Signal-Statistics-Based Look-Up-Table Spacing for Power Amplifier Linearization

The look-up-table based digital adaptive predistortion (DAPD-LUT) is a low-cost and popular power amplifier (PA) linearization scheme. Most existing DAPD-LUT schemes adopt uniform spacing in indexing its LUT entries, completely regardless of the system state information (SSI): 1) the PA characteristics and 2) the input signal statistics, and are therefore sub-optimum. Some other existing DAPD-LUT schemes assume either one or both the SSI are perfectly known, and make use of this informations to design a fixed LUT index spacing. Without prior knowledge of the SSI, we propose a low-complexity iterative procedure to update LUT spacing for a DAPD-LUT scheme, which means the proposed scheme is capable of adapting itself to optimize the DAPD-LUT scheme for PA with all kinds of characteristic processing signals.