ABSTRACT
THE concept of using a second-order section (SOS) as a building block for IIR filters was first introduced in Section 4.3.3. Some advantages of using second-order sections for IIR filters were mentioned, such as the reduction of quantization effects on the filter coefficients. Note that, in practice, second-order sections are seldom used for FIR filters as they provide little to no advantage. For this project, we explore the use of second-order sections further. A block diagram showing how second-order sections can be used as building blocks for higher order filters was provided in Figure 4.18; for convenience, that figure is reproduced here as Figure 12.1. Odd-order filters can be implemented using SOS techniques by adding a first order section at the beginning or end of the cascaded sections.
