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 |
20090041109 | Compact floating point delta encoding for complex data - A method and apparatus for compression of complex data signals within a telecommunications base station. The method includes representing a sample of a complex value discrete time signal using 2(L−N)−S mantissa bits and 2N+S exponent bits to realize peak output signal to noise ratios over a wider dynamic range compared to a conventional L-bit uniform quantization format. The increases in dynamic range and peak output SNR is achieved without increasing the average number of data bits per sample and with relatively simple computational effort. | 02-12-2009 |
20090092195 | METHOD AND SYSTEM FOR ADAPTIVE PEAK TO AVERAGE POWER RATIO REDUCTION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION NETWORKS - A method and system adaptively reduce a peak-to-average power ratio in a communication system. Energy is clipped from at least one peak of a modulated signal. The modulated signal includes a plurality of sub-carriers. At least one data sub-carrier is adaptively selected for peak-to-average power ratio reduction use based on known scheduling information. The clipped energy is distributed among at least one data sub-carrier. | 04-09-2009 |
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 |
20120063548 | DIGITAL RECEIVER AND METHOD - A receiver and method is provided for sigma-delta converting an RF signal to a digital signal and downconverting to a digital baseband signal. The RF signal is split into N phases, as can be accomplished using a sample and hold circuit, and each phase is digitized, as can be accomplished using an analog-to-digital (A/D) sigma-delta converter. Polyphase decimation techniques and demodulation are applied to the phased signals to generate a demodulated digital signal. The demodulated digital signal is further downconverted to the appropriate baseband signal. | 03-15-2012 |
20120119811 | Configurable Basis-Function Generation for Nonlinear Modeling - Digital predistorter circuits with selectable basis function configurations are described. In some embodiments, an input scaling block is introduced prior to a basis function generator structure. The input scaling factor is based on the input signal's average power. In other embodiments, configurable connection coefficients are used to construct the orthogonal basis functions. Multiple sets of tap weights for the predistorter are maintained, each set corresponding to a given basis function configuration. In an example method for pre-distorting an input signal to compensate for distortion introduced by an electronic device, a statistic characterizing the input signal is calculated, and one of a pre-determined set of basis function configurations is selected, based on the statistic. A set of pre-distortion model weights corresponding to the selected basis function configuration are determined, after which the selected basis function configuration and the corresponding set of pre-distortion model weights are applied to the input signal. | 05-17-2012 |
20120128082 | Methods and Systems for Programmable Digital Down-Conversion - A radio communication apparatus operable over a wide range of frequencies including a signal processing device is provided. The device performs an analog to digital conversion at a predetermined sample rate independent of a selected frequency band within the wide range of frequencies to generate a digital signal, and digitally processes the digital signal to output a data signal at baseband associated with the selected frequency band. | 05-24-2012 |
20120128099 | Method and Frequency Agile Pre-distorted Transmitter Using Programmable Digital Up and Down Conversion - Pre-distorted transmitters operable over a wide range of frequencies including a plurality of predetermined frequency bands are provided. The transmitters include a programmable digital up-converter and a programmable digital down-converter, an ADC, a DAC, a power amplifier and at least one analog filter arranged along a transmit signal path and a feedback signal path. | 05-24-2012 |
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 |
20130022092 | Enhanced Wideband Transceiver - A method for operating an integrated transceiver, comprising coupling an operating transmitter and an operating receiver within the integrated wideband receiver, inputting a signal into the operating transmitter, performing a first conversion of the signal, wherein the signal is converted into a second signal, transmitting the second signal into the operating receiver, performing a second conversion of the signal, wherein the signal is converted into a third signal, transmitting the third signal into the operating transmitter, and adjusting the operating transmitter. | 01-24-2013 |
20130027090 | MULTI-BAND PEAK POWER REDUCTION - Peak power reduction in transmit chains of multi-band radiocommunication devices is performed. By using knowledge of the phase transformations which occur at the upconverter to determine how baseband signal samples will combine at the higher (upconverted) frequency, peak prediction and corresponding baseband signal modification can be performed in a way that reduces peak power of the combined signal. | 01-31-2013 |
20130064325 | LINEARIZATION FOR A SINGLE POWER AMPLIFIER IN A MULTI-BAND TRANSMITTER - A multi-band signal is generated by combining two or more input signals separated in frequency. The input signals are combined either before or after predistortion depending on the bandwidth of the multi-band signal. If the bandwidth of the multi-band signal is less than a predetermined bandwidth threshold, the input signals are combined and predistortion is applied to the combined signal to generate the multi-band signal. If the bandwidth of the multi-band signal is greater than the bandwidth threshold, the individual input signals are predistorted and subsequently combined to generate the multi-band signal. | 03-14-2013 |
20130241757 | PROGRAMMABLE DIGITAL UP-CONVERSION FOR CONCURRENT MULTI-BAND SIGNALS - Embodiments of a digital up-conversion system for a concurrent multi-band signal and methods of operation thereof are disclosed. In one embodiment, a digital up-conversion system includes multiple digital up-converter chains, each for a different frequency band of the concurrent multi-band signal, and a digital combiner that combines up-converted signals output by the digital up-converter chains to provide a combined digital signal. The combined digital signal is processed by one or more additional processing components including a digital-to-analog converter (DAC) to provide the concurrent multi-band signal. | 09-19-2013 |
20130279633 | DIGITAL RECEIVER - A receiver and method is provided for sigma-delta converting an RF signal to a digital signal and downconverting to a digital baseband signal. The RF signal is split into N phases, as can be accomplished using a sample and hold circuit, and each phase is digitized, as can be accomplished using an analog-to-digital (A/D) sigma-delta converter. Polyphase decimation techniques and demodulation are applied to the phased signals to generate a demodulated digital signal. The demodulated digital signal is further downconverted to the appropriate baseband signal. | 10-24-2013 |
20130329817 | METHOD AND SYSTEM FOR ADAPTIVE PEAK TO AVERAGE POWER RATIO REDUCTION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION NETWORKS - A method and system adaptively reduce a peak-to-average power ratio in a communication system. Energy is clipped from at least one peak of a modulated signal. The modulated signal includes a plurality of sub-carriers. At least one data sub-carrier is adaptively selected for peak-to-average power ratio reduction use based on known scheduling information. The clipped energy is distributed among at least one data sub-carrier. | 12-12-2013 |
20140028391 | DIGITAL UPCONVERSION FOR MULTI-BAND MULTI-ORDER POWER AMPLIFIERS - The present disclosure relates to digital up-conversion for a multi-band Multi-Order Power Amplifier (MOPA) that enables precise and accurate control of gain, phase, and delay of multi-band split signals input to the multi-band MOPA. In general, a multi-band MOPA is configured to amplify a multi-band signal that is split across a number, N, of inputs of the multi-band MOPA as a number, N, of multi-band split signals, where N is an order of the multi-band MOPA and is greater than or equal to 2. A digital upconversion system for the multi-band MOPA is configured to independently control a gain, phase, and delay for each of a number, M, of frequency bands of the multi-band signal for each of at least N−1, and preferably all, of the multi-band split signals. | 01-30-2014 |
20140029683 | Multi-Band Observation Receiver - Transmitter observation receivers and methods are described that can predistortion-compensate transmitters capable of operating in multiple communication bands and frequency ranges. Such observation receivers and method involve generating at least one compensation signal such that a signal to be transmitted that is within a bandwidth that simultaneously encompasses multiple frequency ranges is compensated. | 01-30-2014 |
20140184325 | SIGNAL SPLITTING APPARATUS SUITABLE FOR USE IN A POWER AMPLIFIER - Disclosed is a signal splitting apparatus useable in a power amplifier having two or more power amplifiers. The apparatus includes a direct gain component; and a derived gain component connected to the direct gain component. The derived gain component derives the derived gain by imposing a constraint which is valid over the entire dynamic range of the input signal, e.g. the sum of the power of the direct split signal and the derived split signal are constrained to be substantially equal to the power of the input signal. The use of combining additional direct gain and derived gain components, as well as a delay element, are disclosed so as to enable n-component splitting that for adaptation to different applications by the use of suitable coefficients. | 07-03-2014 |
20140213206 | UNDERSAMPLED RECEIVER CHARACTERIZATION - Systems and methods for characterizing an undersampled receiver are disclosed. In one embodiment, one or more probe signals are provided to an input of an undersampled receiver. Each of the one or more probe signals has selective frequency components that ensure that aliases in a corresponding output signal of the undersampled receiver are unique. The undersampled receiver is then characterized based on the output signal(s) of the undersampled receiver. The selective frequency components of the one or more probe signals enable un-aliasing of the one or more output signals of the undersampled receiver and, as such, the undersampled receiver can be characterized. | 07-31-2014 |
20140254722 | Digital Receiver - A receiver and method is provided for sigma-delta converting an RF signal to a digital signal and downconverting to a digital baseband signal. The RF signal is split into N phases, as can be accomplished using a sample and hold circuit, and each phase is digitized, as can be accomplished using an analog-to-digital (A/D) sigma-delta converter. Polyphase decimation techniques and demodulation are applied to the phased signals to generate a demodulated digital signal. The demodulated digital signal is further downconverted to the appropriate baseband signal. | 09-11-2014 |
20150036766 | LEVEL DE-MULTEPLEXED DELTA SIGMA MODULATOR BASED TRANSMITTER - This specification discloses a level de-multiplexed DSM based transmitter and a method for providing the same. Broadly embodiments of the present specification enable wireless transmitters that are based on multi-level de-multiplexed DSM. A three-level de-multiplexed DSM based transmitter is disclosed as an example. More generally, the use of m-level de-multiplexed DSM is also taught, the specification thereby being enabling for broader applications to a person skilled in the art. At least one of the efficiency and linearity of transmitters can be enhanced as required for specific applications by a person of skill in the art in view of this specification and the teachings of its disclosed embodiments. | 02-05-2015 |