Improved baseband digital predistortion for linearising PAs with nonlinear memory effects using linearly interpolated LUT
Abstract
An improved baseband Digital PreDistortion (DPD) solution to reduce the nonlinearity of Power Amplifiers (PAs) with memory effects is proposed. It is based on the Memory Polynomial (MP) model and linearly interpolated Look-Up Table (LUT). This predistorter reduces significantly the computational time needed in MP based DPD by using a LUT. A linear interpolation technique is introduced to enhance the indexing of LUT, such that good performance with small table size and low computational complexity is achieved. The proposed solution is validated on a test bench using a PA ZFL-2500 driven by a 16QAM modulated signal.