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BER performance of OFDM systems in mobile multi-hop relaying channels

Orthogonal frequency division multiplexing (OFDM) system has been proposed as a technique for broadcasting digital signals and for wireless communication. The bit-error-rate (BER) performance of the OFDM system is severely affected by the nonlinearity of the high power amplifier and by the Doppler effect impairments. In this paper, we analyze the effects induced on the OFDM signal by the amplifier non-linearity and by the Doppler effect over multi-hop relaying channels. Moreover, simulation results are presented to validate the analysis. It is shown that the resulting inter-carrier interference (ICI) due to the cumulative effects of the phase noise generated by these impairments per hop becomes very significant in a multi-hop relaying communication system, and severely degrades the BER performance of the system. Theoretical results show perfect agreement with those obtained by simulation.