Design and hardware implementation of Look-Up Table predistortion on ALTERA stratix DSP board

This paper presents the design procedure and implementation results of a 16 quadrature amplitude modulation (16-QAM) look up table (LUT) predistortion technique for satellite communications using Altera DSP board. The implementation uses Matlab/Simulink, Altera DSP builder and Altera Stratix DSP EP1S80 development board. The design is first implemented in Matlab/Simulink environment. It is then converted to VHDL level using the signal compiler block of the Altera DSP builder. The design is synthesized and fitted with Quartus II software, and downloaded to Altera Stratix DSP EP1S80 development board. The results show that by using LUT pre-distortion, we can get an undistorted constellation at the output of the Traveling Wave Tube (TWT) amplifier. The paper also presents the quantization effects on Symbol Error Rate (SER) performance and SER performance of a 16-QAM modulation with and without using LUT pre-distortion. The results show that the quantization has effect of about 0.3 dB, and the SER performance can be improved significantly (about 5 dB) when LUT pre-distortion is used.