Patent application number | Description | Published |
20080238544 | AMPLIFIER PRE-DISTORTION SYSTEMS AND METHODS - A method of optimizing performance of a multiple path amplifier includes: splitting an input signal to derive a respective sub-signal for each branch of the multiple path amplifier; independently pre-distorting each sub-signal using a known performance characteristic of its associated branch of the multiple path amplifier; and supplying each pre-distorted sub-signal to its associated branch of the multiple amplifier. | 10-02-2008 |
20090302940 | PREDISTORTION WITH SECTIONED BASIS FUNCTIONS - A predistortion actuator is provided. The predistortion actuator includes a plurality of branches, each of which implements a basis function that acts on a digital input signal. For at least one of the branches, the respective basis function is a sectioned basis function, where each section of the sectioned basis function corresponds to a respective section of a range of at least one input signal characteristic associated with the digital input signal, such as a value range of a magnitude, a temporal characteristic, or a hybrid of the two. A power amplifier system including the predistortion actuator is also provided. Utilizing sectioned basis functions can potentially reduce the hardware resources necessary to realize the predistortion actuator relative to conventional global basis functions. In addition, signal conditioning during coefficient training can potentially be used to reduce the dynamic range of coefficients associated with each sectioned basis function. | 12-10-2009 |
20090316838 | Cordic based complex tuner with exact frequency resolution - Systems and methods are disclosed that include selecting a sampling frequency and a tuning resolution frequency. These systems and methods may further include determining a wordlength of the phase accumulator, a numeric representation of the phase range, and a reduced representable value of a phase accumulator. In addition, these systems and methods may include operating the phase accumulator, where the phase accumulator creates an output phase accumulator signal. These systems and methods may further includes adjusting the angle of the output phase accumulator signal, where the output phase accumulator signal is adjusted based upon the operation of the phase accumulator, where adjusting the angle of the output phase accumulator signal creates an adjusted output phase accumulator signal and operating a CORDIC module, and where the CORDIC module performs operations upon the output phase accumulator signal based upon the parameters of the phase accumulator. | 12-24-2009 |
20100098191 | METHODS AND SYSTEMS FOR PROGRAMMABLE DIGITAL UP-CONVERSION - Methods and apparatus are described herein that make use of complex tuning, the inherently repetitive nature of sampled signals, and programmable digital filtering to create a flexible digital up-conversion system that utilizes a digital-to-analog converter (DAC) with a fixed effective sample rate while still being adapted for tunability over a wide frequency range. With a knowledge of the fixed effective sample rate of the DAC and a desired frequency of up-conversion and combining complex tuning at baseband and up-sampling by a factor of N with a programmable passband filter configured to select one of a plurality of signal images resulting from the up-sampling, it is possible to translate a baseband input signal to a wide range of frequencies above or below F | 04-22-2010 |
20100150256 | SELECTIVE PEAK POWER REDUCTION - The present invention provides a technique for reducing the peak power of a combined signal that has a first signal of a first modulation type and a second signal of a second modulation type. Based on the combined signal, peak reduction distortion is determined. The peak reduction distortion is configured such that, if applied to the entirety of the combined signal, excessive peaks throughout the combined signal would be reduced. However, instead of applying the entirety of the peak reduction distortion, a selected portion of the peak reduction distortion is applied to a corresponding portion of the combined signal to reduce the peak power of the combined signal. | 06-17-2010 |
20100158083 | REDUCING POWER LEVELS ASSOCIATED WITH TWO OR MORE SIGNALS USING PEAK REDUCTION DISTORTION THAT IS DERIVED FROM A COMBINED SIGNAL - The present invention provides a technique for reducing power levels associated with two or more input signals using peak reduction distortion that is derived from a combined signal, which represents a combination of the input signals. | 06-24-2010 |
20100244950 | AMPLIFIER PRE-DISTORTION SYSTEMS AND METHODS - A method of optimizing performance of a multiple path amplifier includes: splitting an input signal to derive a respective sub-signal for each branch of the multiple path amplifier; independently pre-distorting each sub-signal using a known performance characteristic of its associated branch of the multiple path amplifier; and supplying each pre-distorted sub-signal to its associated branch of the multiple amplifier. | 09-30-2010 |
20120057654 | SELECTIVE PEAK POWER REDUCTION - The present invention provides a technique for reducing the peak power of a combined signal that has a first signal of a first modulation type and a second signal of a second modulation type. Based on the combined signal, peak reduction distortion is determined. The peak reduction distortion is configured such that, if applied to the entirety of the combined signal, excessive peaks throughout the combined signal would be reduced. However, instead of applying the entirety of the peak reduction distortion, a selected portion of the peak reduction distortion is applied to a corresponding portion of the combined signal to reduce the peak power of the combined signal. | 03-08-2012 |
20120275543 | SELECTIVE PEAK POWER REDUCTION - A communication system comprising signal processing circuitry and up-conversion circuitry. The signal processing circuitry is configured to: i) generate a first signal of a first modulation type and a second signal of a second modulation type; ii) combine the first and second signals to form a combined input signal; iii) generate peak reduction distortion based on the combined input signal; iv) select a portion of the peak reduction distortion that corresponds to a first frequency band; and v) apply the selected portion of the peak reduction distortion in the first frequency band of the combined input signal to provide a combined output signal. The up-conversion circuitry up-converts the combined output signal to an RF signal for transmission. | 11-01-2012 |
20120281793 | CORDIC Based Complex Tuner with Exact Frequency Resolution - Systems and methods are disclosed that include selecting a sampling frequency and a tuning resolution frequency. These systems and methods may further include determining a wordlength of the phase accumulator, a numeric representation of the phase range, and a reduced representable value of a phase accumulator. In addition, these systems and methods may include operating the phase accumulator, where the phase accumulator creates an output phase accumulator signal. These systems and methods may further includes adjusting the angle of the output phase accumulator signal, where the output phase accumulator signal is adjusted based upon the operation of the phase accumulator, where adjusting the angle of the output phase accumulator signal creates an adjusted output phase accumulator signal and operating a CORDIC module, and where the CORDIC module performs operations upon the output phase accumulator signal based upon the parameters of the phase accumulator. | 11-08-2012 |
20130010894 | Selective Peak Power Reduction - A communication system comprising signal processing circuitry and up-conversion circuitry. The signal processing circuitry is configured to: i) generate a first signal of a first modulation type and a second signal of a second modulation type; ii) combine the first and second signals to form a combined input signal; iii) generate peak reduction distortion based on the combined input signal; iv) select a portion of the peak reduction distortion that corresponds to a first frequency band; and v) apply the selected portion of the peak reduction distortion in the first frequency band of the combined input signal to provide a combined output signal. The up-conversion circuitry up-converts the combined output signal to an RF signal for transmission. | 01-10-2013 |