On OFDM Systems under WSS-US Channels

Using the assumption that (a) the subcarrier symbols are i.i.d., (b) the interference between OFDM symbols is negligible, and (c) the WSS-US channel model holds, we (i) show that the subcarrier response consists of an average of the frequency domain channel samples, (ii) derive the subcarrier correlation and its power spectral density, implying that each subcarrier has same power, (iii) calculate an exact expression for the ICI power, which is found to have equal value for all subcarriers, and (iv) show that the two-path spectrum has the largest ICI for channels with the same maximum Doppler frequency.