Digital FFTs are widely used in signal processing and communication systems. This makes protection against soft errors a requirement for many applications. Communications and signal processing systems are no exceptions to this trend. For some applications, an interesting option is to use algorithmic-based fault tolerance (ABFT) techniques that try to exploit the algorithmic properties to detect and correct errors. Signal processing and communication applications are well suited for ABFT. One example is fast Fourier transforms (FFTs) that are a key building block in many systems. Several protection schemes have been proposed to detect and correct errors in FFTs. Among those, probably the use of the Parseval or sum of squares checks is the most widely known. In modern communication systems, it is increasingly common to find several blocks operating in parallel. Recently, a technique that exploits this fact to implement fault tolerance on parallel filters has been proposed. In this brief, this technique is first applied to protect FFTs. Then, two improved protection schemes that combine the use of error correction codes and Parseval checks are proposed and evaluated. The results show that the proposed schemes can further reduce the implementation cost of protection. The design entry is done in Verilog Hardware Description Language (HDL) and simulated using ISIM Simulator. It is synthesized and implemented using Xilinx ISE 14.7.
Index Terms: Error correction codes (ECCs), fast Fourier transforms (FFTs), soft errors