A signal processing circuit comprising a clip-generation-block. The clip-generation-block is configured to receive an input-signal; and determine a clip-signal that comprises only values of the input-signal that exceed a clipping-threshold. The signal processing circuit also comprises a scaling-block configured to apply a scaling-factor to the clip-signal in order to generate a scaled-clip-signal, wherein the scaling-factor is greater than one; and an adder configured to provide a clipped-signal based on a difference between the scaled-clip-signal and the input signal.

Embodiments of the present disclosure provide an estimation apparatus and compensation apparatus for clipping distortion of multicarrier signals and a receiver. The estimation apparatus includes: a first calculating unit configured to multiply an error signal of each subcarrier in all or part of subcarriers in received multicarrier signals by a conjugation of an error signal of a subcarrier neighboring or spaced apart from each subcarrier; a second calculating unit configured to calculate an average value of all results of multiplication; a third calculating unit configured to calculate parameters of the clipping distortion of the multicarrier signals according to the average value; and an estimating unit configured to estimate the clipping distortion of the multicarrier signals according to the calculated parameters of the clipping distortion. By calculating the parameters of the clipping distortion of the multicarrier signals according to the error signals of the subcarriers, the clipping distortion of the multicarrier signals may be accurately estimated and compensated, with the method of calculation being simple and the bit error rate being low.

A method for decoding a set of packets asynchronously on same nominal carrier frequency transmitted over a common communication medium, receives a signal including a combination of the set of packets modified with noise of the common communication medium, each packet includes a preamble common to all packets in the set and a payload unique for at least some packets in the set. The method determines, using a sparse recovery, a frequency offset of the transmission of each packet from the carrier frequency, a time offset of the transmission of each packet from a common point in time, and a channel gain corresponding to the transmission of each packet over a channel in the common communication medium and decodes the payloads of the packets in the set using the frequency offsets, the time offsets, and the channel gains.

A novel and useful linear, efficient, smart wideband CMOS hybrid power amplifier that combined an analog linear amplification path and a digital power amplification (DPA) path. PA path control logic analyzes the input I and Q signals and determines which amplification paths to steer the input I and Q signals to. The analog linear amplification path comprises digital to analog converters for both I and Q paths and one or more analog linear power amplifiers. The digital power amplification path comprises I and Q up-sampling circuits and I and Q RF DAC circuits (e.g., digital PA circuits). In operation, the PA path control logic compares the I and Q signals to thresholds (which may or may not be different) and based on the comparisons, selects one or more paths for the input I and Q signals. Whether the signals from the analog and digital amplification paths are to be combined or selected (i.e. switched), the PA path control circuit is operative to generate select (switch) control signals which are applied to summer/selector elements which generate the output of the hybrid PA.

Methods, apparatus, and systems for reducing Peak Average Power Ratio (PAPR) in signal transmissions are described. In one example aspect, a wireless communication method includes determining, for a time-domain sequence x(i), an output sequence s(k). The output sequence s(k) is an inverse Fourier transform of a frequency-domain sequence S(j). S(j) is an output of a frequency-domain shaping operation based on a frequency-domain sequence Y(j) and a set of coefficients. Y(j) corresponds to the time-domain sequence x(i) based on a parameter N. The number of non-zero coefficients in the set of coefficients is based on N, and values of the non-zero coefficients correspond to phase values distributed between 0 to π/2 to reduce a peak to average power ratio of the output sequence. The method also includes generating a waveform using the output sequence s(k).

Methods, systems, and devices for wireless communications are described. In one example, a receiving device (e.g., a UE) may transmit, to a transmitting device (e.g., a base station), a capability indicator indicating a capability of the receiving device to perform peak reconstruction using soft metrics (e.g., expected value, covariance) on symbol decisions. The receiving device may receive, from the transmitting device and based on the capability indicator, control signaling indicating a clipping level applied to generate a signal and a subset of peaks clipped from the signal. The receiving device may receive the signal generated in accordance with the control signaling from the transmitting device and may decode a reconstructed signal based on performing the peak reconstruction on the signal using the soft metrics on symbol decisions, the clipping level, and the subset of the peaks clipped from the signal.

Disclosed are a multi-carrier superposition method and device. First, input carrier signals arc superposed, and gain reduction processing is conducted during the superposition process, and then CFR processing and increase processing are conducted on the superposed carrier signals. Thus, under the circumstance of multi-carrier superposition, it can be effectively ensured that signals cannot overflow, and meanwhile the requirement for precision of a system during processing is met.

A method performed by an electronic device is described. The method includes receiving a long training field (LTF) in a preamble of a packet. A power of the LTF is boosted relative to a power of a data field of the packet. The method also includes receiving a power amplifier (PA) model or a PA distortion error from a transmitting device. The method further includes regenerating a post-PA transmitted LTF based on the PA model or the PA distortion error. The method additionally includes demodulating the data field based on an estimated channel with deboosting.

This disclosure provides methods, devices and systems for reducing PAPR in wireless communications. Some implementations more specifically relate to suppressing the amplitudes of a data signal that exceed a threshold amplitude level. The data signal may represent transmit (TX) data associated with a hybrid automatic repeat request (HARQ) process. In some implementations, a transmitting device may detect one or more peaks associated with the data signal. The transmitting device may reduce the amplitudes of the samples associated with the detected peaks to produce the amplitude-suppressed data signal. The transmitting device may further generate peak suppression information indicating the amplitudes of one or more of the samples associated with the peaks. In response to receiving a NACK message, the transmitting device may transmit, to the receiving device, the peak suppression information, one or more coded bits representing the TX data (associated with the HARQ process), or any combination thereof.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a negative acknowledgement message indicating a failure to successfully, autonomously recover a compressed transmission including a saturated signal; and transmit a retransmission to enable distortion recovery on the compressed transmission based at least in part on receiving the negative acknowledgement. Numerous other aspects are provided.