Various examples are directed to systems and methods for digital predistortion (DPD). A linear digital predistortion (DPD) circuit may be programmed to generate a pre-distorted signal linear component based at least in part on a complex baseband signal. A nonlinear DPD circuit may be programmed to generate a pre-distorted signal nonlinear component based at least in part on the complex baseband signal. A mixer circuit programmed to generate a pre-distorted signal based at least in part on the pre-distorted signal linear component and the pre-distorted signal nonlinear component.

The present invention discloses a power amplification apparatus having a digital pre-distortion mechanism that includes a digital pre-distortion circuit and a power amplifier. The digital pre-distortion circuit receives an original digital signal having an original real part and an original imaginary part. When a first one and a second one of the original real part and the original imaginary part are a low state voltage level and a high state voltage level, the digital pre-distortion circuit outputs a first and a second voltage levels equivalent to the low state voltage level as a first pre-distortion part and directly outputs the second one of the original real part and the original imaginary part as a second pre-distortion part to generate an input signal having an input real part and an input imaginary part each corresponding to one of the first pre-distortion part and the second pre-distortion part. The power amplifier receives the input signal to perform power amplification to generate an output signal.

A phase shifter (100) with controllable attenuation and a method for controlling the phase shifter is disclosed, the phase shifter (100) comprising a plurality of transmission line segments (120, 220) coupled in series, wherein each said transmission line segment (120, 220) comprises an attenuation circuit (130, 230), selectively couplable between a signal line (126, 222) of the transmission line segment (120, 220) and ground to selectively attenuate a signal propagating through the transmission line segment (120, 220). Each transmission line segment (120, 220) is switchable between a first configuration providing a first phase shift for a signal propagating through the transmission line segment (120, 220) and a second configuration providing a second phase shift, greater than said first phase shift, for a signal propagating through the transmission line segment (120, 220).

Systems and methods are disclosed herein for providing efficient Digital Predistortion (DPD). In some embodiments, a system comprises a DPD system comprising a DPD actuator. The DPD actuator comprises a Look-Up Table (LUT), selection circuitry, and an approximate multiplication function. Each LUT entry comprises information that represents a first set of values {p.sub.1, p.sub.2, . . . , p.sub.k} and a second set of values {s.sub.1, s.sub.2, . . . , s.sub.k} that represent a LUT value of s.sub.1.Math.2.sup.p.sup.1+s.sub.2.Math.2.sup.p.sup.2+ . . . +s.sub.k.Math.2.sup.p.sup.k where each value s.sub.iϵ{+1,−1} where k≥2. The selection circuitry is operable to, for each input sample of an input signal, select a LUT entry based on a value derived from the input sample that is indicative of a power of the input signal. The approximate multiplication function comprises shifting and combining circuitry that operates to, for each input sample, shift and combine bits that form a binary representation of the input sample in accordance with {p.sub.1, p.sub.2, . . . , p.sub.k} and {s.sub.1, s.sub.2, . . . , s.sub.k} to provide an output sample.

Systems and methods are disclosed herein for selectively compensating for a specific Intermodulation Distortion (IMO) product(s) of an arbitrary order in a transmitter system. In some embodiments, a method of compensating for one or more specific IMO products in a concurrent multi-band transmitter system comprises generating an IMO correction signal for a specific IMO product as a function of two or more frequency band input signals for two or more frequency bands of a concurrent multi-band signal, the IMO product being an arbitrary order IMD product. The method further comprises frequency translating the IMD correction signal to a desired frequency that corresponds to a Radio Frequency (RF) location of the specific IMO product and, after frequency translating the IMO correction signal to the desired frequency, utilizing the IMO correction signal to compensate for the specific IMO product.

A system and method for calibrating digital pre-distortion in a wireless device. A pre-distortion circuit may output a first training signal while a power amplifier of the wireless device is on, to generate a first feedback signal. The first feedback signal may be fed back to the pre-distortion circuit via a receive path of the wireless device. The pre-distortion circuit may output a second training signal while the power amplifier is off, to generate a second feedback signal. The second feedback signal may be fed back to the pre-distortion circuit via the receive path. The pre-distortion circuit may then determine one or more pre-distortion coefficients based on the first and second feedback signals.

Described herein are technologies related to an implementation of a closed-loop system to measure and compensate non-linearity in a transceiver circuitry of a device.

A radio device includes an amplifier; a storage that stores therein distortion compensation coefficients each of which compensates distortion that is generated in the amplifier; an updater that reads, from the storage in a first time section, the distortion compensation coefficients associated with a portion of an input signal input during the first time section and stores the read distortion compensation coefficients in a memory, and that updates, in a second time section, the distortion compensation coefficients stored in the memory and writes the updated distortion compensation coefficients in the storage; and a controller that controls the updater such that, when the same input signal is repeatedly input, the distortion compensation coefficients associated with a portion that is different from the portion of the input signal input the last time are stored in the memory in the first time section.

A method and apparatus is provided. The method includes determining a training data set comprising input and output data of a power amplifier, determining compensation data by regressing the training data using a frequency domain weighting function, storing the compensation data, and linearizing an output of the power amplifier using the stored compensation data.

The application relates to the field of communications technologies, and disclose a signal amplification processing method and apparatus. The method includes setting multiple groups of parameter values for a signal decomposition parameter group, separately performing signal amplification processing based on each group of parameter values, obtaining a power amplification efficiency corresponding to each group of parameter values, obtaining a group of parameter values corresponding to a maximum power amplification efficiency in the power amplification efficiency corresponding to each group of parameter values, and setting the group of parameter values corresponding to the maximum power amplification efficiency as parameter values of the signal decomposition parameter group. Thus, the power amplification efficiency may be improved.