operating currently while incurring the additional insertion loss based on providing the isolation only when needed. In an aspect, an apparatus include a switched filter coupled to an antenna where the switched filter includes a filter and a bypass line along with switching circuitry configured to selectively establish a bypass signal path including the bypass line or a filtered signal path including the filter. The apparatus further includes a switched filter controller configured to cause the switching circuitry to selectively connect a transceiver unit to the antenna via the bypass signal path or via the filtered signal path based at least on a frequency band of a carrier signal and a bandwidth of the carrier signal.

Abstract: Certain aspects of the disclosure related to communications apparatus provides isolation between wireless protocols when operating currently while incurring the additional insertion loss based on providing the isolation only when needed. In an aspect, an apparatus include a switched filter coupled to an antenna where the switched filter includes a filter and a bypass line along with switching circuitry configured to selectively establish a bypass signal path including the bypass line or a filtered signal path including the filter. The apparatus further includes a switched filter controller configured to cause the switching circuitry to selectively connect a transceiver unit to the antenna via the bypass signal path or via the filtered signal path based at least on a frequency band of a carrier signal and a bandwidth of the carrier signal.

Abstract: Certain aspects of the present disclosure introduce transmit chain asymmetry to meet tighter specifications of a band on one side of a spectrum while sacrificing emissions margin of a band on the opposite side of the spectrum. One example apparatus generally includes a distortion module configured to generate an input signal, and an amplifier coupled to the distortion module and configured to generate an amplified signal based on the input signal. In certain aspects, the input signal is generated such that a power of the amplified signal at a first bandwidth is skewed relative to a power of the amplified signal at a second bandwidth, the first and second bandwidths being adjacent to a main channel bandwidth of the amplified signal.

Abstract: Certain aspects of the present disclosure introduce transmit chain asymmetry to meet tighter specifications of a band on one side of a spectrum while sacrificing emissions margin of a band on the opposite side of the spectrum. One example apparatus generally includes a distortion module configured to generate an input signal, and an amplifier coupled to the distortion module and configured to generate an amplified signal based on the input signal. In certain aspects, the input signal is generated such that a power of the amplified signal at a first bandwidth is skewed relative to a power of the amplified signal at a second bandwidth, the first and second bandwidths being adjacent to a main channel bandwidth of the amplified signal.

Abstract: An example apparatus is disclosed for selectable filtering with switching. The apparatus includes an antenna switch module mounted to a surface of a substrate. The antenna switch module includes an antenna node, multiple switchable nodes, and multiple switches configured to connect or disconnect the multiple switchable nodes to or from the antenna node. The antenna switch module also includes a capacitor coupled in series with a first switch of the multiple switches between the antenna node and a first switchable node of the multiple switchable nodes. The capacitor is configured to provide a capacitance for a selectable filter. The apparatus also includes an inductor that is supported by the substrate and coupled between the first switchable node and a ground. The inductor is configured to provide an inductance for the selectable filter.

Abstract: Methods and apparatuses are described that facilitate data communication across a serial bus. In one configuration, a transmitter configures a plurality of devices by assigning one or more trigger registers to each device of the plurality of devices and sends to each device a trigger register assignment command indicating a trigger register assigned to a device and identifying a trigger corresponding to the device. The transmitter then addresses a packet to an assigned trigger register and generates a bit-index field in the packet. Bits in the bit-index field respectively represent triggers corresponding to devices associated with the assigned trigger register, wherein each bit indicates whether one or more corresponding devices are enabled for operation. The transmitter then sends the packet to the plurality of devices via the serial bus.

Abstract: A device includes a tunable filter having an adjustable inductance and an adjustable capacitance, the tunable filter having a first tuning input responsive to a first control signal related to filter frequency band information, and a second tuning input responsive to a second control signal related to a jammer signal.