A technology is described for a repeater. The repeater can be configured to: receive an access level indicator from a spectrum access system (SAS) for a selected contested frequency band; identify one or more sub-bands available to the repeater in the selected contested frequency band based on the access level indicator; and activate the repeater for the one or more sub-bands when the access level permits repeater access.

Techniques for peak-to-average power ratio (PAPR) reduction are described. Wireless devices may use one or more PAPR shaping resources, such as expanded bandwidth and/or pulse-shaping filtering, for shaping a signal to reduce PAPR. For example, expanded bandwidth may be utilized for adding a cyclic affix (CA), such as may comprise a cyclic prefix (CP), cyclic suffix (CS), etc., and combinations thereof, to a frequency domain data signal to provide a CP augmented frequency domain data signal used to generate a reduced PAPR time domain data signal. Additionally or alternatively, pulse-shaping filtering may be applied to a frequency domain signal to provide a pulse-shaped frequency domain data signal used to generate a reduced PAPR time domain data signal. Other aspects and features are also claimed and described.

A user equipment (UE) may multiplex peak suppression information message (PSIM) on a physical uplink shared channel (PUSCH) with data for efficient implementation of PSIMs for peak to average power ratio (PAPR) reduction. A UE may clip peaks from a signal to be transmitted and capture information of the clipped peaks into a PSIM. The UE may then multiplex the PSIM on the PUSCH such that a receiving device (for example, a base station) may receive the signal and reconstruct the signal (for example, PUSCH data) using the PSIM. According to some aspects, each PUSCH symbol may include a PSIM for a previous PUSCH symbol (for example, such that causality is preserved if multiplexing PSIM and data for each PUSCH symbol). Various aspects of the techniques described herein may further provide for PSIM positioning in frequency, PSIM modulation, PSIM channel coding, PSIM multiple-input multiple-output (MIMO) configurations, among other examples.

A dynamic configuration of crest factor reduction in a licensed assisted access radio system. A processing device comprises a detecting block, a clipping pulse generator, a first storage block, a selecting block, a full clipping block and a simplified clipping block. The detecting block performs a listen-before-talk (LBT) procedure on a plurality of carriers in parallel and generates a trigger signal in response to LBT success on one or more carriers. The clipping pulse generator generates, for the carrier(s) with LBT success, a clipping pulse within a time period from the receipt of the trigger signal to the start of user traffic transmission. The first storage block stores the clipping pulse for use by the full clipping block. The selecting block selects the full clipping block when there is user traffic on the carrier(s) and selects the simplified clipping block when there is no user traffic on the carrier(s).

Systems and methods of wireless communication in which wireless devices are adapted to implement adaptive waveform selection are disclosed. For example, operation according to embodiments may provide for use of a waveform design that minimizes peak-to-average power ratio (PAPR), such as single-carrier frequency division multiplexing (SC-FDM), as well as a waveform design that provides higher spectral efficiency, such as orthogonal frequency division multiplexing (OFDM), for scenarios that are not power-limited and the higher PAPR is acceptable. Adaptive waveform selection may be based implicitly on one or more parameters or may be based on explicit signaling. Adaptive waveform selection may be utilized with respect to initially establishing a communication link and/or with respect to an established communication link.

Preventing RF signal distortion and signal error producing memory events in a Radio Frequency (RF) power amplifier (RFPA). An element, disposed prior to the Radio Frequency (RF) power amplifier (RFPA) in a signal path of a RF signal input to the RFPA, may enforce a maximum allowable amplitude in a high PAPR instantaneous high peak of the RF signal. An element may also increase or supplement a bias of the Radio Frequency (RF) power amplifier (RFPA) when a high PAPR instantaneous high peak is detected in the RF signal prior to receipt by the RFPA. Additionally, a first element operable detects when an instantaneous output voltage of the Radio Frequency (RF) power amplifier (RFPA) is below a predetermined voltage, and in response, a second element supplies additional current to prevent the output voltage of the RFPA from falling below a predetermined threshold voltage.

Methods related to wireless communication systems and reducing peak-to-average-power ratio (PAPR) in MU-MIMO transmissions are provided. A base station (BS) generates a plurality of communication signals including data for a plurality of user equipment (UE) devices in a plurality of serving beam subspaces. The BS may also generate a peak-to-average-power ratio (PAPR) reduction signal for one or more of the plurality of communication signals. A first portion of the PAPR reduction signal is in a first serving beam subspace of the plurality of serving beam subspaces based on a first error vector magnitude (EVM) associated with a first UE of the plurality of UEs. A second portion of the PAPR reduction signal is in a non-serving beam subspace. The BS may also transmit, to the plurality of UEs, the plurality of communication signals and the PAPR reduction signal. Other features are also claimed and described.

A user equipment (UE) may multiplex peak suppression information message (PSIM) on a physical uplink shared channel (PUSCH) with data for efficient implementation of PSIMs for peak to average power ratio (PAPR) reduction. A UE may clip peaks from a signal to be transmitted and capture information of the clipped peaks into a PSIM. The UE may then multiplex the PSIM on the PUSCH such that a receiving device (for example, a base station) may receive the signal and reconstruct the signal (for example, PUSCH data) using the PSIM. According to some aspects, each PUSCH symbol may include a PSIM for a previous PUSCH symbol (for example, such that causality is preserved if multiplexing PSIM and data for each PUSCH symbol). Various aspects of the techniques described herein may further provide for PSIM positioning in frequency, PSIM modulation, PSIM channel coding, PSIM multiple-input multiple-output (MIMO) configurations, among other examples.

A base station may multiplex a peak suppression information message (PSIM) on a physical downlink shared channel (PDSCH) with data for efficient implementation of PSIMs for peak to average power ratio (PAPR) reduction. A base station may clip peaks from a signal to be transmitted and capture information of the clipped peaks into a PSIM. The base station may then multiplex the PSIM on the PDSCH such that a receiving device (for example, a user equipment (UE)) may receive the signal and reconstruct the signal (for example, PDSCH data) using the PSIM. According to some aspects, each PDSCH symbol may include a PSIM for a previous PDSCH symbol, or the PSIM may be for the current symbol. Various aspects of the techniques described herein may further provide for PSIM positioning in frequency, PSIM modulation, PSIM channel coding, PSIM multiple-input multiple-output (MIMO) configurations, among other examples.

Disclosed is a method of reducing the Instantaneous to Average Power Ratio, IAR, of a transmitter system, comprising the steps of: receiving an input digital signal comprising a plurality of samples; extracting magnitude information for each of the plurality of samples; selecting a plurality of samples whose magnitude exceeds a predefined threshold; sorting, by magnitude, the selected plurality of samples; selecting from the sorted plurality of samples, only those samples having a spacing more than a first pre-defined spacing and filtering those samples, using an FIR filter; subtracting the output of the FIR filter from a delayed version of the input digital signal to produce an output signal.