Pre- post- and balanced equalization in OFDM

OFDM is regarded as the solution to channel distortion; however, the channel does not have flat amplitude and linear phase-response over the entire bandwidth, thus channel-equalization is still required at the receiver. In this paper three different alternatives for OFDM channel equalization are discussed: pre- post- and balanced equalization. In the zero-forcing (ZF) case, pre- and balanced equalization lead to better BER performances, at the expense of requiring accurate channel measurements and channel state information (CSI) at the transmitter. The results have been produced via simulation in a HIPERLAN/2 system.