Requirements of transmitters increase with upcoming of new communication systems. This brought up new methods to design of modulators which are widely working on a digital base and promise a multipurpose use. In our work we examined the direct digital synthesis, one of these new possibilities. In a first step we built up a running system which was the object of further investigations. The heart of this system is a newest generation synthesizer and a fast signal processor. The realized system is able to generate several types of modulation processes and gives us an idea of the characteristics of the new technology. We could also extended the frequency bandwidth with a modern up-converter to a maximum of over 1GHz. The results of our project allow us conclusions to this method. We concluded that this is a good alternative to classic system designs. Because of the fact that the system is software controlled it can be used for several different purposes. Outputfilters are very essential in this architecture. With a good filter design for the region of interest the generated signals can be directly ibtegrated in a common communication system.