IMD Anaysis-Based TC-CI/OFDM System for PAPR Reduction and BER Improvement

OFDM (orthogonal frequency division multiplexing) is very effective for the high speed communication system. However, this OFDM communication becomes poor because many overlapped time-domain signals produces the high PAPR (peak to average power ratio) and this causes the nonlinear distortion in the HPA (high power amplifier). In this paper, we propose a new TC-CI/OFDM (tone controlled carrier interferometry) to solve the high PAPR problem and apply the IMD (inter-modulation distortion) reduction techniques into this TC-CI/OFDM system in order to improve BER performance. PAPR can be reduced by adding the control tones in each OFDM symbol in the CI/OFDM system. So, TC-CI/OFDM system is more robust to the nonlinearity and IMD. The influences of the third-order term of the nonlinear input/output polynomial expression and the nonlinear HPA are studied by the theoretical and simulation analyses. It can be shown that TC-CI/OFDM system based on the IMD reduction is better than the same system based on PAPR reduction