ABSTRACT
In the previous chapter, specifically in §4.2.3, we studied the frequency response function (FRF) as one of the elementary response models for an LTI system.
The purpose of this chapter is review certain useful facets of the FRF, again with relevance to identification. Subsequently, we advance to the subject of complex-frequency (damped sine waves) representations of LTI systems, also known as the transfer functions, through the use of what are known as z-transforms. We shall in due course observe an interesting resemblance between the transfer function and the transfer function operator representation presented earlier in §4.3.
