ISI (Intersymbol Interference) and ICI (Intercarrier Interference) are one of the major problem in OFDM system. Here a new technique has been proposed to eliminate this problem. For this the packet format of OFDM is needed to modify. After the modification it is found that performance is better than previous one. For simulation we use Network Simulator (NS2). This simulation has been deployed in Mobile Ad-hoc Network (MANET).