Date Added: May 2010
IEEE 802.16d-2004 has been developed for WIMAX wireless communication which is based on OFDM technology and this enables going towards the 4G, in wireless communication reception, the reliability of Orthogonal Frequency Division Multiplexing (OFDM) is limited because of the time-varying nature of the channel. This causes Inter-Carrier Interference (ICI) and increases inaccuracies in channel tracking. This can effectively be avoided at the cost of power loss and bandwidth expansion by inserting a cyclic prefix guard interval before each block of parallel data symbols. However, this guard interval decreases the spectral efficiency of the OFDM system as the corresponding amount.