摘要:
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.
摘要:
A device, system, and method are provided for a power amplifier arrangement. In embodiments of a Vdd modulated power amplifier arrangement, a memory correction block includes a Vdd predictor for predicting waveform distortions of a Vdd modulated power supply and a main-path corrector for pre-distorting the input to the power amplifier arrangement as a function of the input to the power amplifier arrangement, an input envelope signal determined as a function of the input to the power amplifier arrangement, and an output of the Vdd predictor. Embodiments of the invention provide for operating power amplifier arrangements having memory. In some embodiments, methods of training the Vdd predictor and the main-path corrector of the memory correction block are provided.
摘要:
A transmitter and method is provided for digitally upconverting a baseband digital signal to a modulated intermediate frequency (IF) digital signal and sigma-delta modulating the IF digital signal. The baseband digital signal is split into N phases, as can be accomplished using a polyphase interpolation technique (polyphase filter), and modulated. The modulated N phases are not recombined and each phase is further modulated, as can be accomplished using a digital-to-digital sigma-delta modulator that generates digital output signals at the same rate. A high speed digital multiplexer multiplexes the digital output signals into a single bit stream at a higher rate for subsequent power amplification and RF transmission.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.