Power Amplifier Linearization in the Presence of Crosstalk and Measurement Noise in MIMO System

Abstract

The crosstalk and transceiver noise is an intrinsic part of the multiple-input and multiple-output (MIMO) System, becoming more prominent in low-cost systems. Moreover, the power amplifiers (PAs) cause nonlinearity, propagating to the complete chain. The conventional techniques do not provide the joint method for crosstalk, transceiver noise, and PA nonlinearity. This results in the performance limitation of the digital predistortion (DPD). Hence we propose a wavelet multiscale principal component analysis (PCA) based technique to deal with such problems (crosstalk, transceiver noise, and system nonlinearities). It is reported using measurement and simulation that numerical stability issue is no longer an issue when wavelet multiscale PCA-based DPD is applied. The effect of wavelet multiscale PCA on bit-resolution of DPD is shown to be better than established DPD Models. On a field-programmable gate array and direct conversion transceiver-based platform, the performance of the proposed model is analyzed using PA. Parameters like normalized mean square error have shown an improvement of around 23 dB and adjacent channel error power ratio has shown an improvement of around 22 dBc for a ZX60-V63+ power amplifier using LTE-OFDM signals.