Performance of Iterative Turbo Coding with Nonlinearly Distorted OFDM Signal

In this paper, the performance of iterative turbo coding with nonlinearly distorted orthogonal frequency division multiplexing (OFDM) signal is analyzed. System level implementation in Simulink is performed and bit error rate (BER) performance is analyzed. Initially, we have implemented both, the series turbo coder and iterative turbo coder, compared the performance and then using better performed iterative coder, model is implemented in Simulink. In the model, we introduced highly nonlinear distortion signal using solid state power amplifier (SSPA). It is observed that nonlinear distortion results in very high BER. However, BER performance is significantly improved by the use of iterative turbo coder. It is also seen that 6 iterations is found to be optimum. Higher or smaller iteration results in reduced performance.