Performance of pilot jamming on MIMO channels with imperfect synchronization

This paper explores effects of pilot based jamming attacks with synchronization mismatches on MIMO-OFDM systems. Both MIMO and OFDM based systems employ known data called pilot tones to estimate the channel frequency response and perform equalization. Jamming pilot tones can potentially disrupt the channel estimation and equalization, thus making the communication impossible. Our earlier research focused on efficient jamming algorithms, such as pilot jamming for OFDM systems and singularity attack for MIMO systems. It has been shown that pilot based jamming is more efficient than broadband attacks on entire signal. However, pilot based jamming may suffer from time and frequency synchronization mismatches that can degrade the efficacy of attacks. This paper presents channel and equalizer model, builds on various pilot based jamming attacks and further examines the cause and effect of mismatches in the jamming attack. Through simulation we demonstrate that singularity jamming achieves 3 dB gain over barrage jamming at 0.4 bit error rate. For 25% and 50% symbol time offset, singularity jamming loses about 0.25 dB and 1 dB gain, respectively, when perfect CSI is available for the jammer. At 0.2 bit error rate, 0.2 and 0.5 normalized frequency offset, singularity jamming loses about 1 dB and 3 dB over synchronized jamming, respectively, when CSI with 20% error is available at the jammer side.