How to become a professional design researcher? I graduated from BA art design (mostly practical) and MA communication design (where I fell in love with research). 

Now I have been working as a interactive designer (mostly visual) for a digital magazine company for half a year, they don't do any research before launching any new project. But I know design is not what I would do forever, I would like to become a design researcher. 

The problem with finding this kind of post is that most design companies only hire either intern or senior. There seems to be no place for entry level researcher like me, whose research background is just a master's degree. 

Now the question is, how to get on to the right path if I want to apply for a "senior design researcher" job in the future? And how should I lead my own research projects while there is no real projects in hand?
I think that a Ph.D. program in human-computer interaction (HCI), such as this one, or a Ph.D. program in information systems with HCI specialization would be among the right routes toward your goal. Potentially, depending on what areas you're interested in, a degree, certification, postgraduate program or, even, a set of MOOCs in information architecture or information science might be a feasible option. An important point: unless you want to teach HCI at a university level, you can also IMHO consider trying to get your foot in the door without earning a Ph.D. degree - with enough knowledge and right skills, obtaining which should be doable, if you can self-study well.

In regard to performing research temporarily on your own, you can get a lot of ideas by searching for and analyzing information on past and current research projects, small and big, by individual researchers or small groups (review existing literature - peer-reviewed journals, conference proceedings, etc.; consider joining special interest groups (SIGs); visit relevant websites and blogs; consider professional networking by interest) as well as large and well-known research labs and divisions, such as MIT Media Lab and Human -Computer Interaction Institute at CMU. Good luck!