Impact of Carrier Frequency Offset on the Performance of Precoded OFDM Systems



Precoding is a spectrally efficient approach to improve the immunity of orthogonal frequency division multiplexing (OFDM) systems in frequency-selective multipath fading channels. However, the performance of precoded OFDM (P-OFDM) is usually evaluated under the assumption of perfect channel estimation and synchronization conditions. Therefore, the aim of this work is to evaluate the performance of P-OFDM in the presence of carrier frequency offset (CFO). The considered precoding in this work is based on the Walsh-Hadamard transform (WHT). We observe that the signal-to-interference plus noise ratio (SINR) of P-OFDM substantially changes based on the subcarrier index, which is not the case for conventional OFDM systems.