A method for determining a noise shaped quantized parameter contributing to generation of an output signal comprises estimating an error within the output signal using a quantization of the parameter and a quantization of a further parameter contributing to generation of the output signal. The quantization of the parameter is used as the noise shaped quantized parameter according to a selection criterion.

A method for synchronizing a data frame and data symbols in a communication system includes generating a training sequence including a serial sequence of data symbols that are conjugate symmetric, inserting the training sequence in a transmitter-side data frame, converting constituent data symbols of the transmitter-side data frame to communication signals, transmitting the communication signals from a transmitter to a receiver, converting the communication signals to a stream of received data symbols, detecting presence of the training sequence in the stream of received data symbols, and identifying a position of a received data frame from the presence of the training sequence.

A signal shaping device includes: a generation unit to perform plural types of predetermined processes on blocks obtained by dividing plural sequences of bit strings by a predetermined length, and generate a plurality of candidate blocks that are candidates for a shaped block to be transmitted; a calculation unit to calculate, on a candidate-block-by-candidate-block basis, a weight of a one-dimensional modulation symbol when a plurality of bits included in the candidate block are converted into the one-dimensional modulation symbol; a selection unit to select, from among the candidate blocks, the shaped block on a basis of the weight; an addition unit to add, to the shaped block, selection information indicating a selection result; and a symbol mapping unit to generate a one-dimensional modulation signal by converting a plurality of bits included in the shaped block, into the one-dimensional modulation symbol.

An apparatus for interpolation of polar signals in RF transmitters is disclosed. The apparatus comprises an estimation circuit configured to receive an input in-phase (I) quadrature (Q) signal comprising a plurality of input IQ samples having a first sampling rate associated therewith, and determine a selection metric value indicative of a position of an IQ trajectory associated with one or more input IQ samples of the input IQ signal. The apparatus further comprises a selection circuit configured to receive the input IQ signal and the selection metric value; and adaptively provide the input IQ signal to a first interpolation circuit that implements a first interpolation method or to a second interpolation circuit that implements a second, different interpolation method, for generating interpolated polar samples at a second, different sampling rate, from the input IQ signal, based on the selection metric value.

Embodiments disclosed herein relate to improving a power output of a transmitter of an electronic device. To do so, the transmitter may include signal selection circuitry to adjust a sign selection signal to accurately transition between polarities of a quadrature (e.g., I or Q) component signal stored in or for which an indication is stored in a storage cell of a radio frequency digital-to-analog converter. The sign selection signal may generate a separate adjusted sign selection signal for each polarity of each quadrature component signal such that a transition of the selection signal between a first value and a second value (e.g., logic high and low) occurs when the respective quadrature (e.g., +/− and I/Q component signal is a logic low. In this way, the signal selection circuitry reduces an error pulse in the output of the transmitter.

Embodiments provide a pre-distortion circuit and apparatus, a method and computer program for pre-distorting, a transmitter, a radio transceiver, a communication device, a mobile transceiver, a base station transceiver and a storage. The pre-distortion circuit (10) is configured for a digital quadrature signal. The pre-distortion circuit (10) comprises a first input (12) for an inphase component of the quadrature signal and a second input (14) for a quadrature component of the quadrature signal. The pre-distortion circuit 10 comprises a signal processing circuit (16) configured to determine whether polarities of the inphase component and quadrature component are equal, and to determine pre-distortion coefficients based on the amplitude of the inphase component, the amplitude of the quadrature component, and based on whether the polarities are equal.

A system and method for data communication using amplitude-encoded sinusoids. The method includes encoding the input digital data using a plurality of symbol waveforms where each of the plurality of symbol waveforms occupies a period of a composite encoded waveform and represents at least one bit of the input digital data. A first symbol waveform of the plurality of symbol waveforms is defined by a sinusoid of a first amplitude and a second symbol waveform is defined by a sinusoid of a second amplitude different from the first amplitude. The method includes generating an encoded analog waveform from a representation of the composite encoded waveform.

Systems and methods for demodulating a signal is described. A device can receive a modulated signal that encodes data. The device can sample a voltage of the modulated signal to generate a plurality of samples in digital domain. The device can determine in-phase data and quadrature data of the plurality of samples. The device can determine amplitude data and phase data based on the in-phase data and the quadrature data. The device can decode the amplitude data and phase data into digital symbols that represent the data encoded in the modulated signal.

Embodiments disclosed herein relate to improving a power output of a transmitter of an electronic device. To do so, the transmitter may include signal selection circuitry to adjust a sign selection signal to accurately transition between polarities of a quadrature (e.g., I or Q) component signal stored in or for which an indication is stored in a storage cell of a radio frequency digital-to-analog converter. The sign selection signal may generate a separate adjusted sign selection signal for each polarity of each quadrature component signal such that a transition of the selection signal between a first value and a second value (e.g., logic high and low) occurs when the respective quadrature (e.g., +/− and I/Q) component signal is a logic low. In this way, the signal selection circuitry reduces an error pulse in the output of the transmitter.

Methods and apparatuses are provided for generating a quadrature modulated signal for transmission in an electronic device. Samples are obtained from a quadrature amplitude modulation (QAM) signal at a predefined sampling rate to generate a signal spectrum. The samples are interpolated to move the signal spectrum on a frequency axis. Modulation is performed on the interpolated samples based on a digital carrier frequency to move the signal spectrum on the frequency axis. Digital to analog conversion and analog filtering are performed on the modulated samples in a real part of the signal spectrum to generate a quadrature modulated signal for transmission.