Mitigation of Non-linear Distortion Using PTS and IDAR Method for Multi-Level QAM-OFDM System

The future satellite communication systems are required to support the higher transmission data rate for providing the multimedia services by employing the efficient modulation method such as multi-level QAM. The employment of single carrier transmission with multi-level QAM would cause the fatal degradation of signal quality due to the non-linear amplifiers located at the earth station and satellite. To overcome this problem, we have proposed the multilevel QAM-OFDM technique with IDAR (Improved Decision Aided Reconstruction) method designed for non-linear satellite channel. However, the proposed method could not mitigate the non-linear distortion sufficiently when modulation level becomes higher such as 64QAM. This paper proposes the combined scheme of partial transmission sequence (PTS) and OFDM-IDAR methods so as to enable the usage of higher multi-level QAM method, which can achieve the higher transmission data rate with keeping the better bit error rate performance in the non-linear satellite channel. The various computer simulations are conducted in this paper to verify the effectiveness of proposed method in the non-linear satellite channel.