High performance wideband digital predistortion platform for 3G+ applications with better than 55dbc over 40 MHz bandwidth

In this paper, a hardware-software system is proposed for the wideband characterization and linearization of power amplifiers exhibiting memory effects. The designed prototype includes a signal generation and a feedback paths for applications in the 1 GHz to 2.5 GHz frequency band and supports instantaneous bandwidths of up to 60 MHz. The hardware platform is coupled with a software interface that implements the required data processing algorithms for the synthesis of the digital predistortion function. Experimental validation is carried out on a 3G power amplifier driven by an eight-carrier WCDMA signal. The digital predistortion is implemented using the twin-nonlinear two-box model with only 30 parameters and leads to a better than 55 dBc ACLR for an input signal having 40 MHz instantaneous bandwidth. To the best of the authors´ knowledge this represents the best digital predistortion performances in terms of bandwidth and complexity.