Synchronous rectification simulation
LTSpice IV is an excellent simulation tool provided free of charge by Linear Technology.

It is widely used- students use it for research and homework, many companies (including GE) use it to simulate power electronics- motor drives, dc/dc converters, wind inverters, you name it.

PLECS is probably the best tool nowadays but it is not free.

While synchronous rectification is quite simple to grasp, it can be difficult to implement.  Timing is crucial.  Lots of research was done on driving the SR gates with the same signals as the main power switches.

A good app note is here:  http://www.ti.com/lit/an/snva595/snva595.pdf

The issue with high-speed SR lies in parasitic circuit inductances, which tend to offset the turn-on of the rectifying device and hence increase losses, driving the need for increased heat-sinking properties.

Unless your application is very high-speed or high-voltage isolated (where you need to account for the opto-coupler delays), the implementation of synchronous rectification should be quite easy.

I have attached a couple of slides on SR from my university.