TY - THES A1 - Tomashevich, Victor T1 - Fault Tolerance Aspects of Virtual Massive MIMO Systems N2 - Employment of a very large number of antennas is seen as the key technology to provide future users with very high data rates. At the same time, the implementation complexity will rise due to large memories required and sophisticated signal processing algorithms employed. Continuous technology downscaling allows implementation of such complex digital designs. At the same time, its inherent variability and vulnerability to physical disturbances violate the assumption of perfectly reliable hardware operation. This work considers Unique Word OFDM which represents the alternative to the standard Cyclic Prefix OFDM providing superior detection quality. The generalization of Unique Word OFDM to a MIMO system is performed which allows interpretation as a virtual massive MIMO system with only few physical antennas. Detection methods for the introduced generalization are discussed and their performance is quantified. Because of the large memory size required, linear detection represents the cost and performance effective solution. The possible memory errors due to radiation effects or voltage scaling are addressed and the nonlinear MMSE detection algorithm is proposed. This algorithm keeps track of the memory errors and is able to significantly mitigate their effect on the quality of the estimated data. Apart of memory issues, reliability of the actual computational hardware which constitutes the receiver is of concern in this work. An own implementation of the MMSE Sorted Givens Rotations is subjected to transient fault injection. The impact of faults in various parts of the implemented circuit on the detection performance is quantified. Most vulnerable components of the implemented circuit in terms of reliability are identified. Security is another major address of this work, since most current implementations include cryptographic devices. Fault-based attacks on such systems are known to be able to extract the secret key in feasible time. The remaining part of this work addresses such fault injection-based malicious attacks. Countermeasures based on a combination of information and hardware redundancy are considered. Recently introduced robust codes target such attacks by providing guaranteed detection capability. The performance of these codes is assessed by application to actual cryptographic and general purpose circuits. The work introduces metrics that help to identify fault locations in the circuit which could escape detection with high probability. These locations are targeted by transistor resizing that renders fault injection unfeasible. KW - MIMO Systems KW - MIMO KW - Fehlertoleranz Y1 - 2016 UR - https://opus4.kobv.de/opus4-uni-passau/frontdoor/index/index/docId/404 UR - https://nbn-resolving.org/urn:nbn:de:bvb:739-opus4-4047 ER -