Threshold Based Subcarrier Interleaving for Spy Works Prevention in OFDM Systems

OFDM (orthogonal frequency division multiplexing) systems are widely employed in Wireless Communication. but unfortunately they are susceptible overhearing by SPY (intruder). In this paper an anti-spy OFDM system through threshold based on dynamic subcarrier co-ordinate interleaving (coordinate interleaving) is proposed. here some of the OFDM subcarriers perform interleaving in an opportunistic manner at the transmitter. but the secret interleaving is determined by instantaneous channel state information (CSI) between transmitter and actual receiver. here a subcarrier symbol whose channel phase estimate is larger than a predefined threshold is co-ordinate interleaved. consequently spy works are prevented due to mismatched de-interleaving in the spy (EAVESDROPPER).