Reducing specific inter-symbol interference of constant envelope OFDM system through optimizing zero-padding pattern

The application of phase modulation in Constant-Envelope Orthogonal Frequency Division Multiplexing (CE-OFDM) system transforms OFDM signal to a signal with a unity PAPR and exploits frequency diversity, but also induces one specific kind of inter-symbol interference (ISI). In this paper, the expression of such kind of ISI is defined, and indicates that the ISI is dependent on the zero-padding pattern. Hence a method is proposed to reduce such kind of ISI through optimizing zero-padding pattern. Simulation results show that the proposed optimization method can bring obvious BER performance improvement.