Digital pre-distortion systems in transmitters

Abstract

Various digital pre-distortion systems for use in transmitters are disclosed. The digital pre-distortion system comprises an observing path, which performs either undersampling or radio frequency sampling of the output of a power amplifier. Undersampling may be performed at a rate, which causes aliasing to occur in the undersampled frequency domain. Both undersampling and radio frequency sampling reduces the complexity of the digital pre-distortion system by removing any down mixing modules or anti-aliasing modules, while maintaining reasonable performance of the digital pre-distortion systems.

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