Carry save and pipelining techniques for wave digital filters

Wave Digital Filters are known to be superior in many respects to other IIR filter structures and are suitable for high speed filtering applications. In this paper the two-port adaptor is used to implement both the Lattice and Bireciprocal Wave Digital Filters. The main computational element of the twoport adaptor and all other digital domain filters is the multiplier. Carry save techniques can efficiently implement the shift-and-add multiplication algorithm. Selection of which of the filter coefficient and data operands is the actual multiplier leads to the development of two arrays with different data flow characteristics. This paper compares and contrasts these two carry save arithmetic methodologies and applies them to the Bireciprocal and Lattice Wave Digital Filters. Emphasis will be placed on the usage of efficient pipelining schemes