On singularity attacks in MIMO channels

All multiple-input multiple-output (MIMO) systems need a method to estimate and equalise their channel, whether through channel reciprocity or sounding, and most modern orthogonal frequency division multiplexing (OFDM)-based MIMO waveforms use sounding via OFDM pilot tones. Previous research has focused on jamming data transmissions. We instead focus on jamming channel sounding symbols and introduce the MIMO singularity attack, which attempts to reduce the rank of the channel gain matrix estimate by the receiver through transmission of specific jamming signals. More specifically, we introduce and analyse the MIMO singularity attack, in which a multi-antenna jammer tries to manipulate pilot tones to skew the channel state information obtained at the receiver. We prove singularity jamming can be more destructive than data jamming attacks such as barrage or pilot jamming by studying its effects on channel bit error rate and capacity. We develop the constraints associated with jamming MIMO sounding channels and further describe how these attacks specifically impact data symbol estimates for OFDM pilot-based sounding systems. Through simulation, we demonstrate efficiency gains over barrage jamming. Copyright (c) 2013 John Wiley & Sons, Ltd.