Effects of Correlative Coding on OFDM Systems for Intercarrier-Interference Suppression

Orthogonal frequency-division multiplexing (OFDM) is quite sensitive to phase noise, Doppler spread, and frequency offset, which will destroy the orthogonal properties among OFDM subcarriers and cause intercarrier interference (ICI). Correlative coding can be used to suppress the ICI effectively without reducing spectral efficiency. In this paper, a comprehensive expression for the ICI power of OFDM systems with the correlative coding as a function of the correlation of phase noise, the correlation of channel, and the frequency offset is derived. We further develop the upper and lower bounds for the comprehensive expression. Compared with the exact ICI power, these bounds are easier to calculate and tight enough to provide useful insight.