Crestcom, Inc.

Sicom, Inc.

Ccip Corp.

Motorola Corporation

Other

Intersil Americas Inc.

Ronald Duane McCallister

Eric Martin Brombaugh

Bruce Alton Cochran

John M Liebetreu

Bradley Paul Badke

Daniel D Shearer, Iii

James J Crawford

Daniel Davidson MacFarlane Shearer, Iii

Daniel Davidson

Robert John Solem

Robert Jeffrey Dahl

Mary A Bogner

Brendan J Garvey

Methods, apparatuses, and systems that receive a communication signal. The communication signal may be split into a first communication signal and a second communication signal. The first communication signal may be zero padded. The zero padded first communication signal may be excursion compensated to generate an excursion compensated signal. The excursion compensating may be performed by fast Fourier transform logic. Zero padding may allow for efficient fast Fourier transform process by ensuring that the length of data frames processed is an integer power of two.

Excursion compensation in multipath communication systems with a cyclic prefix

A communication system () includes a base station () and a number of peak-managed user equipment apparatuses () that simultaneously transmit peak-reduced FDMA communication signals () to the base station (). The communication system () exclusively assigns payload subcarriers () to the apparatuses () and assigns a few noise-bearing subcarriers () for common simultaneous use by all apparatuses (). Each user equipment apparatus () includes a peak reduction section () that distorts an otherwise undistorted modulated communication signal () into a distorted, peak-reduced communication signal () by generating and adding peak-reduction noise () to the undistorted signal (). The peak-reduction noise () is primarily mapped onto the noise-bearing subcarriers () without conforming to an in-band noise constraint and may be mapped onto the assigned payload subcarriers () to the extent permitted by an in-band noise constraint. The peak-reduction noise () is blocked in unassigned payload subcarriers ().

Communication system with PAPR management using noise-bearing subcarriers

Methods, apparatuses, and systems that compensate for communication excursions in multipath communication systems (e.g. MIMO communication systems) while satisfying performance requirements parameters of the communication system. A plurality of communication signals may be received in a transmitter. The plurality of communication signals may be precoded (e.g. mixed) into a plurality of precoded communication signals. Excursions in the precoded communication signals may be scaled to generate a plurality of excursion compensated precoded communication signals. The scaling may be based on performance requirements parameters of a communication system and based on parameters of the precoding the plurality of communication signals. The plurality of excursion compensated precoded communication signals may then be amplified by a plurality of amplifiers.

Excursion compensation in multipath communication systems having performance requirements parameters

Optimized impedance characteristics of a variable impedance device causes the apparatus to transmit wireless signals with minimal out-of-band transmission at an optimized efficiency of the power amplifier. The variation of impedance characteristics of an antenna cause a change in the coefficients of a mapping function. The relatively fast variations to the power supply voltage of a power amplifier are applied to the mapping function to generate control signals which vary the impedance characteristics of a variable impedance device. The output of the mapping function includes control signals that control optimized impedance characteristics of a variable impedance device as a function of the variation of the supply voltage to a power amplifier. The coefficients of the mapping function may be regularly determined based on a comparison of out-of-band power and in-band power transmitted by an antenna.

Minimizing impedence mismatch effects in a wireless device

Methods, apparatuses, and systems that compensate for communication excursions in multipath communication systems (e.g. MIMO communication systems) while satisfying performance requirements parameters of the communication system. A plurality of communication signals may be received in a transmitter. The plurality of communication signals may be precoded (e.g. mixed) into a plurality of precoded communication signals. Excursions in the precoded communication signals may be scaled to generate a plurality of excursion compensated precoded communication signals. The scaling may be based on performance requirements parameters of a communication system and based on parameters of the preceding the plurality of communication signals. The plurality of excursion compensated precoded communication signals may then be amplified by a plurality of amplifiers.

A transmitter () generates a time-varying stabilized bias signal () from which sub-RF distortion signals () have been cancelled. The distortion signals () are byproducts of imperfect amplification and of biasing networks. An envelope amplifier () includes a high bandwidth differential input, linear, bias signal amplifier () and a low bandwidth switching amplifier () coupled together to achieve both a high bandwidth and high efficiency. A control loop () feeds a portion of the voltage V(t) from a conduction node () of the RF power amplifier () to one of the differential inputs of the linear bias signal amplifier (), while a bias control signal () drives the other differential input. The portion of voltage V(t) fed to bias signal amplifier () is a low power portion from which the RF portion has been removed. A bias signal () may be predistorted to cancel distortion signals ().

Transmitter and method with RF power amplifier having predistorted bias

A transmitter () generates a time-varying stabilized bias signal () from which an amplifier-generated, sub-RF distortion signal () has been canceled. The distortion signal () is a byproduct of amplification and is generated due to imperfect linearity and/or other characteristics of a linear RF power amplifier (). An envelope amplifier () includes a high bandwidth differential input, linear, bias signal amplifier () and a low bandwidth switching amplifier () coupled together to achieve both a high bandwidth and high efficiency. A control loop () feeds a portion of the voltage V(t) from a conduction node () of the RF power amplifier () to one of the differential inputs of the linear bias signal amplifier (), while a bias control signal () drives the other differential input. The portion of voltage V(t) fed to bias signal amplifier () is a low power portion from which the RF portion has been removed.

Transmitter and method with RF power amplifier having control loop stabilized bias

A transmitter () includes a low power nonlinear predistorter () that inserts predistortion configured to compensate for a memoryless nonlinearity () corresponding to gain droop and another memoryless nonlinearity () corresponding to a video signal. When efforts are taken to reduce memory effects, such as configuring a network of components () that couple to an HPA () to avoid resonance frequencies substantially throughout a video bandwidth (), high performance linearization at low power results without extending linearization beyond that provided by the memoryless nonlinear predistorter (). A look-up table () has address inputs responsive to a magnitude parameter () of a communication signal (). A pre-distorted communication signal () is responsive to the output of the look-up table, a derivative signal (), and possibly one or more variable bias parameters (). The look-up table () is updated in response to an LMS control loop.

Transmitter linearized in response to derivative signal and method therefor

An RF transmitter () includes an RF amplifier () that generates an amplified RF signal () including a linear RF signal () and a spurious baseband signal (). The spurious baseband signal () interacts with bias feed networks () to cause the RF amplifier () to generate an unwanted RF distortion at or near the allocated RF bandwidth. A baseband compensation signal () is generated and equalized in an adaptive equalizer () then fed to the RF amplifier (). A feedback signal () is obtained from the RF amplifier () and used to drive the adaptive equalizer (). A feedback loop causes the adaptive equalizer to adjust a baseband signal () supplied to the RF amplifier () so that the RF distortion is minimized.

Distortion-compensated RF transmitter and method therefor

A transmitter () includes a peak reduction section (), a predistorter (), and an amplifying section () biased by a variable bias signal generator (). The peak reduction section () is controlled by a signal magnitude threshold () that defines maximum magnitudes for local peaks () of a reduced-peak communication signal (). The bias signal generator () is controlled by a bias control signal (). Both the signal magnitude threshold () and the bias control signal () are derived from a common reduced bandwidth () peak-tracking signal (). The peak-tracking signal () is derived from an inflated-peak communication signal (). The predistorter () applies distortion to the reduced-peak communication signal () that is configured, at least in part, by the bias control signal ().

Transmitter with peak-tracking PAPR reduction and method therefor

A transmitter () generates a time-varying, detroughed, biasing signal () for an RF power amplifier () so that the RF power amplifier () is biased in accordance with an envelope tracking scheme. A trough-filling section () is responsive to an envelope tracking signal (), which in turn is responsive to a magnitude signal () extracted from a complex baseband communication signal (). The trough-filing section () includes a limiting stage () that forms a raw troughing signal () which expands the bandwidth of the envelope tracking signal (). A filtering stage () reduces the bandwidth of the raw troughing signal () to form a trough-filling signal () that is combined back into the envelope tracking signal () using a linear process that maintains the bandwidth of the envelope tracking signal ().

Transmitter and method for RF power amplifier having a bandwidth controlled, detroughed envelope tracking signal

A communication system includes a transmitting unit with a peak to average power (PAPR) reduction section. The PAPR reduction section modifies the PAPR reduction it effects in a communication signal in accordance with two different error vector magnitude (EVM) constraints for each channel type, where a channel type is a distinct combination of a modulation order and a coding rate. The EVM constraint followed for each subcarrier in an OFDM or OFDMA application is selected in response to whether the subcarrier conveys voice or non-voice data. The PAPR reduction section may include a scaling filter. The scaling filter is efficiently defined through the use of a predetermined sinc function and a first stage scale factor that is calculated in response to a weighted average of excursion signal subcarrier gains, where the weighting follows the distribution of channel types through the subcarriers.

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Scottsdale, AZ, United States of America

Ronald Duane McCallister