Subverting MIMO wireless systems by jamming the channel estimation procedure

Multiple-input multiple-output (MIMO) technologies are popular in emerging wireless systems. Optimal MIMO communication is achieved by applying a waterfilling solution over the parallel subchannels associated with the channel matrix between a transmitter and receiver. The viability of such a method relies on the transmitter and receiver performing the singular value decomposition (SVD) of the estimated channel matrix. The estimation and use of the estimated channel matrix, however, is a point of weakness that can be used to subvert MIMO communication. In this paper, we investigate strategies for disrupting MIMO communications by developing attacks that target the channel estimation procedure of a MIMO system. Specifically, we study the impact that jamming the channel estimation procedure can have on SVD-based MIMO systems. Further, most new standards that employ MIMO incorporate space-time block coding (STBC) to bolster throughput and reliability. Although the choice of STBC varies across the standards, the Alamouti 5 scheme is a common basis for many protocols, including 802.11n, WiMAX, and 3GPP. We present jamming attacks that target the Alamouti scheme, and support their validity and effectiveness in the real world using the USRP/GNU Radio platform.