Frequency domain equalization for OFDM systems with insufficient guard interval using null subcarriers

Frequency domain equalizers (FEQs) have been applied extensively in multicarrier systems to enhance transmission rate by reducing transmit redundancy in the form of guard interval. The proposed equalization algorithm is able to remove intersymbol and intercarrier interference (ISI and ICI) incurred by the reduction or the absence of this redundancy by properly exploiting null subcarriers that are inherent in standardized multicarrier systems. Unlike previous proposed schemes, the proposed algorithm does not require additional temporal nor spatial diversity at the receiver to mitigate the channel-induced interferences. Simulation results show that our approach outperforms those of other schemes in terms of bit error rate.