Freescale Semiconductor,inc.

Motorola Corporation

Intel Corporation

Apple Inc.

Fujitsu Semiconductor Limited

Mahibur Rahman

Charles LeRoy Sobchak

Bing Xu

Christopher T Thomas

Sumit Anil Talwalkar

Clinton C Powell, Ii

James David Hughes

Jorge Ivonnet

Emilio Quiroga

Pravinkumar Premakanthan

Louis Jay Vannatta

Robert Mark Gorday

Manish N Shah

Pravin Premakanthan

Robert K Schweickert

Clive K Tang

Chunmig Zhao

Edgar Herbert Callaway, Jr

James G Mittel

David Ryan Haub

Omid Oliaei

John J Parkes, Jr

Kevin T McLaughlin

Chun-Ye Susan Chang

Michael Milyard

Steven P Hoggarth

Andrew Gerald Zocher

James J Riches

Lynn R Freytag

Homero Luz Guimaraes

Clinton C Powell

James A Kimball

Charles L Sobchak

Embodiments include methods and apparatus for performing transmit power control. A gain application element receives a sequence of digital input samples and a digital gain signal, and combines the digital gain signal with the digital input samples to generate a sequence of gain-compensated digital samples. A power amplifier receives and amplifies an analog version of the gain-compensated digital samples in order to generate an antenna output signal. A feedback path generates an analog feedback signal from the antenna output signal, produces a sequence of digital feedback samples from the analog feedback signal, and generates difference values based on the digital feedback samples. When a specified type of constant modulus symbol is represented in the antenna output symbol, the feedback path accumulates the difference values into an accumulated error value, and produces the digital gain signal from the accumulated error value.

Transmit power measurement and control methods and apparatus

A method may include: determining a signal strength of a signal in a receive path of a wireless communication element, the receive path configured to receive a wireless communication signal and convert the wireless communication signal into a digital signal based at least on an oscillator signal; selecting a current mode from at least one of a first current mode and a second current mode for the wireless communication element based at least on the signal strength; communicating a control signal to the receive path indicative of the current mode; modifying one or more operational parameters of the receive path such that the receive path consumes a different amount of current in each of the current modes.

System and method for controlling current to certain components of a wireless communication device

According to the present disclosure, a method for tracking power levels of a wireless communications signal comprises receiving a feedback signal indicative of a power level of a wireless communication signal associated transmitted from a transmit path to an antenna of a wireless communication element. The method further comprises receiving a reference signal associated with a digital signal converted into the wireless communication signal. Additionally, the method comprises determining a gain of the feedback signal with respect to the reference signal and determining a gain error based on the determined gain and an expected gain.

Method and system for power control of a wireless communication device

An IPtuning circuit (and) for tuning the IPof a mixer (and) to minimize second order intermodulation distortion (IMD) in a receiver (and) of a transceiver (and). An operating characteristic of the mixer related to IMDis changeable by changing a value of a setting of the mixer. Two tones outside a bandpass of the receiver are injected into the mixer and a calibration tone within the bandpass is produced as a result of IMD. Alternatively, a DSSS signal is injected into the mixer and the calibration tone is produced at a chip rate of the DSSS signal. The power of the calibration tone is measured at a plurality of values of the settings. Alternatively, a four-level PN DSSS signal of known content is injected into the mixer, and a two-level PN DSSS signal of known content produced therefrom is correlated with a two-level PN DSSS signal of known content produced by a squaring circuit ().

Tuning a second order intercept point of a mixer in a receiver

In accordance with some embodiments of the present disclosure, a method may include digitally pre-distorting a digital baseband signal with an opposite phase of a C-IM3 distortion term such that the pre-distortion and C-IM3 distortion cancel each other out in a transmitter. The method may also include digitally conditioning the pre-distorted digital signal in order to provide a flat amplitude response of a composite filter comprising a baseband filter and a digital half-band filter of the transmitter, and to provide a linear phase response for the composite filter.

Systems and methods for spurious emission cancellation

A discrete time signal resampling circuit (). A data sample processing module () removes selected samples from a sequential plurality of discrete time signal samples to implement fractional resampling where the data sample processing module stores fewer samples than the number of samples between samples to be removed. A coefficient generator () in the resampling circuit generates a sequence of finite impulse response filter coefficients, with each coefficient in the sequence being associated with a respective distinct portion of a plurality of discrete time signal samples. A coefficient multiplier () multiplies each of the sequential plurality of finite impulse response filter coefficients by its associated respective distinct portion of the plurality of discrete time signal samples. An adder () produces a resampled output sample that consists of a sum of elements of the product vector produced by the coefficient multiplier.

Multirate resampling and filtering system and method

A digital tuning system () for changing a cutoff frequency of an analog filter () includes digital synthesizers (and) for producing a two-tone calibration signal () applied to an input of the filter after a quality factor of the filter is increased. The filter includes at least one R/C circuit with two resistors (and) for changing the quality factor and arrays (and) of capacitors for changing the cutoff frequency. The amplitude of the magnitude responses (and) of the filter to each tone (and) is measured by a two discrete Fourier transform single-frequency bin power detection circuits (and) while the filter is sequenced through a plurality of capacitance settings. An optimal capacitance for the R/C circuit is selected by comparing, to a pre-selected value, a difference between the responses of the filter to each tone, for each capacitance setting.

Controlling the bandwidth of an analog filter

Methods, devices and systems are provided for word synchronizing multiple serial data bitstreams () with a serial framing signal (A). Offset values () are determined () from the relative locations of predetermined data correlation values () stored within the data buffers during a correlation mode to indicate the amount of skew observed between the framing channel and each of serial data channels. Data received during subsequent operation of each data stream is stored a buffer (), and the framing signal (A) is monitored to identify a boundary between data words. When a frame boundary occurs, parallel data is extracted from the buffer using the previously-stored offset values to compensate for bit skew between the data and framing channels.

Methods and apparatus for synchronizing data transferred across a multi-pin asynchronous serial interface

An automatic gain control (AGC) system for a receiver and corresponding method facilitate AGC in a receiver. The automatic gain control system includes an on-channel signal detectorconfigured to provide an on-channel signal level indication corresponding to a narrow band on-channel signal and a wideband signal detectorconfigured to provide a wideband signal level indication corresponding to a wideband signal, where the wideband signal includes the narrow band on-channel signal. Further included is a controllerthat is coupled to the wideband signal level indication and the on-channel signal level indication and that is configured to provide a gain control signal corresponding to the wideband signal level and one or more of a plurality of states of the receiver.

AGC for narrowband receivers

A radio frequency receiver () includes at least one amplifier (and) for amplifying a signal received by the radio frequency receiver, an automatic gain control system () for controlling a gain of the at least one amplifier, and a direct current offset correction filter () for reducing any direct current component of the signal amplified by the at least one amplifier. The direct current offset correction filter has a bandwidth that is dynamically controlled by a change in the gain of the at least one amplifier. The radio frequency receiver also includes a digital automatic gain control unit () having a bandwidth that is dynamically controlled by the change in the gain of the at least one amplifier.

Radio frequency receiver having dynamic bandwidth control and method of operation

A method and apparatus are provided for providing improved radio frequency (RF) receiver signal correction. For RF receiver circuitry () having receive path and a warmup period associated therewith and including at least one analog baseband gain control stage () having a gain associated therewith, the method includes the step of performing a DC correction calculation operation during the warmup period to derive a DC correction value having a first component and a second component for each of the at least one gain control stage (). The DC correction calculation step includes the steps of performing a first closed loop correction () of a baseband path to derive the first component of the DC correction value and performing a second closed loop correction () of the receive path as a function of the () gain during the warmup period to derive the second component of the DC correction value. During operation after the warmup period (), an open loop correction is performed for instantaneous DC correction as function of the PMA () gain and the DC correction value.

DC offset correction system for a receiver with baseband gain control

Embodiments of wireless devices and transmitters are provided, which perform embodiments of automatic gain control methods. The embodiments of wireless devices and transmitters include a ramp generator, a digital gain signal generator, a combiner, and a variable gain amplifier. The ramp generator is adapted to receive a gain control input signal and to generate a gain ramp signal based on the gain control input signal. The digital gain signal generator is adapted to generate and incorporate a gain arc into a digital gain signal. A combiner is adapted to receive and combine a digital input signal with the digital gain signal, to generate a pre-compensated digital signal. The variable gain amplifier is adapted to apply gains indicated in the gain ramp signal to a pre-adjusted analog signal, which is generated based on the pre-compensated digital signal, in order to generate a gain-adjusted analog signal.

Gain control methods for wireless devices and transmitters

A multirate processing circuit () with a resampling filter () to accept a sampled input signal () sampled with a first clock rate and to filter the sampled input signal to remove spectral components above a spectral bandwidth of a second clock rate. The sampled input signal represents a signal that is more efficiently processed at the second clock rate, which is fractionally related to the first clock rate. The multirate processing circuit () also has a discrete time processor () that receives the resampling filter output () and processes that output at an integer power of two multiple of the first clock rate. The discrete time processor () further excludes selected samples from the processing so as to effectively perform discrete time processing of the resampling filter output () at the integer power of two multiple of the second clock rate.

Fractionally related multirate signal processor and method

At least one adjustable gain analog amplifier (and) in an analog line-up () amplifies by a gain an analog signal at an input of the analog line-up (). The at least one adjustable gain analog amplifier (and) is operable at one or more gains. At least one digital estimation device (and) receives signal via an output () of the analog line-up () and provides a digital signal estimate representative of an analog signal at an input of a respective one of the at least one adjustable gain analog amplifier (and) in the analog line-up (). An AGC controller () monitors the digital signal estimate. The AGC controller () adjusts the gain of the at least one analog amplifier (and). An RF receiver and an integrated circuit utilizing the novel features are also disclosed.

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Lake Worth, FL, United States of America

Mahibur Rahman