1. Mathematical System Theory (Esp. Algebraic and Differential Geometric Methods)
2. Multi Rate Digital Signal Processing
3. Applied Linear Algebra, Operator Theory, Differential Geometry
4. Good links...
   a) Good literature survey in Behavioral Approach
   b) People working in Geometric Control
   c) Good introduction to Geometric Control by Slobodan Simic
   d) Linear Control Theory in Geometric Terms
   e) Lecture series in Mathematical Control Theory
    f) Open Problems in Mathematical Systems and Control Theory

  More to come... Pls..Visit again :-)