A Fast FIR filtering technique for multirate filters

•A technique for applying Fast FIR Algorithms to multirate interpolators and decimators is described.•Optimizations based on symmetry exploitation and transposition which can be used to reduce the filter implementation cost are illustrated.•Filter implementation cost is shown to be significantly lower than conventional techniques.

This paper presents a technique for applying Fast FIR Algorithms (FFAs) to interpolation and decimation filters. In the event that the prototype filter has a symmetric impulse response, it is shown that the subfilters which result from the application of the FFA will be jointly symmetric. This fact may be exploited in order to further reduce the computational complexity of the system. The effect of transposition upon the proposed structure is discussed, and it is shown that transposition yields a more economical structure in the case of a decimation filter. The computational complexity of the proposed schemes is shown to compare favorably with that of the standard parallel filtering approach.