Abstract: In this paper, a sorted subcarrier interleaving technique is used for preventing eavesdropping in OFDM system. In each OFDM signal, subcarriers are interleaved according to the sorted order of channel impulse response. Random noise can be added before interleaves to get two tire secrecy rate. The frequently updated subcarrier interleaving pattern can only be shared between legitimate nodes based on channel reciprocity. Without a proper de-interleaving pattern, mismatched information recovery occurs at the eavesdropper, thus preventing eavesdropping. . A subcarrier selection algorithm is investigated to realize a trade-off between the eavesdropping resilience and transmission reliability.
Keywords: Security, wireless communications, orthogonal frequency division multiplexing (OFDM), eavesdropping, subcarrier interleaving.