Patent classifications
H04L27/2624
PEAK SUPPRESSION INFORMATION MULTIPLEXING ON UPLINK SHARED CHANNEL
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.
PEAK SUPPRESSION INFORMATION MULTIPLEXING ON DOWNLINK SHARED CHANNEL
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.
Papr reduction for OFDM signals
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 tone reservation 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.
System and method for controlling combined radio signals
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.
CLIPPING-ENHANCED DATA COMMUNICATION
A system and method for communication of digital data includes receiving a plurality of data bits to be transmitted, and generating an output signal for transmission by a transmitter circuit. The generating includes generating a portion of the output signal comprising values of the output signal with magnitude less than a specified threshold, the specified threshold corresponding to a specified transmitter circuit maximum output power; and generating a portion of the output signal comprising a representation of values of the output signal with magnitude greater than the specified threshold.
IBOC COMPATIBLE SUPERPOSITION MODULATION BY INDEPENDENT MODULATORS UTILIZING CLIPPING NOISE FROM PEAK-TO-AVERAGE POWER REDUCTION
According to an aspect of the present invention, there is provided a method for providing additional bandwidth to receivers that can decode a higher modulation comprising trading a peak-to-average power ratio (PAPR) reduction induced constellation noise of all or a subset of in-band on-channel (IBOC) carriers within an orthogonal frequency division multiplexing (ODFM) waveform with data carrying superposition modulation.
TURBO PEAK RECONSTRUCTION FOR HYBRID PAPR REDUCTION SCHEME
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.
MODIFICATION OF SIGNALS FOR TRANSMISSION
An apparatus, method and computer program is described comprising: receiving a first signal comprising one or more carrier signals comprising a plurality of resource blocks, wherein each resource block is assigned to a unique frequency and time slot of the respective carrier signal; generating a clipping pulse by modifying said first signal; converting the clipping pulse signal into a plurality of narrowband signals, wherein each narrowband signal is a frequency slice of the clipping pulse signal; modifying the plurality of narrowband signals to generate a plurality of modified narrowband signals, wherein said modifying is controlled based on filter weights that define a level of noise to be added to the respective narrowband signals in accordance with a desired error vector magnitude distribution or clipping noise distribution.
ULTRA-WIDEBAND CREST FACTOR REDUCTION
Systems and methods for ultra-wideband Crest Factor Reduction (CFR) are provided. In some embodiments, a method performed by a wireless node for performing CFR includes performing a first CFR step on a plurality of input signals at a first sampling rate with joint peak detection and band-specific noise shaping; and performing a second CFR step on the resulting plurality of input signals at a second sampling rate with joint peak detection and joint noise shaping where the second sampling rate is higher than the first sampling rate. In this way, Peak-to-Average Power Ratio (PAPR) reduction may be increased while the computational complexity is reduced.
Crest factor reduction
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.