Fault tolerant adaptive filters based on the Walsh-Hadamard transform

Previously it has been shown that an FFT-based transform domain adaptive filter (FTAF) operating on real-valued signals can achieve a remarkable degree of fault tolerant performance based on parameter redundancy inherent in the complex arithmetic. In this paper the use of the Walsh-Hadamard transform is considered as a computationally efficient way of achieving fault tolerance. Although the WHT does not provide full fault tolerance it does provide a large degree of fault coverage that may be useful for adaptive filters implemented in highly scaled nano-technology circuits where soft (transient) errors and hard (permanent) faults are of increasing concern.