A method and system for error scaling for crest factor reduction (CFR) are disclosed. According to one aspect, a method for regulating peak to average power ratio (PAR) of an output signal of the CFR circuit is disclosed. In one embodiment, the method includes receiving an input signal at an input of the CFR circuit. The magnitude of the input signal is determined and clipped to a target level to produce an error signal by comparing the input signal magnitude to a threshold in a comparator. The error signal is filtered to produce a processed error signal. The filter provides a bandpass filter frequency response. The PAR of the output signal is regulated by scaling the processed error signal by an error scaling factor to achieve a target signal to noise ratio (SNR) for the output signal corresponding to a target error vector magnitude (EVM).

In embodiments of the presently described subject matter, two efficient PAPR reduction methods for OFDM signals based upon the principle of tone reservation and building upon the clipping noise analysis presented in Analysis of clipping noise and tonereservation algorithms for peak reduction in OFDM systems, L. Wang and C. Tellambura, IEEE Trans. Veh. Technol., vol. 57, pp. 1675-1694, May 2008 are provided, each comprising two stages. The first stage is performed offline to prepare a set of cancellation signals based on the settings of the OFDM system. In particular, these cancellation signals are constructed to cancel signals at different levels of maximum instantaneous power that are above a predefined threshold. The second stage is performed online and in an iterative manner to reduce the peaks of OFDM symbols by using the cancellation signals constructed in the first stage.

Otherwise incompatible crest factor reduction (CFR) and cable tilt compensation can be used together, such as in a cable television or other cable communication system having a frequency-dependent signal loss at higher frequencies. The CFR can be used to limit or reduce peaks of signals provided to a power amplifier, while additional tilt reference and tilt equalizer circuits are included to address deleterious peak regrowth effects that may otherwise arise by using conventional CFR together with cable tilt compensation.

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).

A method for controlling a combined waveform, representing a combination of at least two signals having orthogonal frequency multiplexed signal components, comprising: receiving information defining the at least two signals; transforming the information defining each signal to a representation having orthogonal frequency multiplexed signal components, such that at least one signal has at least two alternate representations of the same information, and combining the transformed information using the at least two alternate representations, in at least two different ways, to define respectively different combinations; analyzing the respectively different combinations with respect to at least one criterion; and outputting a respective combined waveform or information defining the waveform, representing a selected combination of the transformed information from each of the at least two signals selected based on the analysis.

Disclosed are crest factor reduction (CFR) implementations that include a method comprising getting communication system data representative of characteristics of a communication system comprising one or more radio transmission bands, and optimizing, based at least in part on the input communication system data, a plurality of updateable parameters that determine respective pulse shapes for one or more pulses as well as other certain algorithm execution parameters for use in the CFR system. Optimizing the plurality of updateable parameters includes iteratively updating the plurality of updateable parameters based on iterative evaluation of a plurality of performance parameters. The method further includes providing the optimized plurality of updateable parameters to configure the crest reduction system for use in processing signals for radio transmission using a pulse subtraction approach applied to one or more signals communicated through the communication system.

A distributed antenna system includes a plurality of head-end devices for each receiving mobile communication signals from at least one corresponding base station, a hub communicatively coupled to the plurality of head-end devices, and a plurality of remote devices communicatively coupled to the hub, wherein the hub configured to distribute the mobile communication signals received from each of the plurality of head-end devices to the plurality of remote devices, wherein each of the plurality of remote devices is remotely disposed to transmit the distributed mobile communication signals to a terminal in service coverage, and wherein the hub includes a mixing processing stage configured to perform digital mixing processing on the mobile communication signals respectively received from the plurality of head-end devices, and a crest factor reduction (CFR) module disposed posterior to the mixing processing stage, with respect to a signal transmission direction.

Techniques related to a data processing engine for an integrated circuit (IC) are described. In an example, a method is provided for vectorized peak detection. The method includes dividing a set of data samples of a data signal, corresponding to a peak detection window (PDW), into a plurality of subsets of data samples each comprising a number of data samples. The method includes performing vector operations on each of the plurality of subsets of data samples. The method includes determining a running index of a sample with a maximum amplitude over the PDW based on the vector operations.

A method for controlling a combined waveform, representing a combination of at least two signals having orthogonal frequency multiplexed signal components, comprising: receiving information defining the at least two signals; transforming the information defining each signal to a representation having orthogonal frequency multiplexed signal components, such that at least one signal has at least two alternate representations of the same information, and combining the transformed information using the at least two alternate representations, in at least two different ways, to define respectively different combinations; analyzing the respectively different combinations with respect to at least one criterion; and outputting a respective combined waveform or information defining the waveform, representing a selected combination of the transformed information from each of the at least two signals selected based on the analysis.

Methods, systems, and devices for wireless communications are described. The described methods, systems, and devices may include sampling an input signal to obtain one or more signal windows. An amplitude of a first sample within a first signal window of the one or more signal windows may be determined to exceed an amplitude threshold. A series of cancellation pulses may be combined with the first sample within the first signal window to obtain a reduced signal, the reduced signal including one or more reduced samples each having an amplitudes within the amplitude threshold. The series of cancellation pulses may be based on a characteristic of the first sample. The reduced signal may then be transmitted. The series of cancellation pulses may be based on, for example, an envelope of the first sample. In some cases, the series of cancellation pulses may be based on a phase of the first sample.