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.i∈{+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.

The present disclosure is a novel utility of a software defined radio (SDR) based Distributed Antenna System (DAS) that is field reconfigurable and support multi-modulation schemes (modulation-independent), multi-carriers, multi-frequency bands and multi-channels. The present invention enables a high degree of flexibility to manage, control, enhance, facilitate the usage and performance of a distributed wireless network such as Flexible Simulcast, automatic traffic load-balancing, network and radio resource optimization, network calibration, autonomous/assisted commissioning, carrier pooling, automatic frequency selection, frequency carrier placement, traffic monitoring, traffic tagging, pilot beacon, etc. As a result, a DAS in accordance with the present invention can increase the efficiency and traffic capacity of the operators' wireless network.

A power amplifier system includes an input operable to receive an original value that reflects information to be communicated and an address data former operable to generate a digital lookup table key. The power amplifier system also includes a predistortion lookup table coupled to the address data former and a power amplifier having an output and coupled to the predistortion lookup table. The power amplifier system further includes a feedback loop providing a signal associated with the output of the power amplifier to the predistortion lookup table and a switch disposed in the feedback loop and operable to disconnect the predistortion lookup table from the output of the power amplifier.

Systems comprising a low power Digital Predistortion (DPD) system and methods of operation thereof are disclosed herein. In some embodiments, a system comprises a DPD system for digitally predistorting an input signal to provide an output signal. The DPD system comprises a DPD actuator comprising one or more configurable multiplication functions, each configurable to operate in different power modes. The different power modes comprise a first power mode in which the configurable multiplication function multiplies a first value related to an input sample of the input signal and a second value related to a respective DPD value to provide an output value and a second power mode in which the configurable multiplication function outputs, as the output value, are an approximation of a multiplication of the first value and the second value.

Systems and methods are disclosed herein that provide low-complexity Digital Predistortion (DPD) for a transceiver system that uses an Advanced Antenna System (AAS) to provide analog or hybrid beamforming.

Disclosed is a system and a method of baseband linearization for a class G radiofrequency power amplifier, the linearization system including a module for selecting the amplifier power supply voltage, a digital predistortion module, and a module for extracting predistortion coefficients, wherein the linearization system also includes a digital filter with complex coefficients, the input of which is connected to the output of the digital predistortion module, and a module for extracting filter coefficients which is designed to extract filter coefficients used by the digital filter with complex coefficients.

A method of reducing memory effect of a power amplifier (PA), for a look-up table (LUT) based memory digital pre-distortion (DPD) circuit of an electronic device is disclosed. The method comprises generating a pre-distorted signal according to a LUT including parameters of an input signal amplitude and an input signal delay associated with a bandwidth of a signal inputted to the memory DPD circuit, and outputting the pre-distorted signal to the PA for improving the nonlinearity of the PA.

This application provides a power adjustment method and apparatus. The method includes obtaining a to-be-output signal, performing first automatic gain control (AGC) processing on the to-be-output signal to obtain the to-be-output signal on which the first AGC processing is performed, and to obtain a gain value of the to-be-output signal. The method also includes performing digital pre-distortion (DPD) processing on the to-be-output signal on which the first AGC processing is performed, to obtain the to-be-output signal on which the DPD processing is performed. The method further includes calculating an output power back-off (OBO) value based on the gain value, adjusting, based on the OBO value, output power of the to-be-output signal on which the DPD processing is performed, and sending, to a signal receive end, the to-be-output signal on which the power adjustment is performed.

A system includes: a host processor; a transceiver coupled to the host processor; and a power amplifier coupled to an output of the transceiver. The transceiver includes a transmit chain with digital pre-distortion (DPD) logic configured to: perform DPD correction operations on transmit data received by the transmit chain; and output corrected transmit data based on the performed DPD correction operations, wherein the output corrected transmit data is provided to the power amplifier.

A wireless communication apparatus includes: a processor that performs distortion compensation on a transmission signal by using a distortion compensation coefficient; an amplifying unit that amplifies the transmission signal; and a feedback path that feeds back a feedback signal to the processor. The processor executes a process including: acquiring, from a transmission signal at a first timing and feedback signals at a second timing that is before the first timing and at a third timing that is after the first timing, instantaneous delay associated with propagation delay of the feedback signals in the feedback path; calculating a mean value of the instantaneous delay acquired in a predetermined time period; adding delay associated with the calculated mean value to the transmission signal; and updating the distortion compensation coefficient by using the transmission signal to which the delay is added and the feedback signal.