Freescale Semiconductor,inc.

Intel Corporation

Hari Thirumoorthy

Patrick Joseph Pratt

Conor O'Keeffe

A calibration signal generator for use in a balancing circuit calibration device in a radio receiver, the calibration signal generator comprising: a means of amplifying a clocking signal from a clocking signal generator to provide a first calibration signal; a means of generating a second calibration signal from the clocking signal, the first and second calibration signals being transmissible to a one or more mixing circuits in the balancing circuit calibration device; and a means synchronizing the operation of other circuit elements in the balancing circuit calibration device with the clocking signal; characterized in that the clocking signal generator is present in the radio receiver and used therein for other functions.

Calibration signal generator

Embodiments include transceivers and transmit IQ imbalance correction methods. A transmitter lineup, which includes an equalizer and an RF modulator, receives a stream of baseband samples having real and imaginary components, processes the real components along a first channel, and processes the imaginary components along a second channel to produce processed real and imaginary components. The equalizer equalizes at least one of the processed real components and the processed imaginary components to compensate for offset frequency-dependent components of transmitter IQ imbalance. The RF modulator receives and modulates analog versions of the equalized samples, resulting in an analog RF signal. An embodiment also includes a balancer adapted to apply IQ gain and phase correction to the equalized samples to compensate for offset frequency-independent components of the transmitter IQ imbalance. A calibration processing subsystem determines filter coefficients used by the equalizer and IQ gain and phase correction values used by the balancer.

Radio transmitter IQ imbalance measurement and correction methods and apparatus

Digital complex tone generators include a first tone generator configured to generate a first digital tone with selectable first characteristics including a first frequency, a first phase, and a first amplitude; a second tone generator configured to generate a second digital tone with selectable second characteristics including a second frequency, a second phase, and a second amplitude; and a generator adder configured for combining the first tone and the second tone to provide a digital complex tone with programmable characteristics. Corresponding methods include initializing a first and second tone generators based on, respective, selected frequencies, phases, and amplitudes; iteratively generating a first digital tone and a second digital tone; and combining these two tones to provide the digital complex tone.

Digital complex tone generator and corresponding methods

A method, apparatus, and system for scaling a value of an amplitude to a binary value and a method, apparatus and system for reducing an undesirable portion of a signal.

Adaptive scaling and echo reduction

An apparatus and method of decoding variable length codes is provided. According to some embodiments, a method includes receiving a bitstream of a codebook of variable length codes, partitioning the codebook based on leading zeros (0) or ones (1), removing a common prefix, from each codeword to obtain a set of shortened codewords, determining a set of bit-patterns from the shortened codewords, partitioning the shortened codewords based on the set of bit-patterns to obtain sub-sets of the shortened codewords, removing a common prefix from each shortened codeword in the sub-sets of shortened codewords to obtain residual codewords, and forming a codebook based on the residual codewords.

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Chandler, AZ, United States of America

Hari Thirumoorthy