Introduction to Statistical Signal Processing
Sometimes there are courses entitled 'statistical signal processing', that's a good place to start :-)   If your university doesn't have this, try looking for 'detection and estimation', or 'advanced signal processing'.  If you don't have a university handy, you could try http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-432-stochastic-processes-detection-and-estimation-spring-2004/

Much statistical signal processing is linear, so you should learn as much linear algebra as you can. Stocastic processes is a foundational course.  Control theory shares much with SSP, and would be very useful.  

This should be enough for a start :-)