A Simple Data Pre-Distortion Technique for Satellite Communications: Design & Implementation on Altera DSP Board

This paper presents the design procedure and implementation results for a 16 quadrature amplitude modulation (16-QAM) digital data predistortion technique for satellite communications using an Altera digital signal processing (DSP) board. The implementation uses Matlab/Simulink, Altera DSP Builder, and Altera’s Stratix EP1S80 DSP development board. The design is first implemented in the Matlab/Simulink environment. It is then converted to VHDL level using the signal compiler in the Altera DSP Builder block. The design is synthesized and fitted with Quartus II software, and downloaded to an Altera Stratix EP1S80 DSP development board. The results show that using data pre-distortion by modifying the transmitted constellation, we can get a pure (undistorted) constellation at the output of the traveling wave tube (TWT) amplifier. The paper also presents the symbol error rate (SER) performance of a 16-QAM modulation with and without using data pre-distortion. The results show that the SER performance can be improved significantly (about 5 dB) when data pre-distortion is used.