In one embodiment, a dual-mode power amplifier that can operate in different modes includes: a first pair of metal oxide semiconductor field effect transistors (MOSFETs) to receive and pass a constant envelope signal; a second pair of MOSFETs to receive and pass a variable envelope signal, where first terminals of the first pair of MOSFETs are coupled to first terminals of the second pair of MOSFETs, and second terminals of the first pair of MOSFETs are coupled to. second terminals of the second pair of MOSFETs; and a shared MOSFET stack coupled to the first pair of MOSFETs and the second pair of MOSFETs.

In one embodiment, a dual-mode power amplifier that can operate in different modes includes: a first pair of metal oxide semiconductor field effect transistors (MOSFETs) to receive and pass a constant envelope signal; a second pair of MOSFETs to receive and pass a variable envelope signal, where first terminals of the first pair of MOSFETs are coupled to first terminals of the second pair of MOSFETs, and second terminals of the first pair of MOSFETs are coupled to. second terminals of the second pair of MOSFETs; and a shared MOSFET stack coupled to the first pair of MOSFETs and the second pair of MOSFETs.

Aspects of the disclosure provide for a method implemented by a control system for communicating with a remote device. In at least some examples, the method includes determining a frequency of operation of the remote device and determining whether the frequency of operation of the remote device varies from a programmed frequency. The method further includes determining a frequency scaling factor based on whether the frequency of operation of the remote device varies from a programmed frequency. The method further includes generating a frequency shift keying (FSK) signal, scaling the FSK signal to generate a frequency scaled shift keying (FSSK) signal, and transmitting the FSSK signal to the remote device.

Aspects of the disclosure provide for a method implemented by a control system for communicating with a remote device. In at least some examples, the method includes determining a frequency of operation of the remote device and determining whether the frequency of operation of the remote device varies from a programmed frequency. The method further includes determining a frequency scaling factor based on whether the frequency of operation of the remote device varies from a programmed frequency. The method further includes generating a frequency shift keying (FSK) signal, scaling the FSK signal to generate a frequency scaled shift keying (FSSK) signal, and transmitting the FSSK signal to the remote device.

A device for transmitting data includes a transmitter for generating a frequency-modulated output signal. The transmitter includes a phase-locked loop for adjusting an output frequency of the output signal to a carrier frequency, and a coupling circuit for coupling a data stream into the phase-locked loop. The output signal modulated in frequency by the coupled-in data stream has an output frequency variable over time, and the coupling circuit includes a compensation unit, which couples a compensation signal into the phase-locked loop. The compensation signal compensates at least approximately for an adjustment of the output frequency to the carrier frequency carried out by the phase-locked loop.

The disclosure deals with system and method for an over-the-air computation (AirComp) scheme for federated edge learning (FEEL) without channel state information (CSI) at the edge devices (EDs) or edge server (ES). The disclosure adopts the majority vote (MV) principle and defines multiple subcarriers and orthogonal frequency division multiplexing (OFDM) symbols for voting options, which reduces to frequency-shift keying (FSK) over OFDM subcarriers as a special case. Thus, FSK-based over-the-air computation is provided for federated edge learning without channel state information. Since the votes from EDs are separated on orthogonal resources, the proposed scheme eliminates the need for truncated-channel inversion (TCI) at the EDs and allows the ES to detect MV with a non-coherent detector. We also mitigate the peak-to-mean envelope power ratio (PMEPR) of the synthesized signals by using randomization symbols. Simulations show the proposed scheme provides high test accuracy in fading channels for both independent and identically distributed (IID) and non-IID data while resulting in OFDM symbols with lower PMEPRs as compared to one-bit broadband digital aggregation (OBDA) with quadrature amplitude modulation (QAM).

Embodiments of systems and methods for modulating a downlink signals representative of a communication signal are provided herein. An example method comprises receiving an input signal; in a first one or more processing blocks in a one or more processors, performing a first modulation operation on first data packets of the input signal based on a modulation scheme for a receiver of the downlink signal; in a second one or more processing blocks in the one or more processors in parallel with the first one or more processing blocks, performing a second modulation operation on second data packets of the input signal based on the modulation scheme; and generating a waveform as the downlink signal based on performing the first and second modulation operations.

A circuit includes a polar transmitter to generate a radio frequency output from amplitude and phase signal components. The polar transmitter includes an amplifier to combine amplitude and phase signal components. A processor is coupled to the polar transmitter to provide the amplitude and phase signal components. The processor includes: a digital modulation circuit to generate a modulated digital signal including in-phase and quadrature signal components and a correction circuit to calculate and apply a complex digital offset for local oscillator feedthrough of the amplifier. The complex digital offset includes an in-phase offset correction factor and a quadrature offset correction factor.

Embodiments of apparatus and method for transition smoothing implementation on a stream of data are disclosed. In an example, a system on chip (SoC) for wireless communication includes a digital front-end. The digital front-end is configured to obtain a stream of data having one carrier or multi-carriers. The stream of data is divided into a plurality of blocks. The digital front-end is also configured to adjust a gain of the stream of data based on a predetermined frequency corresponding to a length of each of the plurality of blocks. The digital front-end is also configured to append a ramp-down tail sequence to a first block of the stream of data after a last sample of the first block, and generate a ramp-up head sequence for a second block immediately after the first block, based on a head sequence of the second block.

Systems and methods for classifying radio frequency signal modulations include receiving, at a consolidated neural network, a complex quadrature vector of interest representative of a baseband signal derived from a radio frequency signal, generating multiple data representations of the vector of interest, providing each data representation to one of multiple parallel neural networks in the consolidated neural network, and receiving, from the consolidated neural network, a classification result for the baseband signal. The consolidated neural network may be trained to classify baseband signals with respect to known modulation types by receiving complex quadrature training vectors, each including samples of a baseband signal derived from a radio frequency signal of known modulation type, comparing a classification result for the training vector to the known modulation type to determine modulation classification performance, and modifying a configuration parameter of the consolidated neural network dependent on the determined modulation classification performance.