Improved Digital Predistortion System in Transmitter

Abstract

Various digital predistortion systems used in transmitters are disclosed. The digital predistortion system includes an observation path, the observation path performs undersampling or radio frequency sampling of the output of the power amplifier. Undersampling can be performed at rates where aliasing occurs in the undersampled frequency domain. By removing any lower hybrid or anti-aliasing modules while maintaining the reasonable performance of the digital predistortion system, both undersampling and RF sampling reduce the complexity of the digital predistortion system.

Description

technical field [0001] The present disclosure relates generally to digital predistortion, and more particularly to radio frequency (RF) sampling and subsampling for digital predistortion in base transceiver systems. Background technique [0002] Mobile communication networks rely on mobile base transceiver stations (BTS) to facilitate wireless communication between user equipment and the network. A BTS receives and transmits signals between user equipment and the network, and one component of the BTS is its power amplifier (PA). The PA is configured to amplify weak signals without adding distortion. PAs are usually high power consumption, typically consuming 30% (or more) of the total power. Furthermore, PAs are expensive, typically constituting 30% (or more) of the total cost of BT. [0003] A characteristic of a power amplifier is that when the input power is relatively small, the output power is also relatively small. In this workspace, the PA behaves linearly, but th...

AI Technical Summary

Problems solved by technology

Although solutions have been used to correct for non-linear effects, problems due to non-linearity remain difficult to correct because the effects are otherwise dependent on prior signals in the time domain (memory effects)

Images