Practical determination of impulse sample power boosting factor in impulse postfix OFDM systems

An impulse postfix OFDM (IP-OFDM) system, which performs channel estimation in time-domain by exploiting the IP instead of pilot tones, has recently been proposed by Chang et al. Although the proposed system can achieve the enhanced bit error rate (BER) performance compared to that of conventional OFDM systems, there is an important peak-to-average power ratio (PAPR) issue of using the IP that needs to be resolved. In this letter, we propose decision criteria for determining the power boosting factor (PBF) of IP in practical IP-OFDM systems with a high power amplifier (HPA). The analysis is performed with two criteria, the complementary cumulative distribution function of signal PAPR and the input back-off to determine the PBF of IP. The best PBF can be the one which gives an equal power to the IP and the rest of the OFDM symbol. From the analytic results, however, the PBF maximizing the power of the IP out of the HPA turns out to be the best one due to the non-linearities of the HPA. Simulation results demonstrate the effectiveness of the proposed decision criteria for IP-OFDM systems.