Reliable OFDM system design under hostile multi-tone jamming

Along with the advent of reconfigurable radios, hostile jamming is no longer limited to military applications, but has become a serious threat for civilian wireless communications, where OFDM has been identified as one of the most efficient transmission technologies. In this paper, we consider reliable transmission of OFDM systems under multi-tone jamming. We propose to enhance the jamming resistance of OFDM through symbol level precoding. Our approach is to find the optimal precoder and decoder that can minimize the MSE between the transmitted and the estimated symbols, subject to a given transmit power constraint. Closed-form solutions are derived, and further demonstrated through simulation examples. It is observed that adding controlled redundancy at symbol level is an effective way to mitigate hostile jamming in OFDM systems.