Abstract: 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.

Abstract: 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.

Abstract: 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 Fs, without changing the sampling rate of the fixed rate DAC used in the up-conversion process.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Systems and methods for providing digital predistortion to compensate for a non-linearity of a power amplifier in a dual-band transmitter are disclosed. In one embodiment, a first baseband signal is tuned to a first intermediate frequency to provide a first intermediate frequency signal. Likewise, a second baseband signal is tuned to a second intermediate frequency to provide a second intermediate frequency signal. The first and second intermediate frequency signals are combined to provide a combined intermediate frequency signal. The combined intermediate frequency signal is then predistorted to compensate for the non-linearity of the power amplifier in the transmitter to thereby provide a predistorted signal. In one embodiment, a separation between the first and second intermediate frequencies and/or a sampling rate for predistortion is minimized based on a target intermodulation order for the predistortion.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.