Digital predistortion technique for low resource consumption using carrier aggregated 4G/5G signals

Abstract

Carrier aggregation (CA) is an essential part of long-term evolution (LTE) signals for 4G/5G wireless communication. However, CA LTE signals place stringent conditions on the radio-frequency power amplifiers (PAs). The multi-band operation, wider bandwidth, and related hardware cost increase for the implementation of digital predistortion (DPD) for the multi-band PAs. This study presents a novel independent component analysis (ICA) method for the DPD models which is suitable for all three cases (intra-band contiguous, intra-band non-contiguous and inter-band non-contiguous) of CA. It has been established that the memory requirement of ICA-based memory polynomial (MP) model implementation is much lesser than the state-of-the-art low complexity models such as MP model, orthogonal MP model and principal component analysis-based MP model for CA LTE signals. The proof-of-concept is provided with two different measurement setups for establishing its versatility.