Lec 16 MIT 6.451 Principles of Digital Communication II
[WRITING ON CHALKBOARD] PROFESSOR: Good morning. I think I'll start even though people are not quite all here, because it's time. Sorry, I'd hoped to start Chapter 10 last time, but we'll start it this time. When Ashish comes, we'll have handouts for Chapter 10, the new problem set and the old problem set solutions as usual. This chapter is about trellis diagrams for block codes. Binary linear block codes of the kind that we've seen before, it's actually a much more general notion that applies to -- well, linearity is important, although we don't see it very specifically in the trellis diagram. But we'll see that for constructing a unique minimal trellis, linearity is an important aspect. Or more generally, it's just the group property of codes that allows us to construct unique minimal trellis diagrams. And I think it's best to motivate this chapter by an example. Here's a nice example of a code that we know very well. It h...