Computationally fast lattice bilinear digital ladder filters with comparison to circulator WDFs

This paper considers a modified variant of the lossless digital integrator lattice filter structure, which is called a lattice bilinear digital ladder filter (BDLF). It is shown that the structure easily can be modified so that the critical loop reduces from two multipliers to one. This has the potential of significantly improving the computational speed when the filter is implemented directly in hardware. Two test filters of the modified BDLF structure are compared to three-port circulator lattice wave digital filters (WDF), which also have critical loops of only one multiplier. It is shown that for the test filters, the BDLF realizations are similar to the WDF realizations regarding multiplier wordlength requirements, while they are superior regarding quantization noise and structural complexity