On the use of a cyclic extension in OFDM

OFDM (orthogonal frequency division multiplexing) is an effective technique for achieving reliable high-bit-rate transmission over wireless channels. Generally, for wireless applications, a guard interval, most often in the form of a cyclic extension of the OFDM data symbol, is inserted between OFDM blocks to minimize interblock interference. We quantify the penalties incurred when a zero-padded guard interval is used instead of a cyclic extension. Specifically, the resulting interchannel interference is computed and the degradation in the bit error rate is quantified