A method of wireless communications by a user equipment (UE) includes detecting, in response to a bandwidth part (BWP) switch, a first BWP of a first carrier aggregation signal and a second BWP of a second carrier aggregation signal. The first BWP of the first carrier aggregation signal and the second BWP of the second carrier aggregation signal are each within a predetermined frequency range of each other. The method also includes tuning a radio frequency (RF) channel to a center of a wideband channel including the first BWP and the second BWP. The method further includes processing the wideband channel including both the first BWP of the first carrier aggregation signal and the second BWP of the second carrier aggregation signal with a single phase locked loop (PLL).

A wireless power transmitter can receive the results of a characterizing signal transmitted by the wireless power receiver, compute at least two parameters of a model characterizing an in-band communications channel based on the received results of the characterizing signal transmitted by the wireless power receiver, compute a plurality of equalizing filter taps from the at least two parameters, and apply the computed equalizing filter to subsequent signals received by the wireless power transmitter via the in-band communications channel. A first parameter can correspond to a time constant of the channel, and a second parameter can correspond to a damping value of the communications channel. The wireless power transmitter can transmit to a wireless power receiver a request to transmit a characterizing signal through the in-band communication channel, wherein the characterizing signal transmitted by the wireless power receiver is sent in response to the transmitted request.

A wireless power transmitter can receive the results of a characterizing signal transmitted by the wireless power receiver, compute at least two parameters of a model characterizing an in-band communications channel based on the received results of the characterizing signal transmitted by the wireless power receiver, compute a plurality of equalizing filter taps from the at least two parameters, and apply the computed equalizing filter to subsequent signals received by the wireless power transmitter via the in-band communications channel. A first parameter can correspond to a time constant of the channel, and a second parameter can correspond to a damping value of the communications channel. The wireless power transmitter can transmit to a wireless power receiver a request to transmit a characterizing signal through the in-band communication channel, wherein the characterizing signal transmitted by the wireless power receiver is sent in response to the transmitted request.

Methods, systems, and devices that support variable modulation schemes for memory are described. A device may switch between different modulation schemes for communication based on one or more operating parameters associated with the device or a component of the device. The modulation schemes may involve amplitude modulation in which different levels of a signal represent different data values. For instance, the device may use a first modulation scheme that represents data using two levels and a second modulation scheme that represents data using four levels. In one example, the device may switch from the first modulation scheme to the second modulation scheme when bandwidth demand is high, and the device may switch from the second modulation scheme to the first modulation scheme when power conservation is in demand. The device may also, based on the operating parameter, change the frequency of the signal pulses communicated using the modulation schemes.

Communicating using spread spectrum. A legacy RF signal is intercepted from a legacy radio. spread spectrum processing is performed on the legacy RF signal to create a spread signal. The spread signal is transmitted to a receiver, whereafter the spread signal is de-spread to recover the legacy RF signal.

Communicating using spread spectrum. A legacy RF signal is intercepted from a legacy radio. spread spectrum processing is performed on the legacy RF signal to create a spread signal. The spread signal is transmitted to a receiver, whereafter the spread signal is de-spread to recover the legacy RF signal.

A tracking and rejection filter for use in a receiver of a radio includes a selectable filter configured to provide an output digital in-phase signal and an output digital quadrature signal based on a center frequency, a digital in-phase signal corresponding to an in-phase component of a received radio frequency signal, and a digital quadrature signal corresponding to a quadrature component of the received radio frequency signal. The tracking and rejection filter includes a select circuit configured to select the center frequency of the selectable filter according to whether an interfering signal is detected in a target frequency band of the received radio frequency signal. The center frequency is selected from a predetermined frequency and an estimated center frequency determined using an instantaneous frequency signal. The instantaneous frequency signal is based on the digital in-phase signal and the digital quadrature signal.

A tracking and rejection filter for use in a receiver of a radio includes a selectable filter configured to provide an output digital in-phase signal and an output digital quadrature signal based on a center frequency, a digital in-phase signal corresponding to an in-phase component of a received radio frequency signal, and a digital quadrature signal corresponding to a quadrature component of the received radio frequency signal. The tracking and rejection filter includes a select circuit configured to select the center frequency of the selectable filter according to whether an interfering signal is detected in a target frequency band of the received radio frequency signal. The center frequency is selected from a predetermined frequency and an estimated center frequency determined using an instantaneous frequency signal. The instantaneous frequency signal is based on the digital in-phase signal and the digital quadrature signal.

A digital down converter (DDC) that improves efficiency by taking advantage of the periodicity of the coarse mixing process and the memory inherent in the convolution operation performed by decimation filters. In embodiments, the DDC filters and decimates a received signal to generate subfilter outputs and coarse mixes the subfilter outputs for each frequency band of interest. Accordingly, the DDC eliminates the need for separate decimation filters for each of the in-phase (I-phase) and quadrature (Q-phase) signals of each frequency band. In some embodiments, for each frequency band, the DDC combines the subfilter outputs into partial sums for each of the I- and Q-phases. In some of those embodiments, the coarse mixing operation is performed by multiplying the partial sums by real multiplicands and performing a simple post-rotation operation. In those embodiments, the DDC significantly reduces the number of multiplication operations required to perform the coarse mixing process.

A digital down converter (DDC) that improves efficiency by taking advantage of the periodicity of the coarse mixing process and the memory inherent in the convolution operation performed by decimation filters. In embodiments, the DDC filters and decimates a received signal to generate subfilter outputs and coarse mixes the subfilter outputs for each frequency band of interest. Accordingly, the DDC eliminates the need for separate decimation filters for each of the in-phase (I-phase) and quadrature (Q-phase) signals of each frequency band. In some embodiments, for each frequency band, the DDC combines the subfilter outputs into partial sums for each of the I- and Q-phases. In some of those embodiments, the coarse mixing operation is performed by multiplying the partial sums by real multiplicands and performing a simple post-rotation operation. In those embodiments, the DDC significantly reduces the number of multiplication operations required to perform the coarse mixing process.