Performance evaluation for OFDM and SC-FDE systems with high power amplifier

We utilize new performance criteria to evaluate performance of orthogonal frequency division multiplexing (OFDM) and single carrier modulation with frequency-domain equalization (SC-FDE), which is described as the required ratio of average transmitted energy per bit to power spectral density of noise at a certain bit error rate (BER). The criteria takes not only received BER performance into account, but the power loss caused by input power back off (IBO) that depends on the requirement of adjacent channel interference (ACI) at transmitter. Simulation results indicate that IBO for unique-word-aided SC-FDE is about 4 dB lower than that for OFDM and pilot-aided SC-FDE to keep ACI below −30dB. Under the new performance criteria, although OFDM system has poorer performance in static and slow dispersive fading channel, it has advantages over SC-FDE systems especially in fast dispersive fading channels.